note on the resemblances and differences in the structure and the development of the brain in man and apes by professor t. h. huxley, f.r.s. [this essay is taken from 'the descent of man and selection in relation to sex' by charles darwin where it appears at the end of chapter vii which is also the end of part i. footnotes are numbered as they appear in 'the descent of man.'] the controversy respecting the nature and the extent of the differences in the structure of the brain in man and the apes, which arose some fifteen years ago, has not yet come to an end, though the subject matter of the dispute is, at present, totally different from what it was formerly. it was originally asserted and re-asserted, with singular pertinacity, that the brain of all the apes, even the highest, differs from that of man, in the absence of such conspicuous structures as the posterior lobes of the cerebral hemispheres, with the posterior cornu of the lateral ventricle and the hippocampus minor, contained in those lobes, which are so obvious in man. but the truth that the three structures in question are as well developed in apes' as in human brains, or even better; and that it is characteristic of all the primates (if we exclude the lemurs) to have these parts well developed, stands at present on as secure a basis as any proposition in comparative anatomy. moreover, it is admitted by every one of the long series of anatomists who, of late years, have paid special attention to the arrangement of the complicated sulci and gyri which appear upon the surface of the cerebral hemispheres in man and the higher apes, that they are disposed after the very same pattern in him, as in them. every principal gyrus and sulcus of a chimpanzee's brain is clearly represented in that of a man, so that the terminology which applies to the one answers for the other. on this point there is no difference of opinion. some years since, professor bischoff published a memoir (70. 'die grosshirn-windungen des menschen;' 'abhandlungen der k. bayerischen akademie,' b. x. 1868.) on the cerebral convolutions of man and apes; and as the purpose of my learned colleague was certainly not to diminish the value of the differences between apes and men in this respect, i am glad to make a citation from him. "that the apes, and especially the orang, chimpanzee and gorilla, come very close to man in their organisation, much nearer than to any other animal, is a well known fact, disputed by nobody. looking at the matter from the point of view of organisation alone, no one probably would ever have disputed the view of linnaeus, that man should be placed, merely as a peculiar species, at the head of the mammalia and of those apes. both shew, in all their organs, so close an affinity, that the most exact anatomical investigation is needed in order to demonstrate those differences which really exist. so it is with the brains. the brains of man, the orang, the chimpanzee, the gorilla, in spite of all the important differences which they present, come very close to one another" (loc. cit. p. 101). there remains, then, no dispute as to the resemblance in fundamental characters, between the ape's brain and man's: nor any as to the wonderfully close similarity between the chimpanzee, orang and man, in even the details of the arrangement of the gyri and sulci of the cerebral hemispheres. nor, turning to the differences between the brains of the highest apes and that of man, is there any serious question as to the nature and extent of these differences. it is admitted that the man's cerebral hemispheres are absolutely and relatively larger than those of the orang and chimpanzee; that his frontal lobes are less excavated by the upward protrusion of the roof of the orbits; that his gyri and sulci are, as a rule, less symmetrically disposed, and present a greater number of secondary plications. and it is admitted that, as a rule, in man, the temporo-occipital or "external perpendicular" fissure, which is usually so strongly marked a feature of the ape's brain is but faintly marked. but it is also clear, that none of these differences constitutes a sharp demarcation between the man's and the ape's brain. in respect to the external perpendicular fissure of gratiolet, in the human brain for instance, professor turner remarks: (71. 'convolutions of the human cerebrum topographically considered,' 1866, p. 12.) "in some brains it appears simply as an indentation of the margin of the hemisphere, but, in others, it extends for some distance more or less transversely outwards. i saw it in the right hemisphere of a female brain pass more than two inches outwards; and on another specimen, also the right hemisphere, it proceeded for four-tenths of an inch outwards, and then extended downwards, as far as the lower margin of the outer surface of the hemisphere. the imperfect definition of this fissure in the majority of human brains, as compared with its remarkable distinctness in the brain of most quadrumana, is owing to the presence, in the former, of certain superficial, well marked, secondary convolutions which bridge it over and connect the parietal with the occipital lobe. the closer the first of these bridging gyri lies to the longitudinal fissure, the shorter is the external parieto-occipital fissure" (loc. cit. p. 12). the obliteration of the external perpendicular fissure of gratiolet, therefore, is not a constant character of the human brain. on the other hand, its full development is not a constant character of the higher ape's brain. for, in the chimpanzee, the more or less extensive obliteration of the external perpendicular sulcus by "bridging convolutions," on one side or the other, has been noted over and over again by prof. rolleston, mr. marshall, m. broca and professor turner. at the conclusion of a special paper on this subject the latter writes: (72. notes more especially on the bridging convolutions in the brain of the chimpanzee, 'proceedings of the royal society of edinburgh,' 1865-6.) "the three specimens of the brain of a chimpanzee, just described, prove, that the generalisation which gratiolet has attempted to draw of the complete absence of the first connecting convolution and the concealment of the second, as essentially characteristic features in the brain of this animal, is by no means universally applicable. in only one specimen did the brain, in these particulars, follow the law which gratiolet has expressed. as regards the presence of the superior bridging convolution, i am inclined to think that it has existed in one hemisphere, at least, in a majority of the brains of this animal which have, up to this time, been figured or described. the superficial position of the second bridging convolution is evidently less frequent, and has as yet, i believe, only been seen in the brain (a) recorded in this communication. the asymmetrical arrangement in the convolutions of the two hemispheres, which previous observers have referred to in their descriptions, is also well illustrated in these specimens" (pp. 8, 9). even were the presence of the temporo-occipital, or external perpendicular, sulcus, a mark of distinction between the higher apes and man, the value of such a distinctive character would be rendered very doubtful by the structure of the brain in the platyrrhine apes. in fact, while the temporo-occipital is one of the most constant of sulci in the catarrhine, or old world, apes, it is never very strongly developed in the new world apes; it is absent in the smaller platyrrhini; rudimentary in pithecia (73. flower, 'on the anatomy of pithecia monachus,' 'proceedings of the zoological society,' 1862.); and more or less obliterated by bridging convolutions in ateles. a character which is thus variable within the limits of a single group can have no great taxonomic value. it is further established, that the degree of asymmetry of the convolution of the two sides in the human brain is subject to much individual variation; and that, in those individuals of the bushman race who have been examined, the gyri and sulci of the two hemispheres are considerably less complicated and more symmetrical than in the european brain, while, in some individuals of the chimpanzee, their complexity and asymmetry become notable. this is particularly the case in the brain of a young male chimpanzee figured by m. broca. ('l'ordre des primates,' p. 165, fig. 11.) again, as respects the question of absolute size, it is established that the difference between the largest and the smallest healthy human brain is greater than the difference between the smallest healthy human brain and the largest chimpanzee's or orang's brain. moreover, there is one circumstance in which the orang's and chimpanzee's brains resemble man's, but in which they differ from the lower apes, and that is the presence of two corpora candicantia--the cynomorpha having but one. in view of these facts i do not hesitate in this year 1874, to repeat and insist upon the proposition which i enunciated in 1863: (74. 'man's place in nature,' p. 102.) "so far as cerebral structure goes, therefore, it is clear that man differs less from the chimpanzee or the orang, than these do even from the monkeys, and that the difference between the brain of the chimpanzee and of man is almost insignificant when compared with that between the chimpanzee brain and that of a lemur." in the paper to which i have referred, professor bischoff does not deny the second part of this statement, but he first makes the irrelevant remark that it is not wonderful if the brains of an orang and a lemur are very different; and secondly, goes on to assert that, "if we successively compare the brain of a man with that of an orang; the brain of this with that of a chimpanzee; of this with that of a gorilla, and so on of a hylobates, semnopithecus, cynocephalus, cercopithecus, macacus, cebus, callithrix, lemur, stenops, hapale, we shall not meet with a greater, or even as great a, break in the degree of development of the convolutions, as we find between the brain of a man and that of an orang or chimpanzee." to which i reply, firstly, that whether this assertion be true or false, it has nothing whatever to do with the proposition enunciated in 'man's place in nature,' which refers not to the development of the convolutions alone, but to the structure of the whole brain. if professor bischoff had taken the trouble to refer to p. 96 of the work he criticises, in fact, he would have found the following passage: "and it is a remarkable circumstance that though, so far as our present knowledge extends, there is one true structural break in the series of forms of simian brains, this hiatus does not lie between man and the manlike apes, but between the lower and the lowest simians, or in other words, between the old and new world apes and monkeys and the lemurs. every lemur which has yet been examined, in fact, has its cerebellum partially visible from above; and its posterior lobe, with the contained posterior cornu and hippocampus minor, more or less rudimentary. every marmoset, american monkey, old world monkey, baboon or manlike ape, on the contrary, has its cerebellum entirely hidden, posteriorly, by the cerebral lobes, and possesses a large posterior cornu with a well-developed hippocampus minor." this statement was a strictly accurate account of what was known when it was made; and it does not appear to me to be more than apparently weakened by the subsequent discovery of the relatively small development of the posterior lobes in the siamang and in the howling monkey. notwithstanding the exceptional brevity of the posterior lobes in these two species, no one will pretend that their brains, in the slightest degree, approach those of the lemurs. and if, instead of putting hapale out of its natural place, as professor bischoff most unaccountably does, we write the series of animals he has chosen to mention as follows: homo, pithecus, troglodytes, hylobates, semnopithecus, cynocephalus, cercopithecus, macacus, cebus, callithrix, hapale, lemur, stenops, i venture to reaffirm that the great break in this series lies between hapale and lemur, and that this break is considerably greater than that between any other two terms of that series. professor bischoff ignores the fact that long before he wrote, gratiolet had suggested the separation of the lemurs from the other primates on the very ground of the difference in their cerebral characters; and that professor flower had made the following observations in the course of his description of the brain of the javan loris: (75. 'transactions of the zoological society,' vol. v. 1862.) "and it is especially remarkable that, in the development of the posterior lobes, there is no approximation to the lemurine, short hemisphered brain, in those monkeys which are commonly supposed to approach this family in other respects, viz. the lower members of the platyrrhine group." so far as the structure of the adult brain is concerned, then, the very considerable additions to our knowledge, which have been made by the researches of so many investigators, during the past ten years, fully justify the statement which i made in 1863. but it has been said, that, admitting the similarity between the adult brains of man and apes, they are nevertheless, in reality, widely different, because they exhibit fundamental differences in the mode of their development. no one would be more ready than i to admit the force of this argument, if such fundamental differences of development really exist. but i deny that they do exist. on the contrary, there is a fundamental agreement in the development of the brain in men and apes. gratiolet originated the statement that there is a fundamental difference in the development of the brains of apes and that of man--consisting in this; that, in the apes, the sulci which first make their appearance are situated on the posterior region of the cerebral hemispheres, while, in the human foetus, the sulci first become visible on the frontal lobes. (76. "chez tous les singes, les plis posterieurs se developpent les premiers; les plis anterieurs se developpent plus tard, aussi la vertebre occipitale et la parietale sont-elles relativement tres-grandes chez le foetus. l'homme presente une exception remarquable quant a l'epoque de l'apparition des plis frontaux, qui sont les premiers indiques; mais le developpement general du lobe frontal, envisage seulement par rapport a son volume, suit les memes lois que dans les singes:" gratiolet, 'memoire sur les plis cerebres de l'homme et des primateaux,' p. 39, tab. iv, fig. 3.) this general statement is based upon two observations, the one of a gibbon almost ready to be born, in which the posterior gyri were "well developed," while those of the frontal lobes were "hardly indicated" (77. gratiolet's words are (loc. cit. p. 39): "dans le foetus dont il s'agit les plis cerebraux posterieurs sont bien developpes, tandis que les plis du lobe frontal sont a peine indiques." the figure, however (pl. iv, fig. 3), shews the fissure of rolando, and one of the frontal sulci plainly enough. nevertheless, m. alix, in his 'notice sur les travaux anthropologiques de gratiolet' ('mem. de la societe d'anthropologie de paris,' 1868, page 32), writes thus: "gratiolet a eu entre les mains le cerveau d'un foetus de gibbon, singe eminemment superieur, et tellement rapproche de l'orang, que des naturalistes tres-competents l'ont range parmi les anthropoides. m. huxley, par exemple, n'hesite pas sur ce point. eh bien, c'est sur le cerveau d'un foetus de gibbon que gratiolet a vu les circonvolutions du lobe temporo-sphenoidal deja developpees lorsqu'il n'existent pas encore de plis sur le lobe frontal. il etait donc bien autorise a dire que, chez l'homme les circonvolutions apparaissent d'a en w, tandis que chez les singes elles se developpent d'w en a."), and the other of a human foetus at the 22nd or 23rd week of uterogestation, in which gratiolet notes that the insula was uncovered, but that nevertheless "des incisures sement de lobe anterieur, une scissure peu profonde indique la separation du lobe occipital, tres-reduit, d'ailleurs des cette epoque. le reste de la surface cerebrale est encore absolument lisse." three views of this brain are given in plate ii, figs. 1, 2, 3, of the work cited, shewing the upper, lateral and inferior views of the hemispheres, but not the inner view. it is worthy of note that the figure by no means bears out gratiolet's description, inasmuch as the fissure (antero-temporal) on the posterior half of the face of the hemisphere is more marked than any of those vaguely indicated in the anterior half. if the figure is correct, it in no way justifies gratiolet's conclusion: "il y a donc entre ces cerveaux [those of a callithrix and of a gibbon] et celui du foetus humain une difference fondamental. chez celui-ci, longtemps avant que les plis temporaux apparaissent, les plis frontaux, essayent d'exister." since gratiolet's time, however, the development of the gyri and sulci of the brain has been made the subject of renewed investigation by schmidt, bischoff, pansch (78. 'ueber die typische anordnung der furchen und windungen auf den grosshirn-hemispharen des menschen und der affen,' 'archiv fur anthropologie,' iii. 1868.), and more particularly by ecker (79. 'zur entwicklungs geschichte der furchen und windungen der grosshirn-hemispharen im foetus des menschen.' 'archiv fur anthropologie,' iii. 1868.), whose work is not only the latest, but by far the most complete, memoir on the subject. the final results of their inquiries may be summed up as follows:-1. in the human foetus, the sylvian fissure is formed in the course of the third month of uterogestation. in this, and in the fourth month, the cerebral hemispheres are smooth and rounded (with the exception of the sylvian depression), and they project backwards far beyond the cerebellum. 2. the sulci, properly so called, begin to appear in the interval between the end of the fourth and the beginning of the sixth month of foetal life, but ecker is careful to point out that, not only the time, but the order, of their appearance is subject to considerable individual variation. in no case, however, are either the frontal or the temporal sulci the earliest. the first which appears, in fact, lies on the inner face of the hemisphere (whence doubtless gratiolet, who does not seem to have examined that face in his foetus, overlooked it), and is either the internal perpendicular (occipito-parietal), or the calcarine sulcus, these two being close together and eventually running into one another. as a rule the occipito-parietal is the earlier of the two. 3. at the latter part of this period, another sulcus, the "posterio-parietal," or "fissure of rolando" is developed, and it is followed, in the course of the sixth month, by the other principal sulci of the frontal, parietal, temporal and occipital lobes. there is, however, no clear evidence that one of these constantly appears before the other; and it is remarkable that, in the brain at the period described and figured by ecker (loc. cit. pp. 212-213, taf. ii, figs. 1, 2, 3, 4), the antero-temporal sulcus (scissure parallele) so characteristic of the ape's brain, is as well, if not better developed than the fissure of rolando, and is much more marked than the proper frontal sulci. taking the facts as they now stand, it appears to me that the order of the appearance of the sulci and gyri in the foetal human brain is in perfect harmony with the general doctrine of evolution, and with the view that man has been evolved from some ape-like form; though there can be no doubt that form was, in many respects, different from any member of the primates now living. von baer taught us, half a century ago, that, in the course of their development, allied animals put on at first, the characters of the greater groups to which they belong, and, by degrees, assume those which restrict them within the limits of their family, genus, and species; and he proved, at the same time, that no developmental stage of a higher animal is precisely similar to the adult condition of any lower animal. it is quite correct to say that a frog passes through the condition of a fish, inasmuch as at one period of its life the tadpole has all the characters of a fish, and if it went no further, would have to be grouped among fishes. but it is equally true that a tadpole is very different from any known fish. in like manner, the brain of a human foetus, at the fifth month, may correctly be said to be, not only the brain of an ape, but that of an arctopithecine or marmoset-like ape; for its hemispheres, with their great posterior lobster, and with no sulci but the sylvian and the calcarine, present the characteristics found only in the group of the arctopithecine primates. but it is equally true, as gratiolet remarks, that, in its widely open sylvian fissure, it differs from the brain of any actual marmoset. no doubt it would be much more similar to the brain of an advanced foetus of a marmoset. but we know nothing whatever of the development of the brain in the marmosets. in the platyrrhini proper, the only observation with which i am acquainted is due to pansch, who found in the brain of a foetal cebus apella, in addition to the sylvian fissure and the deep calcarine fissure, only a very shallow antero-temporal fissure (scissure parallele of gratiolet). now this fact, taken together with the circumstance that the antero-temporal sulcus is present in such platyrrhini as the saimiri, which present mere traces of sulci on the anterior half of the exterior of the cerebral hemispheres, or none at all, undoubtedly, so far as it goes, affords fair evidence in favour of gratiolet's hypothesis, that the posterior sulci appear before the anterior, in the brains of the platyrrhini. but, it by no means follows, that the rule which may hold good for the platyrrhini extends to the catarrhini. we have no information whatever respecting the development of the brain in the cynomorpha; and, as regards the anthropomorpha, nothing but the account of the brain of the gibbon, near birth, already referred to. at the present moment there is not a shadow of evidence to shew that the sulci of a chimpanzee's, or orang's, brain do not appear in the same order as a man's. gratiolet opens his preface with the aphorism: "il est dangereux dans les sciences de conclure trop vite." i fear he must have forgotten this sound maxim by the time he had reached the discussion of the differences between men and apes, in the body of his work. no doubt, the excellent author of one of the most remarkable contributions to the just understanding of the mammalian brain which has ever been made, would have been the first to admit the insufficiency of his data had he lived to profit by the advance of inquiry. the misfortune is that his conclusions have been employed by persons incompetent to appreciate their foundation, as arguments in favour of obscurantism. (80. for example, m. l'abbe lecomte in his terrible pamphlet, 'le darwinisme et l'origine de l'homme,' 1873.) but it is important to remark that, whether gratiolet was right or wrong in his hypothesis respecting the relative order of appearance of the temporal and frontal sulci, the fact remains; that before either temporal or frontal sulci, appear, the foetal brain of man presents characters which are found only in the lowest group of the primates (leaving out the lemurs); and that this is exactly what we should expect to be the case, if man has resulted from the gradual modification of the same form as that from which the other primates have sprung. the perpetuation of living beings, hereditary transmission and variation by thomas henry huxley the inquiry which we undertook, at our last meeting, into the state of our knowledge of the causes of the phenomena of organic nature,--of the past and of the present,--resolved itself into two subsidiary inquiries: the first was, whether we know anything, either historically or experimentally, of the mode of origin of living beings; the second subsidiary inquiry was, whether, granting the origin, we know anything about the perpetuation and modifications of the forms of organic beings. the reply which i had to give to the first question was altogether negative, and the chief result of my last lecture was, that, neither historically nor experimentally, do we at present know anything whatsoever about the origin of living forms. we saw that, historically, we are not likely to know anything about it, although we may perhaps learn something experimentally; but that at present we are an enormous distance from the goal i indicated. i now, then, take up the next question, what do we know of the reproduction, the perpetuation, and the modifications of the forms of living beings, supposing that we have put the question as to their origination on one side, and have assumed that at present the causes of their origination are beyond us, and that we know nothing about them? upon this question the state of our knowledge is extremely different; it is exceedingly large, and, if not complete, our experience is certainly most extensive. it would be impossible to lay it all before you, and the most i can do, or need do to-night, is to take up the principal points and put them before you with such prominence as may subserve the purposes of our present argument. the method of the perpetuation of organic beings is of two kinds,--the asexual and the sexual. in the first the perpetuation takes place from and by a particular act of an individual organism, which sometimes may not be classed as belonging to any sex at all. in the second case, it is in consequence of the mutual action and interaction of certain portions of the organisms of usually two distinct individuals,--the male and the female. the cases of asexual perpetuation are by no means so common as the cases of sexual perpetuation; and they are by no means so common in the animal as in the vegetable world. you are all probably familiar with the fact, as a matter of experience, that you can propagate plants by means of what are called "cuttings;" for example, that by taking a cutting from a geranium plant, and rearing it properly, by supplying it with light and warmth and nourishment from the earth, it grows up and takes the form of its parent, having all the properties and peculiarities of the original plant. sometimes this process, which the gardener performs artificially, takes place naturally; that is to say, a little bulb, or portion of the plant, detaches itself, drops off, and becomes capable of growing as a separate thing. that is the case with many bulbous plants, which throw off in this way secondary bulbs, which are lodged in the ground and become developed into plants. this is an asexual process, and from it results the repetition or reproduction of the form of the original being from which the bulb proceeds. among animals the same thing takes place. among the lower forms of animal life, the infusorial animalculae we have already spoken of throw off certain portions, or break themselves up in various directions, sometimes transversely or sometimes longitudinally; or they may give off buds, which detach themselves and develop into their proper forms. there is the common fresh-water polype, for instance, which multiplies itself in this way. just in the same way as the gardener is able to multiply and reproduce the peculiarities and characters of particular plants by means of cuttings, so can the physiological experimentalist--as was shown by the abbe trembley many years ago--so can he do the same thing with many of the lower forms of animal life. m. de trembley showed that you could take a polype and cut it into two, or four, or many pieces, mutilating it in all directions, and the pieces would still grow up and reproduce completely the original form of the animal. these are all cases of asexual multiplication, and there are other instances, and still more extraordinary ones, in which this process takes place naturally, in a more hidden, a more recondite kind of way. you are all of you familiar with those little green insects, the 'aphis' or blight, as it is called. these little animals, during a very considerable part of their existence, multiply themselves by means of a kind of internal budding, the buds being developed into essentially asexual animals, which are neither male nor female; they become converted into young 'aphides', which repeat the process, and their offspring after them, and so on again; you may go on for nine or ten, or even twenty or more successions; and there is no very good reason to say how soon it might terminate, or how long it might not go on if the proper conditions of warmth and nourishment were kept up. sexual reproduction is quite a distinct matter. here, in all these cases, what is required is the detachment of two portions of the parental organisms, which portions we know as the egg and the spermatozoon. in plants it is the ovule and the pollen-grain, as in the flowering plants, or the ovule and the antherozooid, as in the flowerless. among all forms of animal life, the spermatozoa proceed from the male sex, and the egg is the product of the female. now, what is remarkable about this mode of reproduction is this, that the egg by itself, or the spermatozoa by themselves, are unable to assume the parental form; but if they be brought into contact with one another, the effect of the mixture of organic substances proceeding from two sources appears to confer an altogether new vigour to the mixed product. this process is brought about, as we all know, by the sexual intercourse of the two sexes, and is called the act of impregnation. the result of this act on the part of the male and female is, that the formation of a new being is set up in the ovule or egg; this ovule or egg soon begins to be divided and subdivided, and to be fashioned into various complex organisms, and eventually to develop into the form of one of its parents, as i explained in the first lecture. these are the processes by which the perpetuation of organic beings is secured. why there should be the two modes--why this re-invigoration should be required on the part of the female element we do not know; but it is most assuredly the fact, and it is presumable, that, however long the process of asexual multiplication could be continued, i say there is good reason to believe that it would come to an end if a new commencement were not obtained by a conjunction of the two sexual elements. that character which is common to these two distinct processes is this, that, whether we consider the reproduction, or perpetuation, or modification of organic beings as they take place asexually, or as they may take place sexually,--in either case, i say, the offspring has a constant tendency to assume, speaking generally, the character of the parent. as i said just now, if you take a slip of a plant, and tend it with care, it will eventually grow up and develop into a plant like that from which it had sprung; and this tendency is so strong that, as gardeners know, this mode of multiplying by means of cuttings is the only secure mode of propagating very many varieties of plants; the peculiarity of the primitive stock seems to be better preserved if you propagate it by means of a slip than if you resort to the sexual mode. again, in experiments upon the lower animals, such as the polype, to which i have referred, it is most extraordinary that, although cut up into various pieces, each particular piece will grow up into the form of the primitive stock; the head, if separated, will reproduce the body and the tail; and if you cut off the tail, you will find that that will reproduce the body and all the rest of the members, without in any way deviating from the plan of the organism from which these portions have been detached. and so far does this go, that some experimentalists have carefully examined the lower orders of animals,--among them the abbe spallanzani, who made a number of experiments upon snails and salamanders,--and have found that they might mutilate them to an incredible extent; that you might cut off the jaw or the greater part of the head, or the leg or the tail, and repeat the experiment several times, perhaps, cutting off the same member again and again; and yet each of those types would be reproduced according to the primitive type: nature making no mistake, never putting on a fresh kind of leg, or head, or tail, but always tending to repeat and to return to the primitive type. it is the same in sexual reproduction: it is a matter of perfectly common experience, that the tendency on the part of the offspring always is, speaking broadly, to reproduce the form of the parents. the proverb has it that the thistle does not bring forth grapes; so, among ourselves, there is always a likeness, more or less marked and distinct, between children and their parents. that is a matter of familiar and ordinary observation. we notice the same thing occurring in the cases of the domestic animals--dogs, for instance, and their offspring. in all these cases of propagation and perpetuation, there seems to be a tendency in the offspring to take the characters of the parental organisms. to that tendency a special name is given--it is called 'atavism', it expresses this tendency to revert to the ancestral type, and comes from the latin word 'atavus', ancestor. well, this 'atavism' which i shall speak of, is, as i said before, one of the most marked and striking tendencies of organic beings; but, side by side with this hereditary tendency there is an equally distinct and remarkable tendency to variation. the tendency to reproduce the original stock has, as it were, its limits, and side by side with it there is a tendency to vary in certain directions, as if there were two opposing powers working upon the organic being, one tending to take it in a straight line, and the other tending to make it diverge from that straight line, first to one side and then to the other. so that you see these two tendencies need not precisely contradict one another, as the ultimate result may not always be very remote from what would have been the case if the line had been quite straight. this tendency to variation is less marked in that mode of propagation which takes place asexually; it is in that mode that the minor characters of animal and vegetable structures are most completely preserved. still, it will happen sometimes, that the gardener, when he has planted a cutting of some favourite plant, will find, contrary to his expectation, that the slip grows up a little different from the primitive stock--that it produces flowers of a different colour or make, or some deviation in one way or another. this is what is called the 'sporting' of plants. in animals the phenomena of asexual propagation are so obscure, that at present we cannot be said to know much about them; but if we turn to that mode of perpetuation which results from the sexual process, then we find variation a perfectly constant occurrence, to a certain extent; and, indeed, i think that a certain amount of variation from the primitive stock is the necessary result of the method of sexual propagation itself; for, inasmuch as the thing propagated proceeds from two organisms of different sexes and different makes and temperaments, and as the offspring is to be either of one sex or the other, it is quite clear that it cannot be an exact diagonal of the two, or it would be of no sex at all; it cannot be an exact intermediate form between that of each of its parents--it must deviate to one side or the other. you do not find that the male follows the precise type of the male parent, nor does the female always inherit the precise characteristics of the mother,--there is always a proportion of the female character in the male offspring, and of the male character in the female offspring. that must be quite plain to all of you who have looked at all attentively on your own children or those of your neighbours; you will have noticed how very often it may happen that the son shall exhibit the maternal type of character, or the daughter possess the characteristics of the father's family. there are all sorts of intermixtures and intermediate conditions between the two, where complexion, or beauty, or fifty other different peculiarities belonging to either side of the house, are reproduced in other members of the same family. indeed, it is sometimes to be remarked in this kind of variation, that the variety belongs, strictly speaking, to neither of the immediate parents; you will see a child in a family who is not like either its father or its mother; but some old person who knew its grandfather or grandmother, or, it may be, an uncle, or, perhaps, even a more distant relative, will see a great similarity between the child and one of these. in this way it constantly happens that the characteristic of some previous member of the family comes out and is reproduced and recognised in the most unexpected manner. but apart from that matter of general experience, there are some cases which put that curious mixture in a very clear light. you are aware that the offspring of the ass and the horse, or rather of the he-ass and the mare, is what is called a mule; and, on the other hand, the offspring of the stallion and the she-ass is what is called a 'hinny'. i never saw one myself; but they have been very carefully studied. now, the curious thing is this, that although you have the same elements in the experiment in each case, the offspring is entirely different in character, according as the male influence comes from the ass or the horse. where the ass is the male, as in the case of the mule, you find that the head is like that of the ass, that the ears are long, the tail is tufted at the end, the feet are small, and the voice is an unmistakable bray; these are all points of similarity to the ass; but, on the other hand, the barrel of the body and the cut of the neck are much more like those of the mare. then, if you look at the hinny,--the result of the union of the stallion and the she-ass, then you find it is the horse that has the predominance; that the head is more like that of the horse, the ears are shorter, the legs coarser, and the type is altogether altered; while the voice, instead of being a bray, is the ordinary neigh of the horse. here, you see, is a most curious thing: you take exactly the same elements, ass and horse, but you combine the sexes in a different manner, and the result is modified accordingly. you have in this case, however, a result which is not general and universal--there is usually an important preponderance, but not always on the same side. here, then, is one intelligible, and, perhaps, necessary cause of variation: the fact, that there are two sexes sharing in the production of the offspring, and that the share taken by each is different and variable, not only for each combination, but also for different members of the same family. secondly, there is a variation, to a certain extent--though, in all probability, the influence of this cause has been very much exaggerated--but there is no doubt that variation is produced, to a certain extent, by what are commonly known as external conditions,--such as temperature, food, warmth, and moisture. in the long run, every variation depends, in some sense, upon external conditions, seeing that everything has a cause of its own. i use the term "external conditions" now in the sense in which it is ordinarily employed: certain it is, that external conditions have a definite effect. you may take a plant which has single flowers, and by dealing with the soil, and nourishment, and so on, you may by-and-by convert single flowers into double flowers, and make thorns shoot out into branches. you may thicken or make various modifications in the shape of the fruit. in animals, too, you may produce analogous changes in this way, as in the case of that deep bronze colour which persons rarely lose after having passed any length of time in tropical countries. you may also alter the development of the muscles very much, by dint of training; all the world knows that exercise has a great effect in this way; we always expect to find the arm of a blacksmith hard and wiry, and possessing a large development of the brachial muscles. no doubt training, which is one of the forms of external conditions, converts what are originally only instructions, teachings, into habits, or, in other words, into organizations, to a great extent; but this second cause of variation cannot be considered to be by any means a large one. the third cause that i have to mention, however, is a very extensive one. it is one that, for want of a better name, has been called "spontaneous variation;" which means that when we do not know anything about the cause of phenomena, we call it spontaneous. in the orderly chain of causes and effects in this world, there are very few things of which it can be said with truth that they are spontaneous. certainly not in these physical matters,--in these there is nothing of the kind,--everything depends on previous conditions. but when we cannot trace the cause of phenomena, we call them spontaneous. of these variations, multitudinous as they are, but little is known with perfect accuracy. i will mention to you some two or three cases, because they are very remarkable in themselves, and also because i shall want to use them afterwards. reaumur, a famous french naturalist, a great many years ago, in an essay which he wrote upon the art of hatching chickens,--which was indeed a very curious essay,--had occasion to speak of variations and monstrosities. one very remarkable case had come under his notice of a variation in the form of a human member, in the person of a maltese, of the name of gratio kelleia, who was born with six fingers upon each hand, and the like number of toes to each of his feet. that was a case of spontaneous variation. nobody knows why he was born with that number of fingers and toes, and as we don't know, we call it a case of "spontaneous" variation. there is another remarkable case also. i select these, because they happen to have been observed and noted very carefully at the time. it frequently happens that a variation occurs, but the persons who notice it do not take any care in noting down the particulars, until at length, when inquiries come to be made, the exact circumstances are forgotten; and hence, multitudinous as may be such "spontaneous" variations, it is exceedingly difficult to get at the origin of them. the second case is one of which you may find the whole details in the "philosophical transactions" for the year 1813, in a paper communicated by colonel humphrey to the president of the royal society,--"on a new variety in the breed of sheep," giving an account of a very remarkable breed of sheep, which at one time was well known in the northern states of america, and which went by the name of the ancon or the otter breed of sheep. in the year 1791, there was a farmer of the name of seth wright in massachusetts, who had a flock of sheep, consisting of a ram and, i think, of some twelve or thirteen ewes. of this flock of ewes, one at the breeding-time bore a lamb which was very singularly formed; it had a very long body, very short legs, and those legs were bowed! i will tell you by-and-by how this singular variation in the breed of sheep came to be noted, and to have the prominence that it now has. for the present, i mention only these two cases; but the extent of variation in the breed of animals is perfectly obvious to any one who has studied natural history with ordinary attention, or to any person who compares animals with others of the same kind. it is strictly true that there are never any two specimens which are exactly alike; however similar, they will always differ in some certain particular. now let us go back to atavism,--to the hereditary tendency i spoke of. what will come of a variation when you breed from it, when atavism comes, if i may say so, to intersect variation? the two cases of which i have mentioned the history, give a most excellent illustration of what occurs. gratio kelleia, the maltese, married when he was twenty-two years of age, and, as i suppose there were no six-fingered ladies in malta, he married an ordinary five-fingered person. the result of that marriage was four children; the first, who was christened salvator, had six fingers and six toes, like his father; the second was george, who had five fingers and toes, but one of them was deformed, showing a tendency to variation; the third was andre; he had five fingers and five toes, quite perfect; the fourth was a girl, marie; she had five fingers and five toes, but her thumbs were deformed, showing a tendency toward the sixth. these children grew up, and when they came to adult years, they all married, and of course it happened that they all married five-fingered and five-toed persons. now let us see what were the results. salvator had four children; they were two boys, a girl, and another boy; the first two boys and the girl were six-fingered and six-toed like their grandfather; the fourth boy had only five fingers and five toes. george had only four children; there were two girls with six fingers and six toes; there was one girl with six fingers and five toes on the right side, and five fingers and five toes on the left side, so that she was half and half. the last, a boy, had five fingers and five toes. the third, andre, you will recollect, was perfectly well-formed, and he had many children whose hands and feet were all regularly developed. marie, the last, who, of course, married a man who had only five fingers, had four children; the first, a boy, was born with six toes, but the other three were normal. now observe what very extraordinary phenomena are presented here. you have an accidental variation arising from what you may call a monstrosity; you have that monstrosity tendency or variation diluted in the first instance by an admixture with a female of normal construction, and you would naturally expect that, in the results of such an union, the monstrosity, if repeated, would be in equal proportion with the normal type; that is to say, that the children would be half and half, some taking the peculiarity of the father, and the others being of the purely normal type of the mother; but you see we have a great preponderance of the abnormal type. well, this comes to be mixed once more with the pure, the normal type, and the abnormal is again produced in large proportion, notwithstanding the second dilution. now what would have happened if these abnormal types had intermarried with each other; that is to say, suppose the two boys of salvator had taken it into their heads to marry their first cousins, the two first girls of george, their uncle? you will remember that these are all of the abnormal type of their grandfather. the result would probably have been, that their offspring would have been in every case a further development of that abnormal type. you see it is only in the fourth, in the person of marie, that the tendency, when it appears but slightly in the second generation, is washed out in the third, while the progeny of andre, who escaped in the first instance, escape altogether. we have in this case a good example of nature's tendency to the perpetuation of a variation. here it is certainly a variation which carried with it no use or benefit; and yet you see the tendency to perpetuation may be so strong, that, notwithstanding a great admixture of pure blood, the variety continues itself up to the third generation, which is largely marked with it. in this case, as i have said, there was no means of the second generation intermarrying with any but five-fingered persons, and the question naturally suggests itself, what would have been the result of such marriage? reaumur narrates this case only as far as the third generation. certainly it would have been an exceedingly curious thing if we could have traced this matter any further; had the cousins intermarried, a six-fingered variety of the human race might have been set up. to show you that this supposition is by no means an unreasonable one, let me now point out what took place in the case of seth wright's sheep, where it happened to be a matter of moment to him to obtain a breed or raise a flock of sheep like that accidental variety that i have described--and i will tell you why. in that part of massachusetts where seth wright was living, the fields were separated by fences, and the sheep, which were very active and robust, would roam abroad, and without much difficulty jump over these fences into other people's farms. as a matter of course, this exuberant activity on the part of the sheep constantly gave rise to all sorts of quarrels, bickerings, and contentions among the farmers of the neighbourhood; so it occurred to seth wright, who was, like his successors, more or less 'cute, that if he could get a stock of sheep like those with the bandy legs, they would not be able to jump over the fences so readily, and he acted upon that idea. he killed his old ram, and as soon as the young one arrived at maturity, he bred altogether from it. the result was even more striking than in the human experiment which i mentioned just now. colonel humphreys testifies that it always happened that the offspring were either pure ancons or pure ordinary sheep; that in no case was there any mixing of the ancons with the others. in consequence of this, in the course of a very few years, the farmer was able to get a very considerable flock of this variety, and a large number of them were spread throughout massachusetts. most unfortunately, however--i suppose it was because they were so common--nobody took enough notice of them to preserve their skeletons; and although colonel humphreys states that he sent a skeleton to the president of the royal society at the same time that he forwarded his paper, i am afraid that the variety has entirely disappeared; for a short time after these sheep had become prevalent in that district, the merino sheep were introduced; and as their wool was much more valuable, and as they were a quiet race of sheep, and showed no tendency to trespass or jump over fences, the otter breed of sheep, the wool of which was inferior to that of the merino, was gradually allowed to die out. you see that these facts illustrate perfectly well what may be done if you take care to breed from stocks that are similar to each other. after having got a variation, if, by crossing a variation with the original stock, you multiply that variation, and then take care to keep that variation distinct from the original stock, and make them breed together,--then you may almost certainly produce a race whose tendency to continue the variation is exceedingly strong. this is what is called "selection"; and it is by exactly the same process as that by which seth wright bred his ancon sheep, that our breeds of cattle, dogs, and fowls, are obtained. there are some possibilities of exception, but still, speaking broadly, i may say that this is the way in which all our varied races of domestic animals have arisen; and you must understand that it is not one peculiarity or one characteristic alone in which animals may vary. there is not a single peculiarity or characteristic of any kind, bodily or mental, in which offspring may not vary to a certain extent from the parent and other animals. among ourselves this is well known. the simplest physical peculiarity is mostly reproduced. i know a case of a man whose wife has the lobe of one of her ears a little flattened. an ordinary observer might scarcely notice it, and yet every one of her children has an approximation to the same peculiarity to some extent. if you look at the other extreme, too, the gravest diseases, such as gout, scrofula, and consumption, may be handed down with just the same certainty and persistence as we noticed in the perpetuation of the bandy legs of the ancon sheep. however, these facts are best illustrated in animals, and the extent of the variation, as is well known, is very remarkable in dogs. for example, there are some dogs very much smaller than others; indeed, the variation is so enormous that probably the smallest dog would be about the size of the head of the largest; there are very great variations in the structural forms not only of the skeleton but also in the shape of the skull, and in the proportions of the face and the disposition of the teeth. the pointer, the retriever, bulldog, and the terrier, differ very greatly, and yet there is every reason to believe that every one of these races has arisen from the same source,--that all the most important races have arisen by this selective breeding from accidental variation. a still more striking case of what may be done by selective breeding, and it is a better case, because there is no chance of that partial infusion of error to which i alluded, has been studied very carefully by mr. darwin,--the case of the domestic pigeons. i dare say there may be some among you who may be pigeon 'fanciers', and i wish you to understand that in approaching the subject, i would speak with all humility and hesitation, as i regret to say that i am not a pigeon fancier. i know it is a great art and mystery, and a thing upon which a man must not speak lightly; but i shall endeavour, as far as my understanding goes, to give you a summary of the published and unpublished information which i have gained from mr. darwin. among the enormous variety,--i believe there are somewhere about a hundred and fifty kinds of pigeons,--there are four kinds which may be selected as representing the extremest divergences of one kind from another. their names are the carrier, the pouter, the fantail, and the tumbler. in the large diagrams they are each represented in their relative sizes to each other. this first one is the carrier; you will notice this large excrescence on its beak; it has a comparatively small head; there is a bare space round the eyes; it has a long neck, a very long beak, very strong legs, large feet, long wings, and so on. the second one is the pouter, a very large bird, with very long legs and beak. it is called the pouter because it is in the habit of causing its gullet to swell up by inflating it with air. i should tell you that all pigeons have a tendency to do this at times, but in the pouter it is carried to an enormous extent. the birds appear to be quite proud of their power of swelling and puffing themselves out in this way; and i think it is about as droll a sight as you can well see to look at a cage full of these pigeons puffing and blowing themselves out in this ridiculous manner. the third kind i mentioned--the fantail--is a small bird, with exceedingly small legs and a very small beak. it is most curiously distinguished by the size and extent of its tail, which, instead of containing twelve feathers, may have many more,--say thirty, or even more--i believe there are some with as many as forty-two. this bird has a curious habit of spreading out the feathers of its tail in such a way that they reach forward, and touch its head; and if this can be accomplished, i believe it is looked upon as a point of great beauty. but here is the last great variety,--the tumbler; and of that great variety, one of the principal kinds, and one most prized, is the specimen represented here--the short-faced tumbler. its beak is reduced to a mere nothing. just compare the beak of this one and that of the first one, the carrier--i believe the orthodox comparison of the head and beak of a thoroughly well-bred tumbler is to stick an oat into a cherry, and that will give you the proper relative proportions of the head and beak. the feet and legs are exceedingly small, and the bird appears to be quite a dwarf when placed side by side with this great carrier. these are differences enough in regard to their external appearance; but these differences are by no means the whole or even the most important of the differences which obtain between these birds. there is hardly a single point of their structure which has not become more or less altered; and to give you an idea of how extensive these alterations are, i have here some very good skeletons, for which i am indebted to my friend, mr. tegetmeier, a great authority in these matters; by means of which, if you examine them by-and-by, you will be able to see the enormous difference in their bony structures. i had the privilege, some time ago, of access to some important mss. of mr. darwin, who, i may tell you, has taken very great pains and spent much valuable time and attention on the investigation of these variations, and getting together all the facts that bear upon them. i obtained from these mss. the following summary of the differences between the domestic breeds of pigeons; that is to say, a notification of the various points in which their organization differs. in the first place, the back of the skull may differ a good deal, and the development of the bones of the face may vary a great deal; the back varies a good deal; the shape of the lower jaw varies; the tongue varies very greatly, not only in correlation to the length and size of the beak, but it seems also to have a kind of independent variation of its own. then the amount of naked skin round the eyes, and at the base of the beak, may vary enormously; so may the length of the eyelids, the shape of the nostrils, and the length of the neck. i have already noticed the habit of blowing out the gullet, so remarkable in the pouter, and comparatively so in the others. there are great differences, too, in the size of the female and the male, the shape of the body, the number and width of the processes of the ribs, the development of the ribs, and the size, shape, and development of the breastbone. we may notice, too,--and i mention the fact because it has been disputed by what is assumed to be high authority,--the variation in the number of the sacral vertebrae. the number of these varies from eleven to fourteen, and that without any diminution in the number of the vertebrae of the back or of the tail. then the number and position of the tail-feathers may vary enormously, and so may the number of the primary and secondary feathers of the wings. again, the length of the feet and of the beak,--although they have no relation to each other, yet appear to go together,--that is, you have a long beak wherever you have long feet. there are differences also in the periods of the acquirement of the perfect plumage,--the size and shape of the eggs,--the nature of flight, and the powers of flight,--so-called "homing" birds having enormous flying powers; [1] while, on the other hand, the little tumbler is so called because of its extraordinary faculty of turning head over heels in the air, instead of pursuing a direct course. and, lastly, the dispositions and voices of the birds may vary. thus the case of the pigeons shows you that there is hardly a single particular,--whether of instinct, or habit, or bony structure, or of plumage,--of either the internal economy or the external shape, in which some variation or change may not take place, which, by selective breeding, may become perpetuated, and form the foundation of, and give rise to, a new race. [footnote 1: the "carrier," i learn from mr. tegetmeier, does not 'carry'; a high-bred bird of this breed being but a poor flier. the birds which fly long distances, and come home,--"homing" birds,--and are consequently used as carriers, are not "carriers" in the fancy sense.] if you carry in your mind's eye these four varieties of pigeons, you will bear with you as good a notion as you can have, perhaps, of the enormous extent to which a deviation from a primitive type may be carried by means of this process of selective breeding. the past condition of organic nature lecture ii. (of vi.), lectures to working men, at the museum of practical geology, 1863, on darwin's work: "origin of species". by thomas h. huxley in the lecture which i delivered last monday evening, i endeavoured to sketch in a very brief manner, but as well as the time at my disposal would permit, the present condition of organic nature, meaning by that large title simply an indication of the great, broad, and general principles which are to be discovered by those who look attentively at the phenomena of organic nature as at present displayed. the general result of our investigations might be summed up thus: we found that the multiplicity of the forms of animal life, great as that may be, may be reduced to a comparatively few primitive plans or types of construction; that a further study of the development of those different forms revealed to us that they were again reducible, until we at last brought the infinite diversity of animal, and even vegetable life, down to the primordial form of a single cell. we found that our analysis of the organic world, whether animals or plants, showed, in the long run, that they might both be reduced into, and were, in fact, composed of, the same constituents. and we saw that the plant obtained the materials constituting its substance by a peculiar combination of matters belonging entirely to the inorganic world; that, then, the animal was constantly appropriating the nitrogenous matters of the plant to its own nourishment, and returning them back to the inorganic world, in what we spoke of as its waste; and that finally, when the animal ceased to exist, the constituents of its body were dissolved and transmitted to that inorganic world whence they had been at first abstracted. thus we saw in both the blade of grass and the horse but the same elements differently combined and arranged. we discovered a continual circulation going on,--the plant drawing in the elements of inorganic nature and combining them into food for the animal creation; the animal borrowing from the plant the matter for its own support, giving off during its life products which returned immediately to the inorganic world; and that, eventually, the constituent materials of the whole structure of both animals and plants were thus returned to their original source: there was a constant passage from one state of existence to another, and a returning back again. lastly, when we endeavoured to form some notion of the nature of the forces exercised by living beings, we discovered that they--if not capable of being subjected to the same minute analysis as the constituents of those beings themselves--that they were correlative with--that they were the equivalents of the forces of inorganic nature--that they were, in the sense in which the term is now used, convertible with them. that was our general result. and now, leaving the present, i must endeavour in the same manner to put before you the facts that are to be discovered in the past history of the living world, in the past conditions of organic nature. we have, to-night, to deal with the facts of that history--a history involving periods of time before which our mere human records sink into utter insignificance--a history the variety and physical magnitude of whose events cannot even be foreshadowed by the history of human life and human phenomena--a history of the most varied and complex character. we must deal with the history, then, in the first place, as we should deal with all other histories. the historical student knows that his first business should be to inquire into the validity of his evidence, and the nature of the record in which the evidence is contained, that he may be able to form a proper estimate of the correctness of the conclusions which have been drawn from that evidence. so, here, we must pass, in the first place, to the consideration of a matter which may seem foreign to the question under discussion. we must dwell upon the nature of the records, and the credibility of the evidence they contain; we must look to the completeness or incompleteness of those records themselves, before we turn to that which they contain and reveal. the question of the credibility of the history, happily for us, will not require much consideration, for, in this history, unlike those of human origin, there can be no cavilling, no differences as to the reality and truth of the facts of which it is made up; the facts state themselves, and are laid out clearly before us. but, although one of the greatest difficulties of the historical student is cleared out of our path, there are other difficulties--difficulties in rightly interpreting the facts as they are presented to us--which may be compared with the greatest difficulties of any other kinds of historical study. what is this record of the past history of the globe, and what are the questions which are involved in an inquiry into its completeness or incompleteness? that record is composed of mud; and the question which we have to investigate this evening resolves itself into a question of the formation of mud. you may think, perhaps, that this is a vast step--of almost from the sublime to the ridiculous--from the contemplation of the history of the past ages of the world's existence to the consideration of the history of the formation of mud! but, in nature, there is nothing mean and unworthy of attention; there is nothing ridiculous or contemptible in any of her works; and this inquiry, you will soon see, i hope, takes us to the very root and foundations of our subject. how, then, is mud formed? always, with some trifling exception, which i need not consider now--always, as the result of the action of water, wearing down and disintegrating the surface of the earth and rocks with which it comes in contact--pounding and grinding it down, and carrying the particles away to places where they cease to be disturbed by this mechanical action, and where they can subside and rest. for the ocean, urged by winds, washes, as we know, a long extent of coast, and every wave, loaded as it is with particles of sand and gravel as it breaks upon the shore, does something towards the disintegrating process. and thus, slowly but surely, the hardest rocks are gradually ground down to a powdery substance; and the mud thus formed, coarser or finer, as the case may be, is carried by the rush of the tides, or currents, till it reaches the comparatively deeper parts of the ocean, in which it can sink to the bottom, that is, to parts where there is a depth of about fourteen or fifteen fathoms, a depth at which the water is, usually, nearly motionless, and in which, of course, the finer particles of this detritus, or mud as we call it, sinks to the bottom. or, again, if you take a river, rushing down from its mountain sources, brawling over the stones and rocks that intersect its path, loosening, removing, and carrying with it in its downward course the pebbles and lighter matters from its banks, it crushes and pounds down the rocks and earths in precisely the same way as the wearing action of the sea waves. the matters forming the deposit are torn from the mountain-side and whirled impetuously into the valley, more slowly over the plain, thence into the estuary, and from the estuary they are swept into the sea. the coarser and heavier fragments are obviously deposited first, that is, as soon as the current begins to lose its force by becoming amalgamated with the stiller depths of the ocean, but the finer and lighter particles are carried further on, and eventually deposited in a deeper and stiller portion of the ocean. it clearly follows from this that mud gives us a chronology; for it is evident that supposing this, which i now sketch, to be the sea bottom, and supposing this to be a coast-line; from the washing action of the sea upon the rock, wearing and grinding it down into a sediment of mud, the mud will be carried down, and at length, deposited in the deeper parts of this sea bottom, where it will form a layer; and then, while that first layer is hardening, other mud which is coming from the same source will, of course, be carried to the same place; and, as it is quite impossible for it to get beneath the layer already there, it deposits itself above it, and forms another layer, and in that way you gradually have layers of mud constantly forming and hardening one above the other, and conveying a record of time. it is a necessary result of the operation of the law of gravitation that the uppermost layer shall be the youngest and the lowest the oldest, and that the different beds shall be older at any particular point or spot in exactly the ratio of their depth from the surface. so that if they were upheaved afterwards, and you had a series of these different layers of mud, converted into sandstone, or limestone, as the case might be, you might be sure that the bottom layer was deposited first, and that the upper layers were formed afterwards. here, you see, is the first step in the history--these layers of mud give us an idea of time. the whole surface of the earth,--i speak broadly, and leave out minor qualifications,--is made up of such layers of mud, so hard, the majority of them, that we call them rock whether limestone or sandstone, or other varieties of rock. and, seeing that every part of the crust of the earth is made up in this way, you might think that the determination of the chronology, the fixing of the time which it has taken to form this crust is a comparatively simple matter. take a broad average, ascertain how fast the mud is deposited upon the bottom of the sea, or in the estuary of rivers; take it to be an inch, or two, or three inches a year, or whatever you may roughly estimate it at; then take the total thickness of the whole series of stratified rocks, which geologists estimate at twelve or thirteen miles, or about seventy thousand feet, make a sum in short division, divide the total thickness by that of the quantity deposited in one year, and the result will, of course, give you the number of years which the crust has taken to form. truly, that looks a very simple process! it would be so except for certain difficulties, the very first of which is that of finding how rapidly sediments are deposited; but the main difficulty--a difficulty which renders any certain calculations of such a matter out of the question--is this, the sea-bottom on which the deposit takes place is continually shifting. instead of the surface of the earth being that stable, fixed thing that it is popularly believed to be, being, in common parlance, the very emblem of fixity itself, it is incessantly moving, and is, in fact, as unstable as the surface of the sea, except that its undulations are infinitely slower and enormously higher and deeper. now, what is the effect of this oscillation? take the case to which i have previously referred. the finer or coarser sediments that are carried down by the current of the river, will only be carried out a certain distance, and eventually, as we have already seen, on reaching the stiller part of the ocean, will be deposited at the bottom. let c y (fig. 4) be the sea-bottom, y d the shore, x y the sea-level, then the coarser deposit will subside over the region b, the finer over a, while beyond a there will be no deposit at all; and, consequently, no record will be kept, simply because no deposit is going on. now, suppose that the whole land, c, d, which we have regarded as stationary, goes down, as it does so, both a and b go further out from the shore, which will be at y1; x1, y1, being the new sea-level. the consequence will be that the layer of mud (a), being now, for the most part, further than the force of the current is strong enough to convey even the finest 'debris', will, of course, receive no more deposits, and having attained a certain thickness will now grow no thicker. we should be misled in taking the thickness of that layer, whenever it may be exposed to our view, as a record of time in the manner in which we are now regarding this subject, as it would give us only an imperfect and partial record: it would seem to represent too short a period of time. [illustration: fig.4.] suppose, on the other hand, that the land (c d) had gone on rising slowly and gradually--say an inch or two inches in the course of a century,--what would be the practical effect of that movement? why, that the sediment a and b which has been already deposited, would eventually be brought nearer to the shore-level, and again subjected to the wear and tear of the sea; and directly the sea begins to act upon it, it would of course soon cut up and carry it away, to a greater or less extent, to be re-deposited further out. well, as there is, in all probability, not one single spot on the whole surface of the earth, which has not been up and down in this way a great many times, it follows that the thickness of the deposits formed at any particular spot cannot be taken (even supposing we had at first obtained correct data as to the rate at which they took place) as affording reliable information as to the period of time occupied in its deposit. so that you see it is absolutely necessary from these facts, seeing that our record entirely consists of accumulations of mud, superimposed one on the other; seeing in the next place that any particular spots on which accumulations have occurred, have been constantly moving up and down, and sometimes out of the reach of a deposit, and at other times its own deposit broken up and carried away, it follows that our record must be in the highest degree imperfect, and we have hardly a trace left of thick deposits, or any definite knowledge of the area that they occupied, in a great many cases. and mark this! that supposing even that the whole surface of the earth had been accessible to the geologist,--that man had had access to every part of the earth, and had made sections of the whole, and put them all together,--even then his record must of necessity be imperfect. but to how much has man really access? if you will look at this map you will see that it represents the proportion of the sea to the earth: this coloured part indicates all the dry land, and this other portion is the water. you will notice at once that the water covers three-fifths of the whole surface of the globe, and has covered it in the same manner ever since man has kept any record of his own observations, to say nothing of the minute period during which he has cultivated geological inquiry. so that three-fifths of the surface of the earth is shut out from us because it is under the sea. let us look at the other two-fifths, and see what are the countries in which anything that may be termed searching geological inquiry has been carried out: a good deal of france, germany, and great britain and ireland, bits of spain, of italy, and of russia, have been examined, but of the whole great mass of africa, except parts of the southern extremity, we know next to nothing; little bits of india, but of the greater part of the asiatic continent nothing; bits of the northern american states and of canada, but of the greater part of the continent of north america, and in still larger proportion, of south america, nothing! under these circumstances, it follows that even with reference to that kind of imperfect information which we can possess, it is only of about the ten-thousandth part of the accessible parts of the earth that has been examined properly. therefore, it is with justice that the most thoughtful of those who are concerned in these inquiries insist continually upon the imperfection of the geological record; for, i repeat, it is absolutely necessary, from the nature of things, that that record should be of the most fragmentary and imperfect character. unfortunately this circumstance has been constantly forgotten. men of science, like young colts in a fresh pasture, are apt to be exhilarated on being turned into a new field of inquiry, to go off at a hand-gallop, in total disregard of hedges and ditches, losing sight of the real limitation of their inquiries, and to forget the extreme imperfection of what is really known. geologists have imagined that they could tell us what was going on at all parts of the earth's surface during a given epoch; they have talked of this deposit being contemporaneous with that deposit, until, from our little local histories of the changes at limited spots of the earth's surface, they have constructed a universal history of the globe as full of wonders and portents as any other story of antiquity. but what does this attempt to construct a universal history of the globe imply? it implies that we shall not only have a precise knowledge of the events which have occurred at any particular point, but that we shall be able to say what events, at any one spot, took place at the same time with those at other spots. let us see how far that is in the nature of things practicable. suppose that here i make a section of the lake of killarney, and here the section of another lake--that of loch lomond in scotland for instance. the rivers that flow into them are constantly carrying down deposits of mud, and beds, or strata, are being as constantly formed, one above the other, at the bottom of those lakes. now, there is not a shadow of doubt that in these two lakes the lower beds are all older than the upper--there is no doubt about that; but what does 'this' tell us about the age of any given bed in loch lomond, as compared with that of any given bed in the lake of killarney? it is, indeed, obvious that if any two sets of deposits are separated and discontinuous, there is absolutely no means whatever given you by the nature of the deposit of saying whether one is much younger or older than the other; but you may say, as many have said and think, that the case is very much altered if the beds which we are comparing are continuous. suppose two beds of mud hardened into rock,--a and b-are seen in section. (fig. 5.) [illustration: fig. 5.] well, you say, it is admitted that the lowermost bed is always the older. very well; b, therefore, is older than a. no doubt, 'as a whole', it is so; or if any parts of the two beds which are in the same vertical line are compared, it is so. but suppose you take what seems a very natural step further, and say that the part 'a' of the bed a is younger than the part 'b' of the bed b. is this sound reasoning? if you find any record of changes taking place at 'b', did they occur before any events which took place while 'a' was being deposited? it looks all very plain sailing, indeed, to say that they did; and yet there is no proof of anything of the kind. as the former director of this institution, sir h. de la beche, long ago showed, this reasoning may involve an entire fallacy. it is extremely possible that 'a' may have been deposited ages before 'b'. it is very easy to understand how that can be. to return to fig. 4; when a and b were deposited, they were 'substantially' contemporaneous; a being simply the finer deposit, and b the coarser of the same detritus or waste of land. now suppose that that sea-bottom goes down (as shown in fig. 4), so that the first deposit is carried no farther than 'a', forming the bed al, and the coarse no farther than 'b', forming the bed b1, the result will be the formation of two continuous beds, one of fine sediment (a a1) over-lapping another of coarse sediment (b b1). now suppose the whole sea-bottom is raised up, and a section exposed about the point al; no doubt, 'at this spot', the upper bed is younger than the lower. but we should obviously greatly err if we concluded that the mass of the upper bed at a was younger than the lower bed at b; for we have just seen that they are contemporaneous deposits. still more should we be in error if we supposed the upper bed at a to be younger than the continuation of the lower bed at bl; for a was deposited long before b1. in fine, if, instead of comparing immediately adjacent parts of two beds, one of which lies upon another, we compare distant parts, it is quite possible that the upper may be any number of years older than the under, and the under any number of years younger than the upper. now you must not suppose that i put this before you for the purpose of raising a paradoxical difficulty; the fact is, that the great mass of deposits have taken place in sea-bottoms which are gradually sinking, and have been formed under the very conditions i am here supposing. do not run away with the notion that this subverts the principle i laid down at first. the error lies in extending a principle which is perfectly applicable to deposits in the same vertical line to deposits which are not in that relation to one another. it is in consequence of circumstances of this kind, and of others that i might mention to you, that our conclusions on and interpretations of the record are really and strictly only valid so long as we confine ourselves to one vertical section. i do not mean to tell you that there are no qualifying circumstances, so that, even in very considerable areas, we may safely speak of conformably superimposed beds being older or younger than others at many different points. but we can never be quite sure in coming to that conclusion, and especially we cannot be sure if there is any break in their continuity, or any very great distance between the points to be compared. well now, so much for the record itself,--so much for its imperfections,--so much for the conditions to be observed in interpreting it, and its chronological indications, the moment we pass beyond the limits of a vertical linear section. now let us pass from the record to that which it contains,--from the book itself to the writing and the figures on its pages. this writing and these figures consist of remains of animals and plants which, in the great majority of cases, have lived and died in the very spot in which we now find them, or at least in the immediate vicinity. you must all of you be aware--and i referred to the fact in my last lecture--that there are vast numbers of creatures living at the bottom of the sea. these creatures, like all others, sooner or later die, and their shells and hard parts lie at the bottom; and then the fine mud which is being constantly brought down by rivers and the action of the wear and tear of the sea, covers them over and protects them from any further change or alteration; and, of course, as in process of time the mud becomes hardened and solidified, the shells of these animals are preserved and firmly imbedded in the limestone or sandstone which is being thus formed. you may see in the galleries of the museum up stairs specimens of limestones in which such fossil remains of existing animals are imbedded. there are some specimens in which turtles' eggs have been imbedded in calcareous sand, and before the sun had hatched the young turtles, they became covered over with calcareous mud, and thus have been preserved and fossilized. not only does this process of imbedding and fossilization occur with marine and other aquatic animals and plants, but it affects those land animals and plants which are drifted away to sea, or become buried in bogs or morasses; and the animals which have been trodden down by their fellows and crushed in the mud at the river's bank, as the herd have come to drink. in any of these cases, the organisms may be crushed or be mutilated, before or after putrefaction, in such a manner that perhaps only a part will be left in the form in which it reaches us. it is, indeed, a most remarkable fact, that it is quite an exceptional case to find a skeleton of any one of all the thousands of wild land animals that we know are constantly being killed, or dying in the course of nature: they are preyed on and devoured by other animals or die in places where their bodies are not afterwards protected by mud. there are other animals existing in the sea, the shells of which form exceedingly large deposits. you are probably aware that before the attempt was made to lay the atlantic telegraphic cable, the government employed vessels in making a series of very careful observations and soundings of the bottom of the atlantic; and although, as we must all regret, up to the present time that project has not succeeded, we have the satisfaction of knowing that it yielded some most remarkable results to science. the atlantic ocean had to be sounded right across, to depths of several miles in some places, and the nature of its bottom was carefully ascertained. well, now, a space of about 1,000 miles wide from east to west, and i do not exactly know how many from north to south, but at any rate 600 or 700 miles, was carefully examined, and it was found that over the whole of that immense area an excessively fine chalky mud is being deposited; and this deposit is entirely made up of animals whose hard parts are deposited in this part of the ocean, and are doubtless gradually acquiring solidity and becoming metamorphosed into a chalky limestone. thus, you see, it is quite possible in this way to preserve unmistakable records of animal and vegetable life. whenever the sea-bottom, by some of those undulations of the earth's crust that i have referred to, becomes upheaved, and sections or borings are made, or pits are dug, then we become able to examine the contents and constituents of these ancient sea-bottoms, and find out what manner of animals lived at that period. now it is a very important consideration in its bearing on the completeness of the record, to inquire how far the remains contained in these fossiliferous limestones are able to convey anything like an accurate or complete account of the animals which were in existence at the time of its formation. upon that point we can form a very clear judgment, and one in which there is no possible room for any mistake. there are of course a great number of animals--such as jelly-fishes, and other animals--without any hard parts, of which we cannot reasonably expect to find any traces whatever: there is nothing of them to preserve. within a very short time, you will have noticed, after they are removed from the water, they dry up to a mere nothing; certainly they are not of a nature to leave any very visible traces of their existence on such bodies as chalk or mud. then again, look at land animals; it is, as i have said, a very uncommon thing to find a land animal entire after death. insects and other carnivorous animals very speedily pull them to pieces, putrefaction takes place, and so, out of the hundreds of thousands that are known to die every year, it is the rarest thing in the world to see one imbedded in such a way that its remains would be preserved for a lengthened period. not only is this the case, but even when animal remains have been safely imbedded, certain natural agents may wholly destroy and remove them. almost all the hard parts of animals--the bones and so on--are composed chiefly of phosphate of lime and carbonate of lime. some years ago, i had to make an inquiry into the nature of some very curious fossils sent to me from the north of scotland. fossils are usually hard bony structures that have become imbedded in the way i have described, and have gradually acquired the nature and solidity of the body with which they are associated; but in this case i had a series of 'holes' in some pieces of rock, and nothing else. those holes, however, had a certain definite shape about them, and when i got a skilful workman to make castings of the interior of these holes, i found that they were the impressions of the joints of a backbone and of the armour of a great reptile, twelve or more feet long. this great beast had died and got buried in the sand; the sand had gradually hardened over the bones, but remained porous. water had trickled through it, and that water being probably charged with a superfluity of carbonic acid, had dissolved all the phosphate and carbonate of lime, and the bones themselves had thus decayed and entirely disappeared; but as the sandstone happened to have consolidated by that time, the precise shape of the bones was retained. if that sandstone had remained soft a little longer, we should have known nothing whatsoever of the existence of the reptile whose bones it had encased. how certain it is that a vast number of animals which have existed at one period on this earth have entirely perished, and left no trace whatever of their forms, may be proved to you by other considerations. there are large tracts of sandstone in various parts of the world, in which nobody has yet found anything but footsteps. not a bone of any description, but an enormous number of traces of footsteps. there is no question about them. there is a whole valley in connecticut covered with these footsteps, and not a single fragment of the animals which made them has yet been found. let me mention another case while upon that matter, which is even more surprising than those to which i have yet referred. there is a limestone formation near oxford, at a place called stonesfield, which has yielded the remains of certain very interesting mammalian animals, and up to this time, if i recollect rightly, there have been found seven specimens of its lower jaws, and not a bit of anything else, neither limb-bones nor skull, or any part whatever; not a fragment of the whole system! of course, it would be preposterous to imagine that the beasts had nothing else but a lower jaw! the probability is, as dr. buckland showed, as the result of his observations on dead dogs in the river thames, that the lower jaw, not being secured by very firm ligaments to the bones of the head, and being a weighty affair, would easily be knocked off, or might drop away from the body as it floated in water in a state of decomposition. the jaw would thus be deposited immediately, while the rest of the body would float and drift away altogether, ultimately reaching the sea, and perhaps becoming destroyed. the jaw becomes covered up and preserved in the river silt, and thus it comes that we have such a curious circumstance as that of the lower jaws in the stonesfield slates. so that, you see, faulty as these layers of stone in the earth's crust are, defective as they necessarily are as a record, the account of contemporaneous vital phenomena presented by them is, by the necessity of the case, infinitely more defective and fragmentary. it was necessary that i should put all this very strongly before you, because, otherwise, you might have been led to think differently of the completeness of our knowledge by the next facts i shall state to you. the researches of the last three-quarters of a century have, in truth, revealed a wonderful richness of organic life in those rocks. certainly not fewer than thirty or forty thousand different species of fossils have been discovered. you have no more ground for doubting that these creatures really lived and died at or near the places in which we find them than you have for like scepticism about a shell on the sea-shore. the evidence is as good in the one case as in the other. our next business is to look at the general character of these fossil remains, and it is a subject which it will be requisite to consider carefully; and the first point for us is to examine how much the extinct 'flora' and 'fauna' as a 'whole'--disregarding altogether the 'succession' of their constituents, of which i shall speak afterwards--differ from the 'flora' and 'fauna' of the present day;--how far they differ in what we 'do' know about them, leaving altogether out of consideration speculations based upon what we 'do not' know. i strongly imagine that if it were not for the peculiar appearance that fossilised animals have, any of you might readily walk through a museum which contains fossil remains mixed up with those of the present forms of life, and i doubt very much whether your uninstructed eyes would lead you to see any vast or wonderful difference between the two. if you looked closely, you would notice, in the first place, a great many things very like animals with which you are acquainted now: you would see differences of shape and proportion, but on the whole a close similarity. i explained what i meant by orders the other day, when i described the animal kingdom as being divided in sub-kingdoms, classes and orders. if you divide the animal kingdom into orders, you will find that there are about one hundred and twenty. the number may vary on one side or the other, but this is a fair estimate. that is the sum total of the orders of all the animals which we know now, and which have been known in past times, and left remains behind. now, how many of those are absolutely extinct? that is to say, how many of these orders of animals have lived at a former period of the world's history, but have at present no representatives? that is the sense in which i meant to use the word "extinct." i mean that those animals did live on this earth at one time, but have left no one of their kind with us at the present moment. so that estimating the number of extinct animals is a sort of way of comparing the past creation as a whole with the present as a whole. among the mammalia and birds there are none extinct; but when we come to the reptiles there is a most wonderful thing: out of the eight orders, or thereabouts, which you can make among reptiles, one-half are extinct. these diagrams of the plesiosaurus, the ichthyosaurus, the pterodactyle, give you a notion of some of these extinct reptiles. and here is a cast of the pterodactyle and bones of the ichthyosaurus and the plesiosaurus, just as fresh as if it had been recently dug up in a churchyard. thus, in the reptile class, there are no less than half of the orders which are absolutely extinct. if we turn to the 'amphibia', there was one extinct order, the labyrinthodonts, typified by the large salamander-like beast shown in this diagram. no order of fishes is known to be extinct. every fish that we find in the strata--to which i have been referring--can be identified and placed in one of the orders which exist at the present day. there is not known to be a single ordinal form of insect extinct. there are only two orders extinct among the 'crustacea'. there is not known to be an extinct order of these creatures, the parasitic and other worms; but there are two, not to say three, absolutely extinct orders of this class, the 'echinodermata'; out of all the orders of the 'coelenterata' and 'protozoa' only one, the rugose corals. so that, you see, out of somewhere about 120 orders of animals, taking them altogether, you will not, at the outside estimate, find above ten or a dozen extinct. summing up all the orders of animals which have left remains behind them, you will not find above ten or a dozen which cannot be arranged with those of the present day; that is to say, that the difference does not amount to much more than ten per cent.: and the proportion of extinct orders of plants is still smaller. i think that that is a very astounding, a most astonishing fact, seeing the enormous epochs of time which have elapsed during the constitution of the surface of the earth as it at present exists; it is, indeed, a most astounding thing that the proportion of extinct ordinal types should be so exceedingly small. but now, there is another point of view in which we must look at this past creation. suppose that we were to sink a vertical pit through the floor beneath us, and that i could succeed in making a section right through in the direction of new zealand, i should find in each of the different beds through which i passed the remains of animals which i should find in that stratum and not in the others. first, i should come upon beds of gravel or drift containing the bones of large animals, such as the elephant, rhinoceros, and cave tiger. rather curious things to fall across in piccadilly! if i should dig lower still, i should come upon a bed of what we call the london clay, and in this, as you will see in our galleries upstairs, are found remains of strange cattle, remains of turtles, palms, and large tropical fruits; with shell-fish such as you see the like of now only in tropical regions. if i went below that, i should come upon the chalk, and there i should find something altogether different, the remains of ichthyosauri and pterodactyles, and ammonites, and so forth. i do not know what mr. godwin austin would say comes next, but probably rocks containing more ammonites, and more ichthyosauri and plesiosauri, with a vast number of other things; and under that i should meet with yet older rocks, containing numbers of strange shells and fishes; and in thus passing from the surface to the lowest depths of the earth's crust, the forms of animal life and vegetable life which i should meet with in the successive beds would, looking at them broadly, be the more different the further that i went down. or, in other words, inasmuch as we started with the clear principle, that in a series of naturally-disposed mud beds the lowest are the oldest, we should come to this result, that the further we go back in time the more difference exists between the animal and vegetable life of an epoch and that which now exists. that was the conclusion to which i wished to bring you at the end of this lecture. a critical examination of the position of mr. darwin's work, "on the origin of species," in relation to the complete theory of the causes of the phenomena of organic nature by thomas h. huxley in the preceding five lectures i have endeavoured to give you an account of those facts, and of those reasonings from facts, which form the data upon which all theories regarding the causes of the phenomena of organic nature must be based. and, although i have had frequent occasion to quote mr. darwin--as all persons hereafter, in speaking upon these subjects, will have occasion to quote his famous book on the "origin of species,"--you must yet remember that, wherever i have quoted him, it has not been upon theoretical points, or for statements in any way connected with his particular speculations, but on matters of fact, brought forward by himself, or collected by himself, and which appear incidentally in his book. if a man 'will' make a book, professing to discuss a single question, an encyclopaedia, i cannot help it. now, having had an opportunity of considering in this sort of way the different statements bearing upon all theories whatsoever, i have to lay before you, as fairly as i can, what is mr. darwin's view of the matter and what position his theories hold, when judged by the principles which i have previously laid down, as deciding our judgments upon all theories and hypotheses. i have already stated to you that the inquiry respecting the causes of the phenomena of organic nature resolves itself into two problems--the first being the question of the origination of living or organic beings; and the second being the totally distinct problem of the modification and perpetuation of organic beings when they have already come into existence. the first question mr. darwin does not touch; he does not deal with it at all; but he says--given the origin of organic matter--supposing its creation to have already taken place, my object is to show in consequence of what laws and what demonstrable properties of organic matter, and of its environments, such states of organic nature as those with which we are acquainted must have come about. this, you will observe, is a perfectly legitimate proposition; every person has a right to define the limits of the inquiry which he sets before himself; and yet it is a most singular thing that in all the multifarious, and, not unfrequently, ignorant attacks which have been made upon the 'origin of species', there is nothing which has been more speciously criticised than this particular limitation. if people have nothing else to urge against the book, they say--"well, after all, you see, mr. darwin's explanation of the 'origin of species' is not good for much, because, in the long run, he admits that he does not know how organic matter began to exist. but if you admit any special creation for the first particle of organic matter you may just as well admit it for all the rest; five hundred or five thousand distinct creations are just as intelligible, and just as little difficult to understand, as one." the answer to these cavils is two-fold. in the first place, all human inquiry must stop somewhere; all our knowledge and all our investigation cannot take us beyond the limits set by the finite and restricted character of our faculties, or destroy the endless unknown, which accompanies, like its shadow, the endless procession of phenomena. so far as i can venture to offer an opinion on such a matter, the purpose of our being in existence, the highest object that human beings can set before themselves, is not the pursuit of any such chimera as the annihilation of the unknown; but it is simply the unwearied endeavour to remove its boundaries a little further from our little sphere of action. i wonder if any historian would for a moment admit the objection, that it is preposterous to trouble ourselves about the history of the roman empire, because we do not know anything positive about the origin and first building of the city of rome! would it be a fair objection to urge, respecting the sublime discoveries of a newton, or a kepler, those great philosophers, whose discoveries have been of the profoundest benefit and service to all men,--to say to them--"after all that you have told us as to how the planets revolve, and how they are maintained in their orbits, you cannot tell us what is the cause of the origin of the sun, moon, and stars. so what is the use of what you have done?" yet these objections would not be one whit more preposterous than the objections which have been made to the 'origin of species.' mr. darwin, then, had a perfect right to limit his inquiry as he pleased, and the only question for us--the inquiry being so limited--is to ascertain whether the method of his inquiry is sound or unsound; whether he has obeyed the canons which must guide and govern all investigation, or whether he has broken them; and it was because our inquiry this evening is essentially limited to that question, that i spent a good deal of time in a former lecture (which, perhaps, some of you thought might have been better employed), in endeavouring to illustrate the method and nature of scientific inquiry in general. we shall now have to put in practice the principles that i then laid down. i stated to you in substance, if not in words, that wherever there are complex masses of phenomena to be inquired into, whether they be phenomena of the affairs of daily life, or whether they belong to the more abstruse and difficult problems laid before the philosopher, our course of proceeding in unravelling that complex chain of phenomena with a view to get at its cause, is always the same; in all cases we must invent an hypothesis; we must place before ourselves some more or less likely supposition respecting that cause; and then, having assumed an hypothesis, having supposed cause for the phenomena in question, we must endeavour, on the one hand, to demonstrate our hypothesis, or, on the other, to upset and reject it altogether, by testing it in three ways. we must, in the first place, be prepared to prove that the supposed causes of the phenomena exist in nature; that they are what the logicians call 'vera causae'--true causes;--in the next place, we should be prepared to show that the assumed causes of the phenomena are competent to produce such phenomena as those which we wish to explain by them; and in the last place, we ought to be able to show that no other known causes are competent to produce those phenomena. if we can succeed in satisfying these three conditions we shall have demonstrated our hypothesis; or rather i ought to say we shall have proved it as far as certainty is possible for us; for, after all, there is no one of our surest convictions which may not be upset, or at any rate modified by a further accession of knowledge. it was because it satisfied these conditions that we accepted the hypothesis as to the disappearance of the tea-pot and spoons in the case i supposed in a previous lecture; we found that our hypothesis on that subject was tenable and valid, because the supposed cause existed in nature, because it was competent to account for the phenomena, and because no other known cause was competent to account for them; and it is upon similar grounds that any hypothesis you choose to name is accepted in science as tenable and valid. what is mr. darwin's hypothesis? as i apprehend it--for i have put it into a shape more convenient for common purposes than i could find 'verbatim' in his book--as i apprehend it, i say, it is, that all the phenomena of organic nature, past and present, result from, or are caused by, the inter-action of those properties of organic matter, which we have called atavism and variability, with the conditions of existence; or, in other words,--given the existence of organic matter, its tendency to transmit its properties, and its tendency occasionally to vary; and, lastly, given the conditions of existence by which organic matter is surrounded--that these put together are the causes of the present and of the past conditions of organic nature. such is the hypothesis as i understand it. now let us see how it will stand the various tests which i laid down just now. in the first place, do these supposed causes of the phenomena exist in nature? is it the fact that in nature these properties of organic matter--atavism and variability--and those phenomena which we have called the conditions of existence,--is it true that they exist? well, of course, if they do not exist, all that i have told you in the last three or four lectures must be incorrect, because i have been attempting to prove that they do exist, and i take it that there is abundant evidence that they do exist; so far, therefore, the hypothesis does not break down. but in the next place comes a much more difficult inquiry:--are the causes indicated competent to give rise to the phenomena of organic nature? i suspect that this is indubitable to a certain extent. it is demonstrable, i think, as i have endeavoured to show you, that they are perfectly competent to give rise to all the phenomena which are exhibited by races in nature. furthermore, i believe that they are quite competent to account for all that we may call purely structural phenomena which are exhibited by species in nature. on that point also i have already enlarged somewhat. again, i think that the causes assumed are competent to account for most of the physiological characteristics of species, and i not only think that they are competent to account for them, but i think that they account for many things which otherwise remain wholly unaccountable and inexplicable, and i may say incomprehensible. for a full exposition of the grounds on which this conviction is based, i must refer you to mr. darwin's work; all that i can do now is to illustrate what i have said by two or three cases taken almost at random. i drew your attention, on a previous evening, to the facts which are embodied in our systems of classification, which are the results of the examination and comparison of the different members of the animal kingdom one with another. i mentioned that the whole of the animal kingdom is divisible into five sub-kingdoms; that each of these sub-kingdoms is again divisible into provinces; that each province may be divided into classes, and the classes into the successively smaller groups, orders, families, genera, and species. now, in each of these groups, the resemblance in structure among the members of the group is closer in proportion as the group is smaller. thus, a man and a worm are members of the animal kingdom in virtue of certain apparently slight though really fundamental resemblances which they present. but a man and a fish are members of the same sub-kingdom 'vertebrata', because they are much more like one another than either of them is to a worm, or a snail, or any member of the other sub-kingdoms. for similar reasons men and horses are arranged as members of the same class, 'mammalia'; men and apes as members of the same order, 'primates'; and if there were any animals more like men than they were like any of the apes, and yet different from men in important and constant particulars of their organization, we should rank them as members of the same family, or of the same genus, but as of distinct species. that it is possible to arrange all the varied forms of animals into groups, having this sort of singular subordination one to the other, is a very remarkable circumstance; but, as mr. darwin remarks, this is a result which is quite to be expected, if the principles which he lays down be correct. take the case of the races which are known to be produced by the operation of atavism and variability, and the conditions of existence which check and modify these tendencies. take the case of the pigeons that i brought before you; there it was shown that they might be all classed as belonging to some one of five principal divisions, and that within these divisions other subordinate groups might be formed. the members of these groups are related to one another in just the same way as the genera of a family, and the groups themselves as the families of an order, or the orders of a class; while all have the same sort of structural relations with the wild rock-pigeon, as the members of any great natural group have with a real or imaginary typical form. now, we know that all varieties of pigeons of every kind have arisen by a process of selective breeding from a common stock, the rock-pigeon; hence, you see, that if all species of animals have proceeded from some common stock, the general character of their structural relations, and of our systems of classification, which express those relations, would be just what we find them to be. in other words, the hypothetical cause is, so far, competent to produce effects similar to those of the real cause. take, again, another set of very remarkable facts,--the existence of what are called rudimentary organs, organs for which we can find no obvious use, in the particular animal economy in which they are found, and yet which are there. such are the splint-like bones in the leg of the horse, which i here show you, and which correspond with bones which belong to certain toes and fingers in the human hand and foot. in the horse you see they are quite rudimentary, and bear neither toes nor fingers; so that the horse has only one "finger" in his fore-foot and one "toe" in his hind foot. but it is a very curious thing that the animals closely allied to the horse show more toes than he; as the rhinoceros, for instance: he has these extra toes well formed, and anatomical facts show very clearly that he is very closely related to the horse indeed. so we may say that animals, in an anatomical sense nearly related to the horse, have those parts which are rudimentary in him, fully developed. again, the sheep and the cow have no cutting-teeth, but only a hard pad in the upper jaw. that is the common characteristic of ruminants in general. but the calf has in its upper jaw some rudiments of teeth which never are developed, and never play the part of teeth at all. well, if you go back in time, you find some of the older, now extinct, allies of the ruminants have well-developed teeth in their upper jaws; and at the present day the pig (which is in structure closely connected with ruminants) has well-developed teeth in its upper jaw; so that here is another instance of organs well-developed and very useful, in one animal, represented by rudimentary organs, for which we can discover no purpose whatsoever, in another closely allied animal. the whalebone whale, again, has horny "whalebone" plates in its mouth, and no teeth; but the young foetal whale, before it is born, has teeth in its jaws; they, however, are never used, and they never come to anything. but other members of the group to which the whale belongs have well-developed teeth in both jaws. upon any hypothesis of special creation, facts of this kind appear to me to be entirely unaccountable and inexplicable, but they cease to be so if you accept mr. darwin's hypothesis, and see reason for believing that the whalebone whale and the whale with teeth in its mouth both sprang from a whale that had teeth, and that the teeth of the foetal whale are merely remnants--recollections, if we may so say--of the extinct whale. so in the case of the horse and the rhinoceros: suppose that both have descended by modification from some earlier form which had the normal number of toes, and the persistence of the rudimentary bones which no longer support toes in the horse becomes comprehensible. in the language that we speak in england, and in the language of the greeks, there are identical verbal roots, or elements entering into the composition of words. that fact remains unintelligible so long as we suppose english and greek to be independently created tongues; but when it is shown that both languages are descended from one original, the sanscrit, we give an explanation of that resemblance. in the same way the existence of identical structural roots, if i may so term them, entering into the composition of widely different animals, is striking evidence in favour of the descent of those animals from a common original. to turn to another kind of illustration:--if you regard the whole series of stratified rocks--that enormous thickness of sixty or seventy thousand feet that i have mentioned before, constituting the only record we have of a most prodigious lapse of time, that time being, in all probability, but a fraction of that of which we have no record;--if you observe in these successive strata of rocks successive groups of animals arising and dying out, a constant succession, giving you the same kind of impression, as you travel from one group of strata to another, as you would have in travelling from one country to another;--when you find this constant succession of forms, their traces obliterated except to the man of science,--when you look at this wonderful history, and ask what it means, it is only a paltering with words if you are offered the reply,--'they were so created.' but if, on the other hand, you look on all forms of organized beings as the results of the gradual modification of a primitive type, the facts receive a meaning, and you see that these older conditions are the necessary predecessors of the present. viewed in this light the facts of palaeontology receive a meaning--upon any other hypothesis, i am unable to see, in the slightest degree, what knowledge or signification we are to draw out of them. again, note as bearing upon the same point, the singular likeness which obtains between the successive faunae and florae, whose remains are preserved on the rocks: you never find any great and enormous difference between the immediately successive faunae and florae, unless you have reason to believe there has also been a great lapse of time or a great change of conditions. the animals, for instance, of the newest tertiary rocks, in any part of the world, are always, and without exception, found to be closely allied with those which now live in that part of the world. for example, in europe, asia, and africa, the large mammals are at present rhinoceroses, hippopotamuses, elephants, lions, tigers, oxen, horses, etc.; and if you examine the newest tertiary deposits, which contain the animals and plants which immediately preceded those which now exist in the same country, you do not find gigantic specimens of ant-eaters and kangaroos, but you find rhinoceroses, elephants, lions, tigers, etc.,--of different species to those now living,--but still their close allies. if you turn to south america, where, at the present day, we have great sloths and armadilloes and creatures of that kind, what do you find in the newest tertiaries? you find the great sloth-like creature, the 'megatherium', and the great armadillo, the 'glyptodon', and so on. and if you go to australia you find the same law holds good, namely, that that condition of organic nature which has preceded the one which now exists, presents differences perhaps of species, and of genera, but that the great types of organic structure are the same as those which now flourish. what meaning has this fact upon any other hypothesis or supposition than one of successive modification? but if the population of the world, in any age, is the result of the gradual modification of the forms which peopled it in the preceding age,--if that has been the case, it is intelligible enough; because we may expect that the creature that results from the modification of an elephantine mammal shall be something like an elephant, and the creature which is produced by the modification of an armadillo-like mammal shall be like an armadillo. upon that supposition, i say, the facts are intelligible; upon any other, that i am aware of, they are not. so far, the facts of palaeontology are consistent with almost any form of the doctrine of progressive modification; they would not be absolutely inconsistent with the wild speculations of de maillet, or with the less objectionable hypothesis of lamarck. but mr. darwin's views have one peculiar merit; and that is, that they are perfectly consistent with an array of facts which are utterly inconsistent with and fatal to, any other hypothesis of progressive modification which has yet been advanced. it is one remarkable peculiarity of mr. darwin's hypothesis that it involves no necessary progression or incessant modification, and that it is perfectly consistent with the persistence for any length of time of a given primitive stock, contemporaneously with its modifications. to return to the case of the domestic breeds of pigeons, for example; you have the dove-cot pigeon, which closely resembles the rock pigeon, from which they all started, existing at the same time with the others. and if species are developed in the same way in nature, a primitive stock and its modifications may, occasionally, all find the conditions fitted for their existence; and though they come into competition, to a certain extent, with one another, the derivative species may not necessarily extirpate the primitive one, or 'vice versa'. now palaeontology shows us many facts which are perfectly harmonious with these observed effects of the process by which mr. darwin supposes species to have originated, but which appear to me to be totally inconsistent with any other hypothesis which has been proposed. there are some groups of animals and plants, in the fossil world, which have been said to belong to "persistent types," because they have persisted, with very little change indeed, through a very great range of time, while everything about them has changed largely. there are families of fishes whose type of construction has persisted all the way from the carboniferous rock right up to the cretaceous; and others which have lasted through almost the whole range of the secondary rocks, and from the lias to the older tertiaries. it is something stupendous this--to consider a genus lasting without essential modifications through all this enormous lapse of time while almost everything else was changed and modified. thus i have no doubt that mr. darwin's hypothesis will be found competent to explain the majority of the phenomena exhibited by species in nature; but in an earlier lecture i spoke cautiously with respect to its power of explaining all the physiological peculiarities of species. there is, in fact, one set of these peculiarities which the theory of selective modification, as it stands at present, is not wholly competent to explain, and that is the group of phenomena which i mentioned to you under the name of hybridism, and which i explained to consist in the sterility of the offspring of certain species when crossed one with another. it matters not one whit whether this sterility is universal, or whether it exists only in a single case. every hypothesis is bound to explain, or, at any rate, not be inconsistent with, the whole of the facts which it professes to account for; and if there is a single one of these facts which can be shown to be inconsistent with (i do not merely mean inexplicable by, but contrary to) the hypothesis, the hypothesis falls to the ground,--it is worth nothing. one fact with which it is positively inconsistent is worth as much, and as powerful in negativing the hypothesis, as five hundred. if i am right in thus defining the obligations of an hypothesis, mr. darwin, in order to place his views beyond the reach of all possible assault, ought to be able to demonstrate the possibility of developing from a particular stock by selective breeding, two forms, which should either be unable to cross one with another, or whose cross-bred offspring should be infertile with one another. for, you see, if you have not done that you have not strictly fulfilled all the conditions of the problem; you have not shown that you can produce, by the cause assumed, all the phenomena which you have in nature. here are the phenomena of hybridism staring you in the face, and you cannot say, 'i can, by selective modification, produce these same results.' now, it is admitted on all hands that, at present, so far as experiments have gone, it has not been found possible to produce this complete physiological divergence by selective breeding. i stated this very clearly before, and i now refer to the point, because, if it could be proved, not only that this 'has' not been done, but that it 'cannot' be done; if it could be demonstrated that it is impossible to breed selectively, from any stock, a form which shall not breed with another, produced from the same stock; and if we were shown that this must be the necessary and inevitable results of all experiments, i hold that mr. darwin's hypothesis would be utterly shattered. but has this been done? or what is really the state of the case? it is simply that, so far as we have gone yet with our breeding, we have not produced from a common stock two breeds which are not more or less fertile with one another. i do not know that there is a single fact which would justify any one in saying that any degree of sterility has been observed between breeds absolutely known to have been produced by selective breeding from a common stock. on the other hand, i do not know that there is a single fact which can justify any one in asserting that such sterility cannot be produced by proper experimentation. for my own part, i see every reason to believe that it may, and will be so produced. for, as mr. darwin has very properly urged, when we consider the phenomena of sterility, we find they are most capricious; we do not know what it is that the sterility depends on. there are some animals which will not breed in captivity; whether it arises from the simple fact of their being shut up and deprived of their liberty, or not, we do not know, but they certainly will not breed. what an astounding thing this is, to find one of the most important of all functions annihilated by mere imprisonment! so, again, there are cases known of animals which have been thought by naturalists to be undoubted species, which have yielded perfectly fertile hybrids; while there are other species which present what everybody believes to be varieties [1] which are more or less infertile with one another. there are other cases which are truly extraordinary; there is one, for example, which has been carefully examined,--of two kinds of sea-weed, of which the male element of the one, which we may call a, fertilizes the female element of the other, b; while the male element of b will not fertilize the female element of a; so that, while the former experiment seems to show us that they are 'varieties', the latter leads to the conviction that they are 'species'. when we see how capricious and uncertain this sterility is, how unknown the conditions on which it depends, i say that we have no right to affirm that those conditions will not be better understood by and by, and we have no ground for supposing that we may not be able to experiment so as to obtain that crucial result which i mentioned just now. so that though mr. darwin's hypothesis does not completely extricate us from this difficulty at present, we have not the least right to say it will not do so. there is a wide gulf between the thing you cannot explain and the thing that upsets you altogether. there is hardly any hypothesis in this world which has not some fact in connection with it which has not been explained, but that is a very different affair to a fact that entirely opposes your hypothesis; in this case all you can say is, that your hypothesis is in the same position as a good many others. now, as to the third test, that there are no other causes competent to explain the phenomena, i explained to you that one should be able to say of an hypothesis, that no other known causes than those supposed by it are competent to give rise to the phenomena. here, i think, mr. darwin's view is pretty strong. i really believe that the alternative is either darwinism or nothing, for i do not know of any rational conception or theory of the organic universe which has any scientific position at all beside mr. darwin's. i do not know of any proposition that has been put before us with the intention of explaining the phenomena of organic nature, which has in its favour a thousandth part of the evidence which may be adduced in favour of mr. darwin's views. whatever may be the objections to his views, certainly all others are absolutely out of court. take the lamarckian hypothesis, for example. lamarck was a great naturalist, and to a certain extent went the right way to work; he argued from what was undoubtedly a true cause of some of the phenomena of organic nature. he said it is a matter of experience that an animal may be modified more or less in consequence of its desires and consequent actions. thus, if a man exercise himself as a blacksmith, his arms will become strong and muscular; such organic modification is a result of this particular action and exercise. lamarck thought that by a very simple supposition based on this truth he could explain the origin of the various animal species: he said, for example, that the short-legged birds which live on fish had been converted into the long-legged waders by desiring to get the fish without wetting their bodies, and so stretching their legs more and more through successive generations. if lamarck could have shown experimentally, that even races of animals could be produced in this way, there might have been some ground for his speculations. but he could show nothing of the kind, and his hypothesis has pretty well dropped into oblivion, as it deserved to do. i said in an earlier lecture that there are hypotheses and hypotheses, and when people tell you that mr. darwin's strongly-based hypothesis is nothing but a mere modification of lamarck's, you will know what to think of their capacity for forming a judgment on this subject. but you must recollect that when i say i think it is either mr. darwin's hypothesis or nothing; that either we must take his view, or look upon the whole of organic nature as an enigma, the meaning of which is wholly hidden from us; you must understand that i mean that i accept it provisionally, in exactly the same way as i accept any other hypothesis. men of science do not pledge themselves to creeds; they are bound by articles of no sort; there is not a single belief that it is not a bounden duty with them to hold with a light hand and to part with it cheerfully, the moment it is really proved to be contrary to any fact, great or small. and if, in course of time i see good reasons for such a proceeding, i shall have no hesitation in coming before you, and pointing out any change in my opinion without finding the slightest occasion to blush for so doing. so i say that we accept this view as we accept any other, so long as it will help us, and we feel bound to retain it only so long as it will serve our great purpose--the improvement of man's estate and the widening of his knowledge. the moment this, or any other conception, ceases to be useful for these purposes, away with it to the four winds; we care not what becomes of it! but to say truth, although it has been my business to attend closely to the controversies roused by the publication of mr. darwin's book, i think that not one of the enormous mass of objections and obstacles which have been raised is of any very great value, except that sterility case which i brought before you just now. all the rest are misunderstandings of some sort, arising either from prejudice, or want of knowledge, or still more from want of patience and care in reading the work. for you must recollect that it is not a book to be read with as much ease as its pleasant style may lead you to imagine. you spin through it as if it were a novel the first time you read it, and think you know all about it; the second time you read it you think you know rather less about it; and the third time, you are amazed to find how little you have really apprehended its vast scope and objects. i can positively say that i never take it up without finding in it some new view, or light, or suggestion that i have not noticed before. that is the best characteristic of a thorough and profound book; and i believe this feature of the 'origin of species' explains why so many persons have ventured to pass judgment and criticisms upon it which are by no means worth the paper they are written on. before concluding these lectures there is one point to which i must advert,--though, as mr. darwin has said nothing about man in his book, it concerns myself rather than him;--for i have strongly maintained on sundry occasions that if mr. darwin's views are sound, they apply as much to man as to the lower mammals, seeing that it is perfectly demonstrable that the structural differences which separate man from the apes are not greater than those which separate some apes from others. there cannot be the slightest doubt in the world that the argument which applies to the improvement of the horse from an earlier stock, or of ape from ape, applies to the improvement of man from some simpler and lower stock than man. there is not a single faculty--functional or structural, moral, intellectual, or instinctive,--there is no faculty whatever that is not capable of improvement; there is no faculty whatsoever which does not depend upon structure, and as structure tends to vary, it is capable of being improved. well, i have taken a good deal of pains at various times to prove this, and i have endeavoured to meet the objections of those who maintain, that the structural differences between man and the lower animals are of so vast a character and enormous extent, that even if mr. darwin's views are correct, you cannot imagine this particular modification to take place. it is, in fact, easy matter to prove that, so far as structure is concerned, man differs to no greater extent from the animals which are immediately below him than these do from other members of the same order. upon the other hand, there is no one who estimates more highly than i do the dignity of human nature, and the width of the gulf in intellectual and moral matters, which lies between man and the whole of the lower creation. but i find this very argument brought forward vehemently by some. "you say that man has proceeded from a modification of some lower animal, and you take pains to prove that the structural differences which are said to exist in his brain do not exist at all, and you teach that all functions, intellectual, moral, and others, are the expression or the result, in the long run, of structures, and of the molecular forces which they exert." it is quite true that i do so. "well, but," i am told at once, somewhat triumphantly, "you say in the same breath that there is a great moral and intellectual chasm between man and the lower animals. how is this possible when you declare that moral and intellectual characteristics depend on structure, and yet tell us that there is no such gulf between the structure of man and that of the lower animals?" i think that objection is based upon a misconception of the real relations which exist between structure and function, between mechanism and work. function is the expression of molecular forces and arrangements no doubt; but, does it follow from this, that variation in function so depends upon variation in structure that the former is always exactly proportioned to the latter? if there is no such relation, if the variation in function which follows on a variation in structure, may be enormously greater than the variation of the structure, then, you see, the objection falls to the ground. take a couple of watches--made by the same maker, and as completely alike as possible; set them upon the table, and the function of each--which is its rate of going--will be performed in the same manner, and you shall be able to distinguish no difference between them; but let me take a pair of pincers, and if my hand is steady enough to do it, let me just lightly crush together the bearings of the balance-wheel, or force to a slightly different angle the teeth of the escapement of one of them, and of course you know the immediate result will be that the watch, so treated, from that moment will cease to go. but what proportion is there between the structural alteration and the functional result? is it not perfectly obvious that the alteration is of the minutest kind, yet that slight as it is, it has produced an infinite difference in the performance of the functions of these two instruments? well, now, apply that to the present question. what is it that constitutes and makes man what he is? what is it but his power of language--that language giving him the means of recording his experience--making every generation somewhat wiser than its predecessor,--more in accordance with the established order of the universe? what is it but this power of speech, of recording experience, which enables men to be men--looking before and after and, in some dim sense, understanding the working of this wondrous universe--and which distinguishes man from the whole of the brute world? i say that this functional difference is vast, unfathomable, and truly infinite in its consequences; and i say at the same time, that it may depend upon structural differences which shall be absolutely inappreciable to us with our present means of investigation. what is this very speech that we are talking about? i am speaking to you at this moment, but if you were to alter, in the minutest degree, the proportion of the nervous forces now active in the two nerves which supply the muscles of my glottis, i should become suddenly dumb. the voice is produced only so long as the vocal chords are parallel; and these are parallel only so long as certain muscles contract with exact equality; and that again depends on the equality of action of those two nerves i spoke of. so that a change of the minutest kind in the structure of one of these nerves, or in the structure of the part in which it originates, or of the supply of blood to that part, or of one of the muscles to which it is distributed, might render all of us dumb. but a race of dumb men, deprived of all communication with those who could speak, would be little indeed removed from the brutes. and the moral and intellectual difference between them and ourselves would be practically infinite, though the naturalist should not be able to find a single shadow of even specific structural difference. but let me dismiss this question now, and, in conclusion, let me say that you may go away with it as my mature conviction, that mr. darwin's work is the greatest contribution which has been made to biological science since the publication of the 'regne animal' of cuvier, and since that of the 'history of development' of von baer. i believe that if you strip it of its theoretical part it still remains one of the greatest encyclopaedias of biological doctrine that any one man ever brought forth; and i believe that, if you take it as the embodiment of an hypothesis, it is destined to be the guide of biological and psychological speculation for the next three or four generations. [footnote 1: and as i conceive with very good reason; but if any objector urges that we cannot prove that they have been produced by artificial or natural selection, the objection must be admitted-ultrasceptical as it is. but in science, scepticism is a duty.] the present condition of organic nature lecture i. (of vi.), "lectures to working men", at the museum of practical geology, 1863, on darwin's work: "origin of species". by thomas h. huxley editor's note of the great thinkers of the nineteenth century, thomas henry huxley, son of an ealing schoolmaster, was undoubtedly the most noteworthy. his researches in biology, his contributions to scientific controversy, his pungent criticisms of conventional beliefs and thoughts have probably had greater influence than the work of any other english scientist. and yet he was a "self-made" intellectualist. in spite of the fact that his father was a schoolmaster he passed through no regular course of education. "i had," he said, "two years of a pandemonium of a school (between eight and ten) and after that neither help nor sympathy in any intellectual direction till i reached manhood." when he was twelve a craving for reading found satisfaction in hutton's "geology," and when fifteen in hamilton's "logic." at seventeen huxley entered as a student at charing cross hospital, and three years later he was m.b. and the possessor of the gold medal for anatomy and physiology. an appointment as surgeon in the navy proved to be the entry to huxley's great scientific career, for he was gazetted to the "rattlesnake", commissioned for surveying work in torres straits. he was attracted by the teeming surface life of tropical seas and his study of it was the commencement of that revolution in scientific knowledge ultimately brought about by his researches. thomas henry huxley was born at ealing on may 4, 1825, and died at eastbourne june 29, 1895. lectures and essays by t.h. huxley on our knowledge of the causes of the phenomena of organic nature notice to the first edition. the publisher of these interesting lectures, having made an arrangement for their publication with mr. j. a. mays, the reporter, begs to append the following note from professor huxley:-"mr. j. aldous mays, who is taking shorthand notes of my 'lectures to working men,' has asked me to allow him, on his own account, to print those notes for the use of my audience. i willingly accede to this request, on the understanding that a notice is prefixed to the effect that i have no leisure to revise the lectures, or to make alterations in them, beyond the correction of any important error in a matter of fact." the present condition of organic nature. when it was my duty to consider what subject i would select for the six lectures [*to working men, at the museum of practical geology, 1863.] which i shall now have the pleasure of delivering to you, it occurred to me that i could not do better than endeavour to put before you in a true light, or in what i might perhaps with more modesty call, that which i conceive myself to be the true light, the position of a book which has been more praised and more abused, perhaps, than any book which has appeared for some years;--i mean mr. darwin's work on the "origin of species". that work, i doubt not, many of you have read; for i know the inquiring spirit which is rife among you. at any rate, all of you will have heard of it,--some by one kind of report and some by another kind of report; the attention of all and the curiosity of all have been probably more or less excited on the subject of that work. all i can do, and all i shall attempt to do, is to put before you that kind of judgment which has been formed by a man, who, of course, is liable to judge erroneously; but, at any rate, of one whose business and profession it is to form judgments upon questions of this nature. and here, as it will always happen when dealing with an extensive subject, the greater part of my course--if, indeed, so small a number of lectures can be properly called a course--must be devoted to preliminary matters, or rather to a statement of those facts and of those principles which the work itself dwells upon, and brings more or less directly before us. i have no right to suppose that all or any of you are naturalists; and even if you were, the misconceptions and misunderstandings prevalent even among naturalists on these matters would make it desirable that i should take the course i now propose to take,--that i should start from the beginning,--that i should endeavour to point out what is the existing state of the organic world,--that i should point out its past condition,--that i should state what is the precise nature of the undertaking which mr. darwin has taken in hand; that i should endeavour to show you what are the only methods by which that undertaking can be brought to an issue, and to point out to you how far the author of the work in question has satisfied those conditions, how far he has not satisfied them, how far they are satisfiable by man, and how far they are not satisfiable by man. to-night, in taking up the first part of this question, i shall endeavour to put before you a sort of broad notion of our knowledge of the condition of the living world. there are many ways of doing this. i might deal with it pictorially and graphically. following the example of humboldt in his "aspects of nature", i might endeavour to point out the infinite variety of organic life in every mode of its existence, with reference to the variations of climate and the like; and such an attempt would be fraught with interest to us all; but considering the subject before us, such a course would not be that best calculated to assist us. in an argument of this kind we must go further and dig deeper into the matter; we must endeavour to look into the foundations of living nature, if i may so say, and discover the principles involved in some of her most secret operations. i propose, therefore, in the first place, to take some ordinary animal with which you are all familiar, and, by easily comprehensible and obvious examples drawn from it, to show what are the kind of problems which living beings in general lay before us; and i shall then show you that the same problems are laid open to us by all kinds of living beings. but first, let me say in what sense i have used the words "organic nature." in speaking of the causes which lead to our present knowledge of organic nature, i have used it almost as an equivalent of the word "living," and for this reason,--that in almost all living beings you can distinguish several distinct portions set apart to do particular things and work in a particular way. these are termed "organs," and the whole together is called "organic." and as it is universally characteristic of them, this term "organic" has been very conveniently employed to denote the whole of living nature,--the whole of the plant world, and the whole of the animal world. few animals can be more familiar to you than that whose skeleton is shown on our diagram. you need not bother yourselves with this "equus caballus" written under it; that is only the latin name of it, and does not make it any better. it simply means the common horse. suppose we wish to understand all about the horse. our first object must be to study the structure of the animal. the whole of his body is inclosed within a hide, a skin covered with hair; and if that hide or skin be taken off, we find a great mass of flesh, or what is technically called muscle, being the substance which by its power of contraction enables the animal to move. these muscles move the hard parts one upon the other, and so give that strength and power of motion which renders the horse so useful to us in the performance of those services in which we employ him. and then, on separating and removing the whole of this skin and flesh, you have a great series of bones, hard structures, bound together with ligaments, and forming the skeleton which is represented here. [illustration: figure 1. (section through a horse.)] [illustration: figure 2. (section through a cell.)] in that skeleton there are a number of parts to be recognized. the long series of bones, beginning from the skull and ending in the tail, is called the spine, and those in front are the ribs; and then there are two pairs of limbs, one before and one behind; and there are what we all know as the fore-legs and the hind-legs. if we pursue our researches into the interior of this animal, we find within the framework of the skeleton a great cavity, or rather, i should say, two great cavities,--one cavity beginning in the skull and running through the neck-bones, along the spine, and ending in the tail, containing the brain and the spinal marrow, which are extremely important organs. the second great cavity, commencing with the mouth, contains the gullet, the stomach, the long intestine, and all the rest of those internal apparatus which are essential for digestion; and then in the same great cavity, there are lodged the heart and all the great vessels going from it; and, besides that, the organs of respiration--the lungs: and then the kidneys, and the organs of reproduction, and so on. let us now endeavour to reduce this notion of a horse that we now have, to some such kind of simple expression as can be at once, and without difficulty, retained in the mind, apart from all minor details. if i make a transverse section, that is, if i were to saw a dead horse across, i should find that, if i left out the details, and supposing i took my section through the anterior region, and through the fore-limbs, i should have here this kind of section of the body (fig. 1). here would be the upper part of the animal--that great mass of bones that we spoke of as the spine (a, fig. 1). here i should have the alimentary canal (b, fig. 1). here i should have the heart (c, fig. 1); and then you see, there would be a kind of double tube, the whole being inclosed within the hide; the spinal marrow would be placed in the upper tube (a, fig. 1), and in the lower tube (d d, fig. 1), there would be the alimentary canal (b), and the heart (c); and here i shall have the legs proceeding from each side. for simplicity's sake, i represent them merely as stumps (e e, fig. 1). now that is a horse--as mathematicians would say--reduced to its most simple expression. carry that in your minds, if you please, as a simplified idea of the structure of the horse. the considerations which i have now put before you belong to what we technically call the 'anatomy' of the horse. now, suppose we go to work upon these several parts,--flesh and hair, and skin and bone, and lay open these various organs with our scalpels, and examine them by means of our magnifying-glasses, and see what we can make of them. we shall find that the flesh is made up of bundles of strong fibres. the brain and nerves, too, we shall find, are made up of fibres, and these queer-looking things that are called ganglionic corpuscles. if we take a slice of the bone and examine it, we shall find that it is very like this diagram of a section of the bone of an ostrich, though differing, of course, in some details; and if we take any part whatsoever of the tissue, and examine it, we shall find it all has a minute structure, visible only under the microscope. all these parts constitute microscopic anatomy or 'histology.' these parts are constantly being changed; every part is constantly growing, decaying, and being replaced during the life of the animal. the tissue is constantly replaced by new material; and if you go back to the young state of the tissue in the case of muscle, or in the case of skin, or any of the organs i have mentioned, you will find that they all come under the same condition. every one of these microscopic filaments and fibres (i now speak merely of the general character of the whole process)--every one of these parts--could be traced down to some modification of a tissue which can be readily divided into little particles of fleshy matter, of that substance which is composed of the chemical elements, carbon, hydrogen, oxygen, and nitrogen, having such a shape as this (fig. 2). these particles, into which all primitive tissues break up, are called cells. if i were to make a section of a piece of the skin of my hand, i should find that it was made up of these cells. if i examine the fibres which form the various organs of all living animals, i should find that all of them, at one time or other, had been formed out of a substance consisting of similar elements; so that you see, just as we reduced the whole body in the gross to that sort of simple expression given in fig. 1, so we may reduce the whole of the microscopic structural elements to a form of even greater simplicity; just as the plan of the whole body may be so represented in a sense (fig. 1), so the primary structure of every tissue may be represented by a mass of cells (fig. 2). having thus, in this sort of general way, sketched to you what i may call, perhaps, the architecture of the body of the horse (what we term technically its morphology), i must now turn to another aspect. a horse is not a mere dead structure: it is an active, living, working machine. hitherto we have, as it were, been looking at a steam-engine with the fires out, and nothing in the boiler; but the body of the living animal is a beautifully-formed active machine, and every part has its different work to do in the working of that machine, which is what we call its life. the horse, if you see him after his day's work is done, is cropping the grass in the fields, as it may be, or munching the oats in his stable. what is he doing? his jaws are working as a mill--and a very complex mill too--grinding the corn, or crushing the grass to a pulp. as soon as that operation has taken place, the food is passed down to the stomach, and there it is mixed with the chemical fluid called the gastric juice, a substance which has the peculiar property of making soluble and dissolving out the nutritious matter in the grass, and leaving behind those parts which are not nutritious; so that you have, first, the mill, then a sort of chemical digester; and then the food, thus partially dissolved, is carried back by the muscular contractions of the intestines into the hinder parts of the body, while the soluble portions are taken up into the blood. the blood is contained in a vast system of pipes, spreading through the whole body, connected with a force pump,--the heart,--which, by its position and by the contractions of its valves, keeps the blood constantly circulating in one direction, never allowing it to rest; and then, by means of this circulation of the blood, laden as it is with the products of digestion, the skin, the flesh, the hair, and every other part of the body, draws from it that which it wants, and every one of these organs derives those materials which are necessary to enable it to do its work. the action of each of these organs, the performance of each of these various duties, involve in their operation a continual absorption of the matters necessary for their support, from the blood, and a constant formation of waste products, which are returned to the blood, and conveyed by it to the lungs and the kidneys, which are organs that have allotted to them the office of extracting, separating, and getting rid of these waste products; and thus the general nourishment, labour, and repair of the whole machine is kept up with order and regularity. but not only is it a machine which feeds and appropriates to its own support the nourishment necessary to its existence--it is an engine for locomotive purposes. the horse desires to go from one place to another; and to enable it to do this, it has those strong contractile bundles of muscles attached to the bones of its limbs, which are put in motion by means of a sort of telegraphic apparatus formed by the brain and the great spinal cord running through the spine or backbone; and to this spinal cord are attached a number of fibres termed nerves, which proceed to all parts of the structure. by means of these the eyes, nose, tongue, and skin--all the organs of perception--transmit impressions or sensations to the brain, which acts as a sort of great central telegraph-office, receiving impressions and sending messages to all parts of the body, and putting in motion the muscles necessary to accomplish any movement that may be desired. so that you have here an extremely complex and beautifully-proportioned machine, with all its parts working harmoniously together towards one common object--the preservation of the life of the animal. now, note this: the horse makes up its waste by feeding, and its food is grass or oats, or perhaps other vegetable products; therefore, in the long run, the source of all this complex machinery lies in the vegetable kingdom. but where does the grass, or the oat, or any other plant, obtain this nourishing food-producing material? at first it is a little seed, which soon begins to draw into itself from the earth and the surrounding air matters which in themselves contain no vital properties whatever; it absorbs into its own substance water, an inorganic body; it draws into its substance carbonic acid, an inorganic matter; and ammonia, another inorganic matter, found in the air; and then, by some wonderful chemical process, the details of which chemists do not yet understand, though they are near foreshadowing them, it combines them into one substance, which is known to us as 'protein,' a complex compound of carbon, hydrogen, oxygen, and nitrogen, which alone possesses the property of manifesting vitality and of permanently supporting animal life. so that, you see, the waste products of the animal economy, the effete materials which are continually being thrown off by all living beings, in the form of organic matters, are constantly replaced by supplies of the necessary repairing and rebuilding materials drawn from the plants, which in their turn manufacture them, so to speak, by a mysterious combination of those same inorganic materials. let us trace out the history of the horse in another direction. after a certain time, as the result of sickness or disease, the effect of accident, or the consequence of old age, sooner or later, the animal dies. the multitudinous operations of this beautiful mechanism flag in their performance, the horse loses its vigour, and after passing through the curious series of changes comprised in its formation and preservation, it finally decays, and ends its life by going back into that inorganic world from which all but an inappreciable fraction of its substance was derived. its bones become mere carbonate and phosphate of lime; the matter of its flesh, and of its other parts, becomes, in the long run, converted into carbonic acid, into water, and into ammonia. you will now, perhaps, understand the curious relation of the animal with the plant, of the organic with the inorganic world, which is shown in this diagram (fig. 3). [illustration: figure 3. (diagram showing material relationship of the vegetable, animal and inorganic worlds.)] the plant gathers these inorganic materials together and makes them up into its own substance. the animal eats the plant and appropriates the nutritious portions to its own sustenance, rejects and gets rid of the useless matters; and, finally, the animal itself dies, and its whole body is decomposed and returned into the inorganic world. there is thus a constant circulation from one to the other, a continual formation of organic life from inorganic matters, and as constant a return of the matter of living bodies to the inorganic world; so that the materials of which our bodies are composed are largely, in all probability, the substances which constituted the matter of long extinct creations, but which have in the interval constituted a part of the inorganic world. thus we come to the conclusion, strange at first sight, that the matter constituting the living world is identical with that which forms the inorganic world. and not less true is it that, remarkable as are the powers or, in other words, as are the forces which are exerted by living beings, yet all these forces are either identical with those which exist in the inorganic world, or they are convertible into them; i mean in just the same sense as the researches of physical philosophers have shown that heat is convertible into electricity, that electricity is convertible into magnetism, magnetism into mechanical force or chemical force, and any one of them with the other, each being measurable in terms of the other,--even so, i say, that great law is applicable to the living world. consider why is the skeleton of this horse capable of supporting the masses of flesh and the various organs forming the living body, unless it is because of the action of the same forces of cohesion which combines together the particles of matter composing this piece of chalk? what is there in the muscular contractile power of the animal but the force which is expressible, and which is in a certain sense convertible, into the force of gravity which it overcomes? or, if you go to more hidden processes, in what does the process of digestion differ from those processes which are carried on in the laboratory of the chemist? even if we take the most recondite and most complex operations of animal life--those of the nervous system, these of late years have been shown to be--i do not say identical in any sense with the electrical processes--but this has been shown, that they are in some way or other associated with them; that is to say, that every amount of nervous action is accompanied by a certain amount of electrical disturbance in the particles of the nerves in which that nervous action is carried on. in this way the nervous action is related to electricity in the same way that heat is related to electricity; and the same sort of argument which demonstrates the two latter to be related to one another shows that the nervous forces are correlated to electricity; for the experiments of m. dubois reymond and others have shown that whenever a nerve is in a state of excitement, sending a message to the muscles or conveying an impression to the brain, there is a disturbance of the electrical condition of that nerve which does not exist at other times; and there are a number of other facts and phenomena of that sort; so that we come to the broad conclusion that not only as to living matter itself, but as to the forces that matter exerts, there is a close relationship between the organic and the inorganic world--the difference between them arising from the diverse combination and disposition of identical forces, and not from any primary diversity, so far as we can see. i said just now that the horse eventually died and became converted into the same inorganic substances from whence all but an inappreciable fraction of its substance demonstrably originated, so that the actual wanderings of matter are as remarkable as the transmigrations of the soul fabled by indian tradition. but before death has occurred, in the one sex or the other, and in fact in both, certain products or parts of the organism have been set free, certain parts of the organisms of the two sexes have come into contact with one another, and from that conjunction, from that union which then takes place, there results the formation of a new being. at stated times the mare, from a particular part of the interior of her body, called the ovary, gets rid of a minute particle of matter comparable in all essential respects with that which we called a cell a little while since, which cell contains a kind of nucleus in its centre, surrounded by a clear space and by a viscid mass of protein substance (fig. 2); and though it is different in appearance from the eggs which we are mostly acquainted with, it is really an egg. after a time this minute particle of matter, which may only be a small fraction of a grain in weight, undergoes a series of changes,--wonderful, complex changes. finally, upon its surface there is fashioned a little elevation, which afterwards becomes divided and marked by a groove. the lateral boundaries of the groove extend upwards and downwards, and at length give rise to a double tube. in the upper smaller tube the spinal marrow and brain are fashioned; in the lower, the alimentary canal and heart; and at length two pairs of buds shoot out at the sides of the body, which are the rudiments of the limbs. in fact a true drawing of a section of the embryo in this state would in all essential respects resemble that diagram of a horse reduced to its simplest expression, which i first placed before you (fig. 1). slowly and gradually these changes take place. the whole of the body, at first, can be broken up into "cells," which become in one place metamorphosed into muscle,--in another place into gristle and bone,--in another place into fibrous tissue,--and in another into hair; every part becoming gradually and slowly fashioned, as if there were an artificer at work in each of these complex structures that we have mentioned. this embryo, as it is called, then passes into other conditions. i should tell you that there is a time when the embryos of neither dog, nor horse, nor porpoise, nor monkey, nor man, can be distinguished by any essential feature one from the other; there is a time when they each and all of them resemble this one of the dog. but as development advances, all the parts acquire their speciality, till at length you have the embryo converted into the form of the parent from which it started. so that you see, this living animal, this horse, begins its existence as a minute particle of nitrogenous matter, which, being supplied with nutriment (derived, as i have shown, from the inorganic world), grows up according to the special type and construction of its parents, works and undergoes a constant waste, and that waste is made good by nutriment derived from the inorganic world; the waste given off in this way being directly added to the inorganic world; and eventually the animal itself dies, and, by the process of decomposition, its whole body is returned to those conditions of inorganic matter in which its substance originated. this, then, is that which is true of every living form, from the lowest plant to the highest animal--to man himself. you might define the life of every one in exactly the same terms as those which i have now used; the difference between the highest and the lowest being simply in the complexity of the developmental changes, the variety of the structural forms, the diversity of the physiological functions which are exerted by each. if i were to take an oak tree as a specimen of the plant world, i should find that it originated in an acorn, which, too, commenced in a cell; the acorn is placed in the ground, and it very speedily begins to absorb the inorganic matters i have named, adds enormously to its bulk, and we can see it, year after year, extending itself upward and downward, attracting and appropriating to itself inorganic materials, which it vivifies, and eventually, as it ripens, gives off its own proper acorns, which again run the same course. but i need not multiply examples,--from the highest to the lowest the essential features of life are the same, as i have described in each of these cases. so much, then, for these particular features of the organic world, which you can understand and comprehend, so long as you confine yourself to one sort of living being, and study that only. but, as you know, horses are not the only living creatures in the world; and again, horses, like all other animals, have certain limits--are confined to a certain area on the surface of the earth on which we live,--and, as that is the simpler matter, i may take that first. in its wild state, and before the discovery of america, when the natural state of things was interfered with by the spaniards, the horse was only to be found in parts of the earth which are known to geographers as the old world; that is to say, you might meet with horses in europe, asia, or africa; but there were none in australia, and there were none whatsoever in the whole continent of america, from labrador down to cape horn. this is an empirical fact, and it is what is called, stated in the way i have given it you, the 'geographical distribution' of the horse. why horses should be found in europe, asia, and africa, and not in america, is not obvious; the explanation that the conditions of life in america are unfavourable to their existence, and that, therefore, they had not been created there, evidently does not apply; for when the invading spaniards, or our own yeomen farmers, conveyed horses to these countries for their own use, they were found to thrive well and multiply very rapidly; and many are even now running wild in those countries, and in a perfectly natural condition. now, suppose we were to do for every animal what we have here done for the horse,--that is, to mark off and distinguish the particular district or region to which each belonged; and supposing we tabulated all these results, that would be called the geographical distribution of animals, while a corresponding study of plants would yield as a result the geographical distribution of plants. i pass on from that now, as i merely wished to explain to you what i meant by the use of the term 'geographical distribution.' as i said, there is another aspect, and a much more important one, and that is, the relations of the various animals to one another. the horse is a very well-defined matter-of-fact sort of animal, and we are all pretty familiar with its structure. i dare say it may have struck you, that it resembles very much no other member of the animal kingdom, except perhaps the zebra or the ass. but let me ask you to look along these diagrams. here is the skeleton of the horse, and here the skeleton of the dog. you will notice that we have in the horse a skull, a backbone and ribs, shoulder-blades and haunch-bones. in the fore-limb, one upper arm-bone, two fore arm-bones, wrist-bones (wrongly called knee), and middle hand-bones, ending in the three bones of a finger, the last of which is sheathed in the horny hoof of the fore-foot: in the hind-limb, one thigh-bone, two leg-bones, anklebones, and middle foot-bones, ending in the three bones of a toe, the last of which is encased in the hoof of the hind-foot. now turn to the dog's skeleton. we find identically the same bones, but more of them, there being more toes in each foot, and hence more toe-bones. well, that is a very curious thing! the fact is that the dog and the horse--when one gets a look at them without the outward impediments of the skin--are found to be made in very much the same sort of fashion. and if i were to make a transverse section of the dog, i should find the same organs that i have already shown you as forming parts of the horse. well, here is another skeleton--that of a kind of lemur--you see he has just the same bones; and if i were to make a transverse section of it, it would be just the same again. in your mind's eye turn him round, so as to put his backbone in a position inclined obliquely upwards and forwards, just as in the next three diagrams, which represent the skeletons of an orang, a chimpanzee, a gorilla, and you find you have no trouble in identifying the bones throughout; and lastly turn to the end of the series, the diagram representing a man's skeleton, and still you find no great structural feature essentially altered. there are the same bones in the same relations. from the horse we pass on and on, with gradual steps, until we arrive at last at the highest known forms. on the other hand, take the other line of diagrams, and pass from the horse downwards in the scale to this fish; and still, though the modifications are vastly greater, the essential framework of the organization remains unchanged. here, for instance, is a porpoise: here is its strong backbone, with the cavity running through it, which contains the spinal cord; here are the ribs, here the shoulder blade; here is the little short upper-arm bone, here are the two forearm bones, the wrist-bone, and the finger-bones. strange, is it not, that the porpoise should have in this queer-looking affair--its flapper (as it is called), the same fundamental elements as the fore-leg of the horse or the dog, or the ape or man; and here you will notice a very curious thing,--the hinder limbs are absent. now, let us make another jump. let us go to the codfish: here you see is the forearm, in this large pectoral fin--carrying your mind's eye onward from the flapper of the porpoise. and here you have the hinder limbs restored in the shape of these ventral fins. if i were to make a transverse section of this, i should find just the same organs that we have before noticed. so that, you see, there comes out this strange conclusion as the result of our investigations, that the horse, when examined and compared with other animals, is found by no means to stand alone in nature; but that there are an enormous number of other creatures which have backbones, ribs, and legs, and other parts arranged in the same general manner, and in all their formation exhibiting the same broad peculiarities. i am sure that you cannot have followed me even in this extremely elementary exposition of the structural relations of animals, without seeing what i have been driving at all through, which is, to show you that, step by step, naturalists have come to the idea of a unity of plan, or conformity of construction, among animals which appeared at first sight to be extremely dissimilar. and here you have evidence of such a unity of plan among all the animals which have backbones, and which we technically call "vertebrata". but there are multitudes of other animals, such as crabs, lobsters, spiders, and so on, which we term "annulosa". in these i could not point out to you the parts that correspond with those of the horse,--the backbone, for instance,--as they are constructed upon a very different principle, which is also common to all of them; that is to say, the lobster, the spider, and the centipede, have a common plan running through their whole arrangement, in just the same way that the horse, the dog, and the porpoise assimilate to each other. yet other creatures--whelks, cuttlefishes, oysters, snails, and all their tribe ("mollusca")--resemble one another in the same way, but differ from both "vertebrata" and "annulosa"; and the like is true of the animals called "coelenterata" (polypes) and "protozoa" (animalcules and sponges). now, by pursuing this sort of comparison, naturalists have arrived at the conviction that there are,--some think five, and some seven,--but certainly not more than the latter number--and perhaps it is simpler to assume five--distinct plans or constructions in the whole of the animal world; and that the hundreds of thousands of species of creatures on the surface of the earth, are all reducible to those five, or, at most, seven, plans of organization. but can we go no further than that? when one has got so far, one is tempted to go on a step and inquire whether we cannot go back yet further and bring down the whole to modifications of one primordial unit. the anatomist cannot do this; but if he call to his aid the study of development, he can do it. for we shall find that, distinct as those plans are, whether it be a porpoise or man, or lobster, or any of those other kinds i have mentioned, every one begins its existence with one and the same primitive form,--that of the egg, consisting, as we have seen, of a nitrogenous substance, having a small particle or nucleus in the centre of it. furthermore, the earlier changes of each are substantially the same. and it is in this that lies that true "unity of organization" of the animal kingdom which has been guessed at and fancied for many years; but which it has been left to the present time to be demonstrated by the careful study of development. but is it possible to go another step further still, and to show that in the same way the whole of the organic world is reducible to one primitive condition of form? is there among the plants the same primitive form of organization, and is that identical with that of the animal kingdom? the reply to that question, too, is not uncertain or doubtful. it is now proved that every plant begins its existence under the same form; that is to say, in that of a cell--a particle of nitrogenous matter having substantially the same conditions. so that if you trace back the oak to its first germ, or a man, or a horse, or lobster, or oyster, or any other animal you choose to name, you shall find each and all of these commencing their existence in forms essentially similar to each other: and, furthermore, that the first processes of growth, and many of the subsequent modifications, are essentially the same in principle in almost all. in conclusion, let me, in a few words, recapitulate the positions which i have laid down. and you must understand that i have not been talking mere theory; i have been speaking of matters which are as plainly demonstrable as the commonest propositions of euclid--of facts that must form the basis of all speculations and beliefs in biological science. we have gradually traced down all organic forms, or, in other words, we have analyzed the present condition of animated nature, until we found that each species took its origin in a form similar to that under which all the others commence their existence. we have found the whole of the vast array of living forms, with which we are surrounded, constantly growing, increasing, decaying and disappearing; the animal constantly attracting, modifying, and applying to its sustenance the matter of the vegetable kingdom, which derived its support from the absorption and conversion of inorganic matter. and so constant and universal is this absorption, waste, and reproduction, that it may be said with perfect certainty that there is left in no one of our bodies at the present moment a millionth part of the matter of which they were originally formed! we have seen, again, that not only is the living matter derived from the inorganic world, but that the forces of that matter are all of them correlative with and convertible into those of inorganic nature. this, for our present purposes, is the best view of the present condition of organic nature which i can lay before you: it gives you the great outlines of a vast picture, which you must fill up by your own study. in the next lecture i shall endeavour in the same way to go back into the past, and to sketch in the same broad manner the history of life in epochs preceding our own. the conditions of existence as affecting the perpetuation of living beings lecture v. (of vi.), lectures to working men, at the museum of practical geology, 1863, on darwin's work: "origin of species". by thomas h. huxley in the last lecture i endeavoured to prove to you that, while, as a general rule, organic beings tend to reproduce their kind, there is in them, also, a constantly recurring tendency to vary--to vary to a greater or to a less extent. such a variety, i pointed out to you, might arise from causes which we do not understand; we therefore called it spontaneous; and it might come into existence as a definite and marked thing, without any gradations between itself and the form which preceded it. i further pointed out, that such a variety having once arisen, might be perpetuated to some extent, and indeed to a very marked extent, without any direct interference, or without any exercise of that process which we called selection. and then i stated further, that by such selection, when exercised artificially--if you took care to breed only from those forms which presented the same peculiarities of any variety which had arisen in this manner--the variation might be perpetuated, as far as we can see, indefinitely. the next question, and it is an important one for us, is this: is there any limit to the amount of variation from the primitive stock which can be produced by this process of selective breeding? in considering this question, it will be useful to class the characteristics, in respect of which organic beings vary, under two heads: we may consider structural characteristics, and we may consider physiological characteristics. in the first place, as regards structural characteristics, i endeavoured to show you, by the skeletons which i had upon the table, and by reference to a great many well-ascertained facts, that the different breeds of pigeons, the carriers, pouters, and tumblers, might vary in any of their internal and important structural characters to a very great degree; not only might there be changes in the proportions of the skull, and the characters of the feet and beaks, and so on; but that there might be an absolute difference in the number of the vertebrae of the back, as in the sacral vertebrae of the pouter; and so great is the extent of the variation in these and similar characters that i pointed out to you, by reference to the skeletons and the diagrams, that these extreme varieties may absolutely differ more from one another in their structural characters than do what naturalists call distinct species of pigeons; that is to say, that they differ so much in structure that there is a greater difference between the pouter and the tumbler than there is between such wild and distinct forms as the rock pigeon or the ring pigeon, or the ring pigeon and the stock dove; and indeed the differences are of greater value than this, for the structural differences between these domesticated pigeons are such as would be admitted by a naturalist, supposing he knew nothing at all about their origin, to entitle them to constitute even distinct genera. as i have used this term species, and shall probably use it a good deal, i had better perhaps devote a word or two to explaining what i mean by it. animals and plants are divided into groups, which become gradually smaller, beginning with a kingdom, which is divided into sub-kingdoms; then come the smaller divisions called provinces; and so on from a province to a class from a class to an order, from orders to families, and from these to genera, until we come at length to the smallest groups of animals which can be defined one from the other by constant characters, which are not sexual; and these are what naturalists call species in practice, whatever they may do in theory. if, in a state of nature, you find any two groups of living beings, which are separated one from the other by some constantly-recurring characteristic, i don't care how slight and trivial, so long as it is defined and constant, and does not depend on sexual peculiarities, then all naturalists agree in calling them two species; that is what is meant by the use of the word species--that is to say, it is, for the practical naturalist, a mere question of structural differences. [1] we have seen now--to repeat this point once more, and it is very essential that we should rightly understand it--we have seen that breeds, known to have been derived from a common stock by selection, may be as different in their structure from the original stock as species may be distinct from each other. but is the like true of the physiological characteristics of animals? do the physiological differences of varieties amount in degree to those observed between forms which naturalists call distinct species? this is a most important point for us to consider. as regards the great majority of physiological characteristics, there is no doubt that they are capable of being developed, increased, and modified by selection. there is no doubt that breeds may be made as different as species in many physiological characters. i have already pointed out to you very briefly the different habits of the breeds of pigeons, all of which depend upon their physiological peculiarities,--as the peculiar habit of tumbling, in the tumbler--the peculiarities of flight, in the "homing" birds,--the strange habit of spreading out the tail, and walking in a peculiar fashion, in the fantail,--and, lastly, the habit of blowing out the gullet, so characteristic of the pouter. these are all due to physiological modifications, and in all these respects these birds differ as much from each other as any two ordinary species do. so with dogs in their habits and instincts. it is a physiological peculiarity which leads the greyhound to chase its prey by sight,--that enables the beagle to track it by the scent,--that impels the terrier to its rat-hunting propensity,--and that leads the retriever to its habit of retrieving. these habits and instincts are all the results of physiological differences and peculiarities, which have been developed from a common stock, at least there is every reason to believe so. but it is a most singular circumstance, that while you may run through almost the whole series of physiological processes, without finding a check to your argument, you come at last to a point where you do find a check, and that is in the reproductive processes. for there is a most singular circumstance in respect to natural species--at least about some of them--and it would be sufficient for the purposes of this argument if it were true of only one of them, but there is, in fact, a great number of such cases--and that is, that, similar as they may appear to be to mere races or breeds, they present a marked peculiarity in the reproductive process. if you breed from the male and female of the same race, you of course have offspring of the like kind, and if you make the offspring breed together, you obtain the same result, and if you breed from these again, you will still have the same kind of offspring; there is no check. but if you take members of two distinct species, however similar they may be to each other and make them breed together, you will find a check, with some modifications and exceptions, however, which i shall speak of presently. if you cross two such species with each other, then,--although you may get offspring in the case of the first cross, yet, if you attempt to breed from the products of that crossing, which are what are called hybrids--that is, if you couple a male and a female hybrid--then the result is that in ninety-nine cases out of a hundred you will get no offspring at all; there will be no result whatsoever. the reason of this is quite obvious in some cases; the male hybrids, although possessing all the external appearances and characteristics of perfect animals, are physiologically imperfect and deficient in the structural parts of the reproductive elements necessary to generation. it is said to be invariably the case with the male mule, the cross between the ass and the mare; and hence it is, that, although crossing the horse with the ass is easy enough, and is constantly done, as far as i am aware, if you take two mules, a male and a female, and endeavour to breed from them, you get no offspring whatever; no generation will take place. this is what is called the sterility of the hybrids between two distinct species. you see that this is a very extraordinary circumstance; one does not see why it should be. the common teleological explanation is, that it is to prevent the impurity of the blood resulting from the crossing of one species with another, but you see it does not in reality do anything of the kind. there is nothing in this fact that hybrids cannot breed with each other, to establish such a theory; there is nothing to prevent the horse breeding with the ass, or the ass with the horse. so that this explanation breaks down, as a great many explanations of this kind do, that are only founded on mere assumptions. thus you see that there is a great difference between "mongrels," which are crosses between distinct races, and "hybrids," which are crosses between distinct species. the mongrels are, so far as we know, fertile with one another. but between species, in many cases, you cannot succeed in obtaining even the first cross: at any rate it is quite certain that the hybrids are often absolutely infertile one with another. here is a feature, then, great or small as it may be, which distinguishes natural species of animals. can we find any approximation to this in the different races known to be produced by selective breeding from a common stock? up to the present time the answer to that question is absolutely a negative one. as far as we know at present, there is nothing approximating to this check. in crossing the breeds between the fantail and the pouter, the carrier and the tumbler, or any other variety or race you may name--so far as we know at present--there is no difficulty in breeding together the mongrels. take the carrier and the fantail, for instance, and let them represent the horse and the ass in the case of distinct species; then you have, as the result of their breeding, the carrier-fantail mongrel,--we will say the male and female mongrel,--and, as far as we know, these two when crossed would not be less fertile than the original cross, or than carrier with carrier. here, you see, is a physiological contrast between the races produced by selective modification and natural species. i shall inquire into the value of this fact, and of some modifying circumstances by and by; for the present i merely put it broadly before you. but while considering this question of the limitations of species, a word must be said about what is called recurrence--the tendency of races which have been developed by selective breeding from varieties to return to their primitive type. this is supposed by many to put an absolute limit to the extent of selective and all other variations. people say, "it is all very well to talk about producing these different races, but you know very well that if you turned all these birds wild, these pouters, and carriers, and so on, they would all return to their primitive stock." this is very commonly assumed to be a fact, and it is an argument that is commonly brought forward as conclusive; but if you will take the trouble to inquire into it rather closely, i think you will find that it is not worth very much. the first question of course is, do they thus return to the primitive stock? and commonly as the thing is assumed and accepted, it is extremely difficult to get anything like good evidence of it. it is constantly said, for example, that if domesticated horses are turned wild, as they have been in some parts of asia minor and south america, that they return at once to the primitive stock from which they were bred. but the first answer that you make to this assumption is, to ask who knows what the primitive stock was; and the second answer is, that in that case the wild horses of asia minor ought to be exactly like the wild horses of south america. if they are both like the same thing, they ought manifestly to be like each other! the best authorities, however, tell you that it is quite different. the wild horse of asia is said to be of a dun colour, with a largish head, and a great many other peculiarities; while the best authorities on the wild horses of south america tell you that there is no similarity between their wild horses and those of asia minor; the cut of their heads is very different, and they are commonly chestnut or bay-coloured. it is quite clear, therefore, that as by these facts there ought to have been two primitive stocks, they go for nothing in support of the assumption that races recur to one primitive stock, and so far as this evidence is concerned, it falls to the ground. suppose for a moment that it were so, and that domesticated races, when turned wild, did return to some common condition, i cannot see that this would prove much more than that similar conditions are likely to produce similar results; and that when you take back domesticated animals into what we call natural conditions, you do exactly the same thing as if you carefully undid all the work you had gone through, for the purpose of bringing the animal from its wild to its domesticated state. i do not see anything very wonderful in the fact, if it took all that trouble to get it from a wild state, that it should go back into its original state as soon as you removed the conditions which produced the variation to the domesticated form. there is an important fact, however, forcibly brought forward by mr. darwin, which has been noticed in connection with the breeding of domesticated pigeons; and it is, that however different these breeds of pigeons may be from each other, and we have already noticed the great differences in these breeds, that if, among any of those variations, you chance to have a blue pigeon turn up, it will be sure to have the black bars across the wings, which are characteristic of the original wild stock, the rock pigeon. now, this is certainly a very remarkable circumstance; but i do not see myself how it tells very strongly either one way or the other. i think, in fact, that this argument in favour of recurrence to the primitive type might prove a great deal too much for those who so constantly bring it forward. for example, mr. darwin has very forcibly urged, that nothing is commoner than if you examine a dun horse--and i had an opportunity of verifying this illustration lately, while in the islands of the west highlands, where there are a great many dun horses--to find that horse exhibit a long black stripe down his back, very often stripes on his shoulder, and very often stripes on his legs. i, myself, saw a pony of this description a short time ago, in a baker's cart, near rothesay, in bute: it had the long stripe down the back, and stripes on the shoulders and legs, just like those of the ass, the quagga, and the zebra. now, if we interpret the theory of recurrence as applied to this case, might it not be said that here was a case of a variation exhibiting the characters and conditions of an animal occupying something like an intermediate position between the horse, the ass, the quagga, and the zebra, and from which these had been developed? in the same way with regard even to man. every anatomist will tell you that there is nothing commoner, in dissecting the human body, than to meet with what are called muscular variations--that is, if you dissect two bodies very carefully, you will probably find that the modes of attachment and insertion of the muscles are not exactly the same in both, there being great peculiarities in the mode in which the muscles are arranged; and it is very singular, that in some dissections of the human body you will come upon arrangements of the muscles very similar indeed to the same parts in the apes. is the conclusion in that case to be, that this is like the black bars in the case of the pigeon, and that it indicates a recurrence to the primitive type from which the animals have been probably developed? truly, i think that the opponents of modification and variation had better leave the argument of recurrence alone, or it may prove altogether too strong for them. to sum up,--the evidence as far as we have gone is against the argument as to any limit to divergences, so far as structure is concerned; and in favour of a physiological limitation. by selective breeding we can produce structural divergences as great as those of species, but we cannot produce equal physiological divergences. for the present i leave the question there. now, the next problem that lies before us--and it is an extremely important one--is this: does this selective breeding occur in nature? because, if there is no proof of it, all that i have been telling you goes for nothing in accounting for the origin of species. are natural causes competent to play the part of selection in perpetuating varieties? here we labour under very great difficulties. in the last lecture i had occasion to point out to you the extreme difficulty of obtaining evidence even of the first origin of those varieties which we know to have occurred in domesticated animals. i told you, that almost always the origin of these varieties is overlooked, so that i could only produce two of three cases, as that of gratio kelleia and of the ancon sheep. people forget, or do not take notice of them until they come to have a prominence; and if that is true of artificial cases, under our own eyes, and in animals in our own care, how much more difficult it must be to have at first hand good evidence of the origin of varieties in nature! indeed, i do not know that it is possible by direct evidence to prove the origin of a variety in nature, or to prove selective breeding; but i will tell you what we can prove--and this comes to the same thing--that varieties exist in nature within the limits of species, and, what is more, that when a variety has come into existence in nature, there are natural causes and conditions, which are amply competent to play the part of a selective breeder; and although that is not quite the evidence that one would like to have--though it is not direct testimony--yet it is exceeding good and exceedingly powerful evidence in its way. as to the first point, of varieties existing among natural species, i might appeal to the universal experience of every naturalist, and of any person who has ever turned any attention at all to the characteristics of plants and animals in a state of nature; but i may as well take a few definite cases, and i will begin with man himself. i am one of those who believe that, at present, there is no evidence whatever for saying, that mankind sprang originally from any more than a single pair; i must say, that i cannot see any good ground whatever, or even any tenable sort of evidence, for believing that there is more than one species of man. nevertheless, as you know, just as there are numbers of varieties in animals, so there are remarkable varieties of men. i speak not merely of those broad and distinct variations which you see at a glance. everybody, of course, knows the difference between a negro and a white man, and can tell a chinaman from an englishman. they each have peculiar characteristics of colour and physiognomy; but you must recollect that the characters of these races go very far deeper--they extend to the bony structure, and to the characters of that most important of all organs to us--the brain; so that, among men belonging to different races, or even within the same race, one man shall have a brain a third, or half, or even seventy per cent. bigger than another; and if you take the whole range of human brains, you will find a variation in some cases of a hundred per cent. apart from these variations in the size of the brain, the characters of the skull vary. thus if i draw the figures of a mongul and of a negro head on the blackboard, in the case of the last the breadth would be about seven-tenths, and in the other it would be nine-tenths of the total length. so that you see there is abundant evidence of variation among men in their natural condition. and if you turn to other animals there is just the same thing. the fox, for example, which has a very large geographical distribution all over europe, and parts of asia, and on the american continent, varies greatly. there are mostly large foxes in the north, and smaller ones in the south. in germany alone, the foresters reckon some eight different sorts. of the tiger, no one supposes that there is more than one species; they extend from the hottest parts of bengal, into the dry, cold, bitter steppes of siberia, into a latitude of 50 degrees,--so that they may even prey upon the reindeer. these tigers have exceedingly different characteristics, but still they all keep their general features, so that there is no doubt as to their being tigers. the siberian tiger has a thick fur, a small mane, and a longitudinal stripe down the back, while the tigers of java and sumatra differ in many important respects from the tigers of northern asia. so lions vary; so birds vary; and so, if you go further back and lower down in creation, you find that fishes vary. in different streams, in the same country even, you will find the trout to be quite different to each other and easily recognisable by those who fish in the particular streams. there is the same differences in leeches; leech collectors can easily point out to you the differences and the peculiarities which you yourself would probably pass by; so with fresh-water mussels; so, in fact, with every animal you can mention. in plants there is the same kind of variation. take such a case even as the common bramble. the botanists are all at war about it; some of them wanting to make out that there are many species of it, and others maintaining that they are but many varieties of one species; and they cannot settle to this day which is a species and which is a variety! so that there can be no doubt whatsoever that any plant and any animal may vary in nature; that varieties may arise in the way i have described,--as spontaneous varieties,--and that those varieties may be perpetuated in the same way that i have shown you spontaneous varieties are perpetuated; i say, therefore, that there can be no doubt as to the origin and perpetuation of varieties in nature. but the question now is:--does selection take place in nature? is there anything like the operation of man in exercising selective breeding, taking place in nature? you will observe that, at present, i say nothing about species; i wish to confine myself to the consideration of the production of those natural races which everybody admits to exist. the question is, whether in nature there are causes competent to produce races, just in the same way as man is able to produce by selection, such races of animals as we have already noticed. when a variety has arisen, the conditions of existence are such as to exercise an influence which is exactly comparable to that of artificial selection. by conditions of existence i mean two things,--there are conditions which are furnished by the physical, the inorganic world, and there are conditions of existence which are furnished by the organic world. there is, in the first place, climate; under that head i include only temperature and the varied amount of moisture of particular places. in the next place there is what is technically called station, which means--given the climate, the particular kind of place in which an animal or a plant lives or grows; for example, the station of a fish is in the water, of a fresh-water fish in fresh water; the station of a marine fish is in the sea, and a marine animal may have a station higher or deeper. so again with land animals: the differences in their stations are those of different soils and neighbourhoods; some being best adapted to a calcareous, and others to an arenaceous soil. the third condition of existence is food, by which i mean food in the broadest sense, the supply of the materials necessary to the existence of an organic being; in the case of a plant the inorganic matters, such as carbonic acid, water, ammonia, and the earthy salts or salines; in the case of the animal the inorganic and organic matters, which we have seen they require; then these are all, at least the two first, what we may call the inorganic or physical conditions of existence. food takes a mid-place, and then come the organic conditions; by which i mean the conditions which depend upon the state of the rest of the organic creation, upon the number and kind of living beings, with which an animal is surrounded. you may class these under two heads: there are organic beings, which operate as 'opponents', and there are organic beings which operate as 'helpers' to any given organic creature. the opponents may be of two kinds: there are the 'indirect opponents', which are what we may call 'rivals'; and there are the 'direct opponents', those which strive to destroy the creature; and these we call 'enemies'. by rivals i mean, of course, in the case of plants, those which require for their support the same kind of soil and station, and, among animals, those which require the same kind of station, or food, or climate; those are the indirect opponents; the direct opponents are, of course, those which prey upon an animal or vegetable. the 'helpers' may also be regarded as direct and indirect: in the case of a carnivorous animal, for example, a particular herbaceous plant may in multiplying be an indirect helper, by enabling the herbivora on which the carnivore preys to get more food, and thus to nourish the carnivore more abundantly; the direct helper may be best illustrated by reference to some parasitic creature, such as the tape-worm. the tape-worm exists in the human intestines, so that the fewer there are of men the fewer there will be of tape-worms, other things being alike. it is a humiliating reflection, perhaps, that we may be classed as direct helpers to the tape-worm, but the fact is so: we can all see that if there were no men there would be no tape-worms. it is extremely difficult to estimate, in a proper way, the importance and the working of the conditions of existence. i do not think there were any of us who had the remotest notion of properly estimating them until the publication of mr. darwin's work, which has placed them before us with remarkable clearness; and i must endeavour, as far as i can in my own fashion, to give you some notion of how they work. we shall find it easiest to take a simple case, and one as free as possible from every kind of complication. i will suppose, therefore, that all the habitable part of this globe--the dry land, amounting to about 51,000,000 square miles,--i will suppose that the whole of that dry land has the same climate, and that it is composed of the same kind of rock or soil, so that there will be the same station everywhere; we thus get rid of the peculiar influence of different climates and stations. i will then imagine that there shall be but one organic being in the world, and that shall be a plant. in this we start fair. its food is to be carbonic acid, water and ammonia, and the saline matters in the soil, which are, by the supposition, everywhere alike. we take one single plant, with no opponents, no helpers, and no rivals; it is to be a "fair field, and no favour". now, i will ask you to imagine further that it shall be a plant which shall produce every year fifty seeds, which is a very moderate number for a plant to produce; and that, by the action of the winds and currents, these seeds shall be equally and gradually distributed over the whole surface of the land. i want you now to trace out what will occur, and you will observe that i am not talking fallaciously any more than a mathematician does when he expounds his problem. if you show that the conditions of your problem are such as may actually occur in nature and do not transgress any of the known laws of nature in working out your proposition, then you are as safe in the conclusion you arrive at as is the mathematician in arriving at the solution of his problem. in science, the only way of getting rid of the complications with which a subject of this kind is environed, is to work in this deductive method. what will be the result, then? i will suppose that every plant requires one square foot of ground to live upon; and the result will be that, in the course of nine years, the plant will have occupied every single available spot in the whole globe! i have chalked upon the blackboard the figures by which i arrive at the result:-plants. plants 1 x 50 in 1st year = 50 50 x 50 " 2nd " = 2,500 2,500 x 50 " 3rd " = 125,000 125,000 x 50 " 4th " = 6,250,000 6,250,000 x 50 " 5th " = 312,500,000 312,500,000 x 50 " 6th " = 15,625,000,000 15,625,000,000 x 50 " 7th " = 781,250,000,000 781,250,000,000 x 50 " 8th " = 39,062,500,000,000 39,062,500,000,000 x 50& " 9th " = 1,953,125,000,000,000 51,000,000 sq. miles--the dry surface of the earth x 27,878,400--the number of sq. ft. in 1 sq. mile = sq. ft. 1,421,798,400,000,000 being 531,326,600,000,000 square feet less than would be required at the end of the ninth year. you will see from this that, at the end of the first year the single plant will have produced fifty more of its kind; by the end of the second year these will have increased to 2,500; and so on, in succeeding years, you get beyond even trillions; and i am not at all sure that i could tell you what the proper arithmetical denomination of the total number really is; but, at any rate, you will understand the meaning of all those noughts. then you see that, at the bottom, i have taken the 51,000,000 of square miles, constituting the surface of the dry land; and as the number of square feet are placed under and subtracted from the number of seeds that would be produced in the ninth year, you can see at once that there would be an immense number more of plants than there would be square feet of ground for their accommodation. this is certainly quite enough to prove my point; that between the eighth and ninth year after being planted the single plant would have stocked the whole available surface of the earth. this is a thing which is hardly conceivable--it seems hardly imaginable--yet it is so. it is indeed simply the law of malthus exemplified. mr. malthus was a clergyman, who worked out this subject most minutely and truthfully some years ago; he showed quite clearly,--and although he was much abused for his conclusions at the time, they have never yet been disproved and never will be--he showed that in consequence of the increase in the number of organic beings in a geometrical ratio, while the means of existence cannot be made to increase in the same ratio, that there must come a time when the number of organic beings will be in excess of the power of production of nutriment, and that thus some check must arise to the further increase of those organic beings. at the end of the ninth year we have seen that each plant would not be able to get its full square foot of ground, and at the end of another year it would have to share that space with fifty others the produce of the seeds which it would give off. what, then, takes place? every plant grows up, flourishes, occupies its square foot of ground, and gives off its fifty seeds; but notice this, that out of this number only one can come to anything; there is thus, as it were, forty-nine chances to one against its growing up; it depends upon the most fortuitous circumstances whether any one of these fifty seeds shall grow up and flourish, or whether it shall die and perish. this is what mr. darwin has drawn attention to, and called the "struggle for existence"; and i have taken this simple case of a plant because some people imagine that the phrase seems to imply a sort of fight. i have taken this plant and shown you that this is the result of the ratio of the increase, the necessary result of the arrival of a time coming for every species when exactly as many members must be destroyed as are born; that is the inevitable ultimate result of the rate of production. now, what is the result of all this? i have said that there are forty-nine struggling against every one; and it amounts to this, that the smallest possible start given to any one seed may give it an advantage which will enable it to get ahead of all the others; anything that will enable any one of these seeds to germinate six hours before any of the others will, other things being alike, enable it to choke them out altogether. i have shown you that there is no particular in which plants will not vary from each other; it is quite possible that one of our imaginary plants may vary in such a character as the thickness of the integument of its seeds; it might happen that one of the plants might produce seeds having a thinner integument, and that would enable the seeds of that plant to germinate a little quicker than those of any of the others, and those seeds would most inevitably extinguish the forty-nine times as many that were struggling with them. i have put it in this way, but you see the practical result of the process is the same as if some person had nurtured the one and destroyed the other seeds. it does not matter how the variation is produced, so long as it is once allowed to occur. the variation in the plant once fairly started tends to become hereditary and reproduce itself; the seeds would spread themselves in the same way and take part in the struggle with the forty-nine hundred, or forty-nine thousand, with which they might be exposed. thus, by degrees, this variety, with some slight organic change or modification, must spread itself over the whole surface of the habitable globe, and extirpate or replace the other kinds. that is what is meant by natural selection; that is the kind of argument by which it is perfectly demonstrable that the conditions of existence may play exactly the same part for natural varieties as man does for domesticated varieties. no one doubts at all that particular circumstances may be more favourable for one plant and less so for another, and the moment you admit that, you admit the selective power of nature. now, although i have been putting a hypothetical case, you must not suppose that i have been reasoning hypothetically. there are plenty of direct experiments which bear out what we may call the theory of natural selection; there is extremely good authority for the statement that if you take the seed of mixed varieties of wheat and sow it, collecting the seed next year and sowing it again, at length you will find that out of all your varieties only two or three have lived, or perhaps even only one. there were one or two varieties which were best fitted to get on, and they have killed out the other kinds in just the same way and with just the same certainty as if you had taken the trouble to remove them. as i have already said, the operation of nature is exactly the same as the artificial operation of man. but if this be true of that simple case, which i put before you, where there is nothing but the rivalry of one member of a species with others, what must be the operation of selective conditions, when you recollect as a matter of fact, that for every species of animal or plant there are fifty or a hundred species which might all, more or less, be comprehended in the same climate, food, and station;--that every plant has multitudinous animals which prey upon it, and which are its direct opponents; and that these have other animals preying upon them,--that every plant has its indirect helpers in the birds that scatter abroad its seed, and the animals that manure it with their dung;--i say, when these things are considered, it seems impossible that any variation which may arise in a species in nature should not tend in some way or other either to be a little better or worse than the previous stock; if it is a little better it will have an advantage over and tend to extirpate the latter in this crush and struggle; and if it is a little worse it will itself be extirpated. i know nothing that more appropriately expresses this, than the phrase, "the struggle for existence"; because it brings before your minds, in a vivid sort of way, some of the simplest possible circumstances connected with it. when a struggle is intense there must be some who are sure to be trodden down, crushed, and overpowered by others; and there will be some who just manage to get through only by the help of the slightest accident. i recollect reading an account of the famous retreat of the french troops, under napoleon, from moscow. worn out, tired, and dejected, they at length came to a great river over which there was but one bridge for the passage of the vast army. disorganised and demoralised as that army was, the struggle must certainly have been a terrible one--every one heeding only himself, and crushing through the ranks and treading down his fellows. the writer of the narrative, who was himself one of those who were fortunate enough to succeed in getting over, and not among the thousands who were left behind or forced into the river, ascribed his escape to the fact that he saw striding onward through the mass a great strong fellow,--one of the french cuirassiers, who had on a large blue cloak--and he had enough presence of mind to catch and retain a hold of this strong man's cloak. he says, "i caught hold of his cloak, and although he swore at me and cut at and struck me by turns, and at last, when he found he could not shake me off, fell to entreating me to leave go or i should prevent him from escaping, besides not assisting myself, i still kept tight hold of him, and would not quit my grasp until he had at last dragged me through." here you see was a case of selective saving--if we may so term it--depending for its success on the strength of the cloth of the cuirassier's cloak. it is the same in nature; every species has its bridge of beresina; it has to fight its way through and struggle with other species; and when well nigh overpowered, it may be that the smallest chance, something in its colour, perhaps--the minutest circumstance--will turn the scale one way or the other. suppose that by a variation of the black race it had produced the white man at any time--you know that the negroes are said to believe this to have been the case, and to imagine that cain was the first white man, and that we are his descendants--suppose that this had ever happened, and that the first residence of this human being was on the west coast of africa. there is no great structural difference between the white man and the negro, and yet there is something so singularly different in the constitution of the two, that the malarias of that country, which do not hurt the black at all, cut off and destroy the white. then you see there would have been a selective operation performed; if the white man had risen in that way, he would have been selected out and removed by means of the malaria. now there really is a very curious case of selection of this sort among pigs, and it is a case of selection of colour too. in the woods of florida there are a great many pigs, and it is a very curious thing that they are all black, every one of them. professor wyman was there some years ago, and on noticing no pigs but these black ones, he asked some of the people how it was that they had no white pigs, and the reply was that in the woods of florida there was a root which they called the paint root, and that if the white pigs were to eat any of it, it had the effect of making their hoofs crack, and they died, but if the black pigs eat any of it, it did not hurt them at all. here was a very simple case of natural selection. a skilful breeder could not more carefully develope the black breed of pigs, and weed out all the white pigs, than the paint root does. to show you how remarkably indirect may be such natural selective agencies as i have referred to, i will conclude by noticing a case mentioned by mr. darwin, and which is certainly one of the most curious of its kind. it is that of the humble bee. it has been noticed that there are a great many more humble bees in the neighbourhood of towns, than out in the open country; and the explanation of the matter is this: the humble bees build nests, in which they store their honey and deposit the larvae and eggs. the field mice are amazingly fond of the honey and larvae; therefore, wherever there are plenty of field mice, as in the country, the humble bees are kept down; but in the neighbourhood of towns, the number of cats which prowl about the fields eat up the field mice, and of course the more mice they eat up the less there are to prey upon the larvae of the bees--the cats are therefore the indirect helpers of the bees! [2] coming back a step farther we may say that the old maids are also indirect friends of the humble bees, and indirect enemies of the field mice, as they keep the cats which eat up the latter! this is an illustration somewhat beneath the dignity of the subject, perhaps, but it occurs to me in passing, and with it i will conclude this lecture. [footnote 1: i lay stress here on the 'practical' signification of "species." whether a physiological test between species exist or not, it is hardly ever applicable by the practical naturalist.] [footnote 2: the humble bees, on the other hand, are direct helpers of some plants, such as the heartsease and red clover, which are fertilized by the visits of the bees; and they are indirect helpers of the numerous insects which are more or less completely supported by the heartsease and red clover.] criticisms on "the origin of species" 'the natural history review', 1864 [1] by thomas h. huxley in the course of the present year several foreign commentaries upon mr. darwin's great work have made their appearance. those who have perused that remarkable chapter of the 'antiquity of man,' in which sir charles lyell draws a parallel between the development of species and that of languages, will be glad to hear that one of the most eminent philologers of germany, professor schleicher, has, independently, published a most instructive and philosophical pamphlet (an excellent notice of which is to be found in the 'reader', for february 27th of this year) supporting similar views with all the weight of his special knowledge and established authority as a linguist. professor haeckel, to whom schleicher addresses himself, previously took occasion, in his splendid monograph on the 'radiolaria' [2], to express his high appreciation of, and general concordance with, mr. darwin's views. but the most elaborate criticisms of the 'origin of species' which have appeared are two works of very widely different merit, the one by professor kolliker, the well-known anatomist and histologist of wurzburg; the other by m. flourens, perpetual secretary of the french academy of sciences. professor kolliker's critical essay 'upon the darwinian theory' is, like all that proceeds from the pen of that thoughtful and accomplished writer, worthy of the most careful consideration. it comprises a brief but clear sketch of darwin's views, followed by an enumeration of the leading difficulties in the way of their acceptance; difficulties which would appear to be insurmountable to professor kolliker, inasmuch as he proposes to replace mr. darwin's theory by one which he terms the 'theory of heterogeneous generation.' we shall proceed to consider first the destructive, and secondly, the constructive portion of the essay. we regret to find ourselves compelled to dissent very widely from many of professor kolliker's remarks; and from none more thoroughly than from those in which he seeks to define what we may term the philosophical position of darwinism. "darwin," says professor kolliker, "is, in the fullest sense of the word, a teleologist. he says quite distinctly (first edition, pp. 199, 200) that every particular in the structure of an animal has been created for its benefit, and he regards the whole series of animal forms only from this point of view." and again: "7. the teleological general conception adopted by darwin is a mistaken one. "varieties arise irrespectively of the notion of purpose, or of utility, according to general laws of nature, and may be either useful, or hurtful, or indifferent. "the assumption that an organism exists only on account of some definite end in view, and represents something more than the incorporation of a general idea, or law, implies a one-sided conception of the universe. assuredly, every organ has, and every organism fulfils, its end, but its purpose is not the condition of its existence. every organism is also sufficiently perfect for the purpose it serves, and in that, at least, it is useless to seek for a cause of its improvement." it is singular how differently one and the same book will impress different minds. that which struck the present writer most forcibly on his first perusal of the 'origin of species' was the conviction that teleology, as commonly understood, had received its deathblow at mr. darwin's hands. for the teleological argument runs thus: an organ or organism (a) is precisely fitted to perform a function or purpose (b); therefore it was specially constructed to perform that function. in paley's famous illustration, the adaptation of all the parts of the watch to the function, or purpose, of showing the time, is held to be evidence that the watch was specially contrived to that end; on the ground, that the only cause we know of, competent to produce such an effect as a watch which shall keep time, is a contriving intelligence adapting the means directly to that end. suppose, however, that any one had been able to show that the watch had not been made directly by any person, but that it was the result of the modification of another watch which kept time but poorly; and that this again had proceeded from a structure which could hardly be called a watch at all--seeing that it had no figures on the dial and the hands were rudimentary; and that going back and back in time we came at last to a revolving barrel as the earliest traceable rudiment of the whole fabric. and imagine that it had been possible to show that all these changes had resulted, first, from a tendency of the structure to vary indefinitely; and secondly, from something in the surrounding world which helped all variations in the direction of an accurate time-keeper, and checked all those in other directions; then it is obvious that the force of paley's argument would be gone. for it would be demonstrated that an apparatus thoroughly well adapted to a particular purpose might be the result of a method of trial and error worked by unintelligent agents, as well as of the direct application of the means appropriate to that end, by an intelligent agent. now it appears to us that what we have here, for illustration's sake, supposed to be done with the watch, is exactly what the establishment of darwin's theory will do for the organic world. for the notion that every organism has been created as it is and launched straight at a purpose, mr. darwin substitutes the conception of something which may fairly be termed a method of trial and error. organisms vary incessantly; of these variations the few meet with surrounding conditions which suit them and thrive; the many are unsuited and become extinguished. according to teleology, each organism is like a rifle bullet fired straight at a mark; according to darwin, organisms are like grapeshot of which one hits something and the rest fall wide. for the teleologist an organism exists because it was made for the conditions in which it is found; for the darwinian an organism exists because, out of many of its kind, it is the only one which has been able to persist in the conditions in which it is found. teleology implies that the organs of every organism are perfect and cannot be improved; the darwinian theory simply affirms that they work well enough to enable the organism to hold its own against such competitors as it has met with, but admits the possibility of indefinite improvement. but an example may bring into clearer light the profound opposition between the ordinary teleological, and the darwinian, conception. cats catch mice, small birds and the like, very well. teleology tells us that they do so because they were expressly constructed for so doing--that they are perfect mousing apparatuses, so perfect and so delicately adjusted that no one of their organs could be altered, without the change involving the alteration of all the rest. darwinism affirms on the contrary, that there was no express construction concerned in the matter; but that among the multitudinous variations of the feline stock, many of which died out from want of power to resist opposing influences, some, the cats, were better fitted to catch mice than others, whence they throve and persisted, in proportion to the advantage over their fellows thus offered to them. far from imagining that cats exist 'in order' to catch mice well, darwinism supposes that cats exist 'because' they catch mice well--mousing being not the end, but the condition, of their existence. and if the cat type has long persisted as we know it, the interpretation of the fact upon darwinian principles would be, not that the cats have remained invariable, but that such varieties as have incessantly occurred have been, on the whole, less fitted to get on in the world than the existing stock. if we apprehend the spirit of the 'origin of species' rightly, then, nothing can be more entirely and absolutely opposed to teleology, as it is commonly understood, than the darwinian theory. so far from being a "teleologist in the fullest sense of the word," we would deny that he is a teleologist in the ordinary sense at all; and we should say that, apart from his merits as a naturalist, he has rendered a most remarkable service to philosophical thought by enabling the student of nature to recognise, to their fullest extent, those adaptations to purpose which are so striking in the organic world, and which teleology has done good service in keeping before our minds, without being false to the fundamental principles of a scientific conception of the universe. the apparently diverging teachings of the teleologist and of the morphologist are reconciled by the darwinian hypothesis. but leaving our own impressions of the 'origin of species,' and turning to those passages especially cited by professor kolliker, we cannot admit that they bear the interpretation he puts upon them. darwin, if we read him rightly, does 'not' affirm that every detail in the structure of an animal has been created for its benefit. his words are (p. 199):-"the foregoing remarks lead me to say a few words on the protest lately made by some naturalists against the utilitarian doctrine that every detail of structure has been produced for the good of its possessor. they believe that very many structures have been created for beauty in the eyes of man, or for mere variety. this doctrine, if true, would be absolutely fatal to my theory--yet i fully admit that many structures are of no direct use to their possessor." and after sundry illustrations and qualifications, he concludes (p. 200):-"hence every detail of structure in every living creature (making some little allowance for the direct action of physical conditions) may be viewed either as having been of special use to some ancestral form, or as being now of special use to the descendants of this form--either directly, or indirectly, through the complex laws of growth." but it is one thing to say, darwinically, that every detail observed in an animal's structure is of use to it, or has been of use to its ancestors; and quite another to affirm, teleologically, that every detail of an animal's structure has been created for its benefit. on the former hypothesis, for example, the teeth of the foetal balaena have a meaning; on the latter, none. so far as we are aware, there is not a phrase in the 'origin of species', inconsistent with professor kolliker's position, that "varieties arise irrespectively of the notion of purpose, or of utility, according to general laws of nature, and may be either useful, or hurtful, or indifferent." on the contrary, mr. darwin writes (summary of chap. v.):-"our ignorance of the laws of variation is profound. not in one case out of a hundred can we pretend to assign any reason why this or that part varies more or less from the same part in the parents.... the external conditions of life, as climate and food, etc., seem to have induced some slight modifications. habit, in producing constitutional differences, and use, in strengthening, and disuse, in weakening and diminishing organs, seem to have been more potent in their effects." and finally, as if to prevent all possible misconception, mr. darwin concludes his chapter on variation with these pregnant words:-"whatever the cause may be of each slight difference in the offspring from their parents--and a cause for each must exist--it is the steady accumulation, through natural selection of such differences, when beneficial to the individual, that gives rise to all the more important modifications of structure which the innumerable beings on the face of the earth are enabled to struggle with each other, and the best adapted to survive." we have dwelt at length upon this subject, because of its great general importance, and because we believe that professor kolliker's criticisms on this head are based upon a misapprehension of mr. darwin's views--substantially they appear to us to coincide with his own. the other objections which professor kolliker enumerates and discusses are the following [3]:-"1. no transitional forms between existing species are known; and known varieties, whether selected or spontaneous, never go so far as to establish new species." to this professor kolliker appears to attach some weight. he makes the suggestion that the short-faced tumbler pigeon may be a pathological product. "2. no transitional forms of animals are met with among the organic remains of earlier epochs." upon this, professor kolliker remarks that the absence of transitional forms in the fossil world, though not necessarily fatal to darwin's views, weakens his case. "3. the struggle for existence does not take place." to this objection, urged by pelzeln, kolliker, very justly, attaches no weight. "4. a tendency of organisms to give rise to useful varieties, and a natural selection, do not exist. "the varieties which are found arise in consequence of manifold external influences, and it is not obvious why they all, or partially, should be particularly useful. each animal suffices for its own ends, is perfect of its kind, and needs no further development. should, however, a variety be useful and even maintain itself, there is no obvious reason why it should change any further. the whole conception of the imperfection of organisms and the necessity of their becoming perfected is plainly the weakest side of darwin's theory, and a 'pis aller' (nothbehelf) because darwin could think of no other principle by which to explain the metamorphoses which, as i also believe, have occurred." here again we must venture to dissent completely from professor kolliker's conception of mr. darwin's hypothesis. it appears to us to be one of the many peculiar merits of that hypothesis that it involves no belief in a necessary and continual progress of organisms. again, mr. darwin, if we read him aright, assumes no special tendency of organisms to give rise to useful varieties, and knows nothing of needs of development, or necessity of perfection. what he says is, in substance: all organisms vary. it is in the highest degree improbable that any given variety should have exactly the same relations to surrounding conditions as the parent stock. in that case it is either better fitted (when the variation may be called useful), or worse fitted, to cope with them. if better, it will tend to supplant the parent stock; if worse, it will tend to be extinguished by the parent stock. if (as is hardly conceivable) the new variety is so perfectly adapted to the conditions that no improvement upon it is possible,--it will persist, because, though it does not cease to vary, the varieties will be inferior to itself. if, as is more probable, the new variety is by no means perfectly adapted to its conditions, but only fairly well adapted to them, it will persist, so long as none of the varieties which it throws off are better adapted than itself. on the other hand, as soon as it varies in a useful way, i.e. when the variation is such as to adapt it more perfectly to its conditions, the fresh variety will tend to supplant the former. so far from a gradual progress towards perfection forming any necessary part of the darwinian creed, it appears to us that it is perfectly consistent with indefinite persistence in one estate, or with a gradual retrogression. suppose, for example, a return of the glacial epoch and a spread of polar climatal conditions over the whole globe. the operation of natural selection under these circumstances would tend, on the whole, to the weeding out of the higher organisms and the cherishing of the lower forms of life. cryptogamic vegetation would have the advantage over phanerogamic; hydrozoa over corals; crustacea over insecta, and amphipoda and isopoda over the higher crustacea; cetaceans and seals over the primates; the civilization of the esquimaux over that of the european. "5. pelzeln has also objected that if the later organisms have proceeded from the earlier, the whole developmental series, from the simplest to the highest, could not now exist; in such a case the simpler organisms must have disappeared." to this professor kolliker replies, with perfect justice, that the conclusion drawn by pelzeln does not really follow from darwin's premisses, and that, if we take the facts of palaeontology as they stand, they rather support than oppose darwin's theory. "6. great weight must be attached to the objection brought forward by huxley, otherwise a warm supporter of darwin's hypothesis, that we know of no varieties which are sterile with one another, as is the rule among sharply distinguished animal forms. "if darwin is right, it must be demonstrated that forms may be produced by selection, which, like the present sharply distinguished animal forms, are infertile, when coupled with one another, and this has not been done." the weight of this objection is obvious; but our ignorance of the conditions of fertility and sterility, the want of carefully conducted experiments extending over long series of years, and the strange anomalies presented by the results of the cross-fertilization of many plants, should all, as mr. darwin has urged, be taken into account in considering it. the seventh objection is that we have already discussed ('supra', p. 178). the eighth and last stands as follows:-"8. the developmental theory of darwin is not needed to enable us to understand the regular harmonious progress of the complete series of organic forms from the simpler to the more perfect. "the existence of general laws of nature explains this harmony, even if we assume that all beings have arisen separately and independent of one another. darwin forgets that inorganic nature, in which there can be no thought of genetic connexion of forms, exhibits the same regular plan, the same harmony, as the organic world; and that, to cite only one example, there is as much a natural system of minerals as of plants and animals." we do not feel quite sure that we seize professor kolliker's meaning here, but he appears to suggest that the observation of the general order and harmony which pervade inorganic nature, would lead us to anticipate a similar order and harmony in the organic world. and this is no doubt true, but it by no means follows that the particular order and harmony observed among them should be that which we see. surely the stripes of dun horses, and the teeth of the foetal 'balaena', are not explained by the "existence of general laws of nature." mr. darwin endeavours to explain the exact order of organic nature which exists; not the mere fact that there is some order. and with regard to the existence of a natural system of minerals; the obvious reply is that there may be a natural classification of any objects--of stones on a sea-beach, or of works of art; a natural classification being simply an assemblage of objects in groups, so as to express their most important and fundamental resemblances and differences. no doubt mr. darwin believes that those resemblances and differences upon which our natural systems or classifications of animals and plants are based, are resemblances and differences which have been produced genetically, but we can discover no reason for supposing that he denies the existence of natural classifications of other kinds. and, after all, is it quite so certain that a genetic relation may not underlie the classification of minerals? the inorganic world has not always been what we see it. it has certainly had its metamorphoses, and, very probably, a long "entwickelungsgeschichte" out of a nebular blastema. who knows how far that amount of likeness among sets of minerals, in virtue of which they are now grouped into families and orders, may not be the expression of the common conditions to which that particular patch of nebulous fog, which may have been constituted by their atoms, and of which they may be, in the strictest sense, the descendants, was subjected? it will be obvious from what has preceded, that we do not agree with professor kolliker in thinking the objections which he brings forward so weighty as to be fatal to darwin's view. but even if the case were otherwise, we should be unable to accept the "theory of heterogeneous generation" which is offered as a substitute. that theory is thus stated:-"the fundamental conception of this hypothesis is, that, under the influence of a general law of development, the germs of organisms produce others different from themselves. this might happen (1) by the fecundated ova passing, in the course of their development, under particular circumstances, into higher forms; (2) by the primitive and later organisms producing other organisms without fecundation, out of germs or eggs (parthenogenesis)." in favour of this hypothesis, professor kolliker adduces the well-known facts of agamogenesis, or "alternate generation"; the extreme dissimilarity of the males and females of many animals; and of the males, females, and neuters of those insects which live in colonies: and he defines its relations to the darwinian theory as follows:-"it is obvious that my hypothesis is apparently very similar to darwin's, inasmuch as i also consider that the various forms of animals have proceeded directly from one another. my hypothesis of the creation of organisms by heterogeneous generation, however, is distinguished very essentially from darwin's by the entire absence of the principle of useful variations and their natural selection: and my fundamental conception is this, that a great plan of development lies at the foundation of the origin of the whole organic world, impelling the simpler forms to more and more complex developments. how this law operates, what influences determine the development of the eggs and germs, and impel them to assume constantly new forms, i naturally cannot pretend to say; but i can at least adduce the great analogy of the alternation of generations. if a 'bipinnaria', a 'brachialaria', a 'pluteus', is competent to produce the echinoderm, which is so widely different from it; if a hydroid polype can produce the higher medusa; if the vermiform trematode 'nurse' can develop within itself the very unlike 'cercaria', it will not appear impossible that the egg, or ciliated embryo, of a sponge, for once, under special conditions, might become a hydroid polype, or the embryo of a medusa, an echinoderm." it is obvious, from these extracts, that professor kolliker's hypothesis is based upon the supposed existence of a close analogy between the phenomena of agamogenesis and the production of new species from pre-existing ones. but is the analogy a real one? we think that it is not, and, by the hypothesis, cannot be. for what are the phenomena of agamogenesis, stated generally? an impregnated egg develops into an asexual form, a; this gives rise, asexually, to a second form or forms, b, more or less different from a. b may multiply asexually again; in the simpler cases, however, it does not, but, acquiring sexual characters, produces impregnated eggs from whence a, once more, arises. no case of agamogenesis is known in which, 'when a differs widely from b', it is itself capable of sexual propagation. no case whatever is known in which the progeny of b, by sexual generation, is other than a reproduction of a. but if this be a true statement of the nature of the process of agamogenesis, how can it enable us to comprehend the production of new species from already existing ones? let us suppose hyaenas to have preceded dogs, and to have produced the latter in this way. then the hyena will represent a, and the dog, b. the first difficulty that presents itself is that the hyena must be asexual, or the process will be wholly without analogy in the world of agamogenesis. but passing over this difficulty, and supposing a male and female dog to be produced at the same time from the hyaena stock, the progeny of the pair, if the analogy of the simpler kinds of agamogenesis [4] is to be followed, should be a litter, not of puppies, but of young hyenas. for the agamogenetic series is always, as we have seen, a: b: a: b, etc.; whereas, for the production of a new species, the series must be a: b: b: b, etc. the production of new species, or genera, is the extreme permanent divergence from the primitive stock. all known agamogenetic processes, on the other hand, end in a complete return to the primitive stock. how then is the production of new species to be rendered intelligible by the analogy of agamogenesis? the other alternative put by professor kolliker--the passage of fecundated ova in the course of their development into higher forms--would, if it occurred, be merely an extreme case of variation in the darwinian sense, greater in degree than, but perfectly similar in kind to, that which occurred when the well-known ancon ram was developed from an ordinary ewe's ovum. indeed we have always thought that mr. darwin has unnecessarily hampered himself by adhering so strictly to his favourite "natura non facit saltum." we greatly suspect that she does make considerable jumps in the way of variation now and then, and that these saltations give rise to some of the gaps which appear to exist in the series of known forms. strongly and freely as we have ventured to disagree with professor kolliker, we have always done so with regret, and we trust without violating that respect which is due, not only to his scientific eminence and to the careful study which he has devoted to the subject, but to the perfect fairness of his argumentation, and the generous appreciation of the worth of mr. darwin's labours which he always displays. it would be satisfactory to be able to say as much for m. flourens. but the perpetual secretary of the french academy of sciences deals with mr. darwin as the first napoleon would have treated an "ideologue;" and while displaying a painful weakness of logic and shallowness of information, assumes a tone of authority, which always touches upon the ludicrous, and sometimes passes the limits of good breeding. for example (p. 56):-"m. darwin continue: 'aucune distinction absolue n'a ete et ne pout etre etablie entre les especes et les varietes.' je vous ai deja dit que vous vous trompiez; une distinction absolue separe les varietes d'avec les especes." "je vous ai deja dit; moi, m. le secretaire perpetuel de l'academie des sciences: et vous 'qui n'etes rien, pas meme academicien;' what do you mean by asserting the contrary?' being devoid of the blessings of an academy in england, we are unaccustomed to see our ablest men treated in this fashion, even by a "perpetual secretary." or again, considering that if there is any one quality of mr. darwin's work to which friends and foes have alike borne witness, it is his candour and fairness in admitting and discussing objections, what is to be thought of m. flourens' assertion, that "m. darwin ne cite que les auteurs qui partagent ses opinions." (p. 40.) once more (p. 65):-"enfin l'ouvrage de m. darwin a paru. on ne peut qu'etre frappe du talent de l'auteur. mais que d'idees obscures, que d'idees fausses! quel jargon metaphysique jete mal a propos dans l'histoire naturelle, qui tombe dans le galimatias des qu'elle sort des idees claires, des idees justes! quel langage pretentieux et vide! quelles personifications pueriles et surannees! o lucidite! o solidite de l'esprit francais, que devenez-vous?" "obscure ideas," "metaphysical jargon," "pretentious and empty language," "puerile and superannuated personifications." mr. darwin has many and hot opponents on this side of the channel and in germany, but we do not recollect to have found precisely these sins in the long catalogue of those hitherto laid to his charge. it is worth while, therefore, to examine into these discoveries effected solely by the aid of the "lucidity and solidity" of the mind of m. flourens. according to m. flourens, mr. darwin's great error is that he has personified nature (p. 10), and further that he has "imagined a natural selection: he imagines afterwards that this power of selection (pouvoir d'lire) which he gives to nature is similar to the power of man. these two suppositions admitted, nothing stops him: he plays with nature as he likes, and makes her do all he pleases." (p. 6.) and this is the way m. flourens extinguishes natural selection: "voyons donc encore une fois, ce qu'il peut y avoir de fonde dans ce qu'on nomme election naturelle. "l'election naturelle n'est sous un autre nom que la nature. pour un etre organise, la nature n'est que l'organisation, ni plus ni moins. "il faudra donc aussi personnifier l'organisation, et dire que l'organisation choisit l'organisation. l'election naturelle est cette forme substantielle dont on jouait autrefois avec tant de facilite. aristote disait que 'si l'art de batir etait dans le bois, cet art agirait comme la nature.' a la place de l'art de batir m. darwin met l'election naturelle, et c'est tout un: l'un n'est pas plus chimerique que l'autre." (p.31.) and this is really all that m. flourens can make of natural selection. we have given the original, in fear lest a translation should be regarded as a travesty; but with the original before the reader, we may try to analyse the passage. "for an organized being, nature is only organization, neither more nor less." organized beings then have absolutely no relation to inorganic nature: a plant does not, depend on soil or sunshine, climate, depth in the ocean, height above it; the quantity of saline matters in water have no influence upon animal life; the substitution of carbonic acid for oxygen in our atmosphere would hurt nobody! that these are absurdities no one should know better than m. flourens; but they are logical deductions from the assertion just quoted, and from the further statement that natural selection means only that "organization chooses and selects organization." for if it be once admitted (what no sane man denies) that the chances of life of any given organism are increased by certain conditions (a) and diminished by their opposites (b), then it is mathematically certain that any change of conditions in the direction of (a) will exercise a selective influence in favour of that organism, tending to its increase and multiplication, while any change in the direction of (b) will exercise a selective influence against that organism, tending to its decrease and extinction. or, on the other hand, conditions remaining the same, let a given organism vary (and no one doubts that they do vary) in two directions: into one form (a) better fitted to cope with these conditions than the original stock, and a second (b) less well adapted to them. then it is no less certain that the conditions in question must exercise a selective influence in favour of (a) and against ( b), so that (a) will tend to predominance, and (b) to extirpation. that m. flourens should be unable to perceive the logical necessity of these simple arguments, which lie at the foundation of all mr. darwin's reasoning; that he should confound an irrefragable deduction from the observed relations of organisms to the conditions which lie around them, with a metaphysical "forme substantielle," or a chimerical personification of the powers of nature, would be incredible, were it not that other passages of his work leave no room for doubt upon the subject. "on imagine une 'election naturelle' que, pour plus de menagement, on me dit etre inconsciente, sans s'apercevoir que le contre-sens litteral est precisement la: 'election inconsciente'." (p. 52.) "j'ai deja dit ce qu'il faut penser de 'l'election naturelle'. ou 'l'election naturelle' n'est rien, ou c'est la nature: mais la nature douee 'd'election', mais la nature personnifiee: derniere erreur du dernier siecle: le xixe fait plus de personnifications." (p. 53.) m. flourens cannot imagine an unconscious selection--it is for him a contradiction in terms. did m. flourens ever visit one of the prettiest watering-places of "la belle france," the baie d'arcachon? if so, he will probably have passed through the district of the landes, and will have had an opportunity of observing the formation of "dunes" on a grand scale. what are these "dunes"? the winds and waves of the bay of biscay have not much consciousness, and yet they have with great care "selected," from among an infinity of masses of silex of all shapes and sizes, which have been submitted to their action, all the grains of sand below a certain size, and have heaped them by themselves over a great area. this sand has been "unconsciously selected" from amidst the gravel in which it first lay with as much precision as if man had "consciously selected" it by the aid of a sieve. physical geology is full of such selections--of the picking out of the soft from the hard, of the soluble from the insoluble, of the fusible from the infusible, by natural agencies to which we are certainly not in the habit of ascribing consciousness. but that which wind and sea are to a sandy beach, the sum of influences, which we term the "conditions of existence," is to living organisms. the weak are sifted out from the strong. a frosty night "selects" the hardy plants in a plantation from among the tender ones as effectually as if it were the wind, and they, the sand and pebbles, of our illustration; or, on the other hand, as if the intelligence of a gardener had been operative in cutting the weaker organisms down. the thistle, which has spread over the pampas, to the destruction of native plants, has been more effectually "selected" by the unconscious operation of natural conditions than if a thousand agriculturists had spent their time in sowing it. it is one of mr. darwin's many great services to biological science that he has demonstrated the significance of these facts. he has shown that--given variation and given change of conditions--the inevitable result is the exercise of such an influence upon organisms that one is helped and another is impeded; one tends to predominate, another to disappear; and thus the living world bears within itself, and is surrounded by, impulses towards incessant change. but the truths just stated are as certain as any other physical laws, quite independently of the truth, or falsehood, of the hypothesis which mr. darwin has based upon them; and that m. flourens, missing the substance and grasping at a shadow, should be blind to the admirable exposition of them, which mr. darwin has given, and see nothing there but a "derniere erreur du dernier siecle "--a personification of nature--leads us indeed to cry with him: "o lucidite! o solidite de l'esprit francais, que devenez-vous?" m. flourens has, in fact, utterly failed to comprehend the first principles of the doctrine which he assails so rudely. his objections to details are of the old sort, so battered and hackneyed on this side of the channel, that not even a quarterly reviewer could be induced to pick them up for the purpose of pelting mr. darwin over again. we have cuvier and the mummies; m. roulin and the domesticated animals of america; the difficulties presented by hybridism and by palaeontology; darwinism a 'rifacciamento' of de maillet and lamarck; darwinism a system without a commencement, and its author bound to believe in m. pouchet, etc. etc. how one knows it all by heart, and with what relief one reads at p. 65-"je laisse m. darwin!" but we cannot leave m. flourens without calling our readers' attention to his wonderful tenth chapter, "de la preexistence des germes et de l'epigenese," which opens thus:-"spontaneous generation is only a chimaera. this point established, two hypotheses remain: that of 'pre-existence' and that of 'epigenesis'. the one of these hypotheses has as little foundation as the other." (p. 163.) "the doctrine of 'epigenesis' is derived from harvey: following by ocular inspection the development of the new being in the windsor does, he saw each part appear successively, and taking the moment of 'appearance' for the moment of 'formation' he imagined 'epigenesis'." (p. 165.) on the contrary, says m. flourens (p. 167), "the new being is formed at a stroke ('tout d'un coup') as a whole, instantaneously; it is not formed part by part, and at different times. it is formed at once at the single 'individual' moment at which the conjunction of the male and female elements takes place." it will be observed that m. flourens uses language which cannot be mistaken. for him, the labours of von baer, of rathke, of coste, and their contemporaries and successors in germany, france, and england, are non-existent: and, as darwin "imagina" natural selection, so harvey "imagina" that doctrine which gives him an even greater claim to the veneration of posterity than his better known discovery of the circulation of the blood. language such as that we have quoted is, in fact, so preposterous, so utterly incompatible with anything but absolute ignorance of some of the best established facts, that we should have passed it over in silence had it not appeared to afford some clue to m. flourens' unhesitating, 'a priori', repudiation of all forms of the doctrine of progressive modification of living beings. he whose mind remains uninfluenced by an acquaintance with the phenomena of development, must indeed lack one of the chief motives towards the endeavour to trace a genetic relation between the different existing forms of life. those who are ignorant of geology, find no difficulty in believing that the world was made as it is; and the shepherd, untutored in history, sees no reason to regard the green mounds which indicate the site of a roman camp, as aught but part and parcel of the primeval hill-side. so m. flourens, who believes that embryos are formed "tout d'un coup," naturally finds no difficulty in conceiving that species came into existence in the same way. [footnote 1: the natural history review', 1864. 1. ueber die darwin'sche sch pfungstheorie; ein vortrag, von a. k lliker. leipzig, 1864. 2. examination du livre de m. darwin sur l'origine des especes. par p. flourens. paris, 1864.] [footnote 2: 'die radiolarien: eine monographie', p. 231.] [footnote 3: space will not allow us to give professor kolliker's arguments in detail; our readers will find a full and accurate version of them in the 'reader' for august 13th and 20th, 1864.] [footnote 4: if, on the contrary, we follow the analogy of the more complex forms of agamogenesis, such as that exhibited by some 'trematoda' and by the 'aphides', the hyaena must produce, asexually, a brood of asexual dogs, from which other sexless dogs must proceed. at the end of a certain number of terms of the series, the dogs would acquire sexes and generate young; but these young would be, not dogs, but hyaenas. in fact, we have 'demonstrated', in agamogenetic phenomena, that inevitable recurrence to the original type, which is 'asserted' to be true of variations in general, by mr. darwin's opponents; and which, if the assertion could be changed into a demonstration would, in fact, be fatal to his hypothesis.] the method by which the causes of the present and past conditions of organic nature are to be discovered.--the origination of living beings lecture iii. (of vi.), lectures to working men, at the museum of practical geology, 1863, on darwin's work: "origin of species". by thomas h. huxley in the two preceding lectures i have endeavoured to indicate to you the extent of the subject-matter of the inquiry upon which we are engaged; and now, having thus acquired some conception of the past and present phenomena of organic nature, i must now turn to that which constitutes the great problem which we have set before ourselves;--i mean, the question of what knowledge we have of the causes of these phenomena of organic nature, and how such knowledge is obtainable. here, on the threshold of the inquiry, an objection meets us. there are in the world a number of extremely worthy, well-meaning persons, whose judgments and opinions are entitled to the utmost respect on account of their sincerity, who are of opinion that vital phenomena, and especially all questions relating to the origin of vital phenomena, are questions quite apart from the ordinary run of inquiry, and are, by their very nature, placed out of our reach. they say that all these phenomena originated miraculously, or in some way totally different from the ordinary course of nature, and that therefore they conceive it to be futile, not to say presumptuous, to attempt to inquire into them. to such sincere and earnest persons, i would only say, that a question of this kind is not to be shelved upon theoretical or speculative grounds. you may remember the story of the sophist who demonstrated to diogenes in the most complete and satisfactory manner that he could not walk; that, in fact, all motion was an impossibility; and that diogenes refuted him by simply getting up and walking round his tub. so, in the same way, the man of science replies to objections of this kind, by simply getting up and walking onward, and showing what science has done and is doing--by pointing to that immense mass of facts which have been ascertained and systematized under the forms of the great doctrines of morphology, of development, of distribution, and the like. he sees an enormous mass of facts and laws relating to organic beings, which stand on the same good sound foundation as every other natural law; and therefore, with this mass of facts and laws before us, therefore, seeing that, as far as organic matters have hitherto been accessible and studied, they have shown themselves capable of yielding to scientific investigation, we may accept this as proof that order and law reign there as well as in the rest of nature; and the man of science says nothing to objectors of this sort, but supposes that we can and shall walk to a knowledge of the origin of organic nature, in the same way that we have walked to a knowledge of the laws and principles of the inorganic world. but there are objectors who say the same from ignorance and ill-will. to such i would reply that the objection comes ill from them, and that the real presumption, i may almost say the real blasphemy, in this matter, is in the attempt to limit that inquiry into the causes of phenomena which is the source of all human blessings, and from which has sprung all human prosperity and progress; for, after all, we can accomplish comparatively little; the limited range of our own faculties bounds us on every side,--the field of our powers of observation is small enough, and he who endeavours to narrow the sphere of our inquiries is only pursuing a course that is likely to produce the greatest harm to his fellow-men. but now, assuming, as we all do, i hope, that these phenomena are properly accessible to inquiry, and setting out upon our search into the causes of the phenomena of organic nature, or, at any rate, setting out to discover how much we at present know upon these abstruse matters, the question arises as to what is to be our course of proceeding, and what method we must lay down for our guidance. i reply to that question, that our method must be exactly the same as that which is pursued in any other scientific inquiry, the method of scientific investigation being the same for all orders of facts and phenomena whatsoever. i must dwell a little on this point, for i wish you to leave this room with a very clear conviction that scientific investigation is not, as many people seem to suppose, some kind of modern black art. i say that you might easily gather this impression from the manner in which many persons speak of scientific inquiry, or talk about inductive and deductive philosophy, or the principles of the "baconian philosophy." i do protest that, of the vast number of cants in this world, there are none, to my mind, so contemptible as the pseudoscientific cant which is talked about the "baconian philosophy." to hear people talk about the great chancellor--and a very great man he certainly was,--you would think that it was he who had invented science, and that there was no such thing as sound reasoning before the time of queen elizabeth. of course you say, that cannot possibly be true; you perceive, on a moment's reflection, that such an idea is absurdly wrong, and yet, so firmly rooted is this sort of impression,--i cannot call it an idea, or conception,--the thing is too absurd to be entertained,--but so completely does it exist at the bottom of most men's minds, that this has been a matter of observation with me for many years past. there are many men who, though knowing absolutely nothing of the subject with which they may be dealing, wish, nevertheless, to damage the author of some view with which they think fit to disagree. what they do, then, is not to go and learn something about the subject, which one would naturally think the best way of fairly dealing with it; but they abuse the originator of the view they question, in a general manner, and wind up by saying that, "after all, you know, the principles and method of this author are totally opposed to the canons of the baconian philosophy." then everybody applauds, as a matter of course, and agrees that it must be so. but if you were to stop them all in the middle of their applause, you would probably find that neither the speaker nor his applauders could tell you how or in what way it was so; neither the one nor the other having the slightest idea of what they mean when they speak of the "baconian philosophy." you will understand, i hope, that i have not the slightest desire to join in the outcry against either the morals, the intellect, or the great genius of lord chancellor bacon. he was undoubtedly a very great man, let people say what they will of him; but notwithstanding all that he did for philosophy, it would be entirely wrong to suppose that the methods of modern scientific inquiry originated with him, or with his age; they originated with the first man, whoever he was; and indeed existed long before him, for many of the essential processes of reasoning are exerted by the higher order of brutes as completely and effectively as by ourselves. we see in many of the brute creation the exercise of one, at least, of the same powers of reasoning as that which we ourselves employ. the method of scientific investigation is nothing but the expression of the necessary mode of working of the human mind. it is simply the mode at which all phenomena are reasoned about, rendered precise and exact. there is no more difference, but there is just the same kind of difference, between the mental operations of a man of science and those of an ordinary person, as there is between the operations and methods of a baker or of a butcher weighing out his goods in common scales, and the operations of a chemist in performing a difficult and complex analysis by means of his balance and finely-graduated weights. it is not that the action of the scales in the one case, and the balance in the other, differ in the principles of their construction or manner of working; but the beam of one is set on an infinitely finer axis than the other, and of course turns by the addition of a much smaller weight. you will understand this better, perhaps, if i give you some familiar example. you have all heard it repeated, i dare say, that men of science work by means of induction and deduction, and that by the help of these operations, they, in a sort of sense, wring from nature certain other things, which are called natural laws, and causes, and that out of these, by some cunning skill of their own, they build up hypotheses and theories. and it is imagined by many, that the operations of the common mind can be by no means compared with these processes, and that they have to be acquired by a sort of special apprenticeship to the craft. to hear all these large words, you would think that the mind of a man of science must be constituted differently from that of his fellow men; but if you will not be frightened by terms, you will discover that you are quite wrong, and that all these terrible apparatus are being used by yourselves every day and every hour of your lives. there is a well-known incident in one of moliere's plays, where the author makes the hero express unbounded delight on being told that he had been talking prose during the whole of his life. in the same way, i trust, that you will take comfort, and be delighted with yourselves, on the discovery that you have been acting on the principles of inductive and deductive philosophy during the same period. probably there is not one here who has not in the course of the day had occasion to set in motion a complex train of reasoning, of the very same kind, though differing of course in degree, as that which a scientific man goes through in tracing the causes of natural phenomena. a very trivial circumstance will serve to exemplify this. suppose you go into a fruiterer's shop, wanting an apple,--you take up one, and, on biting it, you find it is sour; you look at it, and see that it is hard and green. you take up another one, and that too is hard, green, and sour. the shopman offers you a third; but, before biting it, you examine it, and find that it is hard and green, and you immediately say that you will not have it, as it must be sour, like those that you have already tried. nothing can be more simple than that, you think; but if you will take the trouble to analyze and trace out into its logical elements what has been done by the mind, you will be greatly surprised. in the first place, you have performed the operation of induction. you found that, in two experiences, hardness and greenness in apples go together with sourness. it was so in the first case, and it was confirmed by the second. true, it is a very small basis, but still it is enough to make an induction from; you generalize the facts, and you expect to find sourness in apples where you get hardness and greenness. you found upon that a general law, that all hard and green apples are sour; and that, so far as it goes, is a perfect induction. well, having got your natural law in this way, when you are offered another apple which you find is hard and green, you say, "all hard and green apples are sour; this apple is hard and green, therefore this apple is sour." that train of reasoning is what logicians call a syllogism, and has all its various parts and terms,--its major premiss, its minor premiss, and its conclusion. and, by the help of further reasoning, which, if drawn out, would have to be exhibited in two or three other syllogisms, you arrive at your final determination, "i will not have that apple." so that, you see, you have, in the first place, established a law by induction, and upon that you have founded a deduction, and reasoned out the special conclusion of the particular case. well now, suppose, having got your law, that at some time afterwards, you are discussing the qualities of apples with a friend: you will say to him, "it is a very curious thing,--but i find that all hard and green apples are sour!" your friend says to you, "but how do you know that?" you at once reply, "oh, because i have tried it over and over again, and have always found them to be so." well, if we were talking science instead of common sense, we should call that an experimental verification. and, if still opposed, you go further, and say, "i have heard from the people in somersetshire and devonshire, where a large number of apples are grown, that they have observed the same thing. it is also found to be the case in normandy, and in north america. in short, i find it to be the universal experience of mankind wherever attention has been directed to the subject." whereupon, your friend, unless he is a very unreasonable man, agrees with you, and is convinced that you are quite right in the conclusion you have drawn. he believes, although perhaps he does not know he believes it, that the more extensive verifications are,--that the more frequently experiments have been made, and results of the same kind arrived at,--that the more varied the conditions under which the same results have been attained, the more certain is the ultimate conclusion, and he disputes the question no further. he sees that the experiment has been tried under all sorts of conditions, as to time, place, and people, with the same result; and he says with you, therefore, that the law you have laid down must be a good one, and he must believe it. in science we do the same thing;--the philosopher exercises precisely the same faculties, though in a much more delicate manner. in scientific inquiry it becomes a matter of duty to expose a supposed law to every possible kind of verification, and to take care, moreover, that this is done intentionally, and not left to a mere accident, as in the case of the apples. and in science, as in common life, our confidence in a law is in exact proportion to the absence of variation in the result of our experimental verifications. for instance, if you let go your grasp of an article you may have in your hand, it will immediately fall to the ground. that is a very common verification of one of the best established laws of nature--that of gravitation. the method by which men of science establish the existence of that law is exactly the same as that by which we have established the trivial proposition about the sourness of hard and green apples. but we believe it in such an extensive, thorough, and unhesitating manner because the universal experience of mankind verifies it, and we can verify it ourselves at any time; and that is the strongest possible foundation on which any natural law can rest. so much by way of proof that the method of establishing laws in science is exactly the same as that pursued in common life. let us now turn to another matter (though really it is but another phase of the same question), and that is, the method by which, from the relations of certain phenomena, we prove that some stand in the position of causes towards the others. i want to put the case clearly before you, and i will therefore show you what i mean by another familiar example. i will suppose that one of you, on coming down in the morning to the parlour of your house, finds that a tea-pot and some spoons which had been left in the room on the previous evening are gone,--the window is open, and you observe the mark of a dirty hand on the window-frame, and perhaps, in addition to that, you notice the impress of a hob-nailed shoe on the gravel outside. all these phenomena have struck your attention instantly, and before two minutes have passed you say, "oh, somebody has broken open the window, entered the room, and run off with the spoons and the tea-pot!" that speech is out of your mouth in a moment. and you will probably add, "i know there has; i am quite sure of it!" you mean to say exactly what you know; but in reality what you have said has been the expression of what is, in all essential particulars, an hypothesis. you do not 'know' it at all; it is nothing but an hypothesis rapidly framed in your own mind! and it is an hypothesis founded on a long train of inductions and deductions. what are those inductions and deductions, and how have you got at this hypothesis? you have observed, in the first place, that the window is open; but by a train of reasoning involving many inductions and deductions, you have probably arrived long before at the general law--and a very good one it is--that windows do not open of themselves; and you therefore conclude that something has opened the window. a second general law that you have arrived at in the same way is, that tea-pots and spoons do not go out of a window spontaneously, and you are satisfied that, as they are not now where you left them, they have been removed. in the third place, you look at the marks on the window-sill, and the shoemarks outside, and you say that in all previous experience the former kind of mark has never been produced by anything else but the hand of a human being; and the same experience shows that no other animal but man at present wears shoes with hob-nails on them such as would produce the marks in the gravel. i do not know, even if we could discover any of those "missing links" that are talked about, that they would help us to any other conclusion! at any rate the law which states our present experience is strong enough for my present purpose.--you next reach the conclusion, that as these kinds of marks have not been left by any other animals than men, or are liable to be formed in any other way than by a man's hand and shoe, the marks in question have been formed by a man in that way. you have, further, a general law, founded on observation and experience, and that, too, is, i am sorry to say, a very universal and unimpeachable one,--that some men are thieves; and you assume at once from all these premisses--and that is what constitutes your hypothesis--that the man who made the marks outside and on the window-sill, opened the window, got into the room, and stole your tea-pot and spoons. you have now arrived at a 'vera causa';--you have assumed a cause which it is plain is competent to produce all the phenomena you have observed. you can explain all these phenomena only by the hypothesis of a thief. but that is a hypothetical conclusion, of the justice of which you have no absolute proof at all; it is only rendered highly probable by a series of inductive and deductive reasonings. i suppose your first action, assuming that you are a man of ordinary common sense, and that you have established this hypothesis to your own satisfaction, will very likely be to go off for the police, and set them on the track of the burglar, with the view to the recovery of your property. but just as you are starting with this object, some person comes in, and on learning what you are about, says, "my good friend, you are going on a great deal too fast. how do you know that the man who really made the marks took the spoons? it might have been a monkey that took them, and the man may have merely looked in afterwards." you would probably reply, "well, that is all very well, but you see it is contrary to all experience of the way tea-pots and spoons are abstracted; so that, at any rate, your hypothesis is less probable than mine." while you are talking the thing over in this way, another friend arrives, one of that good kind of people that i was talking of a little while ago. and he might say, "oh, my dear sir, you are certainly going on a great deal too fast. you are most presumptuous. you admit that all these occurrences took place when you were fast asleep, at a time when you could not possibly have known anything about what was taking place. how do you know that the laws of nature are not suspended during the night? it may be that there has been some kind of supernatural interference in this case." in point of fact, he declares that your hypothesis is one of which you cannot at all demonstrate the truth, and that you are by no means sure that the laws of nature are the same when you are asleep as when you are awake. well, now, you cannot at the moment answer that kind of reasoning. you feel that your worthy friend has you somewhat at a disadvantage. you will feel perfectly convinced in your own mind, however, that you are quite right, and you say to him, "my good friend, i can only be guided by the natural probabilities of the case, and if you will be kind enough to stand aside and permit me to pass, i will go and fetch the police." well, we will suppose that your journey is successful, and that by good luck you meet with a policeman; that eventually the burglar is found with your property on his person, and the marks correspond to his hand and to his boots. probably any jury would consider those facts a very good experimental verification of your hypothesis, touching the cause of the abnormal phenomena observed in your parlour, and would act accordingly. now, in this suppositious case, i have taken phenomena of a very common kind, in order that you might see what are the different steps in an ordinary process of reasoning, if you will only take the trouble to analyse it carefully. all the operations i have described, you will see, are involved in the mind of any man of sense in leading him to a conclusion as to the course he should take in order to make good a robbery and punish the offender. i say that you are led, in that case, to your conclusion by exactly the same train of reasoning as that which a man of science pursues when he is endeavouring to discover the origin and laws of the most occult phenomena. the process is, and always must be, the same; and precisely the same mode of reasoning was employed by newton and laplace in their endeavours to discover and define the causes of the movements of the heavenly bodies, as you, with your own common sense, would employ to detect a burglar. the only difference is, that the nature of the inquiry being more abstruse, every step has to be most carefully watched, so that there may not be a single crack or flaw in your hypothesis. a flaw or crack in many of the hypotheses of daily life may be of little or no moment as affecting the general correctness of the conclusions at which we may arrive; but, in a scientific inquiry, a fallacy, great or small, is always of importance, and is sure to be constantly productive of mischievous, if not fatal results. do not allow yourselves to be misled by the common notion that an hypothesis is untrustworthy simply because it is an hypothesis. it is often urged, in respect to some scientific conclusion, that, after all, it is only an hypothesis. but what more have we to guide us in nine-tenths of the most important affairs of daily life than hypotheses, and often very ill-based ones? so that in science, where the evidence of an hypothesis is subjected to the most rigid examination, we may rightly pursue the same course. you may have hypotheses and hypotheses. a man may say, if he likes, that the moon is made of green cheese: that is an hypothesis. but another man, who has devoted a great deal of time and attention to the subject, and availed himself of the most powerful telescopes and the results of the observations of others, declares that in his opinion it is probably composed of materials very similar to those of which our own earth is made up: and that is also only an hypothesis. but i need not tell you that there is an enormous difference in the value of the two hypotheses. that one which is based on sound scientific knowledge is sure to have a corresponding value; and that which is a mere hasty random guess is likely to have but little value. every great step in our progress in discovering causes has been made in exactly the same way as that which i have detailed to you. a person observing the occurrence of certain facts and phenomena asks, naturally enough, what process, what kind of operation known to occur in nature applied to the particular case, will unravel and explain the mystery? hence you have the scientific hypothesis; and its value will be proportionate to the care and completeness with which its basis had been tested and verified. it is in these matters as in the commonest affairs of practical life: the guess of the fool will be folly, while the guess of the wise man will contain wisdom. in all cases, you see that the value of the result depends on the patience and faithfulness with which the investigator applies to his hypothesis every possible kind of verification. i dare say i may have to return to this point by-and-by; but having dealt thus far with our logical methods, i must now turn to something which, perhaps, you may consider more interesting, or, at any rate, more tangible. but in reality there are but few things that can be more important for you to understand than the mental processes and the means by which we obtain scientific conclusions and theories. [1] having granted that the inquiry is a proper one, and having determined on the nature of the methods we are to pursue and which only can lead to success, i must now turn to the consideration of our knowledge of the nature of the processes which have resulted in the present condition of organic nature. here, let me say at once, lest some of you misunderstand me, that i have extremely little to report. the question of how the present condition of organic nature came about, resolves itself into two questions. the first is: how has organic or living matter commenced its existence? and the second is: how has it been perpetuated? on the second question i shall have more to say hereafter. but on the first one, what i now have to say will be for the most part of a negative character. if you consider what kind of evidence we can have upon this matter, it will resolve itself into two kinds. we may have historical evidence and we may have experimental evidence. it is, for example, conceivable, that inasmuch as the hardened mud which forms a considerable portion of the thickness of the earth's crust contains faithful records of the past forms of life, and inasmuch as these differ more and more as we go further down,--it is possible and conceivable that we might come to some particular bed or stratum which should contain the remains of those creatures with which organic life began upon the earth. and if we did so, and if such forms of organic life were preservable, we should have what i would call historical evidence of the mode in which organic life began upon this planet. many persons will tell you, and indeed you will find it stated in many works on geology, that this has been done, and that we really possess such a record; there are some who imagine that the earliest forms of life of which we have as yet discovered any record, are in truth the forms in which animal life began upon the globe. the grounds on which they base that supposition are these:--that if you go through the enormous thickness of the earth's crust and get down to the older rocks, the higher vertebrate animals--the quadrupeds, birds, and fishes--cease to be found; beneath them you find only the invertebrate animals; and in the deepest and lowest rocks those remains become scantier and scantier, not in any very gradual progression, however, until, at length, in what are supposed to be the oldest rocks, the animal remains which are found are almost always confined to four forms--'oldhamia', whose precise nature is not known, whether plant or animal; 'lingula', a kind of mollusc; 'trilobites', a crustacean animal, having the same essential plan of construction, though differing in many details from a lobster or crab; and hymenocaris, which is also a crustacean. so that you have all the 'fauna' reduced, at this period, to four forms: one a kind of animal or plant that we know nothing about, and three undoubted animals--two crustaceans and one mollusc. i think, considering the organization of these mollusca and crustacea, and looking at their very complex nature, that it does indeed require a very strong imagination to conceive that these were the first created of all living things. and you must take into consideration the fact that we have not the slightest proof that these which we call the oldest beds are really so: i repeat, we have not the slightest proof of it. when you find in some places that in an enormous thickness of rocks there are but very scanty traces of life, or absolutely none at all; and that in other parts of the world rocks of the very same formation are crowded with the records of living forms, i think it is impossible to place any reliance on the supposition, or to feel oneself justified in supposing that these are the forms in which life first commenced. i have not time here to enter upon the technical grounds upon which i am led to this conclusion,--that could hardly be done properly in half a dozen lectures on that part alone;--i must content myself with saying that i do not at all believe that these are the oldest forms of life. i turn to the experimental side to see what evidence we have there. to enable us to say that we know anything about the experimental origination of organization and life, the investigator ought to be able to take inorganic matters, such as carbonic acid, ammonia, water, and salines, in any sort of inorganic combination, and be able to build them up into protein matter, and that that protein matter ought to begin to live in an organic form. that, nobody has done as yet, and i suspect it will be a long while before anybody does do it. but the thing is by no means so impossible as it looks; for the researches of modern chemistry have shown us--i won't say the road towards it, but, if i may so say, they have shown the finger-post pointing to the road that may lead to it. it is not many years ago--and you must recollect that organic chemistry is a young science, not above a couple of generations old,--you must not expect too much of it; it is not many years ago since it was said to be perfectly impossible to fabricate any organic compound; that is to say, any non-mineral compound which is to be found in an organized being. it remained so for a very long period; but it is now a considerable number of years since a distinguished foreign chemist contrived to fabricate urea, a substance of a very complex character, which forms one of the waste products of animal structures. and of late years a number of other compounds, such as butyric acid, and others, have been added to the list. i need not tell you that chemistry is an enormous distance from the goal i indicate; all i wish to point out to you is, that it is by no means safe to say that that goal may not be reached one day. it may be that it is impossible for us to produce the conditions requisite to the origination of life; but we must speak modestly about the matter, and recollect that science has put her foot upon the bottom round of the ladder. truly he would be a bold man who would venture to predict where she will be fifty years hence. there is another inquiry which bears indirectly upon this question, and upon which i must say a few words. you are all of you aware of the phenomena of what is called spontaneous generation. our forefathers, down to the seventeenth century, or thereabouts, all imagined, in perfectly good faith, that certain vegetable and animal forms gave birth, in the process of their decomposition, to insect life. thus, if you put a piece of meat in the sun, and allowed it to putrefy, they conceived that the grubs which soon began to appear were the result of the action of a power of spontaneous generation which the meat contained. and they could give you receipts for making various animal and vegetable preparations which would produce particular kinds of animals. a very distinguished italian naturalist, named redi, took up the question, at a time when everybody believed in it; among others our own great harvey, the discoverer of the circulation of the blood. you will constantly find his name quoted, however, as an opponent of the doctrine of spontaneous generation; but the fact is, and you will see it if you will take the trouble to look into his works, harvey believed it as profoundly as any man of his time; but he happened to enunciate a very curious proposition--that every living thing came from an 'egg'; he did not mean to use the word in the sense in which we now employ it, he only meant to say that every living thing originated in a little rounded particle of organized substance; and it is from this circumstance, probably, that the notion of harvey having opposed the doctrine originated. then came redi, and he proceeded to upset the doctrine in a very simple manner. he merely covered the piece of meat with some very fine gauze, and then he exposed it to the same conditions. the result of this was that no grubs or insects were produced; he proved that the grubs originated from the insects who came and deposited their eggs in the meat, and that they were hatched by the heat of the sun. by this kind of inquiry he thoroughly upset the doctrine of spontaneous generation, for his time at least. then came the discovery and application of the microscope to scientific inquiries, which showed to naturalists that besides the organisms which they already knew as living beings and plants, there were an immense number of minute things which could be obtained apparently almost at will from decaying vegetable and animal forms. thus, if you took some ordinary black pepper or some hay, and steeped it in water, you would find in the course of a few days that the water had become impregnated with an immense number of animalcules swimming about in all directions. from facts of this kind naturalists were led to revive the theory of spontaneous generation. they were headed here by an english naturalist,--needham,--and afterwards in france by the learned buffon. they said that these things were absolutely begotten in the water of the decaying substances out of which the infusion was made. it did not matter whether you took animal or vegetable matter, you had only to steep it in water and expose it, and you would soon have plenty of animalcules. they made an hypothesis about this which was a very fair one. they said, this matter of the animal world, or of the higher plants, appears to be dead, but in reality it has a sort of dim life about it, which, if it is placed under fair conditions, will cause it to break up into the forms of these little animalcules, and they will go through their lives in the same way as the animal or plant of which they once formed a part. the question now became very hotly debated. spallanzani, an italian naturalist, took up opposite views to those of needham and buffon, and by means of certain experiments he showed that it was quite possible to stop the process by boiling the water, and closing the vessel in which it was contained. "oh!" said his opponents; "but what do you know you may be doing when you heat the air over the water in this way? you may be destroying some property of the air requisite for the spontaneous generation of the animalcules." however, spallanzani's views were supposed to be upon the right side, and those of the others fell into discredit; although the fact was that spallanzani had not made good his views. well, then, the subject continued to be revived from time to time, and experiments were made by several persons; but these experiments were not altogether satisfactory. it was found that if you put an infusion in which animalcules would appear if it were exposed to the air into a vessel and boiled it, and then sealed up the mouth of the vessel, so that no air, save such as had been heated to 212 degrees, could reach its contents, that then no animalcules would be found; but if you took the same vessel and exposed the infusion to the air, then you would get animalcules. furthermore, it was found that if you connected the mouth of the vessel with a red-hot tube in such a way that the air would have to pass through the tube before reaching the infusion, that then you would get no animalcules. yet another thing was noticed: if you took two flasks containing the same kind of infusion, and left one entirely exposed to the air, and in the mouth of the other placed a ball of cotton wool, so that the air would have to filter itself through it before reaching the infusion, that then, although you might have plenty of animalcules in the first flask, you would certainly obtain none from the second. these experiments, you see, all tended towards one conclusion--that the infusoria were developed from little minute spores or eggs which were constantly floating in the atmosphere, which lose their power of germination if subjected to heat. but one observer now made another experiment which seemed to go entirely the other way, and puzzled him altogether. he took some of this boiled infusion that i have been speaking of, and by the use of a mercurial bath--a kind of trough used in laboratories--he deftly inverted a vessel containing the infusion into the mercury, so that the latter reached a little beyond the level of the mouth of the 'inverted' vessel. you see that he thus had a quantity of the infusion shut off from any possible communication with the outer air by being inverted upon a bed of mercury. he then prepared some pure oxygen and nitrogen gases, and passed them by means of a tube going from the outside of the vessel, up through the mercury into the infusion; so that he thus had it exposed to a perfectly pure atmosphere of the same constituents as the external air. of course, he expected he would get no infusorial animalcules at all in that infusion; but, to his great dismay and discomfiture, he found he almost always did get them. furthermore, it has been found that experiments made in the manner described above answer well with most infusions; but that if you fill the vessel with boiled milk, and then stop the neck with cotton-wool, you 'will' have infusoria. so that you see there were two experiments that brought you to one kind of conclusion, and three to another; which was a most unsatisfactory state of things to arrive at in a scientific inquiry. some few years after this, the question began to be very hotly discussed in france. there was m. pouchet, a professor at rouen, a very learned man, but certainly not a very rigid experimentalist. he published a number of experiments of his own, some of which were very ingenious, to show that if you went to work in a proper way, there was a truth in the doctrine of spontaneous generation. well, it was one of the most fortunate things in the world that m. pouchet took up this question, because it induced a distinguished french chemist, m. pasteur, to take up the question on the other side; and he has certainly worked it out in the most perfect manner. i am glad to say, too, that he has published his researches in time to enable me to give you an account of them. he verified all the experiments which i have just mentioned to you--and then finding those extraordinary anomalies, as in the case of the mercury bath and the milk, he set himself to work to discover their nature. in the case of milk he found it to be a question of temperature. milk in a fresh state is slightly alkaline; and it is a very curious circumstance, but this very slight degree of alkalinity seems to have the effect of preserving the organisms which fall into it from the air from being destroyed at a temperature of 212 degrees, which is the boiling point. but if you raise the temperature 10 degrees when you boil it, the milk behaves like everything else; and if the air with which it comes in contact, after being boiled at this temperature, is passed through a red-hot tube, you will not get a trace of organisms. he then turned his attention to the mercury bath, and found on examination that the surface of the mercury was almost always covered with a very fine dust. he found that even the mercury itself was positively full of organic matters; that from being constantly exposed to the air, it had collected an immense number of these infusorial organisms from the air. well, under these circumstances he felt that the case was quite clear, and that the mercury was not what it had appeared to m. schwann to be,--a bar to the admission of these organisms; but that, in reality, it acted as a reservoir from which the infusion was immediately supplied with the large quantity that had so puzzled him. but not content with explaining the experiments of others, m. pasteur went to work to satisfy himself completely. he said to himself: "if my view is right, and if, in point of fact, all these appearances of spontaneous generation are altogether due to the falling of minute germs suspended in the atmosphere,--why, i ought not only to be able to show the germs, but i ought to be able to catch and sow them, and produce the resulting organisms." he, accordingly, constructed a very ingenious apparatus to enable him to accomplish this trapping of this "germ dust" in the air. he fixed in the window of his room a glass tube, in the centre of which he had placed a ball of gun-cotton, which, as you all know, is ordinary cotton-wool, which, from having been steeped in strong acid, is converted into a substance of great explosive power. it is also soluble in alcohol and ether. one end of the glass tube was, of course, open to the external air; and at the other end of it he placed an aspirator, a contrivance for causing a current of the external air to pass through the tube. he kept this apparatus going for four-and-twenty hours, and then removed the 'dusted' gun-cotton, and dissolved it in alcohol and ether. he then allowed this to stand for a few hours, and the result was, that a very fine dust was gradually deposited at the bottom of it. that dust, on being transferred to the stage of a microscope, was found to contain an enormous number of starch grains. you know that the materials of our food and the greater portion of plants are composed of starch, and we are constantly making use of it in a variety of ways, so that there is always a quantity of it suspended in the air. it is these starch grains which form many of those bright specks that we see dancing in a ray of light sometimes. but besides these, m. pasteur found also an immense number of other organic substances such as spores of fungi, which had been floating about in the air and had got caged in this way. he went farther, and said to himself, "if these really are the things that give rise to the appearance of spontaneous generation, i ought to be able to take a ball of this 'dusted' gun-cotton and put it into one of my vessels, containing that boiled infusion which has been kept away from the air, and in which no infusoria are at present developed, and then, if i am right, the introduction of this gun-cotton will give rise to organisms." accordingly, he took one of these vessels of infusion, which had been kept eighteen months, without the least appearance of life, and by a most ingenious contrivance, he managed to break it open and introduce such a ball of gun-cotton, without allowing the infusion or the cotton ball to come into contact with any air but that which had been subjected to a red heat, and in twenty-four hours he had the satisfaction of finding all the indications of what had been hitherto called spontaneous generation. he had succeeded in catching the germs and developing organisms in the way he had anticipated. it now struck him that the truth of his conclusions might be demonstrated without all the apparatus he had employed. to do this, he took some decaying animal or vegetable substance, such as urine, which is an extremely decomposable substance, or the juice of yeast, or perhaps some other artificial preparation, and filled a vessel having a long tubular neck with it. he then boiled the liquid and bent that long neck into an s shape or zig-zag, leaving it open at the end. the infusion then gave no trace of any appearance of spontaneous generation, however long it might be left, as all the germs in the air were deposited in the beginning of the bent neck. he then cut the tube close to the vessel, and allowed the ordinary air to have free and direct access; and the result of that was the appearance of organisms in it, as soon as the infusion had been allowed to stand long enough to allow of the growth of those it received from the air, which was about forty-eight hours. the result of m. pasteur's experiments proved, therefore, in the most conclusive manner, that all the appearances of spontaneous generation arose from nothing more than the deposition of the germs of organisms which were constantly floating in the air. to this conclusion, however, the objection was made, that if that were the cause, then the air would contain such an enormous number of these germs, that it would be a continual fog. but m. pasteur replied that they are not there in anything like the number we might suppose, and that an exaggerated view has been held on that subject; he showed that the chances of animal or vegetable life appearing in infusions, depend entirely on the conditions under which they are exposed. if they are exposed to the ordinary atmosphere around us, why, of course, you may have organisms appearing early. but, on the other hand, if they are exposed to air from a great height, or from some very quiet cellar, you will often not find a single trace of life. so that m. pasteur arrived at last at the clear and definite result, that all these appearances are like the case of the worms in the piece of meat, which was refuted by redi, simply germs carried by the air and deposited in the liquids in which they afterwards appear. for my own part, i conceive that, with the particulars of m. pasteur's experiments before us, we cannot fail to arrive at his conclusions; and that the doctrine of spontaneous generation has received a final 'coup de grace'. you, of course, understand that all this in no way interferes with the 'possibility' of the fabrication of organic matters by the direct method to which i have referred, remote as that possibility may be. [footnote 1: those who wish to study fully the doctrines of which i have endeavoured to give some rough and ready illustrations, must read mr. john stuart mill's 'system of logic'.] on the reception of the 'origin of species' by professor thomas henry huxley from the life and letters of charles darwin edited by francis darwin on the reception of the 'origin of species.' to the present generation, that is to say, the people a few years on the hither and thither side of thirty, the name of charles darwin stands alongside of those of isaac newton and michael faraday; and, like them, calls up the grand ideal of a searcher after truth and interpreter of nature. they think of him who bore it as a rare combination of genius, industry, and unswerving veracity, who earned his place among the most famous men of the age by sheer native power, in the teeth of a gale of popular prejudice, and uncheered by a sign of favour or appreciation from the official fountains of honour; as one who in spite of an acute sensitiveness to praise and blame, and notwithstanding provocations which might have excused any outbreak, kept himself clear of all envy, hatred, and malice, nor dealt otherwise than fairly and justly with the unfairness and injustice which was showered upon him; while, to the end of his days, he was ready to listen with patience and respect to the most insignificant of reasonable objectors. and with respect to that theory of the origin of the forms of life peopling our globe, with which darwin's name is bound up as closely as that of newton with the theory of gravitation, nothing seems to be further from the mind of the present generation than any attempt to smother it with ridicule or to crush it by vehemence of denunciation. "the struggle for existence," and "natural selection," have become household words and every-day conceptions. the reality and the importance of the natural processes on which darwin founds his deductions are no more doubted than those of growth and multiplication; and, whether the full potency attributed to them is admitted or not, no one doubts their vast and far-reaching significance. wherever the biological sciences are studied, the 'origin of species' lights the paths of the investigator; wherever they are taught it permeates the course of instruction. nor has the influence of darwinian ideas been less profound, beyond the realms of biology. the oldest of all philosophies, that of evolution, was bound hand and foot and cast into utter darkness during the millennium of theological scholasticism. but darwin poured new life-blood into the ancient frame; the bonds burst, and the revivified thought of ancient greece has proved itself to be a more adequate expression of the universal order of things than any of the schemes which have been accepted by the credulity and welcomed by the superstition of seventy later generations of men. to any one who studies the signs of the times, the emergence of the philosophy of evolution, in the attitude of claimant to the throne of the world of thought, from the limbo of hated and, as many hoped, forgotten things, is the most portentous event of the nineteenth century. but the most effective weapons of the modern champions of evolution were fabricated by darwin; and the 'origin of species' has enlisted a formidable body of combatants, trained in the severe school of physical science, whose ears might have long remained deaf to the speculations of a priori philosophers. i do not think any candid or instructed person will deny the truth of that which has just been asserted. he may hate the very name of evolution, and may deny its pretensions as vehemently as a jacobite denied those of george the second. but there it is--not only as solidly seated as the hanoverian dynasty, but happily independent of parliamentary sanction--and the dullest antagonists have come to see that they have to deal with an adversary whose bones are to be broken by no amount of bad words. even the theologians have almost ceased to pit the plain meaning of genesis against the no less plain meaning of nature. their more candid, or more cautious, representatives have given up dealing with evolution as if it were a damnable heresy, and have taken refuge in one of two courses. either they deny that genesis was meant to teach scientific truth, and thus save the veracity of the record at the expense of its authority; or they expend their energies in devising the cruel ingenuities of the reconciler, and torture texts in the vain hope of making them confess the creed of science. but when the peine forte et dure is over, the antique sincerity of the venerable sufferer always reasserts itself. genesis is honest to the core, and professes to be no more than it is, a repository of venerable traditions of unknown origin, claiming no scientific authority and possessing none. as my pen finishes these passages, i can but be amused to think what a terrible hubbub would have been made (in truth was made) about any similar expressions of opinion a quarter of a century ago. in fact, the contrast between the present condition of public opinion upon the darwinian question; between the estimation in which darwin's views are now held in the scientific world; between the acquiescence, or at least quiescence, of the theologians of the self-respecting order at the present day and the outburst of antagonism on all sides in 1858-9, when the new theory respecting the origin of species first became known to the older generation to which i belong, is so startling that, except for documentary evidence, i should be sometimes inclined to think my memories dreams. i have a great respect for the younger generation myself (they can write our lives, and ravel out all our follies, if they choose to take the trouble, by and by), and i should be glad to be assured that the feeling is reciprocal; but i am afraid that the story of our dealings with darwin may prove a great hindrance to that veneration for our wisdom which i should like them to display. we have not even the excuse that, thirty years ago, mr. darwin was an obscure novice, who had no claims on our attention. on the contrary, his remarkable zoological and geological investigations had long given him an assured position among the most eminent and original investigators of the day; while his charming 'voyage of a naturalist' had justly earned him a wide-spread reputation among the general public. i doubt if there was any man then living who had a better right to expect that anything he might choose to say on such a question as the origin of species would be listened to with profound attention, and discussed with respect; and there was certainly no man whose personal character should have afforded a better safeguard against attacks, instinct with malignity and spiced with shameless impertinences. yet such was the portion of one of the kindest and truest men that it was ever my good fortune to know; and years had to pass away before misrepresentation, ridicule, and denunciation, ceased to be the most notable constituents of the majority of the multitudinous criticisms of his work which poured from the press. i am loth to rake any of these ancient scandals from their well-deserved oblivion; but i must make good a statement which may seem overcharged to the present generation, and there is no piece justificative more apt for the purpose, or more worthy of such dishonour, than the article in the 'quarterly review' for july, 1860. (i was not aware when i wrote these passages that the authorship of the article had been publicly acknowledged. confession unaccompanied by penitence, however, affords no ground for mitigation of judgment; and the kindliness with which mr. darwin speaks of his assailant, bishop wilberforce (vol. ii.), is so striking an exemplification of his singular gentleness and modesty, that it rather increases one's indignation against the presumption of his critic.) since lord brougham assailed dr. young, the world has seen no such specimen of the insolence of a shallow pretender to a master in science as this remarkable production, in which one of the most exact of observers, most cautious of reasoners, and most candid of expositors, of this or any other age, is held up to scorn as a "flighty" person, who endeavours "to prop up his utterly rotten fabric of guess and speculation," and whose "mode of dealing with nature" is reprobated as "utterly dishonourable to natural science." and all this high and mighty talk, which would have been indecent in one of mr. darwin's equals, proceeds from a writer whose want of intelligence, or of conscience, or of both, is so great, that, by way of an objection to mr. darwin's views, he can ask, "is it credible that all favourable varieties of turnips are tending to become men;" who is so ignorant of paleontology, that he can talk of the "flowers and fruits" of the plants of the carboniferous epoch; of comparative anatomy, that he can gravely affirm the poison apparatus of the venomous snakes to be "entirely separate from the ordinary laws of animal life, and peculiar to themselves;" of the rudiments of physiology, that he can ask, "what advantage of life could alter the shape of the corpuscles into which the blood can be evaporated?" nor does the reviewer fail to flavour this outpouring of preposterous incapacity with a little stimulation of the odium theologicum. some inkling of the history of the conflicts between astronomy, geology, and theology, leads him to keep a retreat open by the proviso that he cannot "consent to test the truth of natural science by the word of revelation;" but, for all that, he devotes pages to the exposition of his conviction that mr. darwin's theory "contradicts the revealed relation of the creation to its creator," and is "inconsistent with the fulness of his glory." if i confine my retrospect of the reception of the 'origin of species' to a twelvemonth, or thereabouts, from the time of its publication, i do not recollect anything quite so foolish and unmannerly as the 'quarterly review' article, unless, perhaps, the address of a reverend professor to the dublin geological society might enter into competition with it. but a large proportion of mr. darwin's critics had a lamentable resemblance to the 'quarterly' reviewer, in so far as they lacked either the will, or the wit, to make themselves masters of his doctrine; hardly any possessed the knowledge required to follow him through the immense range of biological and geological science which the 'origin' covered; while, too commonly, they had prejudiced the case on theological grounds, and, as seems to be inevitable when this happens, eked out lack of reason by superfluity of railing. but it will be more pleasant and more profitable to consider those criticisms, which were acknowledged by writers of scientific authority, or which bore internal evidence of the greater or less competency and, often, of the good faith, of their authors. restricting my survey to a twelvemonth, or thereabouts, after the publication of the 'origin,' i find among such critics louis agassiz ("the arguments presented by darwin in favor of a universal derivation from one primary form of all the peculiarities existing now among living beings have not made the slightest impression on my mind." "until the facts of nature are shown to have been mistaken by those who have collected them, and that they have a different meaning from that now generally assigned to them, i shall therefore consider the transmutation theory as a scientific mistake, untrue in its facts, unscientific in its method, and mischievous in its tendency."--silliman's 'journal,' july, 1860, pages 143, 154. extract from the 3rd volume of 'contributions to the natural history of the united states.'); murray, an excellent entomologist; harvey, a botanist of considerable repute; and the author of an article in the 'edinburgh review,' all strongly adverse to darwin. pictet, the distinguished and widely learned paleontogist of geneva, treats mr. darwin with a respect which forms a grateful contrast to the tone of some of the preceding writers, but consents to go with him only a very little way. ("i see no serious objections to the formation of varieties by natural selection in the existing world, and that, so far as earlier epochs are concerned, this law may be assumed to explain the origin of closely allied species, supposing for this purpose a very long period of time." "with regard to simple varieties and closely allied species, i believe that mr. darwin's theory may explain many things, and throw a great light upon numerous questions."--'sur l'origine de l'espece. par charles darwin.' 'archives des sc. de la bibliotheque universelle de geneve,' pages 242, 243, mars 1860.) on the other hand, lyell, up to that time a pillar of the anti-transmutationists (who regarded him, ever afterwards, as pallas athene may have looked at dian, after the endymion affair), declared himself a darwinian, though not without putting in a serious caveat. nevertheless, he was a tower of strength, and his courageous stand for truth as against consistency, did him infinite honour. as evolutionists, sans phrase, i do not call to mind among the biologists more than asa gray, who fought the battle splendidly in the united states; hooker, who was no less vigorous here; the present sir john lubbock and myself. wallace was far away in the malay archipelago; but, apart from his direct share in the promulgation of the theory of natural selection, no enumeration of the influences at work, at the time i am speaking of, would be complete without the mention of his powerful essay 'on the law which has regulated the introduction of new species,' which was published in 1855. on reading it afresh, i have been astonished to recollect how small was the impression it made. in france, the influence of elie de beaumont and of flourens--the former of whom is said to have "damned himself to everlasting fame" by inventing the nickname of "la science moussante" for evolutionism (one is reminded of the effect of another small academic epigram. the so-called vertebral theory of the skull is said to have been nipped in the bud in france by the whisper of an academician to his neighbour, that, in that case, one's head was a "vertebre pensante."),--to say nothing of the ill-will of other powerful members of the institut, produced for a long time the effect of a conspiracy of silence; and many years passed before the academy redeemed itself from the reproach that the name of darwin was not to be found on the list of its members. however, an accomplished writer, out of the range of academical influences, m. laugel, gave an excellent and appreciative notice of the 'origin' in the 'revue des deux mondes.' germany took time to consider; bronn produced a slightly bowdlerized translation of the 'origin'; and 'kladderadatsch' cut his jokes upon the ape origin of man; but i do not call to mind that any scientific notability declared himself publicly in 1860. (however, the man who stands next to darwin in his influence on modern biologists, k.e. von baer, wrote to me, in august 1860, expressing his general assent to evolutionist views. his phrase, "j'ai enonce les memes idees...que m. darwin" (volume ii.) is shown by his subsequent writings to mean no more than this.) none of us dreamed that, in the course of a few years, the strength (and perhaps i may add the weakness) of "darwinismus" would have its most extensive and most brilliant illustrations in the land of learning. if a foreigner may presume to speculate on the cause of this curious interval of silence, i fancy it was that one moiety of the german biologists were orthodox at any price, and the other moiety as distinctly heterodox. the latter were evolutionists, a priori, already, and they must have felt the disgust natural to deductive philosophers at being offered an inductive and experimental foundation for a conviction which they had reached by a shorter cut. it is undoubtedly trying to learn that, though your conclusions may be all right, your reasons for them are all wrong, or, at any rate, insufficient. on the whole, then, the supporters of mr. darwin's views in 1860 were numerically extremely insignificant. there is not the slightest doubt that, if a general council of the church scientific had been held at that time, we should have been condemned by an overwhelming majority. and there is as little doubt that, if such a council gathered now, the decree would be of an exactly contrary nature. it would indicate a lack of sense, as well as of modesty, to ascribe to the men of that generation less capacity or less honesty than their successors possess. what, then, are the causes which led instructed and fair-judging men of that day to arrive at a judgment so different from that which seems just and fair to those who follow them? that is really one of the most interesting of all questions connected with the history of science, and i shall try to answer it. i am afraid that in order to do so i must run the risk of appearing egotistical. however, if i tell my own story it is only because i know it better than that of other people. i think i must have read the 'vestiges' before i left england in 1846; but, if i did, the book made very little impression upon me, and i was not brought into serious contact with the 'species' question until after 1850. at that time, i had long done with the pentateuchal cosmogony, which had been impressed upon my childish understanding as divine truth, with all the authority of parents and instructors, and from which it had cost me many a struggle to get free. but my mind was unbiassed in respect of any doctrine which presented itself, if it professed to be based on purely philosophical and scientific reasoning. it seemed to me then (as it does now) that "creation," in the ordinary sense of the word, is perfectly conceivable. i find no difficulty in imagining that, at some former period, this universe was not in existence; and that it made its appearance in six days (or instantaneously, if that is preferred), in consequence of the volition of some pre-existent being. then, as now, the so-called a priori arguments against theism; and, given a deity, against the possibility of creative acts, appeared to me to be devoid of reasonable foundation. i had not then, and i have not now, the smallest a priori objection to raise to the account of the creation of animals and plants given in 'paradise lost,' in which milton so vividly embodies the natural sense of genesis. far be it from me to say that it is untrue because it is impossible. i confine myself to what must be regarded as a modest and reasonable request for some particle of evidence that the existing species of animals and plants did originate in that way, as a condition of my belief in a statement which appears to me to be highly improbable. and, by way of being perfectly fair, i had exactly the same answer to give to the evolutionists of 1851-8. within the ranks of the biologists, at that time, i met with nobody, except dr. grant, of university college, who had a word to say for evolution--and his advocacy was not calculated to advance the cause. outside these ranks, the only person known to me whose knowledge and capacity compelled respect, and who was, at the same time, a thorough-going evolutionist, was mr. herbert spencer, whose acquaintance i made, i think, in 1852, and then entered into the bonds of a friendship which, i am happy to think, has known no interruption. many and prolonged were the battles we fought on this topic. but even my friend's rare dialectic skill and copiousness of apt illustration could not drive me from my agnostic position. i took my stand upon two grounds: firstly, that up to that time, the evidence in favour of transmutation was wholly insufficient; and secondly, that no suggestion respecting the causes of the transmutation assumed, which had been made, was in any way adequate to explain the phenomena. looking back at the state of knowledge at that time, i really do not see that any other conclusion was justifiable. in those days i had never even heard of treviranus' 'biologie.' however, i had studied lamarck attentively and i had read the 'vestiges' with due care; but neither of them afforded me any good ground for changing my negative and critical attitude. as for the 'vestiges,' i confess that the book simply irritated me by the prodigious ignorance and thoroughly unscientific habit of mind manifested by the writer. if it had any influence on me at all, it set me against evolution; and the only review i ever have qualms of conscience about, on the ground of needless savagery, is one i wrote on the 'vestiges' while under that influence. with respect to the 'philosophie zoologique,' it is no reproach to lamarck to say that the discussion of the species question in that work, whatever might be said for it in 1809, was miserably below the level of the knowledge of half a century later. in that interval of time the elucidation of the structure of the lower animals and plants had given rise to wholly new conceptions of their relations; histology and embryology, in the modern sense, had been created; physiology had been reconstituted; the facts of distribution, geological and geographical, had been prodigiously multiplied and reduced to order. to any biologist whose studies had carried him beyond mere species-mongering in 1850, one-half of lamarck's arguments were obsolete and the other half erroneous, or defective, in virtue of omitting to deal with the various classes of evidence which had been brought to light since his time. moreover his one suggestion as to the cause of the gradual modification of species--effort excited by change of conditions--was, on the face of it, inapplicable to the whole vegetable world. i do not think that any impartial judge who reads the 'philosophie zoologique' now, and who afterwards takes up lyell's trenchant and effectual criticism (published as far back as 1830), will be disposed to allot to lamarck a much higher place in the establishment of biological evolution than that which bacon assigns to himself in relation to physical science generally,--buccinator tantum. (erasmus darwin first promulgated lamarck's fundamental conceptions, and, with greater logical consistency, he had applied them to plants. but the advocates of his claims have failed to show that he, in any respect, anticipated the central idea of the 'origin of species.') but, by a curious irony of fate, the same influence which led me to put as little faith in modern speculations on this subject, as in the venerable traditions recorded in the first two chapters of genesis, was perhaps more potent than any other in keeping alive a sort of pious conviction that evolution, after all, would turn out true. i have recently read afresh the first edition of the 'principles of geology'; and when i consider that this remarkable book had been nearly thirty years in everybody's hands, and that it brings home to any reader of ordinary intelligence a great principle and a great fact--the principle, that the past must be explained by the present, unless good cause be shown to the contrary; and the fact, that, so far as our knowledge of the past history of life on our globe goes, no such cause can be shown (the same principle and the same fact guide the result from all sound historical investigation. grote's 'history of greece' is a product of the same intellectual movement as lyell's 'principles.')--i cannot but believe that lyell, for others, as for myself, was the chief agent for smoothing the road for darwin. for consistent uniformitarianism postulates evolution as much in the organic as in the inorganic world. the origin of a new species by other than ordinary agencies would be a vastly greater "catastrophe" than any of those which lyell successfully eliminated from sober geological speculation. in fact, no one was better aware of this than lyell himself. (lyell, with perfect right, claims this position for himself. he speaks of having "advocated a law of continuity even in the organic world, so far as possible without adopting lamarck's theory of transmutation"... "but while i taught that as often as certain forms of animals and plants disappeared, for reasons quite intelligible to us, others took their place by virtue of a causation which was beyond our comprehension; it remained for darwin to accumulate proof that there is no break between the incoming and the outgoing species, that they are the work of evolution, and not of special creation... "i had certainly prepared the way in this country, in six editions of my work before the 'vestiges of creation' appeared in 1842 [1844], for the reception of darwin's gradual and insensible evolution of species."--'life and letters,' letter to haeckel, volume ii. page 436. november 23, 1868.) if one reads any of the earlier editions of the 'principles' carefully (especially by the light of the interesting series of letters recently published by sir charles lyell's biographer), it is easy to see that, with all his energetic opposition to lamarck, on the one hand, and to the ideal quasi-progressionism of agassiz, on the other, lyell, in his own mind, was strongly disposed to account for the origination of all past and present species of living things by natural causes. but he would have liked, at the same time, to keep the name of creation for a natural process which he imagined to be incomprehensible. in a letter addressed to mantell (dated march 2, 1827), lyell speaks of having just read lamarck; he expresses his delight at lamarck's theories, and his personal freedom from any objection based on theological grounds. and though he is evidently alarmed at the pithecoid origin of man involved in lamarck's doctrine, he observes:-"but, after all, what changes species may really undergo! how impossible will it be to distinguish and lay down a line, beyond which some of the so-called extinct species have never passed into recent ones." again, the following remarkable passage occurs in the postscript of a letter addressed to sir john herschel in 1836:-"in regard to the origination of new species, i am very glad to find that you think it probable that it may be carried on through the intervention of intermediate causes. i left this rather to be inferred, not thinking it worth while to offend a certain class of persons by embodying in words what would only be a speculation." (in the same sense, see the letter to whewell, march 7, 1837, volume ii., page 5:-"in regard to this last subject [the changes from one set of animal and vegetable species to another]...you remember what herschel said in his letter to me. if i had stated as plainly as he has done the possibility of the introduction or origination of fresh species being a natural, in contradistinction to a miraculous process, i should have raised a host of prejudices against me, which are unfortunately opposed at every step to any philosopher who attempts to address the public on these mysterious subjects." see also letter to sedgwick, january 12, 1838 ii. page 35.) he goes on to refer to the criticisms which have been directed against him on the ground that, by leaving species to be originated by miracle, he is inconsistent with his own doctrine of uniformitarianism; and he leaves it to be understood that he had not replied, on the ground of his general objection to controversy. lyell's contemporaries were not without some inkling of his esoteric doctrine. whewell's 'history of the inductive sciences,' whatever its philosophical value, is always worth reading and always interesting, if under no other aspect than that of an evidence of the speculative limits within which a highly-placed divine might, at that time, safely range at will. in the course of his discussion of uniformitarianism, the encyclopaedic master of trinity observes:-"mr. lyell, indeed, has spoken of an hypothesis that 'the successive creation of species may constitute a regular part of the economy of nature,' but he has nowhere, i think, so described this process as to make it appear in what department of science we are to place the hypothesis. are these new species created by the production, at long intervals, of an offspring different in species from the parents? or are the species so created produced without parents? are they gradually evolved from some embryo substance? or do they suddenly start from the ground, as in the creation of the poet?... "some selection of one of these forms of the hypothesis, rather than the others, with evidence for the selection, is requisite to entitle us to place it among the known causes of change, which in this chapter we are considering. the bare conviction that a creation of species has taken place, whether once or many times, so long as it is unconnected with our organical sciences, is a tenet of natural theology rather than of physical philosophy." (whewell's 'history,' volume iii. page 639-640 (edition 2, 1847.)) the earlier part of this criticism appears perfectly just and appropriate; but, from the concluding paragraph, whewell evidently imagines that by "creation" lyell means a preternatural intervention of the deity; whereas the letter to herschel shows that, in his own mind, lyell meant natural causation; and i see no reason to doubt (the following passages in lyell's letters appear to me decisive on this point:-to darwin, october 3, 1859 (ii, 325), on first reading the 'origin.' "i have long seen most clearly that if any concession is made, all that you claim in your concluding pages will follow. "it is this which has made me so long hesitate, always feeling that the case of man and his races, and of other animals, and that of plants, is one and the same, and that if a vera causa be admitted for one instant, [instead] of a purely unknown and imaginary one, such as the word 'creation,' all the consequences must follow." to darwin, march 15, 1863 (volume ii. page 365). "i remember that it was the conclusion he [lamarck] came to about man that fortified me thirty years ago against the great impression which his arguments at first made on my mind, all the greater because constant prevost, a pupil of cuvier's forty years ago, told me his conviction 'that cuvier thought species not real, but that science could not advance without assuming that they were so.'" to hooker, march 9, 1863 (volume ii. page 361), in reference to darwin's feeling about the 'antiquity of man.' "he [darwin] seems much disappointed that i do not go farther with him, or do not speak out more. i can only say that i have spoken out to the full extent of my present convictions, and even beyond my state of feeling as to man's unbroken descent from the brutes, and i find i am half converting not a few who were in arms against darwin, and are even now against huxley." he speaks of having had to abandon "old and long cherished ideas, which constituted the charm to me of the theoretical part of the science in my earlier day, when i believed with pascal in the theory, as hallam terms it, of 'the arch-angel ruined.'" see the same sentiment in the letter to darwin, march 11, 1863, page 363:-"i think the old 'creation' is almost as much required as ever, but of course it takes a new form if lamarck's views improved by yours are adopted.") that, if sir charles could have avoided the inevitable corollary of the pithecoid origin of man--for which, to the end of his life, he entertained a profound antipathy--he would have advocated the efficiency of causes now in operation to bring about the condition of the organic world, as stoutly as he championed that doctrine in reference to inorganic nature. the fact is, that a discerning eye might have seen that some form or other of the doctrine of transmutation was inevitable, from the time when the truth enunciated by william smith that successive strata are characterised by different kinds of fossil remains, became a firmly established law of nature. no one has set forth the speculative consequences of this generalisation better than the historian of the 'inductive sciences':-"but the study of geology opens to us the spectacle of many groups of species which have, in the course of the earth's history, succeeded each other at vast intervals of time; one set of animals and plants disappearing, as it would seem, from the face of our planet, and others, which did not before exist, becoming the only occupants of the globe. and the dilemma then presents itself to us anew:--either we must accept the doctrine of the transmutation of species, and must suppose that the organized species of one geological epoch were transmuted into those of another by some long-continued agency of natural causes; or else, we must believe in many successive acts of creation and extinction of species, out of the common course of nature; acts which, therefore, we may properly call miraculous." (whewell's 'history of the inductive sciences.' edition ii., 1847, volume iii. pages 624-625. see for the author's verdict, pages 638-39.) dr. whewell decides in favour of the latter conclusion. and if any one had plied him with the four questions which he puts to lyell in the passage already cited, all that can be said now is that he would certainly have rejected the first. but would he really have had the courage to say that a rhinoceros tichorhinus, for instance, "was produced without parents;" or was "evolved from some embryo substance;" or that it suddenly started from the ground like milton's lion "pawing to get free his hinder parts." i permit myself to doubt whether even the master of trinity's well-tried courage--physical, intellectual, and moral--would have been equal to this feat. no doubt the sudden concurrence of half-a-ton of inorganic molecules into a live rhinoceros is conceivable, and therefore may be possible. but does such an event lie sufficiently within the bounds of probability to justify the belief in its occurrence on the strength of any attainable, or, indeed, imaginable, evidence? in view of the assertion (often repeated in the early days of the opposition to darwin) that he had added nothing to lamarck, it is very interesting to observe that the possibility of a fifth alternative, in addition to the four he has stated, has not dawned upon dr. whewell's mind. the suggestion that new species may result from the selective action of external conditions upon the variations from their specific type which individuals present--and which we call "spontaneous," because we are ignorant of their causation--is as wholly unknown to the historian of scientific ideas as it was to biological specialists before 1858. but that suggestion is the central idea of the 'origin of species,' and contains the quintessence of darwinism. thus, looking back into the past, it seems to me that my own position of critical expectancy was just and reasonable, and must have been taken up, on the same grounds, by many other persons. if agassiz told me that the forms of life which had successively tenanted the globe were the incarnations of successive thoughts of the deity; and that he had wiped out one set of these embodiments by an appalling geological catastrophe as soon as his ideas took a more advanced shape, i found myself not only unable to admit the accuracy of the deductions from the facts of paleontology, upon which this astounding hypothesis was founded, but i had to confess my want of any means of testing the correctness of his explanation of them. and besides that, i could by no means see what the explanation explained. neither did it help me to be told by an eminent anatomist that species had succeeded one another in time, in virtue of "a continuously operative creational law." that seemed to me to be no more than saying that species had succeeded one another, in the form of a vote-catching resolution, with "law" to please the man of science, and "creational" to draw the orthodox. so i took refuge in that "thatige skepsis" which goethe has so well defined; and, reversing the apostolic precept to be all things to all men, i usually defended the tenability of the received doctrines, when i had to do with the transmutationists; and stood up for the possibility of transmutation among the orthodox--thereby, no doubt, increasing an already current, but quite undeserved, reputation for needless combativeness. i remember, in the course of my first interview with mr. darwin, expressing my belief in the sharpness of the lines of demarcation between natural groups and in the absence of transitional forms, with all the confidence of youth and imperfect knowledge. i was not aware, at that time, that he had then been many years brooding over the species-question; and the humorous smile which accompanied his gentle answer, that such was not altogether his view, long haunted and puzzled me. but it would seem that four or five years' hard work had enabled me to understand what it meant; for lyell ('life and letters,' volume ii. page 212.), writing to sir charles bunbury (under date of april 30, 1856), says:-"when huxley, hooker, and wollaston were at darwin's last week they (all four of them) ran a tilt against species--further, i believe, than they are prepared to go." i recollect nothing of this beyond the fact of meeting mr. wollaston; and except for sir charles' distinct assurance as to "all four," i should have thought my "outrecuidance" was probably a counterblast to wollaston's conservatism. with regard to hooker, he was already, like voltaire's habbakuk, "capable du tout" in the way of advocating evolution. as i have already said, i imagine that most of those of my contemporaries who thought seriously about the matter, were very much in my own state of mind--inclined to say to both mosaists and evolutionists, "a plague on both your houses!" and disposed to turn aside from an interminable and apparently fruitless discussion, to labour in the fertile fields of ascertainable fact. and i may, therefore, further suppose that the publication of the darwin and wallace papers in 1858, and still more that of the 'origin' in 1859, had the effect upon them of the flash of light, which to a man who has lost himself in a dark night, suddenly reveals a road which, whether it takes him straight home or not, certainly goes his way. that which we were looking for, and could not find, was a hypothesis respecting the origin of known organic forms, which assumed the operation of no causes but such as could be proved to be actually at work. we wanted, not to pin our faith to that or any other speculation, but to get hold of clear and definite conceptions which could be brought face to face with facts and have their validity tested. the 'origin' provided us with the working hypothesis we sought. moreover, it did the immense service of freeing us for ever from the dilemma--refuse to accept the creation hypothesis, and what have you to propose that can be accepted by any cautious reasoner? in 1857, i had no answer ready, and i do not think that any one else had. a year later, we reproached ourselves with dullness for being perplexed by such an inquiry. my reflection, when i first made myself master of the central idea of the 'origin,' was, "how extremely stupid not to have thought of that!" i suppose that columbus' companions said much the same when he made the egg stand on end. the facts of variability, of the struggle for existence, of adaptation to conditions, were notorious enough; but none of us had suspected that the road to the heart of the species problem lay through them, until darwin and wallace dispelled the darkness, and the beacon-fire of the 'origin' guided the benighted. whether the particular shape which the doctrine of evolution, as applied to the organic world, took in darwin's hands, would prove to be final or not, was, to me, a matter of indifference. in my earliest criticisms of the 'origin' i ventured to point out that its logical foundation was insecure so long as experiments in selective breeding had not produced varieties which were more or less infertile; and that insecurity remains up to the present time. but, with any and every critical doubt which my sceptical ingenuity could suggest, the darwinian hypothesis remained incomparably more probable than the creation hypothesis. and if we had none of us been able to discern the paramount significance of some of the most patent and notorious of natural facts, until they were, so to speak, thrust under our noses, what force remained in the dilemma--creation or nothing? it was obvious that, hereafter, the probability would be immensely greater, that the links of natural causation were hidden from our purblind eyes, than that natural causation should be incompetent to produce all the phenomena of nature. the only rational course for those who had no other object than the attainment of truth, was to accept "darwinism" as a working hypothesis, and see what could be made of it. either it would prove its capacity to elucidate the facts of organic life, or it would break down under the strain. this was surely the dictate of common sense; and, for once, common sense carried the day. the result has been that complete volte-face of the whole scientific world, which must seem so surprising to the present generation. i do not mean to say that all the leaders of biological science have avowed themselves darwinians; but i do not think that there is a single zoologist, or botanist, or palaeontologist, among the multitude of active workers of this generation, who is other than an evolutionist, profoundly influenced by darwin's views. whatever may be the ultimate fate of the particular theory put forth by darwin, i venture to affirm that, so far as my knowledge goes, all the ingenuity and all the learning of hostile critics have not enabled them to adduce a solitary fact, of which it can be said, this is irreconcilable with the darwinian theory. in the prodigious variety and complexity of organic nature, there are multitudes of phenomena which are not deducible from any generalisations we have yet reached. but the same may be said of every other class of natural objects. i believe that astronomers cannot yet get the moon's motions into perfect accordance with the theory of gravitation. it would be inappropriate, even if it were possible, to discuss the difficulties and unresolved problems which have hitherto met the evolutionist, and which will probably continue to puzzle him for generations to come, in the course of this brief history of the reception of mr. darwin's great work. but there are two or three objections of a more general character, based, or supposed to be based, upon philosophical and theological foundations, which were loudly expressed in the early days of the darwinian controversy, and which, though they have been answered over and over again, crop up now and then to the present day. the most singular of these, perhaps immortal, fallacies, which live on, tithonus-like, when sense and force have long deserted them, is that which charges mr. darwin with having attempted to reinstate the old pagan goddess, chance. it is said that he supposes variations to come about "by chance," and that the fittest survive the "chances" of the struggle for existence, and thus "chance" is substituted for providential design. it is not a little wonderful that such an accusation as this should be brought against a writer who has, over and over again, warned his readers that when he uses the word "spontaneous," he merely means that he is ignorant of the cause of that which is so termed; and whose whole theory crumbles to pieces if the uniformity and regularity of natural causation for illimitable past ages is denied. but probably the best answer to those who talk of darwinism meaning the reign of "chance," is to ask them what they themselves understand by "chance"? do they believe that anything in this universe happens without reason or without a cause? do they really conceive that any event has no cause, and could not have been predicted by any one who had a sufficient insight into the order of nature? if they do, it is they who are the inheritors of antique superstition and ignorance, and whose minds have never been illumined by a ray of scientific thought. the one act of faith in the convert to science, is the confession of the universality of order and of the absolute validity in all times and under all circumstances, of the law of causation. this confession is an act of faith, because, by the nature of the case, the truth of such propositions is not susceptible of proof. but such faith is not blind, but reasonable; because it is invariably confirmed by experience, and constitutes the sole trustworthy foundation for all action. if one of these people, in whom the chance-worship of our remoter ancestors thus strangely survives, should be within reach of the sea when a heavy gale is blowing, let him betake himself to the shore and watch the scene. let him note the infinite variety of form and size of the tossing waves out at sea; or of the curves of their foam-crested breakers, as they dash against the rocks; let him listen to the roar and scream of the shingle as it is cast up and torn down the beach; or look at the flakes of foam as they drive hither and thither before the wind; or note the play of colours, which answers a gleam of sunshine as it falls upon the myriad bubbles. surely here, if anywhere, he will say that chance is supreme, and bend the knee as one who has entered the very penetralia of his divinity. but the man of science knows that here, as everywhere, perfect order is manifested; that there is not a curve of the waves, not a note in the howling chorus, not a rainbow-glint on a bubble, which is other than a necessary consequence of the ascertained laws of nature; and that with a sufficient knowledge of the conditions, competent physico-mathematical skill could account for, and indeed predict, every one of these "chance" events. a second very common objection to mr. darwin's views was (and is), that they abolish teleology, and eviscerate the argument from design. it is nearly twenty years since i ventured to offer some remarks on this subject, and as my arguments have as yet received no refutation, i hope i may be excused for reproducing them. i observed, "that the doctrine of evolution is the most formidable opponent of all the commoner and coarser forms of teleology. but perhaps the most remarkable service to the philosophy of biology rendered by mr. darwin is the reconciliation of teleology and morphology, and the explanation of the facts of both, which his views offer. the teleology which supposes that the eye, such as we see it in man, or one of the higher vertebrata, was made with the precise structure it exhibits, for the purpose of enabling the animal which possesses it to see, has undoubtedly received its death-blow. nevertheless, it is necessary to remember that there is a wider teleology which is not touched by the doctrine of evolution, but is actually based upon the fundamental proposition of evolution. this proposition is that the whole world, living and not living, is the result of the mutual interaction, according to definite laws, of the forces (i should now like to substitute the word powers for "forces.") possessed by the molecules of which the primitive nebulosity of the universe was composed. if this be true, it is no less certain that the existing world lay potentially in the cosmic vapour, and that a sufficient intelligence could, from a knowledge of the properties of the molecules of that vapour, have predicted, say the state of the fauna of britain in 1869, with as much certainty as one can say what will happen to the vapour of the breath on a cold winter's day... ...the teleological and the mechanical views of nature are not, necessarily, mutually exclusive. on the contrary, the more purely a mechanist the speculator is, the more firmly does he assume a primordial molecular arrangement of which all the phenomena of the universe are the consequences, and the more completely is he thereby at the mercy of the teleologist, who can always defy him to disprove that this primordial molecular arrangement was not intended to evolve the phenomena of the universe." (the "genealogy of animals" ('the academy,' 1869), reprinted in 'critiques and addresses.') the acute champion of teleology, paley, saw no difficulty in admitting that the "production of things" may be the result of trains of mechanical dispositions fixed beforehand by intelligent appointment and kept in action by a power at the centre ('natural theology,' chapter xxiii.), that is to say, he proleptically accepted the modern doctrine of evolution; and his successors might do well to follow their leader, or at any rate to attend to his weighty reasonings, before rushing into an antagonism which has no reasonable foundation. having got rid of the belief in chance and the disbelief in design, as in no sense appurtenances of evolution, the third libel upon that doctrine, that it is anti-theistic, might perhaps be left to shift for itself. but the persistence with which many people refuse to draw the plainest consequences from the propositions they profess to accept, renders it advisable to remark that the doctrine of evolution is neither anti-theistic nor theistic. it simply has no more to do with theism than the first book of euclid has. it is quite certain that a normal fresh-laid egg contains neither cock nor hen; and it is also as certain as any proposition in physics or morals, that if such an egg is kept under proper conditions for three weeks, a cock or hen chicken will be found in it. it is also quite certain that if the shell were transparent we should be able to watch the formation of the young fowl, day by day, by a process of evolution, from a microscopic cellular germ to its full size and complication of structure. therefore evolution, in the strictest sense, is actually going on in this and analogous millions and millions of instances, wherever living creatures exist. therefore, to borrow an argument from butler, as that which now happens must be consistent with the attributes of the deity, if such a being exists, evolution must be consistent with those attributes. and, if so, the evolution of the universe, which is neither more nor less explicable than that of a chicken, must also be consistent with them. the doctrine of evolution, therefore, does not even come into contact with theism, considered as a philosophical doctrine. that with which it does collide, and with which it is absolutely inconsistent, is the conception of creation, which theological speculators have based upon the history narrated in the opening of the book of genesis. there is a great deal of talk and not a little lamentation about the so-called religious difficulties which physical science has created. in theological science, as a matter of fact, it has created none. not a solitary problem presents itself to the philosophical theist, at the present day, which has not existed from the time that philosophers began to think out the logical grounds and the logical consequences of theism. all the real or imaginary perplexities which flow from the conception of the universe as a determinate mechanism, are equally involved in the assumption of an eternal, omnipotent and omniscient deity. the theological equivalent of the scientific conception of order is providence; and the doctrine of determinism follows as surely from the attributes of foreknowledge assumed by the theologian, as from the universality of natural causation assumed by the man of science. the angels in 'paradise lost' would have found the task of enlightening adam upon the mysteries of "fate, foreknowledge, and free-will," not a whit more difficult, if their pupil had been educated in a "real-schule" and trained in every laboratory of a modern university. in respect of the great problems of philosophy, the post-darwinian generation is, in one sense, exactly where the prae-darwinian generations were. they remain insoluble. but the present generation has the advantage of being better provided with the means of freeing itself from the tyranny of certain sham solutions. the known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability. our business in every generation is to reclaim a little more land, to add something to the extent and the solidity of our possessions. and even a cursory glance at the history of the biological sciences during the last quarter of a century is sufficient to justify the assertion, that the most potent instrument for the extension of the realm of natural knowledge which has come into men's hands, since the publication of newton's 'principia,' is darwin's 'origin of species.' it was badly received by the generation to which it was first addressed, and the outpouring of angry nonsense to which it gave rise is sad to think upon. but the present generation will probably behave just as badly if another darwin should arise, and inflict upon them that which the generality of mankind most hate--the necessity of revising their convictions. let them, then, be charitable to us ancients; and if they behave no better than the men of my day to some new benefactor, let them recollect that, after all, our wrath did not come to much, and vented itself chiefly in the bad language of sanctimonious scolds. let them as speedily perform a strategic right-about-face, and follow the truth wherever it leads. the opponents of the new truth will discover, as those of darwin are doing, that, after all, theories do not alter facts, and that the universe remains unaffected even though texts crumble. or, it may be, that, as history repeats itself, their happy ingenuity will also discover that the new wine is exactly of the same vintage as the old, and that (rightly viewed) the old bottles prove to have been expressly made for holding it. the origin of species [1] by thomas h. huxley mr. darwin's long-standing and well-earned scientific eminence probably renders him indifferent to that social notoriety which passes by the name of success; but if the calm spirit of the philosopher have not yet wholly superseded the ambition and the vanity of the carnal man within him, he must be well satisfied with the results of his venture in publishing the 'origin of species'. overflowing the narrow bounds of purely scientific circles, the "species question" divides with italy and the volunteers the attention of general society. everybody has read mr. darwin's book, or, at least, has given an opinion upon its merits or demerits; pietists, whether lay or ecclesiastic, decry it with the mild railing which sounds so charitable; bigots denounce it with ignorant invective; old ladies of both sexes consider it a decidedly dangerous book, and even savants, who have no better mud to throw, quote antiquated writers to show that its author is no better than an ape himself; while every philosophical thinker hails it as a veritable whitworth gun in the armoury of liberalism; and all competent naturalists and physiologists, whatever their opinions as to the ultimate fate of the doctrines put forth, acknowledge that the work in which they are embodied is a solid contribution to knowledge and inaugurates a new epoch in natural history. nor has the discussion of the subject been restrained within the limits of conversation. when the public is eager and interested, reviewers must minister to its wants; and the genuine 'litterateur' is too much in the habit of acquiring his knowledge from the book he judges--as the abyssinian is said to provide himself with steaks from the ox which carries him--to be withheld from criticism of a profound scientific work by the mere want of the requisite preliminary scientific acquirement; while, on the other hand, the men of science who wish well to the new views, no less than those who dispute their validity, have naturally sought opportunities of expressing their opinions. hence it is not surprising that almost all the critical journals have noticed mr. darwin's work at greater or less length; and so many disquisitions, of every degree of excellence, from the poor product of ignorance, too often stimulated by prejudice, to the fair and thoughtful essay of the candid student of nature, have appeared, that it seems an almost hopeless task to attempt to say anything new upon the question. but it may be doubted if the knowledge and acumen of prejudged scientific opponents, or the subtlety of orthodox special pleaders, have yet exerted their full force in mystifying the real issues of the great controversy which has been set afoot, and whose end is hardly likely to be seen by this generation; so that, at this eleventh hour, and even failing anything new, it may be useful to state afresh that which is true, and to put the fundamental positions advocated by mr. darwin in such a form that they may be grasped by those whose special studies lie in other directions. and the adoption of this course may be the more advisable, because, notwithstanding its great deserts, and indeed partly on account of them, the 'origin of species' is by no means an easy book to read--if by reading is implied the full comprehension of an author's meaning. we do not speak jestingly in saying that it is mr. darwin's misfortune to know more about the question he has taken up than any man living. personally and practically exercised in zoology, in minute anatomy, in geology; a student of geographical distribution, not on maps and in museums only, but by long voyages and laborious collection; having largely advanced each of these branches of science, and having spent many years in gathering and sifting materials for his present work, the store of accurately registered facts upon which the author of the 'origin of species' is able to draw at will is prodigious. but this very superabundance of matter must have been embarrassing to a writer who, for the present, can only put forward an abstract of his views; and thence it arises, perhaps, that notwithstanding the clearness of the style, those who attempt fairly to digest the book find much of it a sort of intellectual pemmican--a mass of facts crushed and pounded into shape, rather than held together by the ordinary medium of an obvious logical bond; due attention will, without doubt, discover this bond, but it is often hard to find. again, from sheer want of room, much has to be taken for granted which might readily enough be proved; and hence, while the adept, who can supply the missing links in the evidence from his own knowledge, discovers fresh proof of the singular thoroughness with which all difficulties have been considered and all unjustifiable suppositions avoided, at every reperusal of mr. darwin's pregnant paragraphs, the novice in biology is apt to complain of the frequency of what he fancies is gratuitous assumption. thus while it may be doubted if, for some years, any one is likely to be competent to pronounce judgment on all the issues raised by mr. darwin, there is assuredly abundant room for him, who, assuming the humbler, though perhaps as useful, office of an interpreter between the 'origin of species' and the public, contents himself with endeavouring to point out the nature of the problems which it discusses; to distinguish between the ascertained facts and the theoretical views which it contains; and finally, to show the extent to which the explanation it offers satisfies the requirements of scientific logic. at any rate, it is this office which we purpose to undertake in the following pages. it may be safely assumed that our readers have a general conception of the nature of the objects to which the word "species" is applied; but it has, perhaps, occurred to a few, even to those who are naturalists 'ex professo', to reflect, that, as commonly employed, the term has a double sense and denotes two very different orders of relations. when we call a group of animals, or of plants, a species, we may imply thereby, either that all these animals or plants have some common peculiarity of form or structure; or, we may mean that they possess some common functional character. that part of biological science which deals with form and structure is called morphology--that which concerns itself with function, physiology--so that we may conveniently speak of these two senses, or aspects, of "species"--the one as morphological, the other as physiological. regarded from the former point of view, a species is nothing more than a kind of animal or plant, which is distinctly definable from all others, by certain constant, and not merely sexual, morphological peculiarities. thus horses form a species, because the group of animals to which that name is applied is distinguished from all others in the world by the following constantly associated characters. they have--1, a vertebral column; 2, mammae; 3, a placental embryo; 4, four legs; 5, a single well-developed toe in each foot provided with a hoof; 6, a bushy tail; and 7, callosities on the inner sides of both the fore and the hind legs. the asses, again, form a distinct species, because, with the same characters, as far as the fifth in the above list, all asses have tufted tails, and have callosities only on the inner side of the fore-legs. if animals were discovered having the general characters of the horse, but sometimes with callosities only on the fore-legs, and more or less tufted tails; or animals having the general characters of the ass, but with more or less bushy tails, and sometimes with callosities on both pairs of legs, besides being intermediate in other respects--the two species would have to be merged into one. they could no longer be regarded as morphologically distinct species, for they would not be distinctly definable one from the other. however bare and simple this definition of species may appear to be, we confidently appeal to all practical naturalists, whether zoologists, botanists, or palaeontologists, to say if, in the vast majority of cases, they know, or mean to affirm anything more of the group of animals or plants they so denominate than what has just been stated. even the most decided advocates of the received doctrines respecting species admit this. "i apprehend," says professor owen [2], "that few naturalists nowadays, in describing and proposing a name for what they call 'a new species,' use that term to signify what was meant by it twenty or thirty years ago; that is, an originally distinct creation, maintaining its primitive distinction by obstructive generative peculiarities. the proposer of the new species now intends to state no more than he actually knows; as, for example, that the differences on which he founds the specific character are constant in individuals of both sexes, so far as observation has reached; and that they are not due to domestication or to artificially superinduced external circumstances, or to any outward influence within his cognizance; that the species is wild, or is such as it appears by nature." if we consider, in fact, that by far the largest proportion of recorded existing species are known only by the study of their skins, or bones, or other lifeless exuvia; that we are acquainted with none, or next to none, of their physiological peculiarities, beyond those which can be deduced from their structure, or are open to cursory observation; and that we cannot hope to learn more of any of those extinct forms of life which now constitute no inconsiderable proportion of the known flora and fauna of the world: it is obvious that the definitions of these species can be only of a purely structural, or morphological, character. it is probable that naturalists would have avoided much confusion of ideas if they had more frequently borne the necessary limitations of our knowledge in mind. but while it may safely be admitted that we are acquainted with only the morphological characters of the vast majority of species--the functional or physiological, peculiarities of a few have been carefully investigated, and the result of that study forms a large and most interesting portion of the physiology of reproduction. the student of nature wonders the more and is astonished the less, the more conversant he becomes with her operations; but of all the perennial miracles she offers to his inspection, perhaps the most worthy of admiration is the development of a plant or of an animal from its embryo. examine the recently laid egg of some common animal, such as a salamander or newt. it is a minute spheroid in which the best microscope will reveal nothing but a structureless sac, enclosing a glairy fluid, holding granules in suspension. but strange possibilities lie dormant in that semi-fluid globule. let a moderate supply of warmth reach its watery cradle, and the plastic matter undergoes changes so rapid, yet so steady and purposelike in their succession, that one can only compare them to those operated by a skilled modeller upon a formless lump of clay. as with an invisible trowel, the mass is divided and subdivided into smaller and smaller portions, until it is reduced to an aggregation of granules not too large to build withal the finest fabrics of the nascent organism. and, then, it is as if a delicate finger traced out the line to be occupied by the spinal column, and moulded the contour of the body; pinching up the head at one end, the tail at the other, and fashioning flank and limb into due salamandrine proportions, in so artistic a way, that, after watching the process hour by hour, one is almost involuntarily possessed by the notion, that some more subtle aid to vision than an achromatic, would show the hidden artist, with his plan before him, striving with skilful manipulation to perfect his work. as life advances, and the young amphibian ranges the waters, the terror of his insect contemporaries, not only are the nutritious particles supplied by its prey, by the addition of which to its frame, growth takes place, laid down, each in its proper spot, and in such due proportion to the rest, as to reproduce the form, the colour, and the size, characteristic of the parental stock; but even the wonderful powers of reproducing lost parts possessed by these animals are controlled by the same governing tendency. cut off the legs, the tail, the jaws, separately or all together, and, as spallanzani showed long ago, these parts not only grow again, but the redintegrated limb is formed on the same type as those which were lost. the new jaw, or leg, is a newt's, and never by any accident more like that of a frog. what is true of the newt is true of every animal and of every plant; the acorn tends to build itself up again into a woodland giant such as that from whose twig it fell; the spore of the humblest lichen reproduces the green or brown incrustation which gave it birth; and at the other end of the scale of life, the child that resembled neither the paternal nor the maternal side of the house would be regarded as a kind of monster. so that the one end to which, in all living beings, the formative impulse is tending--the one scheme which the archaeus of the old speculators strives to carry out, seems to be to mould the offspring into the likeness of the parent. it is the first great law of reproduction, that the offspring tends to resemble its parent or parents, more closely than anything else. science will some day show us how this law is a necessary consequence of the more general laws which govern matter; but, for the present, more can hardly be said than that it appears to be in harmony with them. we know that the phenomena of vitality are not something apart from other physical phenomena, but one with them; and matter and force are the two names of the one artist who fashions the living as well as the lifeless. hence living bodies should obey the same great laws as other matter--nor, throughout nature, is there a law of wider application than this, that a body impelled by two forces takes the direction of their resultant. but living bodies may be regarded as nothing but extremely complex bundles of forces held in a mass of matter, as the complex forces of a magnet are held in the steel by its coercive force; and, since the differences of sex are comparatively slight, or, in other words, the sum of the forces in each has a very similar tendency, their resultant, the offspring, may reasonably be expected to deviate but little from a course parallel to either, or to both. represent the reason of the law to ourselves by what physical metaphor or analogy we will, however, the great matter is to apprehend its existence and the importance of the consequences deducible from it. for things which are like to the same are like to one another; and if; in a great series of generations, every offspring is like its parent, it follows that all the offspring and all the parents must be like one another; and that, given an original parental stock, with the opportunity of undisturbed multiplication, the law in question necessitates the production, in course of time, of an indefinitely large group, the whole of whose members are at once very similar and are blood relations, having descended from the same parent, or pair of parents. the proof that all the members of any given group of animals, or plants, had thus descended, would be ordinarily considered sufficient to entitle them to the rank of physiological species, for most physiologists consider species to be definable as "the offspring of a single primitive stock." but though it is quite true that all those groups we call species 'may', according to the known laws of reproduction, have descended from a single stock, and though it is very likely they really have done so, yet this conclusion rests on deduction and can hardly hope to establish itself upon a basis of observation. and the primitiveness of the supposed single stock, which, after all, is the essential part of the matter, is not only a hypothesis, but one which has not a shadow of foundation, if by "primitive" he meant "independent of any other living being." a scientific definition, of which an unwarrantable hypothesis forms an essential part, carries its condemnation within itself; but, even supposing such a definition were, in form, tenable, the physiologist who should attempt to apply it in nature would soon find himself involved in great, if not inextricable, difficulties. as we have said, it is indubitable that offspring 'tend' to resemble the parental organism, but it is equally true that the similarity attained never amounts to identity, either in form or in structure. there is always a certain amount of deviation, not only from the precise characters of a single parent, but when, as in most animals and many plants, the sexes are lodged in distinct individuals, from an exact mean between the two parents. and indeed, on general principles, this slight deviation seems as intelligible as the general similarity, if we reflect how complex the co-operating "bundles of forces" are, and how improbable it is that, in any case, their true resultant shall coincide with any mean between the more obvious characters of the two parents. whatever be its cause, however, the co-existence of this tendency to minor variation with the tendency to general similarity, is of vast importance in its bearing on the question of the origin of species. as a general rule, the extent to which an offspring differs from its parent is slight enough; but, occasionally, the amount of difference is much more strongly marked, and then the divergent offspring receives the name of a variety. multitudes, of what there is every reason to believe are such varieties, are known, but the origin of very few has been accurately recorded, and of these we will select two as more especially illustrative of the main features of variation. the first of them is that of the "ancon," or "otter" sheep, of which a careful account is given by colonel david humphreys, f.r.s., in a letter to sir joseph banks, published in the philosophical transactions for 1813. it appears that one seth wright, the proprietor of a farm on the banks of the charles river, in massachusetts, possessed a flock of fifteen ewes and a ram of the ordinary kind. in the year 1791, one of the ewes presented her owner with a male lamb, differing, for no assignable reason, from its parents by a proportionally long body and short bandy legs, whence it was unable to emulate its relatives in those sportive leaps over the neighbours' fences, in which they were in the habit of indulging, much to the good farmer's vexation. the second case is that detailed by a no less unexceptionable authority than reaumur, in his 'art de faire eclore les poulets'. a maltese couple, named kelleia, whose hands and feet were constructed upon the ordinary human model, had born to them a son, gratio, who possessed six perfectly movable fingers on each hand, and six toes, not quite so well formed, on each foot. no cause could be assigned for the appearance of this unusual variety of the human species. two circumstances are well worthy of remark in both these cases. in each, the variety appears to have arisen in full force, and, as it were, 'per saltum'; a wide and definite difference appearing, at once, between the ancon ram and the ordinary sheep; between the six-fingered and six-toed gratio kelleia and ordinary men. in neither case is it possible to point out any obvious reason for the appearance of the variety. doubtless there were determining causes for these as for all other phenomena; but they do not appear, and we can be tolerably certain that what are ordinarily understood as changes in physical conditions, as in climate, in food, or the like, did not take place and had nothing to do with the matter. it was no case of what is commonly called adaptation to circumstances; but, to use a conveniently erroneous phrase, the variations arose spontaneously. the fruitless search after final causes leads their pursuers a long way; but even those hardy teleologists, who are ready to break through all the laws of physics in chase of their favourite will-o'-the-wisp, may be puzzled to discover what purpose could be attained by the stunted legs of seth wright's ram or the hexadactyle members of gratio kelleia. varieties then arise we know not why; and it is more than probable that the majority of varieties have arisen in this "spontaneous" manner, though we are, of course, far from denying that they may be traced, in some cases, to distinct external influences; which are assuredly competent to alter the character of the tegumentary covering, to change colour, to increase or diminish the size of muscles, to modify constitution, and, among plants, to give rise to the metamorphosis of stamens into petals, and so forth. but however they may have arisen, what especially interests us at present is, to remark that, once in existence, varieties obey the fundamental law of reproduction that like tends to produce like; and their offspring exemplify it by tending to exhibit the same deviation from the parental stock as themselves. indeed, there seems to be, in many instances, a pre-potent influence about a newly-arisen variety which gives it what one may call an unfair advantage over the normal descendants from the same stock. this is strikingly exemplified by the case of gratio kelleia, who married a woman with the ordinary pentadactyle extremities, and had by her four children, salvator, george, andre, and marie. of these children salvator, the eldest boy, had six fingers and six toes, like his father; the second and third, also boys, had five fingers and five toes, like their mother, though the hands and feet of george were slightly deformed. the last, a girl, had five fingers and five toes, but the thumbs were slightly deformed. the variety thus reproduced itself purely in the eldest, while the normal type reproduced itself purely in the third, and almost purely in the second and last: so that it would seem, at first, as if the normal type were more powerful than the variety. but all these children grew up and intermarried with normal wives and husband, and then, note what took place: salvator had four children, three of whom exhibited the hexadactyle members of their grandfather and father, while the youngest had the pentadactyle limbs of the mother and grandmother; so that here, notwithstanding a double pentadactyle dilution of the blood, the hexadactyle variety had the best of it. the same pre-potency of the variety was still more markedly exemplified in the progeny of two of the other children, marie and george. marie (whose thumbs only were deformed) gave birth to a boy with six toes, and three other normally formed children; but george, who was not quite so pure a pentadactyle, begot, first, two girls, each of whom had six fingers and toes; then a girl with six fingers on each hand and six toes on the right foot, but only five toes on the left; and lastly, a boy with only five fingers and toes. in these instances, therefore, the variety, as it were, leaped over one generation to reproduce itself in full force in the next. finally, the purely pentadactyle andre was the father of many children, not one of whom departed from the normal parental type. if a variation which approaches the nature of a monstrosity can strive thus forcibly to reproduce itself, it is not wonderful that less aberrant modifications should tend to be preserved even more strongly; and the history of the ancon sheep is, in this respect, particularly instructive. with the "'cuteness" characteristic of their nation, the neighbours of the massachusetts farmer imagined it would be an excellent thing if all his sheep were imbued with the stay-at-home tendencies enforced by nature upon the newly-arrived ram; and they advised wright to kill the old patriarch of his fold, and install the ancon ram in his place. the result justified their sagacious anticipations, and coincided very nearly with what occurred to the progeny of gratio kelleia. the young lambs were almost always either pure ancons, or pure ordinary sheep. [3] but when sufficient ancon sheep were obtained to interbreed with one another, it was found that the offspring was always pure ancon. colonel humphreys, in fact, states that he was acquainted with only "one questionable case of a contrary nature." here, then, is a remarkable and well-established instance, not only of a very distinct race being established 'per saltum', but of that race breeding "true" at once, and showing no mixed forms, even when crossed with another breed. by taking care to select ancons of both sexes, for breeding from, it thus became easy to establish an extremely well-marked race; so peculiar that, even when herded with other sheep, it was noted that the ancons kept together. and there is every reason to believe that the existence of this breed might have been indefinitely protracted; but the introduction of the merino sheep, which were not only very superior to the ancons in wool and meat, but quite as quiet and orderly, led to the complete neglect of the new breed, so that, in 1813, colonel humphreys found it difficult to obtain the specimen, whose skeleton was presented to sir joseph banks. we believe that, for many years, no remnant of it has existed in the united states. gratio kelleia was not the progenitor of a race of six-fingered men, as seth wright's ram became a nation of ancon sheep, though the tendency of the variety to perpetuate itself appears to have been fully as strong in the one case as in the other. and the reason of the difference is not far to seek. seth wright took care not to weaken the ancon blood by matching his ancon ewes with any but males of the same variety, while gratio kelleia's sons were too far removed from the patriarchal times to intermarry with their sisters; and his grandchildren seem not to have been attracted by their six-fingered cousins. in other words, in the one example a race was produced, because, for several generations, care was taken to 'select' both parents of the breeding stock from animals exhibiting a tendency to vary in the same condition; while, in the other, no race was evolved, because no such selection was exercised. a race is a propagated variety; and as, by the laws of reproduction, offspring tend to assume the parental forms, they will be more likely to propagate a variation exhibited by both parents than that possessed by only one. there is no organ of the body of an animal which may not, and does not, occasionally, vary more or less from the normal type; and there is no variation which may not be transmitted and which, if selectively transmitted, may not become the foundation of a race. this great truth, sometimes forgotten by philosophers, has long been familiar to practical agriculturists and breeders; and upon it rest all the methods of improving the breeds of domestic animals, which, for the last century, have been followed with so much success in england. colour, form, size, texture of hair or wool, proportions of various parts, strength or weakness of constitution, tendency to fatten or to remain lean, to give much or little milk, speed, strength, temper, intelligence, special instincts; there is not one of these characters whose transmission is not an every-day occurrence within the experience of cattle-breeders, stock-farmers, horse-dealers, and dog and poultry fanciers. nay, it is only the other day that an eminent physiologist, dr. brown-sequard, communicated to the royal society his discovery that epilepsy, artificially produced in guinea-pigs, by a means which he has discovered, is transmitted to their offspring. but a race, once produced, is no more a fixed and immutable entity than the stock whence it sprang; variations arise among its members, and as these variations are transmitted like any others, new races may be developed out of the pre-existing one 'ad infinitum', or, at least, within any limit at present determined. given sufficient time and sufficiently careful selection, and the multitude of races which may arise from a common stock is as astonishing as are the extreme structural differences which they may present. a remarkable example of this is to be found in the rock-pigeon, which dr. darwin has, in our opinion, satisfactorily demonstrated to be the progenitor of all our domestic pigeons, of which there are certainly more than a hundred well-marked races. the most noteworthy of these races are, the four great stocks known to the "fancy" as tumblers, pouters, carriers, and fantails; birds which not only differ most singularly in size, colour, and habits, but in the form of the beak and of the skull: in the proportions of the beak to the skull; in the number of tail-feathers; in the absolute and relative size of the feet; in the presence or absence of the uropygial gland; in the number of vertebrae in the back; in short, in precisely those characters in which the genera and species of birds differ from one another. and it is most remarkable and instructive to observe, that none of these races can be shown to have been originated by the action of changes in what are commonly called external circumstances, upon the wild rock-pigeon. on the contrary, from time immemorial, pigeon-fanciers have had essentially similar methods of treating their pets, which have been housed, fed, protected and cared for in much the same way in all pigeonries. in fact, there is no case better adapted than that of the pigeons to refute the doctrine which one sees put forth on high authority, that "no other characters than those founded on the development of bone for the attachment of muscles" are capable of variation. in precise contradiction of this hasty assertion, mr. darwin's researches prove that the skeleton of the wings in domestic pigeons has hardly varied at all from that of the wild type; while, on the other hand, it is in exactly those respects, such as the relative length of the beak and skull, the number of the vertebrae, and the number of the tail-feathers, in which muscular exertion can have no important influence, that the utmost amount of variation has taken place. we have said that the following out of the properties exhibited by physiological species would lead us into difficulties, and at this point they begin to be obvious; for if, as the result of spontaneous variation and of selective breeding, the progeny of a common stock may become separated into groups distinguished from one another by constant, not sexual, morphological characters, it is clear that the physiological definition of species is likely to clash with the morphological definition. no one would hesitate to describe the pouter and the tumbler as distinct species, if they were found fossil, or if their skins and skeletons were imported, as those of exotic wild birds commonly are--and without doubt, if considered alone, they are good and distinct morphological species. on the other hand, they are not physiological species, for they are descended from a common stock, the rock-pigeon. under these circumstances, as it is admitted on all sides that races occur in nature, how are we to know whether any apparently distinct animals are really of different physiological species, or not, seeing that the amount of morphological difference is no safe guide? is there any test of a physiological species? the usual answer of physiologists is in the affirmative. it is said that such a test is to be found in the phenomena of hybridization--in the results of crossing races, as compared with the results of crossing species. so far as the evidence goes at present, individuals, of what are certainly known to be mere races produced by selection, however distinct they may appear to be, not only breed freely together, but the offspring of such crossed races are only perfectly fertile with one another. thus, the spaniel and the greyhound, the dray-horse and the arab, the pouter and the tumbler, breed together with perfect freedom, and their mongrels, if matched with other mongrels of the same kind, are equally fertile. on the other hand, there can be no doubt that the individuals of many natural species are either absolutely infertile if crossed with individuals of other species, or, if they give rise to hybrid offspring, the hybrids so produced are infertile when paired together. the horse and the ass, for instance, if so crossed, give rise to the mule, and there is no certain evidence of offspring ever having been produced by a male and female mule. the unions of the rock-pigeon and the ring-pigeon appear to be equally barren of result. here, then, says the physiologist, we have a means of distinguishing any two true species from any two varieties. if a male and a female, selected from each group, produce offspring, and that offspring is fertile with others produced in the same way, the groups are races and not species. if, on the other hand, no result ensues, or if the offspring are infertile with others produced in the same way, they are true physiological species. the test would be an admirable one, if, in the first place, it were always practicable to apply it, and if, in the second, it always yielded results susceptible of a definite interpretation. unfortunately, in the great majority of cases, this touchstone for species is wholly inapplicable. the constitution of many wild animals is so altered by confinement that they will not breed even with their own females, so that the negative results obtained from crosses are of no value; and the antipathy of wild animals of the same species for one another, or even of wild and tame members of the same species, is ordinarily so great, that it is hopeless to look for such unions in nature. the hermaphrodism of most plants, the difficulty in the way of insuring the absence of their own, or the proper working of other pollen, are obstacles of no less magnitude in applying the test to them. and, in both animals and plants, is superadded the further difficulty, that experiments must be continued over a long time for the purpose of ascertaining the fertility of the mongrel or hybrid progeny, as well as of the first crosses from which they spring. not only do these great practical difficulties lie in the way of applying the hybridization test, but even when this oracle can be questioned, its replies are sometimes as doubtful as those of delphi. for example, cases are cited by mr. darwin, of plants which are more fertile with the pollen of another species than with their own; and there are others, such as certain 'fuci', whose male element will fertilize the ovule of a plant of distinct species, while the males of the latter species are ineffective with the females of the first. so that, in the last-named instance, a physiologist, who should cross the two species in one way, would decide that they were true species; while another, who should cross them in the reverse way, would, with equal justice, according to the rule, pronounce them to be mere races. several plants, which there is great reason to believe are mere varieties, are almost sterile when crossed; while both animals and plants, which have always been regarded by naturalists as of distinct species, turn out, when the test is applied, to be perfectly fertile. again, the sterility or fertility of crosses seems to bear no relation to the structural resemblances or differences of the members of any two groups. mr. darwin has discussed this question with singular ability and circumspection, and his conclusions are summed up as follows, at page 276 of his work:-"first crosses between forms sufficiently distinct to be ranked as species, and their hybrids, are very generally, but not universally, sterile. the sterility is of all degrees, and is often so slight that the two most careful experimentalists who have ever lived have come to diametrically opposite conclusions in ranking forms by this test. the sterility is innately variable in individuals of the same species, and is eminently susceptible of favourable and unfavourable conditions. the degree of sterility does not strictly follow systematic affinity, but is governed by several curious and complex laws. it is generally different and sometimes widely different, in reciprocal crosses between the same two species. it is not always equal in degree in a first cross, and in the hybrid produced from this cross. "in the same manner as in grafting trees, the capacity of one species or variety to take on another is incidental on generally unknown differences in their vegetative systems; so in crossing, the greater or less facility of one species to unite with another is incidental on unknown differences in their reproductive systems. there is no more reason to think that species have been specially endowed with various degrees of sterility to prevent them crossing and breeding in nature, than to think that trees have been specially endowed with various and somewhat analogous degrees of difficulty in being grafted together, in order to prevent them becoming inarched in our forests. "the sterility of first crosses between pure species, which have their reproductive systems perfect, seems to depend on several circumstances; in some cases largely on the early death of the embryo. the sterility of hybrids which have their reproductive systems imperfect, and which have had this system and their whole organization disturbed by being compounded of two distinct species, seems closely allied to that sterility which so frequently affects pure species when their natural conditions of life have been disturbed. this view is supported by a parallelism of another kind: namely, that the crossing of forms, only slightly different, is favourable to the vigour and fertility of the offspring; and that slight changes in the conditions of life are apparently favourable to the vigour and fertility of all organic beings. it is not surprising that the degree of difficulty in uniting two species, and the degree of sterility of their hybrid offspring, should generally correspond, though due to distinct causes; for both depend on the amount of difference of some kind between the species which are crossed. nor is it surprising that the facility of effecting a first cross, the fertility of hybrids produced from it, and the capacity of being grafted together--though this latter capacity evidently depends on widely different circumstances--should all run to a certain extent parallel with the systematic affinity of the forms which are subjected to experiment; for systematic affinity attempts to express all kinds of resemblance between all species. "first crosses between forms known to be varieties, or sufficiently alike to be considered as varieties, and their mongrel offspring, are very generally, but not quite universally, fertile. nor is this nearly general and perfect fertility surprising, when we remember how liable we are to argue in a circle with respect to varieties in a state of nature; and when we remember that the greater number of varieties have been produced under domestication by the selection of mere external differences, and not of differences in the reproductive system. in all other respects, excluding fertility, there is a close general resemblance between hybrids and mongrels."--pp. 276-8. we fully agree with the general tenor of this weighty passage; but forcible as are these arguments, and little as the value of fertility or infertility as a test of species may be, it must not be forgotten that the really important fact, so far as the inquiry into the origin of species goes, is, that there are such things in nature as groups of animals and of plants, whose members are incapable of fertile union with those of other groups; and that there are such things as hybrids, which are absolutely sterile when crossed with other hybrids. for, if such phenomena as these were exhibited by only two of those assemblages of living objects, to which the name of species (whether it be used in its physiological or in its morphological sense) is given, it would have to be accounted for by any theory of the origin of species, and every theory which could not account for it would be, so far, imperfect. up to this point, we have been dealing with matters of fact, and the statements which we have laid before the reader would, to the best of our knowledge, be admitted to contain a fair exposition of what is at present known respecting the essential properties of species, by all who have studied the question. and whatever may be his theoretical views, no naturalist will probably be disposed to demur to the following summary of that exposition:-living beings, whether animals or plants, are divisible into multitudes of distinctly definable kinds, which are morphological species. they are also divisible into groups of individuals, which breed freely together, tending to reproduce their like, and are physiological species. normally resembling their parents, the offspring of members of these species are still liable to vary; and the variation may be perpetuated by selection, as a race, which race, in many cases, presents all the characteristics of a morphological species. but it is not as yet proved that a race ever exhibits, when crossed with another race of the same species, those phenomena of hybridization which are exhibited by many species when crossed with other species. on the other hand, not only is it not proved that all species give rise to hybrids infertile 'inter se', but there is much reason to believe that, in crossing, species exhibit every gradation from perfect sterility to perfect fertility. such are the most essential characteristics of species. even were man not one of them--a member of the same system and subject to the same laws--the question of their origin, their causal connexion, that is, with the other phenomena of the universe, must have attracted his attention, as soon as his intelligence had raised itself above the level of his daily wants. indeed history relates that such was the case, and has embalmed for us the speculations upon the origin of living beings, which were among the earliest products of the dawning intellectual activity of man. in those early days positive knowledge was not to be had, but the craving after it needed, at all hazards, to be satisfied, and according to the country, or the turn of thought, of the speculator, the suggestion that all living things arose from the mud of the nile, from a primeval egg, or from some more anthropomorphic agency, afforded a sufficient resting-place for his curiosity. the myths of paganism are as dead as osiris or zeus, and the man who should revive them, in opposition to the knowledge of our time, would be justly laughed to scorn; but the coeval imaginations current among the rude inhabitants of palestine, recorded by writers whose very name and age are admitted by every scholar to be unknown, have unfortunately not yet shared their fate, but, even at this day, are regarded by nine-tenths of the civilized world as the authoritative standard of fact and the criterion of the justice of scientific conclusions, in all that relates to the origin of things, and, among them, of species. in this nineteenth century, as at the dawn of modern physical science, the cosmogony of the semi-barbarous hebrew is the incubus of the philosopher and the opprobrium of the orthodox. who shall number the patient and earnest seekers after truth, from the days of galileo until now, whose lives have been embittered and their good name blasted by the mistaken zeal of bibliolaters? who shall count the host of weaker men whose sense of truth has been destroyed in the effort to harmonize impossibilities--whose life has been wasted in the attempt to force the generous new wine of science into the old bottles of judaism, compelled by the outcry of the same strong party? it is true that if philosophers have suffered, their cause has been amply avenged. extinguished theologians lie about the cradle of every science as the strangled snakes beside that of hercules; and history records that whenever science and orthodoxy have been fairly opposed, the latter has been forced to retire from the lists, bleeding and crushed if not annihilated; scotched, if not slain. but orthodoxy is the bourbon of the world of thought. it learns not, neither can it forget; and though, at present, bewildered and afraid to move, it is as willing as ever to insist that the first chapter of genesis contains the beginning and the end of sound science; and to visit, with such petty thunderbolts as its half-paralysed hands can hurl, those who refuse to degrade nature to the level of primitive judaism. philosophers, on the other hand, have no such aggressive tendencies. with eyes fixed on the noble goal to which "per aspera et ardua" they tend, they may, now and then, be stirred to momentary wrath by the unnecessary obstacles with which the ignorant, or the malicious, encumber, if they cannot bar, the difficult path; but why should their souls be deeply vexed? the majesty of fact is on their side, and the elemental forces of nature are working for them. not a star comes to the meridian at its calculated time but testifies to the justice of their methods--their beliefs are "one with falling rain and with the growing corn." by doubt they are established, and open inquiry is their bosom friend. such men have no fear of traditions however venerable, and no respect for them when they become mischievous and obstructive; but they have better than mere antiquarian business in hand, and if dogmas, which ought to be fossil but are not, are not forced upon their notice, they are too happy to treat them as non-existent. the hypotheses respecting the origin of species which profess to stand upon a scientific basis, and, as such, alone demand serious attention, are of two kinds. the one, the "special creation" hypothesis, presumes every species to have originated from one or more stocks, these not being the result of the modification of any other form of living matter--or arising by natural agencies--but being produced, as such, by a supernatural creative act. the other, the so-called "transmutation" hypothesis, considers that all existing species are the result of the modification of pre-existing species, and those of their predecessors, by agencies similar to those which at the present day produce varieties and races, and therefore in an altogether natural way; and it is a probable, though not a necessary consequence of this hypothesis, that all living beings have arisen from a single stock. with respect to the origin of this primitive stock, or stocks, the doctrine of the origin of species is obviously not necessarily concerned. the transmutation hypothesis, for example, is perfectly consistent either with the conception of a special creation of the primitive germ, or with the supposition of its having arisen, as a modification of inorganic matter, by natural causes. the doctrine of special creation owes its existence very largely to the supposed necessity of making science accord with the hebrew cosmogony; but it is curious to observe that, as the doctrine is at present maintained by men of science, it is as hopelessly inconsistent with the hebrew view as any other hypothesis. if there be any result which has come more clearly out of geological investigation than another, it is, that the vast series of extinct animals and plants is not divisible, as it was once supposed to be, into distinct groups, separated by sharply-marked boundaries. there are no great gulfs between epochs and formations--no successive periods marked by the appearance of plants, of water animals, and of land animals, 'en masse'. every year adds to the list of links between what the older geologists supposed to be widely separated epochs: witness the crags linking the drift with older tertiaries; the maestricht beds linking the tertiaries with the chalk; the st. cassian beds exhibiting an abundant fauna of mixed mesozoic and palaeozoic types, in rocks of an epoch once supposed to be eminently poor in life; witness, lastly, the incessant disputes as to whether a given stratum shall be reckoned devonian or carboniferous, silurian or devonian, cambrian or silurian. this truth is further illustrated in a most interesting manner by the impartial and highly competent testimony of m. pictet, from whose calculations of what percentage of the genera of animals, existing in any formation, lived during the preceding formation, it results that in no case is the proportion less than 'one-third', or 33 per cent. it is the triassic formation, or the commencement of the mesozoic epoch, which has received the smallest inheritance from preceding ages. the other formations not uncommonly exhibit 60, 80, or even 94 per cent. of genera in common with those whose remains are imbedded in their predecessor. not only is this true, but the subdivisions of each formation exhibit new species characteristic of, and found only in, them; and, in many cases, as in the lias for example, the separate beds of these subdivisions are distinguished by well-marked and peculiar forms of life. a section, a hundred feet thick, will exhibit, at different heights, a dozen species of ammonite, none of which passes beyond its particular zone of limestone, or clay, into the zone below it or into that above it; so that those who adopt the doctrine of special creation must be prepared to admit, that at intervals of time, corresponding with the thickness of these beds, the creator thought fit to interfere with the natural course of events for the purpose of making a new ammonite. it is not easy to transplant oneself into the frame of mind of those who can accept such a conclusion as this, on any evidence short of absolute demonstration; and it is difficult to see what is to be gained by so doing, since, as we have said, it is obvious that such a view of the origin of living beings is utterly opposed to the hebrew cosmogony. deserving no aid from the powerful arm of bibliolatry, then, does the received form of the hypothesis of special creation derive any support from science or sound logic? assuredly not much. the arguments brought forward in its favour all take one form: if species were not supernaturally created, we cannot understand the facts 'x' or 'y', or 'z'; we cannot understand the structure of animals or plants, unless we suppose they were contrived for special ends; we cannot understand the structure of the eye, except by supposing it to have been made to see with; we cannot understand instincts, unless we suppose animals to have been miraculously endowed with them. as a question of dialectics, it must be admitted that this sort of reasoning is not very formidable to those who are not to be frightened by consequences. it is an 'argumentum ad ignorantiam'--take this explanation or be ignorant. but suppose we prefer to admit our ignorance rather than adopt a hypothesis at variance with all the teachings of nature? or, suppose for a moment we admit the explanation, and then seriously ask ourselves how much the wiser are we; what does the explanation explain? is it any more than a grandiloquent way of announcing the fact, that we really know nothing about the matter? a phenomenon is explained when it is shown to be a case of some general law of nature; but the supernatural interposition of the creator can, by the nature of the case, exemplify no law, and if species have really arisen in this way, it is absurd to attempt to discuss their origin. or, lastly, let us ask ourselves whether any amount of evidence which the nature of our faculties permits us to attain, can justify us in asserting that any phenomenon is out of the reach of natural causation. to this end it is obviously necessary that we should know all the consequences to which all possible combinations, continued through unlimited time, can give rise. if we knew these, and found none competent to originate species, we should have good ground for denying their origin by natural causation. till we know them, any hypothesis is better than one which involves us in such miserable presumption. but the hypothesis of special creation is not only a mere specious mask for our ignorance; its existence in biology marks the youth and imperfection of the science. for what is the history of every science but the history of the elimination of the notion of creative, or other interferences, with the natural order of the phenomena which are the subject-matter of that science? when astronomy was young "the morning stars sang together for joy," and the planets were guided in their courses by celestial hands. now, the harmony of the stars has resolved itself into gravitation according to the inverse squares of the distances, and the orbits of the planets are deducible from the laws of the forces which allow a schoolboy's stone to break a window. the lightning was the angel of the lord; but it has pleased providence, in these modern times, that science should make it the humble messenger of man, and we know that every flash that shimmers about the horizon on a summer's evening is determined by ascertainable conditions, and that its direction and brightness might, if our knowledge of these were great enough, have been calculated. the solvency of great mercantile companies rests on the validity of the laws which have been ascertained to govern the seeming irregularity of that human life which the moralist bewails as the most uncertain of things; plague, pestilence, and famine are admitted, by all but fools, to be the natural result of causes for the most part fully within human control, and not the unavoidable tortures inflicted by wrathful omnipotence upon his helpless handiwork. harmonious order governing eternally continuous progress--the web and woof of matter and force interweaving by slow degrees, without a broken thread, that veil which lies between us and the infinite--that universe which alone we know or can know; such is the picture which science draws of the world, and in proportion as any part of that picture is in unison with the rest, so may we feel sure that it is rightly painted. shall biology alone remain out of harmony with her sister sciences? such arguments against the hypothesis of the direct creation of species as these are plainly enough deducible from general considerations; but there are, in addition, phenomena exhibited by species themselves, and yet not so much a part of their very essence as to have required earlier mention, which are in the highest degree perplexing, if we adopt the popularly accepted hypothesis. such are the facts of distribution in space and in time; the singular phenomena brought to light by the study of development; the structural relations of species upon which our systems of classification are founded; the great doctrines of philosophical anatomy, such as that of homology, or of the community of structural plan exhibited by large groups of species differing very widely in their habits and functions. the species of animals which inhabit the sea on opposite sides of the isthmus of panama are wholly distinct [4] the animals and plants which inhabit islands are commonly distinct from those of the neighbouring mainlands, and yet have a similarity of aspect. the mammals of the latest tertiary epoch in the old and new worlds belong to the same genera, or family groups, as those which now inhabit the same great geographical area. the crocodilian reptiles which existed in the earliest secondary epoch were similar in general structure to those now living, but exhibit slight differences in their vertebrae, nasal passages, and one or two other points. the guinea-pig has teeth which are shed before it is born, and hence can never subserve the masticatory purpose for which they seem contrived, and, in like manner, the female dugong has tusks which never cut the gum. all the members of the same great group run through similar conditions in their development, and all their parts, in the adult state, are arranged according to the same plan. man is more like a gorilla than a gorilla is like a lemur. such are a few, taken at random, among the multitudes of similar facts which modern research has established; but when the student seeks for an explanation of them from the supporters of the received hypothesis of the origin of species, the reply he receives is, in substance, of oriental simplicity and brevity--"mashallah! it so pleases god!" there are different species on opposite sides of the isthmus of panama, because they were created different on the two sides. the pliocene mammals are like the existing ones, because such was the plan of creation; and we find rudimental organs and similarity of plan, because it has pleased the creator to set before himself a "divine exemplar or archetype," and to copy it in his works; and somewhat ill, those who hold this view imply, in some of them. that such verbal hocus-pocus should be received as science will one day be regarded as evidence of the low state of intelligence in the nineteenth century, just as we amuse ourselves with the phraseology about nature's abhorrence of a vacuum, wherewith torricelli's compatriots were satisfied to explain the rise of water in a pump. and be it recollected that this sort of satisfaction works not only negative but positive ill, by discouraging inquiry, and so depriving man of the usufruct of one of the most fertile fields of his great patrimony, nature. the objections to the doctrine of the origin of species by special creation which have been detailed, must have occurred, with more or less force, to the mind of every one who has seriously and independently considered the subject. it is therefore no wonder that, from time to time, this hypothesis should have been met by counter hypotheses, all as well, and some better founded than itself; and it is curious to remark that the inventors of the opposing views seem to have been led into them as much by their knowledge of geology, as by their acquaintance with biology. in fact, when the mind has once admitted the conception of the gradual production of the present physical state of our globe, by natural causes operating through long ages of time, it will be little disposed to allow that living beings have made their appearance in another way, and the speculations of de maillet and his successors are the natural complement of scilla's demonstration of the true nature of fossils. a contemporary of newton and of leibnitz, sharing therefore in the intellectual activity of the remarkable age which witnessed the birth of modern physical science, benoit de maillet spent a long life as a consular agent of the french government in various mediterranean ports. for sixteen years, in fact, he held the office of consul-general in egypt, and the wonderful phenomena offered by the valley of the nile appear to have strongly impressed his mind, to have directed his attention to all facts of a similar order which came within his observation, and to have led him to speculate on the origin of the present condition of our globe and of its inhabitants. but, with all his ardour for science, de maillet seems to have hesitated to publish views which, notwithstanding the ingenious attempts to reconcile them with the hebrew hypothesis contained in the preface to "telliamed," were hardly likely to be received with favour by his contemporaries. but a short time had elapsed since more than one of the great anatomists and physicists of the italian school had paid dearly for their endeavours to dissipate some of the prevalent errors; and their illustrious pupil, harvey, the founder of modern physiology, had not fared so well, in a country less oppressed by the benumbing influences of theology, as to tempt any man to follow his example. probably not uninfluenced by these considerations, his catholic majesty's consul-general for egypt kept his theories to himself throughout a long life, for 'telliamed,' the only scientific work which is known to have proceeded from his pen, was not printed till 1735, when its author had reached the ripe age of seventy-nine; and though de maillet lived three years longer, his book was not given to the world before 1748. even then it was anonymous to those who were not in the secret of the anagrammatic character of its title; and the preface and dedication are so worded as, in case of necessity, to give the printer a fair chance of falling back on the excuse that the work was intended for a mere 'jeu d'esprit'. the speculations of the suppositious indian sage, though quite as sound as those of many a "mosaic geology," which sells exceedingly well, have no great value if we consider them by the light of modern science. the waters are supposed to have originally covered the whole globe; to have deposited the rocky masses which compose its mountains by processes comparable to those which are now forming mud, sand, and shingle; and then to have gradually lowered their level, leaving the spoils of their animal and vegetable inhabitants embedded in the strata. as the dry land appeared, certain of the aquatic animals are supposed to have taken to it, and to have become gradually adapted to terrestrial and aerial modes of existence. but if we regard the general tenor and style of the reasoning in relation to the state of knowledge of the day, two circumstances appear very well worthy of remark. the first, that de maillet had a notion of the modifiability of living forms (though without any precise information on the subject), and how such modifiability might account for the origin of species; the second, that he very clearly apprehended the great modern geological doctrine, so strongly insisted upon by hutton, and so ably and comprehensively expounded by lyell, that we must look to existing causes for the explanation of past geological events. indeed, the following passage of the preface, in which de maillet is supposed to speak of the indian philosopher telliamed, his 'alter ego', might have been written by the most philosophical uniformitarian of the present day:-"ce qu'il y a d'etonnant, est que pour arriver a ces connoissances il semble avoir perverti l'ordre naturel, puisqu'au lieu de s'attacher d'abord a rechercher l'origine de notre globe il a commence par travailler a s'instruire de la nature. mais a l'entendre, ce renversement de l'ordre a ete pour lui l'effet d'un genie favorable qui l'a conduit pas a pas et comme par la main aux decouvertes les plus sublimes. c'est en decomposant la substance de ce globe par une anatomie exacte de toutes ses parties qu'il a premierement appris de quelles matieres il etait compose et quels arrangemens ces memes matieres observaient entre elles. ces lumieres jointes a l'esprit de comparaison toujours necessaire a quiconque entreprend de percer les voiles dont la nature aime a se cacher, ont servi de guide a notre philosophe pour parvenir a des connoissances plus interessantes. par la matiere et l'arrangement de ces compositions il pretend avoir reconnu quelle est la veritable origine de ce globe que nous habitons, comment et par qui il a ete forme."--pp. xix. xx. but de maillet was before his age, and as could hardly fail to happen to one who speculated on a zoological and botanical question before linnaeus, and on a physiological problem before haller, he fell into great errors here and there; and hence, perhaps, the general neglect of his work. robinet's speculations are rather behind, than in advance of, those of de maillet; and though linnaeus may have played with the hypothesis of transmutation, it obtained no serious support until lamarck adopted it, and advocated it with great ability in his 'philosophie zoologique.' impelled towards the hypothesis of the transmutation of species, partly by his general cosmological and geological views; partly by the conception of a graduated, though irregularly branching, scale of being, which had arisen out of his profound study of plants and of the lower forms of animal life, lamarck, whose general line of thought often closely resembles that of de maillet, made a great advance upon the crude and merely speculative manner in which that writer deals with the question of the origin of living beings, by endeavouring to find physical causes competent to effect that change of one species into another, which de maillet had only supposed to occur. and lamarck conceived that he had found in nature such causes, amply sufficient for the purpose in view. it is a physiological fact, he says, that organs are increased in size by action, atrophied by inaction; it is another physiological fact that modifications produced are transmissible to offspring. change the actions of an animal, therefore, and you will change its structure, by increasing the development of the parts newly brought into use and by the diminution of those less used; but by altering the circumstances which surround it you will alter its actions, and hence, in the long run, change of circumstance must produce change of organization. all the species of animals, therefore, are, in lamarck's view, the result of the indirect action of changes of circumstance, upon those primitive germs which he considered to have originally arisen, by spontaneous generation, within the waters of the globe. it is curious, however, that lamarck should insist so strongly [5] as he has done, that circumstances never in any degree directly modify the form or the organization of animals, but only operate by changing their wants and consequently their actions; for he thereby brings upon himself the obvious question, how, then, do plants, which cannot be said to have wants or actions, become modified? to this he replies, that they are modified by the changes in their nutritive processes, which are effected by changing circumstances; and it does not seem to have occurred to him that such changes might be as well supposed to take place among animals. when we have said that lamarck felt that mere speculation was not the way to arrive at the origin of species, but that it was necessary, in order to the establishment of any sound theory on the subject, to discover by observation or otherwise, some 'vera causa', competent to give rise to them; that he affirmed the true order of classification to coincide with the order of their development one from another; that he insisted on the necessity of allowing sufficient time, very strongly; and that all the varieties of instinct and reason were traced back by him to the same cause as that which has given rise to species, we have enumerated his chief contributions to the advance of the question. on the other hand, from his ignorance of any power in nature competent to modify the structure of animals, except the development of parts, or atrophy of them, in consequence of a change of needs, lamarck was led to attach infinitely greater weight than it deserves to this agency, and the absurdities into which he was led have met with deserved condemnation. of the struggle for existence, on which, as we shall see, mr. darwin lays such great stress, he had no conception; indeed, he doubts whether there really are such things as extinct species, unless they be such large animals as may have met their death at the hands of man; and so little does he dream of there being any other destructive causes at work, that, in discussing the possible existence of fossil shells, he asks, "pourquoi d'ailleurs seroient-ils perdues des que l'homme n'a pu operer leur destruction?" ('phil. zool.,' vol. i. p. 77.) of the influence of selection lamarck has as little notion, and he makes no use of the wonderful phenomena which are exhibited by domesticated animals, and illustrate its powers. the vast influence of cuvier was employed against the lamarckian views, and, as the untenability of some of his conclusions was easily shown, his doctrines sank under the opprobrium of scientific, as well as of theological, heterodoxy. nor have the efforts made of late years to revive them tended to re-establish their credit in the minds of sound thinkers acquainted with the facts of the case; indeed it may be doubted whether lamarck has not suffered more from his friends than from his foes. two years ago, in fact, though we venture to question if even the strongest supporters of the special creation hypothesis had not, now and then, an uneasy consciousness that all was not right, their position seemed more impregnable than ever, if not by its own inherent strength, at any rate by the obvious failure of all the attempts which had been made to carry it. on the other hand, however much the few, who thought deeply on the question of species, might be repelled by the generally received dogmas, they saw no way of escaping from them save by the adoption of suppositions so little justified by experiment or by observation as to be at least equally distasteful. the choice lay between two absurdities and a middle condition of uneasy scepticism; which last, however unpleasant and unsatisfactory, was obviously the only justifiable state of mind under the circumstances. such being the general ferment in the minds of naturalists, it is no wonder that they mustered strong in the rooms of the linnaean society, on the 1st of july of the year 1858, to hear two papers by authors living on opposite sides of the globe, working out their results independently, and yet professing to have discovered one and the same solution of all the problems connected with species. the one of these authors was an able naturalist, mr. wallace, who had been employed for some years in studying the productions of the islands of the indian archipelago, and who had forwarded a memoir embodying his views to mr. darwin, for communication to the linnaean society. on perusing the essay, mr. darwin was not a little surprised to find that it embodied some of the leading ideas of a great work which he had been preparing for twenty years, and parts of which, containing a development of the very same views, had been perused by his private friends fifteen or sixteen years before. perplexed in what manner to do full justice both to his friend and to himself, mr. darwin placed the matter in the hands of dr. hooker and sir charles lyell, by whose advice he communicated a brief abstract of his own views to the linnaean society, at the same time that mr. wallace's paper was read. of that abstract, the work on the 'origin of species' is an enlargement; but a complete statement of mr. darwin's doctrine is looked for in the large and well-illustrated work which he is said to be preparing for publication. the darwinian hypothesis has the merit of being eminently simple and comprehensible in principle, and its essential positions may be stated in a very few words: all species have been produced by the development of varieties from common stocks; by the conversion of these, first into permanent races and then into new species, by the process of 'natural selection', which process is essentially identical with that artificial selection by which man has originated the races of domestic animals--the 'struggle for existence' taking the place of man, and exerting, in the case of natural selection, that selective action which he performs in artificial selection. the evidence brought forward by mr. darwin in support of his hypothesis is of three kinds. first, he endeavours to prove that species may be originated by selection; secondly, he attempts to show that natural causes are competent to exert selection; and thirdly, he tries to prove that the most remarkable and apparently anomalous phenomena exhibited by the distribution, development, and mutual relations of species, can be shown to be deducible from the general doctrine of their origin, which he propounds, combined with the known facts of geological change; and that, even if all these phenomena are not at present explicable by it, none are necessarily inconsistent with it. there cannot be a doubt that the method of inquiry which mr. darwin has adopted is not only rigorously in accordance with the canons of scientific logic, but that it is the only adequate method. critics exclusively trained in classics or in mathematics, who have never determined a scientific fact in their lives by induction from experiment or observation, prate learnedly about mr. darwin's method, which is not inductive enough, not baconian enough, forsooth, for them. but even if practical acquaintance with the process of scientific investigation is denied them, they may learn, by the perusal of mr. mill's admirable chapter "on the deductive method," that there are multitudes of scientific inquiries in which the method of pure induction helps the investigator but a very little way. "the mode of investigation," says mr. mill, "which, from the proved inapplicability of direct methods of observation and experiment, remains to us as the main source of the knowledge we possess, or can acquire, respecting the conditions and laws of recurrence of the more complex phenomena, is called, in its most general expression, the deductive method, and consists of three operations: the first, one of direct induction; the second, of ratiocination; and the third, of verification." now, the conditions which have determined the existence of species are not only exceedingly complex, but, so far as the great majority of them are concerned, are necessarily beyond our cognizance. but what mr. darwin has attempted to do is in exact accordance with the rule laid down by mr. mill; he has endeavoured to determine certain great facts inductively, by observation and experiment; he has then reasoned from the data thus furnished; and lastly, he has tested the validity of his ratiocination by comparing his deductions with the observed facts of nature. inductively, mr. darwin endeavours to prove that species arise in a given way. deductively, he desires to show that, if they arise in that way, the facts of distribution, development, classification, etc., may be accounted for, 'i.e.' may be deduced from their mode of origin, combined with admitted changes in physical geography and climate, during an indefinite period. and this explanation, or coincidence of observed with deduced facts, is, so far as it extends, a verification of the darwinian view. there is no fault to be found with mr. darwin's method, then; but it is another question whether he has fulfilled all the conditions imposed by that method. is it satisfactorily proved, in fact, that species may be originated by selection? that there is such a thing as natural selection? that none of the phenomena exhibited by species are inconsistent with the origin of species in this way? if these questions can be answered in the affirmative, mr. darwin's view steps out of the rank of hypotheses into those of proved theories; but, so long as the evidence at present adduced falls short of enforcing that affirmation, so long, to our minds, must the new doctrine be content to remain among the former--an extremely valuable, and in the highest degree probable, doctrine, indeed the only extant hypothesis which is worth anything in a scientific point of view; but still a hypothesis, and not yet the theory of species. after much consideration, and with assuredly no bias against mr. darwin's views, it is our clear conviction that, as the evidence stands, it is not absolutely proven that a group of animals, having all the characters exhibited by species in nature, has ever been originate by selection, whether artificial or natural. groups having the morphological character of species, distinct and permanent races in fact, have been so produced over and over again; but there is no positive evidence, at present, that any group of animals has, by variation and selective breeding, given rise to another group which was, even in the least degree, infertile with the first. mr. darwin is perfectly aware of this weak point, and brings forward a multitude of ingenious and important arguments to diminish the force of the objection. we admit the value of these arguments to their fullest extent; nay, we will go so far as to express our belief that experiments, conducted by a skilful physiologist, would very probably obtain the desired production of mutually more or less infertile breeds from a common stock, in a comparatively few years; but still, as the case stands at present, this "little rift within the lute" is not to be disguised nor overlooked. in the remainder of mr. darwin's argument our own private ingenuity has not hitherto enabled us to pick holes of any great importance; and judging by what we hear and read, other adventurers in the same field do not seem to have been much more fortunate. it has been urged, for instance, that in his chapters on the struggle for existence and on natural selection, mr. darwin does not so much prove that natural selection does occur, as that it must occur; but, in fact, no other sort of demonstration is attainable. a race does not attract our attention in nature until it has, in all probability, existed for a considerable time, and then it is too late to inquire into the conditions of its origin. again, it is said that there is no real analogy between the selection which takes place under domestication, by human influence, and any operation which can be effected by nature, for man interferes intelligently. reduced to its elements, this argument implies that an effect produced with trouble by an intelligent agent must, 'a fortiori', be more troublesome, if not impossible, to an unintelligent agent. even putting aside the question whether nature, acting as she does according to definite and invariable laws, can be rightly called an unintelligent agent, such a position as this is wholly untenable. mix salt and sand, and it shall puzzle the wisest of men, with his mere natural appliances, to separate all the grains of sand from all the grains of salt; but a shower of rain will effect the same object in ten minutes. and so, while man may find it tax all his intelligence to separate any variety which arises, and to breed selectively from it, the destructive agencies incessantly at work in nature, if they find one variety to be more soluble in circumstances than the other, will inevitably, in the long run, eliminate it. a frequent and a just objection to the lamarckian hypothesis of the transmutation of species is based upon the absence of transitional forms between many species. but against the darwinian hypothesis this argument has no force. indeed, one of the most valuable and suggestive parts of mr. darwin's work is that in which he proves, that the frequent absence of transitions is a necessary consequence of his doctrine, and that the stock whence two or more species have sprung, need in no respect be intermediate between these species. if any two species have arisen from a common stock in the same way as the carrier and the pouter, say, have arisen from the rock-pigeon, then the common stock of these two species need be no more intermediate between the two than the rock-pigeon is between the carrier and pouter. clearly appreciate the force of this analogy, and all the arguments against the origin of species by selection, based on the absence of transitional forms, fall to the ground. and mr. darwin's position might, we think, have been even stronger than it is if he had not embarrassed himself with the aphorism, "natura non facit saltum," which turns up so often in his pages. we believe, as we have said above, that nature does make jumps now and then, and a recognition of the fact is of no small importance in disposing of many minor objections to the doctrine of transmutation. but we must pause. the discussion of mr. darwin's arguments in detail would lead us far beyond the limits within which we proposed, at starting, to confine this article. our object has been attained if we have given an intelligible, however brief, account of the established facts connected with species, and of the relation of the explanation of those facts offered by mr. darwin to the theoretical views held by his predecessors and his contemporaries, and, above all, to the requirements of scientific logic. we have ventured to point out that it does not, as yet, satisfy all those requirements; but we do not hesitate to assert that it is as superior to any preceding or contemporary hypothesis, in the extent of observational and experimental basis on which it rests, in its rigorously scientific method, and in its power of explaining biological phenomena, as was the hypothesis of copernicus to the speculations of ptolemy. but the planetary orbits turned out to be not quite circular after all, and, grand as was the service copernicus rendered to science, kepler and newton had to come after him. what if the orbit of darwinism should be a little too circular? what if species should offer residual phenomena, here and there, not explicable by natural selection? twenty years hence naturalists may be in a position to say whether this is, or is not, the case; but in either event they will owe the author of 'the origin of species' an immense debt of gratitude. we should leave a very wrong impression on the reader's mind if we permitted him to suppose that the value of that work depends wholly on the ultimate justification of the theoretical views which it contains. on the contrary, if they were disproved to-morrow, the book would still be the best of its kind--the most compendious statement of well-sifted facts bearing on the doctrine of species that has ever appeared. the chapters on variation, on the struggle for existence, on instinct, on hybridism, on the imperfection of the geological record, on geographical distribution, have not only no equals, but, so far as our knowledge goes, no competitors, within the range of biological literature. and viewed as a whole, we do not believe that, since the publication of von baer's researches on development, thirty years ago, any work has appeared calculated to exert so large an influence, not only on the future of biology, but in extending the domination of science over regions of thought into which she has, as yet, hardly penetrated. [footnote 1: 'the westminster review', april 1860.] [footnote 2: on the osteology of the chimpanzees and orangs: transactions of the zoological society, 1858.] [footnote 3: colonel humphreys' statements are exceedingly explicit on this point:--"when an ancon ewe is impregnated by a common ram, the increase resembles wholly either the ewe or the ram. the increase of the common ewe impregnated by an ancon ram follows entirely the one or the other, without blending any of the distinguishing and essential peculiarities of both. frequent instances have happened where common ewes have had twins by ancon rams, when one exhibited the complete marks and features of the ewe, the other of the ram. the contrast has been rendered singularly striking, when one short-legged and one long-legged lamb, produced at a birth, have been seen sucking the dam at the same time."--'philosophical transactions', 1813, pt. i. pp. 89, 90.] [footnote 4: recent investigations tend to show that this statement is not strictly accurate.--1870.] [footnote 5: see 'phil. zoologique,' vol. i. p. 222, 'et seq.'] this simian world by: clarence day jr. "how i hate the man who talks about the 'brute creation,' with an ugly emphasis on _brute_.... as for me, i am proud of my close kinship with other animals. i take a jealous pride in my simian ancestry. i like to think that i was once a magnificent hairy fellow living in the trees, and that my frame has come down through geological time via sea jelly and worms and amphioxus, fish, dinosaurs, and apes. who would exchange these for the pallid couple in the garden of eden?" w. n. p. barbellion. i last sunday, potter took me out driving along upper broadway, where those long rows of tall new apartment houses were built a few years ago. it was a mild afternoon and great crowds of people were out. sunday afternoon crowds. they were not going anywhere,--they were just strolling up and down, staring at each other, and talking. there were thousands and thousands of them. "awful, aren't they!" said potter. i didn't know what he meant. when he added, "why, these crowds," i turned and asked, "why, what about them?" i wasn't sure whether he had an idea or a headache. "other creatures don't do it," he replied, with a discouraged expression. "are any other beings ever found in such masses, but vermin? aimless, staring, vacant-minded,--look at them! i can get no sense whatever of individual worth, or of value in men as a race, when i see them like this. it makes one almost despair of civilization." i thought this over for awhile, to get in touch with his attitude. i myself feel differently at different times about us human-beings: sometimes i get pretty indignant when we are attacked (for there is altogether too much abuse of us by spectator philosophers) and yet at other times i too feel like a spectator, an alien: but even then i had never felt so alien or despairing as potter. "let's remember," i said, "it's a simian civilization." potter was staring disgustedly at some vaudeville sign-boards. "yes," i said, "those for example are distinctively simian. why should you feel disappointment at something inevitable?" and i went on to argue that it wasn't as though we were descended from eagles for instance, instead of (broadly speaking) from ape-like or monkeyish beings. being of simian stock, we had simian traits. our development naturally bore the marks of our origin. if we had inherited our dispositions from eagles we should have loathed vaudeville. but as cousins of the bandarlog, we loved it. what could you expect? ii if we had been made directly from clay, the way it says in the bible, and had therefore inherited no intermediate characteristics,--if a god, or some principle of growth, had gone that way to work with us, he or it might have molded us in much more splendid forms. but considering our simian descent, it has done very well. the only people who are disappointed in us are those who still believe that clay story. or who--unconsciously--still let it color their thinking. there certainly seems to be a power at work in the world, by virtue of which every living thing grows and develops. and it tends toward splendor. seeds become trees, and weak little nations grow great. but the push or the force that is doing this, the yeast as it were, has to work in and on certain definite kinds of material. because this yeast is in us there may be great and undreamed of possibilities awaiting mankind; but because of our line of descent there are also queer limitations. iii in those distant invisible epochs before men existed, before even the proud missing link strutted around through the woods (little realizing how we his greatgrandsons would smile wryly at him much as our own descendants may shudder at us, ages hence) the various animals were desperately competing for power. they couldn't or didn't live as equals. certain groups sought the headship. many strange forgotten dynasties rose, met defiance, and fell. in the end it was our ancestors who won, and became simian kings, and bequeathed a whole planet to us--and have never been thanked for it. no monument has been raised to the memory of those first hairy conquerors; yet had they not fought well and wisely in those far-off times, some other race would have been masters, and kept us in cages, or show us for sport in the forest while they ruled the world. so potter and i, developing this train of thought, began to imagine we had lived many ages ago, and somehow or other had alighted here from some older planet. familiar with the ways of evolution elsewhere in the universe, we naturally should have wondered what course it would take on this earth. "even in this out-of-the-way corner of the cosmos," we might have reflected, "and on this tiny star, it may be of interest to consider the trend of events." we should have tried to appraise the different species as they wandered around, each with its own set of good and bad characteristics. which group, we'd have wondered, would ever contrive to rule all the rest? and how great a development could they attain to thereafter? iv if we had landed here after the great saurians had been swept from the scene, we might first have considered the lemurs or apes. they had hands. aesthetically viewed, the poor simians were simply grotesque; but travelers who knew other planets might have known what beauty may spring from an uncouth beginning in this magic universe. still--those frowsy, unlovely hordes of apes and monkeys were so completely lacking in signs of kingship; they were so flighty, too, in their ways, and had so little purpose, and so much love for absurd and idle chatter, that they would have struck us, we thought, as unlikely material. such traits, we should have reminded ourselves, persist. they are not easily left behind, even after long stages; and they form a terrible obstacle to all high advancement. v the bees or the ants might have seemed to us more promising. their smallness of size was not necessarily too much of a handicap. they could have made poison their weapon for the subjugation of rivals. and in these orderly insects there are obviously a capacity for labor, and co-operative labor at that, which could carry them far. we all know that they have a marked genius: great gifts of their own. in a civilization of super-ants or bees, there would have been no problem of the hungry unemployed, no poverty, no unstable government, no riots, no strikes for short hours, no derision of eugenics, no thieves, perhaps no crime at all. ants are good citizens: they place group interests first. but they carry it so far, they have few or no political rights. an ant doesn't have the vote, apparently: he just has his duties. this quality may have something to do with their having groups wars. the egotism of their individual spirits is allowed scant expression, so the egotism of the groups is extremely ferocious and active. is this one of the reasons why ants fight so much? we have seen the same phenomenon occur in certain nations of men. and the ants commit atrocities in and after their battles that are--i wish i could truly say--inhuman. but conversely, ants are absolutely unselfish within the community. they are skilful. ingenious. their nests and buildings are relatively larger than man's. the scientists speak of their paved streets, vaulted halls, their hundreds of different domesticated animals, their pluck and intelligence, their individual initiative, their chaste and industrious lives. darwin said the ant's brain was "one of the most marvelous atoms in the world, perhaps more so than the brain of man"--yes, of present-day man, who for thousands and thousands of years has had so much more chance to develop his brain.... a thoughtful observer would have weighed all these excellent qualities. when we think of these creatures as little men (which is all wrong of course) we see they have their faults. to our eyes they seem too orderly, for instance. repressively so. their ways are more fixed than those of the old egyptians, and their industry is painful to think of, it's hyper-chinese. but we must remember this is a simian comment. the instincts of the species that you and i belong to are of an opposite kind; and that makes it hard for us to judge ants fairly. but we and the ants are alike in one matter: the strong love of property. and instead of merely struggling with nature for it, they also fight other ants. the custom of plunder seems to be a part of most of their wars. this has gone on for ages among them, and continues today. raids, ferocious combats, and loot are part of an ant's regular life. ant reformers, if there were any, might lay this to their property sense, and talk of abolishing property as a cure for the evil. but that would not help for long unless they could abolish the love of it. ants seem to care even more for property than we do ourselves. we men are inclined to ease up a little when we have all we need. but it no so with ants: they can't bear to stop: they keep right on working. this means that ants do not contemplate: they heed nothing outside of their own little rounds. it is almost as though their fondness for labor had closed fast their minds. conceivably they might have developed inquiring minds. but this would have run against their strongest instincts. the ant is knowing and wise; but he doesn't know enough to take a vacation. the worshipper of energy is too physically energetic to see that he cannot explore certain higher fields until he is still. even if such a race had somehow achieved self-consciousness and reason, would they have been able therewith to rule their instincts, or to stop work long enough to examine themselves, or the universe, or to dream of any noble development? probably not. reason is seldom or never the ruler: it is the servant of instinct. it would therefore have told the ants that incessant toil was useful and good. "toil has brought you up from the ruck of things." reason would have plausibly said, "it's by virtue of feverish toil that you have become what you are. being endlessly industrious is the best road--for you--to the heights." and, self-reassured, they would then have had orgies of work; and thus, by devoted exertion, have blocked their advancement. work, and order and gain would have withered their souls. vi let us take the great cats. they are free from this talent for slave-hood. stately beasts like the lion have more independence of mind than the ants,--and a self-respect, we may note, unknown to primates. or consider the leopards, with hearts that no tyrant could master. what fearless and resolute leopard-men they could have fathered! how magnificently such a civilization would have made its force tell! a race of civilized beings descended from these great cats would have been rich in hermits and solitary thinkers. the recluse would not have been stigmatized as peculiar, as he is by us simians. they would not have been a credulous people, or easily religious. false prophets and swindlers would have found few dupes. and what generals they would have made! what consummate politicians! don't imagine them as a collection of tigers walking around on their hind-legs. they would have only been like tigers in the sense that we men are like monkeys. their development in appearance and character would have been quite transforming. instead of the small flat head of the tiger, they would have had clear smooth brows; and those who were not bald would have had neatly parted hair--perhaps striped. their mouths would have been smaller and more sensitive: their faces most dignified. where now they express chiefly savageness, they would have expressed fire and grace. they would have been courteous and suave. no vulgar crowding would have occurred on the streets of their cities. no mobs. no ignominious subway-jams. imagine a cultivated coterie of such men and women, at a ball, dancing. how few of us humans are graceful. they would have all been pavlowas. like ants and bees, the cat race is nervous. their temperaments are high-strung. they would never have become as poised or as placid as--say--super-cows. yet they would have had less insanity, probably, than we. monkeys' (and elephants') minds seem precariously balanced, unstable. the great cats are saner. they are intense, they would have needed sanitariums: but fewer asylums. and their asylums would have been not for weak-minded souls, but for furies. they would have been strong at slander. they would have been far more violent than we, in their hates, and they would have had fewer friendships. yet they might not have been any poorer in real friendships than we. the real friendships among men are so rare than when they occur they are famous. friends as loyal as damon and pythias were, are exceptions. good fellowship is common, but unchanging affection is not. we like those who like us, as a rule, and dislike those who don't. most of our ties have no better footing than that; and those who have many such ties are called warm-hearted. the super-cat-men would have rated cleanliness higher. some of us primates have learned to keep ourselves clean, but it's no large proportion; and even the cleanest of us see no grandeur in soap-manufacturing, and we don't look to manicures and plumbers for social prestige. a feline race would have honored such occupations. j. de courcy tiger would have felt that nothing _but_ making soap, or being a plumber, was compatible with a high social position; and the rich vera pantherbilt would have deigned to dine only with manicures. none but the lowest dregs of such a race would have been lawyers spending their span of life on this mysterious earth studying the long dusty records of dead and gone quarrels. we simians naturally admire a profession full of wrangle and chatter. but that is a monkeyish way of deciding disputes, not feline. we fight best in armies, gregariously, where the risk is reduced; but we disapprove usually of murderers, and of almost all private combat. with the great cats, it would have been just the other way round. (lions and leopards fight each other singly, not in bands, as do monkeys.) as a matter of fact, few of us delight in really serious fighting. we do love to bicker; and we box and knock each other around, to exhibit our strength; but few normal simians are keen about bloodshed and killing; we do it in war only because of patriotism, revenge, duty, glory. a feline civilization would have cared nothing for duty or glory, but they would have taken a far higher pleasure in gore. if a planet of super-cat-men could look down upon ours, they would not know which to think was the most amazing: the way we tamely live, five million or so in a city, with only a few police to keep us quiet, while we commit only one or two murders a day, and hardly have a respectable number of brawls; or the way great armies of us are trained to fight,--not liking it much, and yet doing more killing in wartime and shedding more blood than even the fiercest lion on his cruelest days. which would perplex a gentlemanly super-cat spectator the more, our habits of wholesale slaughter in the field, or our spiritless making a fetish of "order," at home? it is fair to judge peoples by the rights they will sacrifice most for. super-cat-men would have been outraged, had their right of personal combat been questioned. the simian submits with odd readiness to the loss of this privilege. what outrages him is to make him stop wagging his tongue. he becomes most excited and passionate about the right of free speech, even going so far in his emotion as to declare it is sacred. he looks upon other creatures pityingly because they are dumb. if one of his own children is born dumb, he counts it a tragedy. even that mere hesitation in speech, known as stammering, he deems a misfortune. so precious to a simian is the privilege of making sounds with his tongue, that when he wishes to punish severely those men he calls criminals, he forbids them to chatter, and forces them by threats to be silent. it is felt that his punishment is entirely too cruel however and even the worst offenders should be allowed to talk part of each day. whatever a simian does, there must always be some talking about it. he can't even make peace without a kind of chatter called a peace conference. super-cats would not have had to "make" peace: they would have just walked off and stopped fighting. in a world of super-cat-men, i suppose there would have been fewer sailors; and people would have cared less for seaside resorts, or for swimming. cats hate getting wet, so men descended from them might have hated it. they would have felt that even going in wading was sign of great hardihood, and only the most daring young fellows, showing off, would have done it. among them there would have been no antivivisection societies: no young cat christian associations or red cross work: no vegetarians: no early closing laws: much more hunting and trapping: no riding to hounds; that's pure simian. just think how it would have entranced the old-time monkeys to foresee such a game! a game where they'd all prance off on captured horses, tearing pell-mell through the woods in gay red coats, attended by yelping packs of servant-dogs. it is excellent sport--but how cats would scorn to hunt in that way! they would not have knighted explorers--they would have all been explorers. imagine that you are strolling through a super-cat city at night. over yonder is the business quarter, its evening shops blazing with jewels. the great stock-yards lie to the east where you hear those sad sounds: that twittering as of innumerable birds, waiting slaughter. beyond lie the silent aquariums and the crates of fresh mice. (they raise mice instead of hens in the country, in super-cat land.) to the west is a beautiful but weirdly bacchanalian park, with long groves of catnip, where young super-cats have their fling, and where a few crazed catnip addicts live on till they die, unable to break off their strangely undignified orgies. and here where you stand is the sumptuous residence district. houses with spacious grounds everywhere: no densely-packed buildings. the streets have been swept up--or lapped up--until they are spotless. not a scrap of paper is lying around anywhere: no rubbish, no dust. few of the pavements are left bare, as ours are, and those few are polished: the rest have deep soft velvet carpets. no footfalls are heard. there are no lights in these streets, though these people are abroad much at night. all you see are stars overhead and the glowing eyes of cat ladies, of lithe silken ladies who pass you, or of stiff-whiskered men. beware of those men and the gleam of the split-pupiled stare. they are haughty, punctilious, inflammable: self-absorbed too, however. they will probably not even notice you; but if they do, you are lost. they take offense in a flash, abhor strangers, despise hospitality, and would think nothing of killing you or me on their way home to dinner. follow one of them. enter this house. ah what splendor! no servants, though a few abject monkeys wait at the back-doors, and submissively run little errands. but of course they are never let inside: they would seem out of place. gorgeous couches, rich colors, silken walls, an oriental magnificence. in here is the ballroom. but wait: what is this in the corner? a large triumphal statue--of a cat overcoming a dog. and look at this dining-room, its exquisite appointments, its--daintiness: faucets for hot and cold milk in the pantry, and a gold bowl of cream. some one is entering. hush! if i could but describe her! languorous, slender and passionate. sleepy eyes that see everything. an indolent purposeful step. an unimaginable grace. if you were _her_ lover, my boy, you would learn how fierce love can be, how capricious and sudden, how hostile, how ecstatic, how violent! think what the state of the arts would have been in such cities. they would have had few comedies on their stage; no farces. cats care little for fun. in the circus, superlative acrobats. no clowns. in drama and singing they would have surpassed us probably. even in the state of arrested development as mere animals, in which we see cats, they wail with a passionate intensity at night in our yards. imagine how a caruso descended from such beings would sing. in literature they would not have begged for happy endings. they would have been personally more self-assured than we, far freer of cheap imitativeness of each other in manners and art, and hence more original in art; more clearly aware of what they really desired; not cringingly watchful of what was expected of them; less widely observant perhaps, more deeply thoughtful. their artists would have produced less however, even though they felt more. a super-cat artist would have valued the pictures he drew for their effects on himself; he wouldn't have cared a rap whether anyone else saw them or not. he would not have bothered, usually, to give any form to his conceptions. simply to have had the sensation would have for him been enough. but since simians love to be noticed, it does not content them to have a conception; they must wrestle with it until it takes a form in which others can see it. they doom the artistic impulse to toil with its nose to the grindstone, until their idea is expressed in a book or a statue. are they right? i have doubts. the artistic impulse seems not to wish to produce finished work. it certainly deserts us half-way, after the idea is born; and if we go on, art is labor. with the cats, art is joy. but the dominant characteristic of this fine race is cunning. and hence i think it would have been through their craftiness, chiefly, that they would have felt the impulse to study, and the wish to advance. craft is a cat's delight: craft they never can have too much of. so it would have been from one triumph of cunning to another that they would have marched. that would have been the greatest driving force of their civilization. this would have meant great progress in invention and science--or in some fields of science, the economic for instance. but it would have retarded them in others. craft studies the world calculatingly, from without, instead of understandingly from within. especially would it have cheapened the feline philosophies; for not simply how to know but how to circumvent the universe would have been their desire. mankind's curiosity is disinterested; it seems purer by contrast. that is to say, made as we are, it seems purer to us. what we call disinterested, however, super-cats might call aimless. (aimlessness is one of the regular simian traits.) i don't mean to be prejudiced in favor of the simian side. curiosity may be as debasing, i grant you, as craft. and craft might turn into artifices of a kind which would be noble and fine. just as the ignorant and fitful curiosity of some little monkey is hardly to be compared to the astronomer's magnificent search, so the craft and cunning we see in our pussies would bear small relation to the high-minded planning of some ruler of the race we are imagining. and yet--craft _is_ self-defeating in the end. transmute it into its finest possible form, let it be as subtle and civilized as you please, as yearning and noble, as enlightened, it still sets itself over against the wholeness of things; its role is that of the part at war with the whole. milton's lucifer had the mind of a fine super-cat. that craft may defeat itself in the end, however, is not the real point. that doesn't explain why the lions aren't ruling the planet. the trouble is, it would defeat itself in the beginning. it would have too bitterly stressed the struggle for existence. conflict and struggle make civilizations virile, but they do not by themselves make civilizations. mutual aid and support are needed for that. there the felines are lacking. they do not co-operate well; they have small group-devotion. their lordliness, their strong self-regard, and their coolness of heart, have somehow thwarted the chance of their racial progress. vii there are many other beasts that one might once have thought had a chance. some, like horses and deer, were not bold enough; or were stupid, like buffaloes. some had over-trustful characters, like the seals; or exploitable characters, like cows, and chickens, and sheep. such creatures sentence themselves to be captives, by their lack of ambition. dogs? they have more spirit. but they have lost their chance of kingship through worshipping us. the dog's finer qualities can't be praised too warmly; there is a purity about his devotion which makes mere men feel speechless: but with all love for dogs, one must grant they are vassals, not rulers. they are too parasitic--the one willing servant class of the world. and we have betrayed them by making under-simians of them. we have taught them some of our own ways of behaving, and frowned upon theirs. loving us, they let us stop their developing in tune with their natures; and they've patiently tried ever since to adopt ways of ours. they have done it, too; but of course they can't get far: it's not their own road. dogs have more love than integrity. they've been true to us, yes, but they haven't been true to themselves. pigs? the pig is remarkably intelligent and brave,--but he's gross; and grossness delays one's achievement, it takes so much time. the snake too, though wise, has a way of eating himself into stupors. if super-snake-men had had banquets they would have been too vast to describe. each little snake family could have eaten a herd of cattle at christmas. goats, then? bears or turtles? wolves, whales, crows? each had brains and pride, and would have been glad to rule the world if they could; but each had their defects, and their weaknesses for such a position. the elephant? ah! evolution has had its tragedies, hasn't it, as well as its triumphs; and well should the elephant know it. he had the best chance of all. wiser even than the lion, or the wisest of apes, his wisdom furthermore was benign where theirs was sinister. consider his dignity, his poise and skill. he was plastic, too. he had learned to eat many foods and endure many climates. once, some say, this race explored the globe. their bones are found everywhere, in south america even; so the elephants' columbus may have found some road here before ours. they are cosmopolitans, these suave and well-bred beings. they have rich emotional natures, long memories, loyalty; they are steady and sure; and not narrow, not self-absorbed, for they seem interested in everything. what was it then, that put them out of the race? could it have been a quite natural belief that they had already won? and when they saw that they hadn't, and that the monkey-men were getting ahead, were they too great-minded and decent to exterminate their puny rivals? it may have been their tolerance and patience that betrayed them. they wait too long before they resent an imposition or insult. just as ants are too energetic and cats too shrewd for their own highest good, so the elephants suffer from too much patience. their exhibitions of it may seem superb,--such power and such restraint, combined, are noble,--but a quality carried to excess defeats itself. kings who won't lift their scepters must yield in the end; and, the worst of it is, to upstarts who snatch at their crowns. i fancy the elephants would have been gentler masters than we: more live-and-let-live in allowing other species to stay here. our way is to kill good and bad, male and female and babies, till the few last survivors lie hidden away from our guns. all species must surrender unconditionally--those are our terms--and come and live in barns alongside us; or on us, as parasites. the creatures that want to live a life of their own, we call wild. if wild, then no matter how harmless we treat them as outlaws, and those of us who are specially well brought up shoot them for fun. some might be our friends. we don't wish it. we keep them all terrorized. when one of us conquering monkey-men enters the woods, most animals that scent him slink away, or race off in a panic. it is not that we have planned this deliberately: but they know what we're like. race by race they have been slaughtered. soon all will be gone. we give neither freedom nor life-room to those we defeat. if we had been as strong as the elephants, we might have been kinder. when great power comes naturally to people, it is used more urbanely. we use it as parvenus do, because that's what we are. the elephant, being born to it, is easy-going, confident, tolerant. he would have been a more humane king. a race descended from elephants would have had to build on a large scale. imagine a crowd of huge, wrinkled, slow-moving elephant-men getting into a vast elephant omnibus. and would they have ever tried airships? the elephant is stupid when it comes to learning how to use tools. so are all other species except our own. isn't it strange? a tool, in the most primitive sense, is any object, lying around, that can obviously be used as an instrument for this or that purpose. many creatures use objects as _materials_, as birds use twigs for nests. but the step that no animal takes is learning freely to use things as instruments. when an elephant plucks off a branch and swishes his flanks, and thus keeps away insects, he is using a tool. but he does it only by a vague and haphazard association of ideas. if he once became a conscious user of tools he would of course go much further. we ourselves, who are so good at it now, were slow enough in beginning. think of the long epochs that passed before it entered our heads. and all that while the contest for leadership blindly went on, without any species making use of this obvious aid. the lesson to be learned was simple: the reward was the rule of a planet. yet only one species, our own, has ever had that much brains. it makes you wonder what other obvious lessons may still be unlearned. it is not necessarily stupid however, to fail to use tools. to use tools involves using reason, instead of sticking to instinct. now, sticking to instinct has its disadvantages, but so has using reason. whichever faculty you use, the other atrophies, and partly deserts you. we are trying to use both. but we still don't know which has the more value. a sudden vision comes to me of one of the first far-away ape-men who tried to use reason instead of instinct as a guide for his conduct. i imagine him, perched in his tree, torn between those two voices, wailing loudly at night by a river, in his puzzled distress. my poor far-off brother! viii we have been considering which species was on the whole most finely equipped to be rulers, and thereafter achieve a high civilization; but that wasn't the problem. the real problem was which would _do_ it:--a different matter. to do it there was need of a species that had at least these two qualities: some quenchless desire, to urge them on and on; and also adaptability of a thousand kinds to their environment. the rhinoceros cares little for adaptability. he slogs through the world. but we! we are experts. adaptability is what we depend on. we talk of our mastery of nature, which sounds very grand; but the fact is we respectfully adapt ourselves first, to her ways. "we attain no power over nature till we learn natural laws, and our lordship depends on the adroitness with which we learn and conform." adroitness however is merely an ability to win; back of it there must be some spur to make us use our adroitness. why don't we all die or give up when we're sick of the world? because the love of life is reenforced, in most energized beings, by some longing that pushes them forward, in defeat and in darkness. all creatures wish to live, and to perpetuate their species, of course; but those two wishes alone evidently do not carry any race far. in addition to these, a race, to be great, needs some hunger, some itch, to spur it up the hard path we lately have learned to call evolution. the love of toil in the ants, and of craft in cats, are examples (imaginary or not). what other such lust could exert great driving force? with us is it curiosity? endless interest in one's environment? many animals have some curiosity, but "some" is not enough; and in but few is it one of the master passions. by a master passion, i mean a passion that is really your master: some appetite which habitually, day in, day out, makes its subjects forget fatigue or danger, and sacrifice their ease to its gratification. that is the kind of hold that curiosity has on the monkeys. ix imagine a prehistoric prophet observing these beings, and forecasting what kind of civilizations their descendants would build. anyone could have foreseen certain parts of the simians' history: could have guessed that their curiosity would unlock for them, one by one, nature's doors, and--idly--bestow on them stray bits of valuable knowledge: could have pictured them spreading inquiringly all over the globe, stumbling on their inventions--and idly passing on and forgetting them. to have to learn the same thing over and over again wastes the time of a race. but this is continually necessary, with simians, because of their disorder. "disorder," a prophet would have sighed: "that is one of their handicaps; one that they will never get rid of, whatever it costs. having so much curiosity makes a race scatter-brained. "yes," he would have dismally continued, "it will be a queer mixture: these simians will attain to vast stores of knowledge, in time, that is plain. but after spending centuries groping to discover some art, in after-centuries they will now and then find it's forgotten. how incredible it would seem on other planets to hear of lost arts. "there is a strong streak of triviality in them, which you don't see in cats. they won't have fine enough characters to concentrate on the things of most weight. they will talk and think far more of trifles than of what is important. even when they are reasonably civilized, this will be so. great discoveries sometimes will fail to be heard of, because too much else is; and many will thus disappear, and these men will not know it."[1] [1] we did rescue mendel's from the dust heap; but perhaps it was an exception. let me interrupt this lament to say a word for myself and my ancestors. it is easy to blame us as undiscriminating, but we are at least full of zest. and it's well to be interested, eagerly and intensely, in so many things, because there is often no knowing which may turn out important. we don't go around being interested on purpose, hoping to profit by it, but a profit may come. and anyway it is generous of us not to be too self-absorbed. other creatures go to the other extreme to an amazing extent. they are ridiculously oblivious to what is going on. the smallest ant in the garden will ignore the largest woman who visits it. she is a huge and most dangerous super-mammoth in relation to him, and her tread shakes the earth; but he has no time to be bothered, investigating such-like phenomena. he won't even get out of her way. he has his work to do, hang it. birds and squirrels have less of this glorious independence of spirit. they watch you closely--if you move around. but not if you keep still. in other words, they pay no more attention than they can help, even to mammoths. we of course observe everything, or try to. we could spend our lives looking on. consider our museums for instance: they are a sign of our breed. it makes us smile to see birds, like the magpie, with a mania for this collecting--but only monkeyish beings could reverence museums as we do, and pile such heterogeneous trifles and quantities in them. old furniture, egg-shells, watches, bits of stone.... and next door, a "menagerie." though our victory over all other animals is now aeons old, we still bring home captives and exhibit them caged in our cities. and when a species dies out--or is crowded (by us), off the planet--we even collect the bones of the vanquished and show them like trophies. curiosity is a valuable trait. it will make the simians learn many things. but the curiosity of a simian is as excessive as the toil of an ant. each simian will wish to know more than his head can hold, let alone ever deal with; and those whose minds are active will wish to know everything going. it would stretch a god's skull to accomplish such an ambition, yet simians won't like to think it's beyond their powers. even small tradesmen and clerks, no matter how thrifty, will be eager to buy costly encyclopedias, or books of all knowledge. almost every simian family, even the dullest, will think it is due to themselves to keep all knowledge handy. their idea of a liberal education will therefore be a great hodge-pod only. he who narrows his field and digs deep will be viewed as an alien. if more than one man in a hundred should thus dare to concentrate, the ruinous effects of being a specialist will be sadly discussed. it may make a man exceptionally useful, they will have to admit; but still they will feel badly, and fear that civilization will suffer. one of their curious educational ideas--but a natural one--will be shown in the efforts they will make to learn more than one "language." they will set their young to spending a decade or more of their lives in studying duplicate systems--whole systems--of chatter. those who thus learn several different ways to say the same things, will command much respect, and those who learn many will be looked on with awe--by true simians. and persons without this accomplishment will be looked down on a little, and will actually feel quite apologetic about it themselves. consider how enormously complicated a complete language must be, with its long and arbitrary vocabulary, its intricate system of sounds; the many forms that single words may take, especially if they are verbs; the rules of grammar, the sentence structure, the idioms, slang and inflections. heavens, what a genius for tongues these simians have![1] where another race, after the most frightful discord and pains, might have slowly constructed one language before this earth grew cold, this race will create literally hundreds, each complete in itself, and many of them with quaint little systems of writing attached. and the owners of this linguistic gift are so humble about it, they will marvel at bees, for their hives, and at beavers' mere dams. [1] you remember what kipling says in the jungle books, about how disgusted the quiet animals were with the bandarlog, because they were eternally chattering, would never keep still. well, this is the good side of it. to return, however, to their fear of being too narrow, in going to the other extreme they will run to incredible lengths. every civilized simian, every day of his life, in addition to whatever older facts he has picked up, will wish to know all the news of all the world. if he felt any true concern to know it, this would be rather fine of him: it would imply such a close solidarity on the part of this genus. (such a close solidarity would seem crushing, to others; but that is another matter.) it won't be true concern, however, it will be merely a blind inherited instinct. he'll forget what he's read, the very next hour, or moment. yet there he will faithfully sit, the ridiculous creature, reading of bombs in spain or floods in thibet, and especially insisting on all the news he can get of the kind our race loved when they scampered and fought in the forest, news that will stir his most primitive simian feelings,--wars, accidents, love affairs, and family quarrels. to feed himself with this largely purposeless provender, he will pay thousands of simians to be reporters of such events day and night; and they will report them on such a voluminous scale as to smother or obscure more significant news altogether. great printed sheets will be read by every one every day; and even the laziest of this lazy race will not think it labor to perform this toil. they won't like to eat in the morning without their papers, such slaves they will be to this droll greed for knowing. they won't even think it is droll, it is so in their blood. their swollen desire for investigating everything about them, including especially other people's affairs, will be quenchless. few will feel that they really are "fully informed"; and all will give much of each day all their lives to the news. books too will be used to slake this unappeasable thirst. they will actually hold books in deep reverence. books! bottled chatter! things that some other simian has formerly said. they will dress them in costly bindings, keep them under glass, and take an affecting pride in the number they read. libraries --store-houses of books,--will dot their world. the destruction of one will be a crime against civilization. (meaning, again, a simian civilization.) well, it is an offense to be sure--a barbaric offense. but so is defacing forever a beautiful landscape; and they won't even notice that sometimes; they won't shudder anyway, the way they instinctively do at the loss of a "library." all this is inevitable and natural, and they cannot help it. there even are ways one can justify excesses like this. if their hunger for books ever seems indiscriminate to them when they themselves stop to examine it, they will have their excuses. they will argue that some bits of knowledge they once had thought futile, had later on come in most handy, in unthought of ways. true enough! for their scientists. but not for their average men: they will simply be like obstinate housekeepers who clog up their homes, preserving odd boxes and wrappings, and stray lengths of string, to exult if but one is of some trifling use ere they die. it will be in this spirit that simians will cherish their books, and pile them up everywhere into great indiscriminate mounds; and these mounds will seem signs of culture and sagacity to them. those who know many facts will feel wise! they will despise those who don't. they will even believe, many of them, that knowledge is power. unfortunate dupes of this saying will keep on reading, ambitiously, till they have stunned their native initiative, and made their thoughts weak; and will then wonder dazedly what in the world is the matter, and why the great power they were expecting to gain fails to appear. again, if they ever forget what they read, they'll be worried. those who _can_ forget--those with fresh eyes who have swept from their minds such facts as the exact month and day that their children were born, or the numbers on houses, or the names (the mere meaningless labels) of the people they meet,--will be urged to go live in sanitariums or see memory doctors! by nature their itch is rather for knowing, than for understanding or thinking. some of them will learn to think, doubtless, and even to concentrate, but their eagerness to acquire those accomplishments will not be strong or insistent. creatures whose mainspring is curiosity will enjoy the accumulating of facts, far more than the pausing at times to reflect on those facts. if they do not reflect on them, of course they'll be slow to find out about the ideas and relationships lying behind them; and they will be curious about those ideas; so you would suppose they'd reflect. but deep thinking is painful. it means they must channel the spready rivers of their attention. that cannot be done without discipline and drills for the mind; and they will abhor doing that; their minds will work better when they are left free to run off at tangents. compare them in this with other species. each has its own kind of strength. to be compelled to be so quick-minded as the simians would be torture, to cows. cows could dwell on one idea, week by week, without trying at all; but they'd all have brain-fever in an hour at a simian tea. a super-cow people would revel in long thoughtful books on abstruse philosophical subjects, and would sit up late reading them. most of the ambitious simians who try it--out of pride--go to sleep. the typical simian brain is supremely distractable, and it's really too jumpy by nature to endure much reflection. therefore many more of them will be well-informed than sagacious. this will result in their knowing most things far too soon, at too early a stage of civilization to use them aright. they will learn to make valuable explosives at a stage in their growth, when they will use them not only in industries, but for killing brave men. they will devise ways to mine coal efficiently, in enormous amounts, at a stage when they won't know enough to conserve it, and will waste their few stores. they will use up a lot of it in a simian habit[1] called travel. this will consist in queer little hurried runs over the globe, to see ten thousand things in the hope of thus filling their minds. [1] even in a wild state, the monkey is restless and does not live in lairs. their minds will be full enough. their intelligence will be active and keen. it will have a constant tendency however to outstrip their wisdom. their intelligence will enable them to build great industrial systems before they have the wisdom and goodness to run them aright. they will form greater political empires than they will have strength to guide. they will endlessly quarrel about which is the best scheme of government, without stopping to realize that learning to govern comes first. (the average simian will imagine he knows without learning.) the natural result will be industrial and political wars. in a world of unmanageable structures, wild smashes must come. x inventions will come so easily to simians (in comparison with all other creatures) and they will take such childish pleasure in monkeying around, making inventions, that their many devices will be more of a care than a comfort. in their homes a large part of their time will have to be spent keeping their numerous ingenuities in good working order--their elaborate bell-ringing arrangements, their locks and their clocks. in the field of science to be sure, this fertility in invention will lead to a long list of important and beautiful discoveries: telescopes and the calculus, radiographs, and the spectrum. discoveries great enough, almost, to make angels of them. but here again their simian-ness will cheat them of half of their dues, for they will neglect great discoveries of the truest importance, and honor extravagantly those of less value and splendor if only they cater especially to simian traits. to consider examples: a discovery that helps them to talk, just to talk, more and more, will be hailed by these beings as one of the highest of triumphs. talking to each other over wires will come in this class. the lightning when harnessed and tamed will be made to trot round, conveying the most trivial cacklings all day and night. huge seas of talk of every sort and kind, in print, speech, and writing, will roll unceasingly over their civilized realms, involving an unbelievable waste in labor and time, and sapping the intelligence talk is supposed to upbuild. in a simian civilization, great halls will be erected for lectures, and great throngs will actually pay to go inside at night to hear some self-satisfied talk-maker chatter for hours. almost any subject will do for a lecture, or talk; yet very few subjects will be counted important enough for the average man to do any _thinking_ on them, off by himself. in their futurist books they will dream of an even worse state, a more dreadful indulgence in communication than the one just described. this they'll hope to achieve by a system called mental telepathy. they will long to communicate wordlessly, mind impinging on mind, until all their minds are awash with messages every moment, and withdrawal from the stream is impossible anywhere on earth. this will foster the brotherhood of man. (conglomerateness being their ideal.) super-cats would have invented more barriers instead of more channels. discoveries in surgery and medicine will also be over-praised. the reason will be that the race will so need these discoveries. unlike the great cats, simians tend to undervalue the body. having less self-respect, less proper regard for their egos, they care less than the cats do for the casing of the ego,--the body. the more civilized they grow the more they will let their bodies deteriorate. they will let their shoulders stoop, their lungs shrink, and their stomachs grow fat. no other species will be quite so deformed and distorted. athletics they will watch, yes, but on the whole sparingly practise. their snuffy old scholars will even be proud to decry them. where once the simians swung high through forests, or scampered like deer, their descendants will plod around farms, or mince along city streets, moving constrictedly, slowly, their litheness half gone. they will think of nature as "something to go out and look at." they will try to live wholly apart from her and forget they're her sons. forget? they will even deny it, and declare themselves sons of god. in spite of her wonders they will regard nature as somehow too humble to be the true parent of such prominent people as simians. they will lose all respect for the dignity of fair mother earth, and whisper to each other she is an evil and indecent old person. they will snatch at her gifts, pry irreverently into her mysteries, and ignore half the warnings they get from her about how to live. ailments of every kind will abound among such folk, inevitably, and they will resort to extraordinary expedients in their search for relief. although squeamish as a race about inflicting much pain in cold blood, they will systematically infect other animals with their own rank diseases, or cut out other animals' organs, or kill and dissect them, hoping thus to learn how to offset their neglect of themselves. conditions among them will be such that this will really be necessary. few besides impractical sentimentalists will therefore oppose it. but the idea will be to gain health by legerdemain, by a trick, instead of by taking the trouble to live healthy lives. strange barrack-like buildings called hospitals will stand in their cities, where their trick-men, the surgeons, will slice them right open when ill; and thousands of zealous young pharmacists will mix little drugs, which thousands of wise-looking simians will firmly prescribe. each generation will change its mind as to these drugs, and laugh at all former opinions; but each will use some of them, and each will feel assured that in this respect they know the last word. and, in obstinate blindness, this people will wag their poor heads, and attribute their diseases not to simian-ness but to civilization. the advantages that any man or race has, can sometimes be handicaps. having hands, which so aids a race, for instance, can also be harmful. the simians will do so many things with their hands, it will be bad for their bodies. instead of roaming far and wide over the country, getting vigorous exercise, they will use their hands to catch and tame horses, build carriages, motors, and then when they want a good outing they will "go for a ride," with their bodies slumped down, limp and sluggish, and losing their spring. then too their brains will do harm, and great harm, to their bodies. the brain will give them such an advantage over all other animals that they will insensibly be led to rely too much on it, to give it too free a rein, and to find the mirrors in it too fascinating. this organ, this outgrowth, this new part of them, will grow over-active, and its many fears and fancies will naturally injure the body. the interadjustment is delicate and intimate, the strain is continuous. when the brain fails to act with the body, or, worse, works against it, the body will sicken no matter what cures doctors try. as in bodily self-respect, so in racial self-respect, they'll be wanting. they will have plenty of racial pride and prejudice, but that is not the same thing. that will make them angry when simians of one color mate with those of another. but a general deterioration in physique will cause much less excitement. they will _talk_ about improving the race--they will talk about everything--but they won't use their chances to _do_ it. whenever a new discovery makes life less hard, for example, these heedless beings will seldom preserve this advantage, or use their new wealth to take more time thereafter for thought, or to gain health and strength or do anything else to make the race better. instead, they will use the new ease just to increase in numbers; and they will keep on at this until misery once more has checked them. life will then be as hard as ever, naturally, and the chance will be gone. they will have a proverb, "the poor ye have always with you,"--said by one who knew simians. their ingenious minds will have an answer to this. they will argue it is well that life should be spartan and hard, because of the discipline and its strengthening effects on the character. but the good effects of this sort of discipline will be mixed with sad wreckage. and only creatures incapable of disciplining themselves could thus argue. it is an odd expedient to get yourself into trouble just for discipline's sake. the fact is, however, the argument won't be sincere. when their nations grow so over-populous and their families so large it means misery, that will not be a sign of their having felt ready for discipline. it will be a sign of their not having practised it in their sexual lives. xi the simians are always being stirred by desire and passion. it constantly excites them, constantly runs through their minds. wild or tame, primitive or cultured, this is a brand of the breed. other species have times and seasons for sexual matters, but the simian-folk are thus preoccupied all the year round. this super-abundance of desire is not necessarily good or bad, of itself. but to shape it for the best it will have to be studied--and faced. this they will not do. some of them won't like to study it, deeming it bad--deeming it bad yet yielding constantly to it. others will hesitate because they will deem it so sacred, or will secretly fear that study might show them it ought to be curbed. meantime, this part of their nature will be coloring all their activities. it will beautify their arts, and erotically confuse their religions. it will lend a little interest to even their dull social functions. it will keep alive degrading social evils in all their great towns. through these latter evils, too, their politics will be corrupted; especially their best and most democratic attempts at self-government. self-government works best among those who have learned to self-govern. in the far distant ages that lie before us what will be the result of this constant preoccupation with desire? will it kill us or save us? will this trait and our insatiable curiosity interact on each other? that might further eugenics. that might give us a better chance to breed finely than all other species. we already owe a great deal to passion: more than men ever realize. wasn't it darwin who once even risked the conjecture that the vocal organs themselves were developed for sexual purposes, the object being to call or charm one's mate. hence--perhaps--only animals that were continuously concerned with their matings would be at all likely to form an elaborate language. and without an elaborate language, growth is apt to be slow. if we owe this to passion, what follows? does it mean, for example, that the more different mates that each simian once learned to charm, the more rapidly language, and with it civilization, advanced? xii a doctor, who was making a study of monkeys, once told me that he was trying experiments that bore on the polygamy question. he had a young monkey named jack who had mated with a female named jill; and in another cage another newly-wedded pair, arabella and archer. each pair seemed absorbed in each other, and devoted and happy. they even bugged each other at mealtime and exchanged bits of food. after a time their transports grew less fiery, and their affections less fixed. archer got a bit bored. he was decent about it, though, and when arabella cuddled beside him he would more or less perfunctorily embrace her. but when he forgot, she grew cross. the same thing occurred a little later in the jack and jill cage, only there it was jill who became a little tired of jack. soon each pair was quarreling. they usually made up, pretty soon, and started loving again. but it petered out; each time more quickly. meanwhile the two families had become interested in watching each other. when jill had repulsed jack, and he had moped about it awhile, he would begin staring at arabella, over opposite, and trying to attract her attention. this got jack in trouble all around. arabella indignantly made faces at him and then turned her back; and as for jill, she grew furious, and tore out his fur. but in the next stage, they even stopped hating each other. each pair grew indifferent. then the doctor put jack in with arabella, and archer with jill. arabella promptly yielded to jack. new devotion. more transports. jill and archer were shocked. jill clung to the bars of her cage, quivering, and screaming remonstrance; and even blase archer chattered angrily at some of the scenes. then the doctor hung curtains between the cages to shut out the view. jill and archer, left to each other, grew interested. they soon were inseparable. the four monkeys, thus re-distributed, were now happy once more, and full of new liveliness and spirit. but before very long, each pair quarreled--and made up--and quarreled--and then grew indifferent, and had cynical thoughts about life. at this point, the doctor put them back with their original mates. and--they met with a rush! gave cries of recognition and joy, like faithful souls re-united. and when they were tired, they affectionately curled up together; and hugged each other even at mealtime, and exchanged bits of food. this was as far as the doctor had gotten, at the time that i met him; and as i have lost touch with him since, i don't know how things were afterward. his theory at the time was, that variety was good for fidelity. "so how can _we_ help being that way? it's in the blood," he concluded. "some creatures, such as wolves, are more serious; or perhaps more cold-blooded. never mate but once. well--we're not wolves. we can't make wolves our models. if we want to know how to behave, according to the way nature made us, if we want to know what is good for our instincts, we must study the monkeys." to be sure, these particular monkeys were living in idleness. this corresponds to living in high social circles with us, where men do not have to work, and lack some of the common incentives to home-building. the experiment was not conclusive. still, even in low social circles-xiii are we or are we not simians? it is no use for any man to try to think anything else out until he has decided first of all where he stands on that question. it is not only in love affairs: let us lay all that aside for the moment. it is in ethics, economics, art, education, philosophy, what-not. if we are fallen angels, we should go this road: if we are super-apes, that. "our problem is not to discover what we ought to do if we were different, but what we ought to do, being what we are. there is no end to the beings we can imagine different from ourselves; but they do not exist," and we cannot be sure they would be better than we if they did. for, when we imagine them, we must imagine their entire environment; they would have to be a part of some whole that does not now exist. and that new whole, that new reality, being merely a figment of our little minds, "would probably be inferior to the reality that is. for there is this to be said in favor of reality: that we have nothing to compare it with. our fantasies are always incomplete, because they are fantasies. and reality is complete. we cannot compare their incompleteness with its completeness."[1] [1] from an anonymous article entitled "tolstoy and russia" in the london times, sept. 26,1918. too many moralists begin with a dislike of reality: a dislike of men as they are. they are free to dislike them--but not at the same time to be moralists. their feeling leads them to ignore the obligation which should rest on all teachers, "to discover the best that man can do, not to set impossibilities before him and tell him that if he does not perform them he is damned." man is moldable; very; and it is desirable that he should aspire. but he is apt to be hasty about accepting any and all general ideals without figuring out whether they are suitable for simian use. one result of his habit of swallowing whole most of the ideals that occur to him, is that he has swallowed a number that strongly conflict. any ideal whatever strains our digestions if it is hard to assimilate: but when two at once act on us in different ways, it is unbearable. in such a case, the poets will prefer the ideal that's idealest: the hard-headed instinctively choose the one adapted to simians. whenever this is argued, extremists spring up on each side. one extremist will say that being mere simians we cannot transcend much, and will seem to think that having limitations we should preserve them forever. the other will declare that we are not merely simians, never were just plain animals; or, if we were, souls were somehow smuggled in to us, since which time we have been different. we have all been perfect at heart since that date, equipped with beautiful spirits, which only a strange perverse obstinacy leads us to soil. what this obstinacy is, is the problem that confronts theologians. they won't think of it as simian-ness; they call it original sin. they regard it as the voice of some devil, and say good men should not listen to it. the scientists say it isn't a devil, it is part of our nature, which should of course be civilized and guided, but should not be stamped out. (it might mutilate us dangerously to become under-simianized. look at mrs. humphry ward and george washington. worthy souls, but no flavor.) in every field of thought then, two schools appear, that are divided on this: must we forever be at heart high-grade simians? or are we at heart something else? for example, in education, we have in the main two great systems. one depends upon discipline. the other on exciting the interest. the teacher who does not recognize or allow for our simian nature, keeps little children at work for long periods at dull and dry tasks. without some such discipline, he fears that his boys will lack strength. the other system believes they will learn more when their interest is roused; and when their minds, which are mobile by nature, are allowed to keep moving. or in politics: the best government for simians seems to be based on a parliament: a talk-room, where endless vague thoughts can be warmly expressed. this is the natural child of those primeval sessions that gave pleasure to apes. it is neither an ideal nor a rational arrangement, of course. small executive committees would be better. but not if we are simians. or in industry: why do factory workers produce more in eight hours a day than in ten? it is absurd. super-sheep could not do it. but that is the way men are made. to preach to such beings about the dignity of labor is futile. the dignity of labor is not a simian conception at all. true simians hate to have to work steadily: they call it grind and confinement. they are always ready to pity the toilers who are condemned to this fate, and to congratulate those who escape it, or who can do something else. when they see some performer in spangles risk his life, at a circus, swinging around on trapezes, high up in the air, and when they are told he must do it daily, do they pity _him?_ no! super-elephants would say, and quite properly, "what a horrible life!" but it naturally seems stimulating to simians. boys envy the fellow. on the other hand whenever we are told about factory life, we instinctively shudder to think of enduring such evils. we see some old work-man, filling cans with a whirring machine; and we hear the humanitarians telling us, indignant and grieving, that he actually must stand in that nice, warm, dry room every day, safe from storms and wild beasts, and with nothing to do but fill cans; and at once we groan: "how deadly! what monotonous toil! shorten his hours!" his work would seem blissful to super-spiders,--but to us it's intolerable. "grind and confinement?" that's the strong monkey-blood in our veins. our monkey-blood is also apparent in our judgments of crime. if a crime is committed on impulse, we partly forgive it. why? because, being simians, with a weakness for yielding to impulses, we like to excuse ourselves by feeling not accountable for them. elephants would have probably taken an opposite stand. they aren't creatures of impulse, and would be shocked at crimes due to such causes; their fault is the opposite one of pondering too long over injuries, and becoming vindictive in the end, out of all due proportion. if a young super-elephant were to murder another on impulse, they would consider him a dangerous character and string him right up. but if he could prove that he had long thought of doing it, they would tend to forgive him. "poor fellow, he brooded," they would say. "that's upsetting to any one." as to modesty and decency, if we are simians we have done well, considering: but if we are something else--fallen angels--we have indeed fallen far. not being modest by instinct we invent artificial ideals, which are doubtless well-meaning but are inherently of course second-rate, so that even at our best we smell prudish. and as for our worst, when we as we say let ourselves go, we dirty the life-force unspeakably, with chuckles and leers. but a race so indecent by nature as the simians are would naturally have a hard time behaving as though they were not: and the strain of pretending that their thoughts were all pretty and sweet, would naturally send them to smutty extremes for relief. the standards of purity we have adopted are far too strict--for simians. xiv we were speaking a while ago of the fertility with which simians breed. this is partly due to the constant love interest they take in each other, but it is also reenforced by their reliance on numbers. that reliance will be deep, since, to their numbers, they will owe much success. it will be thus that they will drive out other species, and garrison the globe. such a race would naturally come to esteem fertility. it will seem profane not to. as time goes on, however, the advantage of numbers will end; and in their higher stages, large numbers will be a great drawback. the resources of a planet are limited, at each stage of the arts. also, there is only a limited space on a planet. yet it will come hard to them to think of ever checking their increase. they will bring more young into existence than they can either keep well or feed. the earth will be covered with them everywhere, as far as eye can see. north and south, east and west, there will always be simians huddling. their cities will be far more distressing than cities of vermin,--for vermin are healthy and calm and successful in life. ah, those masses of people--unintelligent, superstitious, uncivilized! what a dismal drain they will be on the race's strength! not merely will they lessen its ultimate chance of achievement; their hardships will always distress and preoccupy minds,--fine, generous minds,--that might have done great things if free: that might have done something constructive at least, for their era, instead of being burned out attacking mere anodyne-problems. nature will do what it can to lessen the strain, providing an appropriate remedy for their bad behavior in plagues. many epochs will pass before the simians will learn or dare to control them--for they won't think they can, any more than they dare control propagation. they will reverently call their propagation and plagues "acts of god." when they get tired of reverence and stop their plagues, it will be too soon. their inventiveness will be--as usual--ahead of their wisdom; and they will unfortunately end the good effects of plagues (as a check) before they are advanced enough to keep down their numbers themselves. meanwhile, when, owing to the pressure of other desires, any group of primates does happen to become less prolific, they will feel ashamed, talk of race suicide, and call themselves decadent. and they will often be right: for though some regulation of the birth-rate is an obvious good, and its diminution often desirable in any planet's history, yet among simians it will be apt to come from second-rate motives. greed, selfishness or fear-thoughts will be the incentives, the bribes. contrivances, rather than continence, will be the method. how audacious, and how disconcerting to nature, to baffle her thus! even into her shrine they must thrust their bold paws to control her. another race viewing them in the garlanded chambers of love, unpacking their singular devices, might think them grotesque: but the busy little simians will be blind to such quaint incongruities. still, there is a great gift that their excess of passion will bestow on this race: it will give them romance. it will teach them what little they ever will learn about love. other animals have little romance: there is none in the rut: that seasonal madness that drives them to mate with perhaps the first comer. but the simians will attain to a fine descrimination in love, and this will be their path to the only spiritual heights they can reach. for, in love, their inmost selves will draw near, in the silence of truth; learning little by little what the deepest sincerity means, and what clean hearts and minds and what crystal-clear sight it demands. such intercommunication of spirit with spirit is at the beginning of all true understanding. it is the beginning of silent cosmic wisdom: it may lead to knowing the ways of that power called god. xv not content with the whole of a planet and themselves too, to study, this race's children will also study the heavens. how few kinds of creatures would ever have felt that impulse, and yet how natural it will seem to these! how boundless and magnificent is the curiosity of these tiny beings, who sit and peer out at the night from their small whirling globe, considering deeply the huge cold seas of space, and learning with wonderful skill to measure the stars. in studies so vast, however, they are tested to the core. in these great journeys the traveller must pay dear for his flaws. for it always is when you most finely are exerting your strength that every weakness you have most tells against you. one weakness of the primates is the character of their self-consciousness. this useful faculty, that can probe so-deep, has one naive defect--it relies too readily on its own findings. it doesn't suspect enough its own unconfessed predilections. it assumes that it can be completely impartial--but isn't. to instance an obvious way in which it will betray them: beings that are intensely self-conscious and aware of their selves, will also instinctively feel that their universe is. what active principle animates the world, they will ask. a great blind force? it is possible. but they will recoil from admitting any such possibility. a self-aware purposeful force then? that is better! (more simian.) "a blind force can't have been the creator of all. it's unthinkable." any theory _their_ brains find "unthinkable" cannot be true. (this is not to argue that it really is a blind force--or the opposite. it is merely an instance of how little impartial they are.) a second typical weakness of this race will come from their fears. they are not either self-sufficing or gallant enough to travel great roads without cringing,--clear-eyed, unafraid. they are finely made, but not nobly made,--in that sense. they will therefore have a too urgent need of religion. few primates have the courage to face--alone--the still inner mysteries: infinity, space and time. they will think it too terrible, they will feel it would turn them to water, to live through unearthly moments of vision without creeds or beliefs. so they'll get beliefs first. ah, poor creatures! the cart before the horse! ah, the blasphemy (pitiful!) of their seeking high spiritual temples, with god-maps or bibles about them, made below in advance! think of their entering into the presence of truth, declaring so loudly and boldly they know her already, yet far from willing to stand or fall by her flames--to rise like a phoenix or die as an honorable cinder!--but creeping in, clad in their queer blindfolded beliefs, designed to shield them from her stern, bright tests! think of truth sadly--or merrily--eyeing such worms! xvi imagine you are watching the bandarlog at play in the forest. as you behold them and comprehend their natures, now hugely brave and boastful, now full of dread, the most weakly emotional of any intelligent species, ever trying to attract the notice of some greater animal, not happy indeed unless noticed,--is it not plain they are bound to invent things called gods? don't think for the moment of whether there are gods or not; think of how sure these beings would be to invent them. (not wait to find them.) having small self-reliance they can not bear to face life alone. with no self-sufficingness, they must have the countenance of others. it is these pressing needs that will hurry the primates to build, out of each shred of truth they can possibly twist to their purpose, and out of imaginings that will impress them because they are vast, deity after deity to prop up their souls. what a strange company they will be, these gods, in their day, each of them an old bearded simian up in the sky, who begins by fishing the universe out of a void, like a conjurer taking a rabbit out of a hat. (a hat which, if it resembled a void, wasn't there.) and after creating enormous suns and spheres, and filling the farthest heavens with vaster stars, one god will turn back and long for the smell of roast flesh, another will call desert tribes to "holy" wars, and a third will grieve about divorce or dancing. all gods that any groups of simians ever conceive of, from the woodenest little idol in the forest to the mightiest spirit, no matter how much they may differ, will have one trait in common: a readiness to drop any cosmic affair at short notice, focus their minds on the far-away pellet called earth, and become immediately wholly concerned, aye, engrossed, with any individual worshipper's woes or desires,--a readiness to notice a fellow when he is going to bed. this will bring indescribable comfort to simian hearts; and a god that neglects this duty won't last very long, no matter how competent he may be in other respects. but one must reciprocate. for the maker of the cosmos, as they see him, wants noticing too; he is fond of the deference and attention that simians pay him, and naturally he will be angry if it is withheld;--or if he is not, it will be most magnanimous of him. hence prayers and hymns. hence queer vague attempts at communing with this noble kinsman. to desire communion with gods is a lofty desire, but hard to attain through an ignobly definite creed. dealing with the highest, most wordless states of being, the simians will attempt to conceive them in material form. they will have beliefs, for example, as to the furnishings and occupations in heaven. and why? why, to help men to have religious conceptions without themselves being seers,--which in any true sense of "religious" is an impossible plan. in their efforts to be concrete they will make their creeds amusingly simian. consider the simian amorousness of jupiter, and the brawls on olympus. again, in the old jewish bible, what tempts the first pair? the tree of knowledge, of course. it appealed to the curiosity of their nature, and who could control _that!_ and satan in the bible is distinctly a simian's devil. the snake, it is known, is the animal monkeys most dread. hence when men give their devil a definite form they make him a snake. a race of super-chickens would have pictured their devil a hawk. xvii what are the handicaps this race will have in building religions? the greatest is this: they have such small psychic powers. the over-activity of their minds will choke the birth of such powers, or dull them. the race will be less in touch with nature, some day, than its dogs. it will substitute the compass for its once innate sense of direction. it will lose its gifts of natural intuition, premonition, and rest, by encouraging its use of the mind to be cheaply incessant. this lack of psychic power will cheat them of insight and poise; for minds that are wandering and active, not receptive and still, can seldom or never be hushed to a warm inner peace. one service these restless minds however will do: they eventually will uncritically through the religions they themselves have invented. but ages will be thrown away in repeating this process. a simian creed will not be very hard thus to pierce. when forming a religion, they will be in far too much haste, to wait to apply a strict test to their holy men's visions. furthermore they will have so few visions, that any will awe them; so naturally they will accept any vision as valid. then their rapid and fertile inventiveness will come into play, and spin the wildest creeds from each vision living dust ever dreamed. they will next expect everybody to believe whatever a few men have seen, on the slippery ground that if you simply try believing it, you will then feel it's true. such religions are vicarious; their prophets alone will see god, and the rest will be supposed to be introduced to him by the prophets. these "believers" will have no white insight at all of their own. now, a second-hand believer who is warmed at one remove--if at all --by the breath of the spirit, will want to have exact definitions in the beliefs he accepts. not having had a vision to go by, he needs plain commandments. he will always try to crystallize creeds. and that, plainly, is fatal. for as time goes on, new and remoter aspects of truth are discovered, which can seldom or never be fitted into creeds that are changeless. over and over again, this will be the process: a spiritual personality will be born; see new truth; and be killed. his new truth not only will not fit into too rigid creeds, but whatever false finality is in them it must contradict. so, the seer will be killed. his truth being mighty, however, it will kill the creeds too. there will then be nothing left to believe in--except the dead seer. for a few generations he may then be understandingly honored. but his priests will feel that is not enough: he must be honored uncritically: so uncritically that, whatever his message, it must be deemed the whole truth. some of his message they themselves will have garbled; and it was not, at best, final; but still it will be made into a fixed creed and given his name. truth will be given his name. all men who thereafter seek truth must find only his kind, else they won't be his "followers." (to be his co-seekers won't do.) priests will always hate any new seers who seek further for truth. their feeling will be that their seer found it, and thus ended all that. just believe what he says. the job's over. no more truth need be sought. it's a comforting thing to believe cosmic search nicely settled. thus the mold will be hardened. so new truths, when they come, can but break it. then men will feel distraught and disillusioned, and civilizations will fall. thus each cycle will run. so long as men interwine falsehoods with every seer's visions, both perish, and every civilization that is built on them must perish too. xviii if men can ever learn to accept all their truths as not final, and if they can ever learn to build on something better than dogma, they may not be found saying, discouragedly, every once in so often, that every civilization carries in it the seeds of decay. it will carry such seeds with great certainty, though, when they're put there, by the very race, too, that will later deplore the results. why shouldn't creeds totter when they are jerry-built creeds? on stars where creeds come late in the life of a race; where they spring from the riper, not cruder, reactions of spirit; where they grow out of nobly developed psychic powers that have put their possessors in tune with cosmic music; and where no cheap hallucinations discredit their truths; they perhaps run a finer, more beautiful course than the simians', and open the eyes of the soul to far loftier visions. xix it has always been a serious matter for men when a civilization decayed. but it may at some future day prove far more serious still. our hold on the planet is not absolute. our descendants may lose it. germs may do them out of it. a chestnut fungus springs up, defies us, and kills all our chestnuts. the boll weevil very nearly baffles us. the fly seems unconquerable. only a strong civilization, when such foes are about, can preserve us. and our present efforts to cope with such beings are fumbling and slow. we haven't the habit of candidly facing this danger. we read our biological history but we don't take it in. we blandly assume we were always "intended" to rule, and that no other outcome could even be considered by nature. this is one of the remnants of ignorance certain religions have left: but it's odd that men who don't believe in easter should still believe this. for the facts are of course this is a hard and precarious world, where every mistake and infirmity must be paid for in full. if mankind ever is swept aside as a failure however, what a brilliant and enterprising failure he at least will have been. i felt this with a kind of warm suddenness only today, as i finished these dreamings and drove through the gates of the park. i had been shutting my modern surroundings out of my thoughts, so completely, and living as it were in the wild world of ages ago, that when i let myself come back suddenly to the twentieth century, and stare at the park and the people, the change was tremendous. all around me were the well-dressed descendants of primitive animals, whizzing about in bright motors, past tall, soaring buildings. what gifted, energetic achievers they suddenly seemed! i thought of a photograph i had once seen, of a ship being torpedoed. there it was, the huge, finely made structure, awash in the sea, with tiny black spots hanging on to its side--crew and passengers. the great ship, even while sinking, was so mighty, and those atoms so helpless. yet, it was those tiny beings that had created that ship. they had planned it and built it and guided its bulk through the waves. they had also invented a torpedo that could rend it asunder. it is possible that our race may be an accident, in a meaningless universe, living its brief life uncared-for, on this dark, cooling star: but even so--and all the more--what marvelous creatures we are! what fairy story, what tale from the arabian nights of the jinns, is a hundredth part as wonderful as this true fairy story of simians! it is so much more heartening, too, than the tales we invent. a universe capable of giving birth to many such accidents is--blind or not--a good world to live in, a promising universe. and if there are no other such accidents, if we stand alone, if all the uncountable armies of planets are empty, or peopled by animals only, with no keys to thought, then we have done something so mighty, what may it not lead to! what powers may we not develop before the sun dies! we once thought we lived on god's footstool: it may be a throne. this is no world for pessimists. an amoeba on the beach, blind and helpless, a mere bit of pulp,--that amoeba has grandsons today who read kant and play symphonies. will those grandsons in turn have descendants who will sail through the void, discover the foci of forces, the means to control them, and learn how to marshal the planets and grapple with space? would it after all be any more startling than our rise from the slime? no sensible amoeba would have ever believed for a minute that any of his most remote children would build and run dynamos. few sensible men of today stop to feel, in their hearts, that we live in the very same world where that miracle happened. this world, and our racial adventure, are magical still. xx yet although for high-spirited marchers the march is sufficient, there still is that other way of looking at it that we dare not forget. our adventure may satisfy _us:_ does it satisfy nature? she is letting us camp for awhile here among the wrecked graveyards of mightier dynasties, not one of which met her tests. their bones are the message the epochs she murdered have left us: we have learned to decipher their sickening warning at last. yes, and even if we are permitted to have a long reign, and are not laid away with the failures, are we a success? we need so much spiritual insight, and we have so little. our telescopes may some day disclose to us the hills of arcturus, but how will that help us if we cannot find the soul of the world? is that soul alive and loving? or cruel? or callous? or dead? we have no sure vision. hopes, guesses, beliefs--that is all. there are sounds we are deaf to, there are strange sights invisible to us. there are whole realms of splendor, it may be, of which we are heedless; and which we are as blind to as ants to the call of the sea. life is enormously flexible--look at all that we've done to our dogs,--but we carry our hairy past with us wherever we go. the wise st. bernards and the selfish toy lap-dogs are brothers, and some things are possible for them and others are not. so with us. there are definite limits to simian civilizations, due in part to some primitive traits that help keep us alive, and in part to the mere fact that every being has to be something, and when one is a simian one is not also everything else. our main-springs are fixed, and our principal traits are deep-rooted. we cannot now re-live the ages whose imprint we bear. we have but to look back on our past to have hope in our future: but--it will be only _our_ future, not some other race's. we shall win our own triumphs, yet know that they would have been different, had we cared above all for creativeness, beauty, or love. so we run about, busy and active, marooned on this star, always violently struggling, yet with no clearly seen goal before us. men, animals, insects--what tribe of us asks any object, except to keep trying to satisfy its own master appetite? if the ants were earth's lords they would make no more use of their lordship than to learn and enforce every possible method of foiling. cats would spend their span of life, say, trying new kinds of guile. and we, who crave so much to know, crave so little but knowing. some of us wish to know nature most; those are the scientists. others, the saints and philosophers, wish to know god. both are alike in their hearts, yes, in spite of their quarrels. both seek to assuage to no end, the old simian thirst. if we wanted to _be_ gods--but ah, can we grasp that ambition? also by _clarence day_ the crow's nest thoughts without words god and my father in the green mountain country scenes from the mesozoic life with father this simian _world_ _by_ clarence day _with illustrations by the author_ _new york & london_ alfred·a·knopf 1936 copyright 1920, by clarence day _all rights reserved. no part of this book may be reproduced in any form without permission in writing from the publisher, except by a reviewer who may quote brief passages in a review to be printed in a magazine or newspaper._ _published may 22, 1920_ _reprinted nine times_ _eleventh printing, march, 1936_ _manufactured in the united states of america_ "how i hate the man who talks about the 'brute creation,' with an ugly emphasis on _brute_.... as for me, i am proud of my close kinship with other animals. i take a jealous pride in my simian ancestry. i like to think that i was once a magnificent hairy fellow living in the trees, and that my frame has come down through geological time via sea jelly and worms and amphioxus, fish, dinosaurs, and apes. who would exchange these for the pallid couple in the garden of eden?" w. n. p. barbellion. _this simian world_ _one_ last sunday, potter took me out driving along upper broadway, where those long rows of tall new apartment houses were built a few years ago. it was a mild afternoon and great crowds of people were out. sunday afternoon crowds. they were not going anywhere,--they were just strolling up and down, staring at each other, and talking. there were thousands and thousands of them. "awful, aren't they!" said potter. i didn't know what he meant. when he added, "why, these crowds," i turned and asked, "why, what about them?" i wasn't sure whether he had an idea or a headache. "other creatures don't do it," he replied, with a discouraged expression. "are any other beings ever found in such masses, but vermin? aimless, staring, vacant-minded,--look at them! i can get no sense whatever of individual worth, or of value in men as a race, when i see them like this. it makes one almost despair of civilization." i thought this over for awhile, to get in touch with his attitude. i myself feel differently at different times about us human-beings: sometimes i get pretty indignant when we are attacked (for there is altogether too much abuse of us by spectator philosophers) and yet at other times i too feel like a spectator, an alien: but even then i had never felt so alien or despairing as potter. i cast about for the probable cause of our difference. "let's remember," i said, "it's a simian civilization." potter was staring disgustedly at some vaudeville sign-boards. "yes," i said, "those for example are distinctively simian. why should you feel disappointment at something inevitable?" and i went on to argue that it wasn't as though we were descended from eagles for instance, instead of (broadly speaking) from ape-like or monkeyish beings. being of simian stock, we had simian traits. our development naturally bore the marks of our origin. if we had inherited our dispositions from eagles we should have loathed vaudeville. but as cousins of the bandarlog, we loved it. what could you expect? [illustration: descended from eagles] _two_ if we had been made directly from clay, the way it says in the bible, and had therefore inherited no intermediate characteristics,--if a god, or some principle of growth, had gone that way to work with us, he or it might have molded us into much more splendid forms. but considering our simian descent, it has done very well. the only people who are disappointed in us are those who still believe that clay story. or who--unconsciously--still let it color their thinking. * * * * * there certainly seems to be a power at work in the world, by virtue of which every living thing grows and develops. and it tends toward splendor. seeds become trees, and weak little nations grow great. but the push or the force that is doing this, the yeast as it were, has to work in and on certain definite kinds of material. because this yeast is in us, there may be great and undreamed of possibilities awaiting mankind; but because of our line of descent there are also queer limitations. [illustration: strange forgotten dynasties] _three_ in those distant invisible epochs before men existed, before even the proud missing link strutted around through the woods (little realizing how we his greatgrandsons would smile wryly at him, much as our own descendants may shudder at us, ages hence) the various animals were desperately competing for power. they couldn't or didn't live as equals. certain groups sought the headship. many strange forgotten dynasties rose, met defiance, and fell. in the end it was our ancestors who won, and became simian kings, and bequeathed a whole planet to us--and have never been thanked for it. no monument has been raised to the memory of those first hairy conquerors; yet had they not fought well and wisely in those far-off times, some other race would have been masters, and kept us in cages, or shot us for sport in the forests while they ruled the world. * * * * * so potter and i, developing this train of thought, began to imagine we had lived many ages ago, and somehow or other had alighted here from some older planet. familiar with the ways of evolution elsewhere in the universe, we naturally should have wondered what course it would take on this earth. "even in this out-of-the-way corner of the cosmos," we might have reflected, "and on this tiny star, it may be of interest to consider the trend of events." we should have tried to appraise the different species as they wandered around, each with its own set of good and bad characteristics. which group, we'd have wondered, would ever contrive to rule all the rest? and how great a development could they attain to thereafter? _four_ if we had landed here after the great saurians had been swept from the scene, we might first have considered the lemurs or apes. they had hands. aesthetically viewed, the poor simians were simply grotesque; but travelers who knew other planets might have known what beauty may spring from an uncouth beginning in this magic universe. still--those frowzy, unlovely hordes of apes and monkeys were so completely lacking in signs of kingship; they were so flighty, too, in their ways, and had so little purpose, and so much love for absurd and idle chatter, that they would have struck us, we thought, as unlikely material. such traits, we should have reminded ourselves, persist. they are not easily left behind, even after long stages; and they form a terrible obstacle to all high advancement. _five_ the bees or the ants might have seemed to us more promising. their smallness of size was not necessarily too much of a handicap. they could have made poison their weapon for the subjugation of rivals. and in these orderly insects there was obviously a capacity for labor, and co-operative labor at that, which could carry them far. we all know that they have a marked genius: great gifts of their own. in a civilization of super-ants or bees, there would have been no problem of the hungry unemployed, no poverty, no unstable government, no riots, no strikes for short hours, no derision of eugenics, no thieves, perhaps no crime at all. ants are good citizens: they place group interests first. but they carry it so far, they have few or no political rights. an ant doesn't have the vote, apparently: he just has his duties. this quality may have something to do with their having group wars. the egotism of their individual spirits is allowed scant expression, so the egotism of the group is extremely ferocious and active. is this one of the reasons why ants fight so much? they go in for state socialism, yes, but they are not internationalists. and ants commit atrocities in and after their battles that are--i wish i could truly say--inhuman. but conversely, ants are absolutely unselfish within the community. they are skilful. ingenious. their nests and buildings are relatively larger than man's. the scientists speak of their paved streets, vaulted halls, their hundreds of different domesticated animals, their pluck and intelligence, their individual initiative, their chaste and industrious lives. darwin said the ant's brain was "one of the most marvelous atoms in the world, perhaps more so than the brain of man"--yes, of present-day man, who for thousands and thousands of years has had so much more chance to develop his brain.... a thoughtful observer would have weighed all these excellent qualities. when we think of these creatures as little men (which is all wrong of course) we see they have their faults. to our eyes they seem too orderly, for instance. repressively so. their ways are more fixed than those of the old egyptians, and their industry is painful to think of, it's hyper-chinese. but we must remember this is a simian comment. the instincts of the species that you and i belong to are of an opposite kind; and that makes it hard for us to judge ants fairly. but we and the ants are alike in one matter: the strong love of property. and instead of merely struggling with nature for it, they also fight other ants. the custom of plunder seems to be a part of most of their wars. this has gone on for ages among them, and continues today. raids, ferocious combats, and loot are part of an ant's regular life. ant reformers, if there were any, might lay this to their property sense, and talk of abolishing property as a cure for the evil. but that would not help for long unless they could abolish the love of it. ants seem to care even more for property than we do ourselves. we men are inclined to ease up a little when we have all we need. but it is not so with ants: they can't bear to stop: they keep right on working. this means that ants do not contemplate: they heed nothing outside of their own little rounds. it is almost as though their fondness for labor had closed fast their minds. conceivably they might have developed inquiring minds. but this would have run against their strongest instincts. the ant is knowing and wise; but he doesn't know enough to take a vacation. the worshipper of energy is too physically energetic to see that he cannot explore certain higher fields until he is still. even if such a race had somehow achieved self-consciousness and reason, would they have been able therewith to rule their instincts, or to stop work long enough to examine themselves, or the universe, or to dream of any noble development? probably not. reason is seldom or never the ruler: it is the servant of instinct. it would therefore have told the ants that incessant toil was useful and good. "toil has brought you up from the ruck of things," reason would have plausibly said. "it's by virtue of feverish toil that you have become what you are. being endlessly industrious is the best road--for you--to the heights." and, self-reassured, they would then have had orgies of work; and thus, by devoted exertion, have blocked their advancement. work, and order and gain would have withered their souls. _six_ let us take the great cats. they are free from this talent for slave-hood. stately beasts like the lion have more independence of mind than the ants,--and a self-respect, we may note, unknown to primates. or consider the leopards, with hearts that no tyrant could master. what fearless and resolute leopard-men they could have fathered! how magnificently such a civilization would have made its force tell! a race of civilized beings descended from these great cats would have been rich in hermits and solitary thinkers. the recluse would not have been stigmatized as peculiar, as he is by us simians. they would not have been a credulous people, or easily religious. false prophets and swindlers would have found few dupes. and what generals they would have made! what consummate politicians! don't imagine them as a collection of tigers walking around on their hind-legs. they would have only been like tigers in the sense that we men are like monkeys. their development in appearance and character would have been quite transforming. instead of the small flat head of the tiger, they would have had clear smooth brows; and those who were not bald would have had neatly parted hair--perhaps striped. their mouths would have been smaller and more sensitive: their faces most dignified. where now they express chiefly savageness, they would have expressed fire and grace. they would have been courteous and suave. no vulgar crowding would have occurred on the streets of their cities. no mobs. no ignominious subway-jams. imagine a cultivated coterie of such men and women, at a ball, dancing. how few of us humans are graceful. they would have all been pavlovas. * * * * * like ants and bees, the cat race is nervous. their temperaments are high-strung. they would never have become as poised or as placid as--say--super-cows. yet they would have had less insanity, probably, than we. monkeys' (and elephants') minds seem precariously balanced, unstable. the great cats are saner. they are intense, they would have needed sanitariums: but fewer asylums. and their asylums would have been not for weak-minded souls, but for furies. they would have been strong at slander. they would have been far more violent than we, in their hates, and they would have had fewer friendships. yet they might not have been any poorer in real friendships than we. the real friendships among men are so rare that when they occur they are famous. friends as loyal as damon and pythias were, are exceptions. good fellowship is common, but unchanging affection is not. we like those who like us, as a rule, and dislike those who don't. most of our ties have no better footing than that; and those who have many such ties are called warm-hearted. * * * * * the super-cat-men would have rated cleanliness higher. some of us primates have learned to keep ourselves clean, but it's no large proportion; and even the cleanest of us see no grandeur in soap-manufacturing, and we don't look to manicures and plumbers for social prestige. a feline race would have honored such occupations. j. de courcy tiger would have felt that nothing _but_ making soap, or being a plumber, was compatible with a high social position; and the rich vera pantherbilt would have deigned to dine only with manicures. none but the lowest dregs of such a race would have been lawyers spending their span of life on this mysterious earth studying the long dusty records of dead and gone quarrels. we simians naturally admire a profession full of wrangle and chatter. but that is a monkeyish way of deciding disputes, not a feline. we fight best in armies, gregariously, where the risk is reduced; but we disapprove usually of murderers, and of almost all private combat. with the great cats, it would have been just the other way round. (lions and leopards fight each other singly, not in bands, as do monkeys.) as a matter of fact, few of us delight in really serious fighting. we do love to bicker; and we box and knock each other around, to exhibit our strength; but few normal simians are keen about bloodshed and killing; we do it in war only because of patriotism, revenge, duty, glory. a feline civilization would have cared nothing for duty or glory, but they would have taken a far higher pleasure in gore. if a planet of super-cat-men could look down upon ours, they would not know which to think was the most amazing: the way we tamely live, five million or so in a city, with only a few police to keep us quiet, while we commit only one or two murders a day, and hardly have a respectable number of brawls; or the way great armies of us are trained to fight,--not liking it much, and yet doing more killing in war-time and shedding more blood than even the fiercest lion on his cruelest days. which would perplex a gentlemanly super-cat spectator the more, our habits of wholesale slaughter in the field, or our spiritless making a fetish of "order," at home? * * * * * it is fair to judge peoples by the rights they will sacrifice most for. super-cat-men would have been outraged, had their right of personal combat been questioned. the simian submits with odd readiness to the loss of this privilege. what outrages him is to make him stop wagging his tongue. he becomes most excited and passionate about the right of free speech, even going so far in his emotion as to declare it is sacred. he looks upon other creatures pityingly because they are dumb. if one of his own children is born dumb, he counts it a tragedy. even that mere hesitation in speech, known as stammering, he deems a misfortune. so precious to a simian is the privilege of making sounds with his tongue, that when he wishes to punish severely those men he calls criminals, he forbids them to chatter, and forces them by threats to be silent. it is felt that this punishment is entirely too cruel however, and that even the worst offenders should be allowed to talk part of each day. whatever a simian does, there must always be some talking about it. he can't even make peace without a kind of chatter called a peace conference. super-cats would not have had to "make" peace: they would have just walked off and stopped fighting. * * * * * in a world of super-cat-men, i suppose there would have been fewer sailors; and people would have cared less for seaside resorts, or for swimming. cats hate getting wet, so men descended from them might have hated it. they would have felt that even going in wading was a sign of great hardihood, and only the most daring young fellows, showing off, would have done it. among them there would have been no anti-vivisection societies: no young cats christian associations or red cross work: no vegetarians: no early closing laws: much more hunting and trapping: no riding to hounds; that's pure simian. just think how it would have entranced the old-time monkeys to foresee such a game! a game where they'd all prance off on captured horses, tearing pell-mell through the woods in gay red coats, attended by yelping packs of servant-dogs. it is excellent sport--but how cats would scorn to hunt in that way! they would not have knighted explorers--they would have all been explorers. * * * * * imagine that you are strolling through a super-cat city at night. over yonder is the business quarter, its evening shops blazing with jewels. the great stock-yards lie to the east where you hear those sad sounds: that low mooing as of innumerable herds, waiting slaughter. beyond lie the silent aquariums and the crates of fresh mice. (they raise mice instead of hens in the country, in super-cat land.) to the west is a beautiful but weirdly bacchanalian park, with long groves of catnip, where young super-cats have their fling, and where a few crazed catnip addicts live on till they die, unable to break off their strangely undignified orgies. and here where you stand is the sumptuous residence district. houses with spacious grounds everywhere: no densely-packed buildings. the streets have been swept up--or lapped up--until they are spotless. not a scrap of paper is lying around anywhere: no rubbish, no dust. few of the pavements are left bare, as ours are, and those few are polished: the rest have deep soft velvet carpets. no footfalls are heard. [illustration: punctilious, haughty, inflammable] there are no lights in these streets, though these people are abroad much at night. all you see are stars overhead and the glowing eyes of cat ladies, of lithe silken ladies who pass you, or of stiff-whiskered men. beware of those men and the gleam of their split-pupiled stare. they are haughty, punctilious, inflammable: self-absorbed too, however. they will probably not even notice you; but if they do, you are lost. they take offense in a flash, abhor strangers, despise hospitality, and would think nothing of killing you or me on their way home to dinner. follow one of them. enter this house. ah what splendor! no servants, though a few abject monkeys wait at the back-doors, and submissively run little errands. but of course they are never let inside: they would seem out of place. gorgeous couches, rich colors, silken walls, an oriental magnificence. in here is the ballroom. but wait: what is this in the corner? a large triumphal statue--of a cat overcoming a dog. and look at this dining-room, its exquisite appointments, its daintiness: faucets for hot and cold milk in the pantry, and a gold bowl of cream. some one is entering. hush! if i could but describe her! languorous, slender and passionate. sleepy eyes that see everything. an indolent purposeful step. an unimaginable grace. if you were _her_ lover, my boy, you would learn how fierce love can be, how capricious and sudden, how hostile, how ecstatic, how violent! * * * * * think what the state of the arts would have been in such cities. they would have had few comedies on their stage; no farces. cats care little for fun. in the circus, superlative acrobats. no clowns. [illustration: one of their poets] in drama and singing they would have surpassed us probably. even in the stage of arrested development as mere animals, in which we see cats, they wail with a passionate intensity at night in our yards. imagine how a caruso descended from such beings would sing. in literature they would not have begged for happy endings. they would have been personally more self-assured than we, far freer of cheap imitativeness of each other in manners and art, and hence more original in art; more clearly aware of what they really desired, not cringingly watchful of what was expected of them; less widely observant perhaps, more deeply thoughtful. their artists would have produced less however, even though they felt more. a super-cat artist would have valued the pictures he drew for their effects on himself; he wouldn't have cared a rap whether anyone else saw them or not. he would not have bothered, usually, to give any form to his conceptions. simply to have had the sensation would have for him been enough. but since simians love to be noticed, it does not content them to have a conception; they must wrestle with it until it takes a form in which others can see it. they doom the artistic impulse to toil with its nose to the grindstone, until their idea is expressed in a book or a statue. are they right? i have doubts. the artistic impulse seems not to wish to produce finished work. it certainly deserts us half-way, after the idea is born; and if we go on, art is labor. with the cats, art is joy. * * * * * but the dominant characteristic of this fine race is cunning. and hence i think it would have been through their craftiness, chiefly, that they would have felt the impulse to study, and the wish to advance. craft is a cat's delight: craft they never can have too much of. so it would have been from one triumph of cunning to another that they would have marched. that would have been the greatest driving force of their civilization. this would have meant great progress in invention and science--or in some fields of science, the economic for instance. but it would have retarded them in others. craft studies the world calculatingly, from without, instead of understandingly from within. especially would it have cheapened the feline philosophies; for not simply how to know but how to circumvent the universe would have been their desire. mankind's curiosity is disinterested; it seems purer by contrast. that is to say, made as we are, it seems purer to us. what we call disinterested, however, super-cats might call aimless. (aimlessness is one of the regular simian traits.) i don't mean to be prejudiced in favor of the simian side. curiosity may be as debasing, i grant you, as craft. and craft might turn into artifices of a kind which would be noble and fine. just as the ignorant and fitful curiosity of some little monkey is hardly to be compared to the astronomer's magnificent search, so the craft and cunning we see in our pussies would bear small relation to the high-minded planning of some ruler of the race we are imagining. and yet--craft _is_ self-defeating in the end. transmute it into its finest possible form, let it be as subtle and civilized as you please, as yearning and noble, as enlightened, it still sets itself over against the wholeness of things; its rôle is that of the part at war with the whole. milton's lucifer had the mind of a fine super-cat. that craft may defeat itself in the end, however, is not the real point. that doesn't explain why the lions aren't ruling the planet. the trouble is, it would defeat itself in the beginning. it would have too bitterly stressed the struggle for existence. conflict and struggle make civilizations virile, but they do not by themselves make civilizations. mutual aid and support are needed for that. there the felines are lacking. they do not co-operate well; they have small group-devotion. their lordliness, their strong self-regard, and their coolness of heart, have somehow thwarted the chance of their racial progress. _seven_ there are many other beasts that one might once have thought had a chance. some, like horses and deer, were not bold enough; or were stupid, like buffaloes. some had over-trustful characters, like the seals; or exploitable characters, like cows, and chickens, and sheep. such creatures sentence themselves to be captives, by their lack of ambition. dogs? they have more spirit. but they have lost their chance of kingship through worshipping us. the dog's finer qualities can't be praised too warmly; there is a purity about his devotion which makes mere men feel speechless: but with all love for dogs, one must grant they are vassals, not rulers. they are too parasitic--the one willing servant class of the world. and we have betrayed them by making under-simians of them. we have taught them some of our own ways of behaving, and frowned upon theirs. loving us, they let us stop their developing in tune with their natures; and they've patiently tried ever since to adopt ways of ours. they have done it, too; but of course they can't get far: it's not their own road. dogs have more love than integrity. they've been true to us, yes, but they haven't been true to themselves. pigs? the pig is remarkably intelligent and brave,--but he's gross; and grossness delays one's achievement, it takes so much time. the snake too, though wise, has a way of eating himself into stupors. if super-snake-men had had banquets they would have been too vast to describe. each little snake family could have eaten a herd of cattle at christmas. goats, then? bears or turtles? wolves, whales, crows? each had brains and pride, and would have been glad to rule the world if they could; but each had their defects, and their weaknesses for such a position. the elephant? ah! evolution has had its tragedies, hasn't it, as well as its triumphs; and well should the elephant know it. he had the best chance of all. wiser even than the lion, or the wisest of apes, his wisdom furthermore was benign where theirs was sinister. consider his dignity, his poise and skill. he was plastic, too. he had learned to eat many foods and endure many climates. once, some say, this race explored the globe. their bones are found everywhere, in south america even; so the elephants' columbus may have found some road here before ours. they are cosmopolitans, these suave and well-bred beings. they have rich emotional natures, long memories, loyalty; they are steady and sure; and not narrow, not self-absorbed, for they seem interested in everything. what was it then, that put them out of the race? could it have been a quite natural belief that they had already won? and when they saw that they hadn't, and that the monkey-men were getting ahead, were they too great-minded and decent to exterminate their puny rivals? it may have been their tolerance and patience that betrayed them. they wait too long before they resent an imposition or insult. just as ants are too energetic and cats too shrewd for their own highest good, so the elephants suffer from too much patience. their exhibitions of it may seem superb,--such power and such restraint, combined, are noble,--but a quality carried to excess defeats itself. kings who won't lift their scepters must yield in the end; and, the worst of it is, to upstarts who snatch at their crowns. * * * * * i fancy the elephants would have been gentler masters than we: more live-and-let-live in allowing other species to stay here. our way is to kill good and bad, male and female and babies, till the few last survivors lie hidden away from our guns. all species must surrender unconditionally--those are our terms--and come and live in barns alongside us; or on us, as parasites. the creatures that want to live a life of their own, we call wild. if wild, then no matter how harmless we treat them as outlaws, and those of us who are specially well brought up shoot them for fun. some might be our friends. we don't wish it. we keep them all terrorized. when one of us conquering monkey-men enters the woods, most animals that scent him slink away, or race off in a panic. it is not that we have planned this deliberately: but they know what we're like. race by race they have been slaughtered. soon all will be gone. we give neither freedom nor life-room to those we defeat. if we had been as strong as the elephants, we might have been kinder. when great power comes naturally to people, it is used more urbanely. we use it as parvenus do, because that's what we are. the elephant, being born to it, is easy-going, confident, tolerant. he would have been a more humane king. * * * * * a race descended from elephants would have had to build on a large scale. imagine a crowd of huge, wrinkled, slow-moving elephant-men getting into a vast elephant omnibus. and would they have ever tried airships? the elephant is stupid when it comes to learning how to use tools. so are all other species except our own. isn't it strange? a tool, in the most primitive sense, is any object, lying around, that can obviously be used as an instrument for this or that purpose. many creatures use objects as _materials_, as birds use twigs for nests. but the step that no animal takes is learning freely to use things as instruments. when an elephant plucks off a branch and swishes his flanks, and thus keeps away insects, he is using a tool. but he does it only by a vague and haphazard association of ideas. if he once became a conscious user of tools he would of course go much further. we ourselves, who are so good at it now, were slow enough in beginning. think of the long epochs that passed before it entered our heads. and all that while the contest for leadership blindly went on, without any species making use of this obvious aid. the lesson to be learned was simple: the reward was the rule of a planet. yet only one species, our own, has ever had that much brains. it makes you wonder what other obvious lessons may still be unlearned. * * * * * it is not necessarily stupid however, to fail to use tools. to use tools involves using reason, instead of sticking to instinct. now, sticking to instinct has its disadvantages, but so has using reason. whichever faculty you use, the other atrophies, and partly deserts you. we are trying to use both. but we still don't know which has the more value. * * * * * a sudden vision comes to me of one of the first far-away ape-men who tried to use reason instead of instinct as a guide for his conduct. i imagine him, perched in his tree, torn between those two voices, wailing loudly at night by a river, in his puzzled distress. my poor far-off brother! [illustration: the first thinker.] _eight_ we have been considering which species was on the whole most finely equipped to be rulers, and thereafter achieve a high civilization; but that wasn't the problem. the real problem was which would _do_ it:--a different matter. to do it there was need of a species that had at least these two qualities: some quenchless desire, to urge them on and on; and also adaptability of a thousand kinds to their environment. the rhinoceros cares little for adaptability. he slogs through the world. but we! we are experts. adaptability is what we depend on. we talk of our mastery of nature, which sounds very grand; but the fact is we respectfully adapt ourselves first, to her ways. "we attain no power over nature till we learn natural laws, and our lordship depends on the adroitness with which we learn and conform." adroitness however is merely an ability to win; back of it there must be some spur to make us use our adroitness. why don't we all die or give up when we're sick of the world? because the love of life is reënforced, in most energized beings, by some longing that pushes them forward, in defeat and in darkness. all creatures wish to live, and to perpetuate their species, of course; but those two wishes alone evidently do not carry any race far. in addition to these, a race, to be great, needs some hunger, some itch, to spur it up the hard path we lately have learned to call evolution. the love of toil in the ants, and of craft in cats, are examples (imaginary or not). what other such lust could exert great driving force? with us is it curiosity? endless interest in one's environment? many animals have some curiosity, but "some" is not enough; and in but few is it one of the master passions. by a master passion, i mean a passion that is really your master: some appetite which habitually, day in, day out, makes its subjects forget fatigue or danger, and sacrifice their ease to its gratification. that is the kind of hold that curiosity has on the monkeys. _nine_ imagine a prehistoric prophet observing these beings, and forecasting what kind of civilizations their descendants would build. anyone could have foreseen certain parts of the simians' history: could have guessed that their curiosity would unlock for them, one by one, nature's doors, and--idly--bestow on them stray bits of valuable knowledge: could have pictured them spreading inquiringly all over the globe, stumbling on their inventions--and idly passing on and forgetting them. to have to learn the same thing over and over again wastes the time of a race. but this is continually necessary, with simians, because of their disorder. "disorder," a prophet would have sighed: "that is one of their handicaps; one that they will never get rid of, whatever it costs. having so much curiosity makes a race scatter-brained. "yes," he would have dismally continued, "it will be a queer mixture: these simians will attain to vast stores of knowledge, in time, that is plain. but after spending centuries groping to discover some art, in after-centuries they will now and then find it's forgotten. how incredible it would seem on other planets to hear of lost arts. "there is a strong streak of triviality in them, which you don't see in cats. they won't have fine enough characters to concentrate on the things of most weight. they will talk and think far more of trifles than of what is important. even when they are reasonably civilized, this will be so. great discoveries sometimes will fail to be heard of, because too much else is; and many will thus disappear, and these men will not know it."[1] [1] we did rescue mendel's from the dust heap; but perhaps it was an exception. * * * * * let me interrupt this lament to say a word for myself and my ancestors. it is easy to blame us as undiscriminating, but we are at least full of zest. and it's well to be interested, eagerly and intensely, in so many things, because there is often no knowing which may turn out important. we don't go around being interested on purpose, hoping to profit by it, but a profit may come. and anyway it is generous of us not to be too self-absorbed. other creatures go to the other extreme to an amazing extent. they are ridiculously oblivious to what is going on. the smallest ant in the garden will ignore the largest woman who visits it. she is a huge and most dangerous super-mammoth in relation to him, and her tread shakes the earth; but he has no time to be bothered, investigating such-like phenomena. he won't even get out of her way. he has his work to do, hang it. birds and squirrels have less of this glorious independence of spirit. they watch you closely--if you move around. but not if you keep still. in other words, they pay no more attention than they can help, even to mammoths. we of course observe everything, or try to. we could spend our lives looking on. consider our museums for instance: they are a sign of our breed. it makes us smile to see birds, like the magpie, with a mania for this collecting--but only monkeyish beings could reverence museums as we do, and pile such heterogeneous trifles and quantities in them. old furniture, egg-shells, watches, bits of stone.... and next door, a "menagerie." though our victory over all other animals is now aeons old, we still bring home captives and exhibit them caged in our cities. and when a species dies out--or is crowded (by us) off the planet--we even collect the bones of the vanquished and show them like trophies. * * * * * curiosity is a valuable trait. it will make the simians learn many things. but the curiosity of a simian is as excessive as the toil of an ant. each simian will wish to know more than his head can hold, let alone ever deal with; and those whose minds are active will wish to know everything going. it would stretch a god's skull to accomplish such an ambition, yet simians won't like to think it's beyond their powers. even small tradesmen and clerks, no matter how thrifty, will be eager to buy costly encyclopedias, or books of all knowledge. almost every simian family, even the dullest, will think it is due to themselves to keep all knowledge handy. their idea of a liberal education will therefore be a great hodge-podge; and he who narrows his field and digs deep will be viewed as an alien. if more than one man in a hundred should thus dare to concentrate, the ruinous effects of being a specialist will be sadly discussed. it may make a man exceptionally useful, they will have to admit; but still they will feel badly, and fear that civilization will suffer. * * * * * one of their curious educational ideas--but a natural one--will be shown in the efforts they will make to learn more than one "language." they will set their young to spending a decade or more of their lives in studying duplicate systems--whole systems--of chatter. those who thus learn several different ways to say the same things, will command much respect, and those who learn many will be looked on with awe--by true simians. and persons without this accomplishment will be looked down on a little, and will actually feel quite apologetic about it themselves. consider how enormously complicated a complete language must be, with its long and arbitrary vocabulary, its intricate system of sounds; the many forms that single words may take, especially if they are verbs; the rules of grammar, the sentence structure, the idioms, slang and inflections. heavens, what a genius for tongues these simians have![2] where another race, after the most frightful discord and pains, might have slowly constructed _one_ language before this earth grew cold, this race will create literally hundreds, each complete in itself, and many of them with quaint little systems of writing attached. and the owners of this linguistic gift are so humble about it, they will marvel at bees, for their hives, and at beavers' mere dams. [2] you remember what kipling says in the jungle books, about how disgusted the quiet animals were with the bandarlog, because they were eternally chattering, would never keep still. well, this is the good side of it. * * * * * to return, however, to their fear of being too narrow, in going to the other extreme they will run to incredible lengths. every civilized simian, every day of his life, in addition to whatever older facts he has picked up, will wish to know all the news of all the world. if he felt any true concern to know it, this would be rather fine of him: it would imply such a close solidarity on the part of this genus. (such a close solidarity would seem crushing, to others; but that is another matter.) it won't be true concern, however, it will be merely a blind inherited instinct. he'll forget what he's read, the very next hour, or moment. yet there he will faithfully sit, the ridiculous creature, reading of bombs in spain or floods in thibet, and especially insisting on all the news he can get of the kind our race loved when they scampered and fought in the forest, news that will stir his most primitive simian feelings,--wars, accidents, love affairs, and family quarrels. to feed himself with this largely purposeless provender, he will pay thousands of simians to be reporters of such events day and night; and they will report them on such a voluminous scale as to smother or obscure more significant news altogether. great printed sheets will be read by every one every day; and even the laziest of this lazy race will not think it labor to perform this toil. they won't like to eat in the morning without their papers, such slaves they will be to this droll greed for knowing. they won't even think it is droll, it is so in their blood. their swollen desire for investigating everything about them, including especially other people's affairs, will be quenchless. few will feel that they really are "fully informed"; and all will give much of each day all their lives to the news. books too will be used to slake this unappeasable thirst. they will actually hold books in deep reverence. books! bottled chatter! things that some other simian has formerly said. they will dress them in costly bindings, keep them under glass, and take an affecting pride in the number they read. libraries,--store-houses of books,--will dot their world. the destruction of one will be a crime against civilization. (meaning, again, a simian civilization.) well, it is an offense to be sure--a barbaric offense. but so is defacing forever a beautiful landscape; and they won't even notice that sometimes; they won't shudder anyway, the way they instinctively do at the loss of a "library." * * * * * all this is inevitable and natural, and they cannot help it. there even are ways one can justify excesses like this. if their hunger for books ever seems indiscriminate to them when they themselves stop to examine it, they will have their excuses. they will argue that some bits of knowledge they once had thought futile, had later on come in most handy, in unthought of ways. true enough! for their scientists. but not for their average men: they will simply be like obstinate housekeepers who clog up their homes, preserving odd boxes and wrappings, and stray lengths of string, to exult if but one is of some trifling use ere they die. it will be in this spirit that simians will cherish their books, and pile them up everywhere into great indiscriminate mounds; and these mounds will seem signs of culture and sagacity to them. those who know many facts will feel wise! they will despise those who don't. they will even believe, many of them, that knowledge is power. unfortunate dupes of this saying will keep on reading, ambitiously, till they have stunned their native initiative, and made their thoughts weak; and will then wonder dazedly what in the world is the matter, and why the great power they were expecting to gain fails to appear. again, if they ever forget what they read, they'll be worried. those who _can_ forget--those with fresh eyes who have swept from their minds such facts as the exact month and day that their children were born, or the numbers on houses, or the names (the mere meaningless labels) of the people they meet,--will be urged to go live in sanitariums or see memory doctors! * * * * * by nature their itch is rather for knowing, than for understanding or thinking. some of them will learn to think, doubtless, and even to concentrate, but their eagerness to acquire those accomplishments will not be strong or insistent. creatures whose mainspring is curiosity will enjoy the accumulating of facts, far more than the pausing at times to reflect on those facts. if they do not reflect on them, of course they'll be slow to find out about the ideas and relationships lying behind them; and they will be curious about those ideas; so you would suppose they'd reflect. but deep thinking is painful. it means they must channel the spready rivers of their attention. that cannot be done without discipline and drills for the mind; and they will abhor doing that; their minds will work better when they are left free to run off at tangents. compare them in this with other species. each has its own kind of strength. to be compelled to be so quick-minded as the simians would be torture, to cows. cows could dwell on one idea, week by week, without trying at all; but they'd all have brain-fever in an hour at a simian tea. a super-cow people would revel in long thoughtful books on abstruse philosophical subjects, and would sit up late reading them. most of the ambitious simians who try it--out of pride--go to sleep. the typical simian brain is supremely distractable, and it's really too jumpy by nature to endure much reflection. therefore many more of them will be well-informed than sagacious. this will result in their knowing most things far too soon, at too early a stage of civilization to use them aright. they will learn to make valuable explosives at a stage in their growth, when they will use them not only in industries, but for killing brave men. they will devise ways to mine coal efficiently, in enormous amounts, at a stage when they won't know enough to conserve it, and will waste their few stores. they will use up a lot of it in a simian habit[3] called travel. this will consist in queer little hurried runs over the globe, to see ten thousand things in the hope of thus filling their minds. [3] even in a wild state, the monkey is restless and does not live in lairs. their minds will be full enough. their intelligence will be active and keen. it will have a constant tendency however to outstrip their wisdom. their intelligence will enable them to build great industrial systems before they have the wisdom and goodness to run them aright. they will form greater political empires than they will have strength to guide. they will endlessly quarrel about which is the best scheme of government, without stopping to realize that learning to govern comes first. (the average simian will imagine he knows without learning.) the natural result will be industrial and political wars. in a world of unmanageable structures, wild smashes must come. _ten_ inventions will come so easily to simians (in comparison with all other creatures) and they will take such childish pleasure in monkeying around, making inventions, that their many devices will be more of a care than a comfort. in their homes a large part of their time will have to be spent keeping their numerous ingenuities in good working order--their elaborate bell-ringing arrangements, their locks and their clocks. in the field of science to be sure, this fertility in invention will lead to a long list of important and beautiful discoveries: telescopes and the calculus, radiographs, and the spectrum. discoveries great enough, almost, to make angels of them. but here again their simian-ness will cheat them of half of their dues, for they will neglect great discoveries of the truest importance, and honor extravagantly those of less value and splendor if only they cater especially to simian traits. to consider examples: a discovery that helps them to talk, just to talk, more and more, will be hailed by these beings as one of the highest of triumphs. talking to each other over wires will come in this class. the lightning when harnessed and tamed will be made to trot round, conveying the most trivial cacklings all day and night. huge seas of talk of every sort and kind, in print, speech, and writing, will roll unceasingly over their civilized realms, involving an unbelievable waste in labor and time, and sapping the intelligence talk is supposed to upbuild. in a simian civilization, great halls will be erected for lectures, and great throngs will actually pay to go inside at night to hear some self-satisfied talk-maker chatter for hours. almost any subject will do for a lecture, or talk; yet very few subjects will be counted important enough for the average man to do any _thinking_ on them, off by himself. in their futurist books they will dream of an even worse state, a more dreadful indulgence in communication than the one just described. this they'll hope to achieve by a system called mental telepathy. they will long to communicate wordlessly, mind impinging on mind, until all their minds are awash with messages every moment, and withdrawal from the stream is impossible anywhere on earth. this will foster the brotherhood of man. (conglomerateness being their ideal.) super-cats would have invented more barriers instead of more channels. discoveries in surgery and medicine will also be over-praised. the reason will be that the race will so need these discoveries. unlike the great cats, simians tend to undervalue the body. having less self-respect, less proper regard for their egos, they care less than the cats do for the casing of the ego,--the body. the more civilized they grow the more they will let their bodies deteriorate. they will let their shoulders stoop, their lungs shrink, and their stomachs grow fat. no other species will be quite so deformed and distorted. athletics they will watch, yes, but on the whole sparingly practise. their snuffy old scholars will even be proud to decry them. where once the simians swung high through forests, or scampered like deer, their descendants will plod around farms, or mince along city streets, moving constrictedly, slowly, their litheness half gone. they will think of nature as "something to go out and look at." they will try to live wholly apart from her and forget they're her sons. forget? they will even deny it, and declare themselves sons of god. in spite of her wonders they will regard nature as somehow too humble to be the true parent of such prominent people as simians. they will lose all respect for the dignity of fair mother earth, and whisper to each other she is an evil and indecent old person. they will snatch at her gifts, pry irreverently into her mysteries, and ignore half the warnings they get from her about how to live. ailments of every kind will abound among such folk, inevitably, and they will resort to extraordinary expedients in their search for relief. although squeamish as a race about inflicting much pain in cold blood, they will systematically infect other animals with their own rank diseases, or cut out other animals' organs, or kill and dissect them, hoping thus to learn how to offset their neglect of themselves. conditions among them will be such that this will really be necessary. few besides impractical sentimentalists will therefore oppose it. but the idea will be to gain health by legerdemain, by a trick, instead of by taking the trouble to live healthy lives. strange barrack-like buildings called hospitals will stand in their cities, where their trick-men, the surgeons, will slice them right open when ill; and thousands of zealous young pharmacists will mix little drugs, which thousands of wise-looking simians will firmly prescribe. each generation will change its mind as to these drugs, and laugh at all former opinions; but each will use some of them, and each will feel assured that in this respect they know the last word. and, in obstinate blindness, this people will wag their poor heads, and attribute their diseases not to simian-ness but to civilization. the advantages that any man or race has, can sometimes be handicaps. having hands, which so aids a race, for instance, can also be harmful. the simians will do so many things with their hands, it will be bad for their bodies. instead of roaming far and wide over the country, getting vigorous exercise, they will use their hands to catch and tame horses, build carriages, motors, and then when they want a good outing they will "go for a ride," with their bodies slumped down, limp and sluggish, and losing their spring. then too their brains will do harm, and great harm, to their bodies. the brain will give them such an advantage over all other animals that they will insensibly be led to rely too much on it, to give it too free a rein, and to find the mirrors in it too fascinating. this organ, this outgrowth, this new part of them, will grow over-active, and its many fears and fancies will naturally injure the body. the interadjustment is delicate and intimate, the strain is continuous. when the brain fails to act with the body, or, worse, works against it, the body will sicken no matter what cures doctors try. as in bodily self-respect, so in racial self-respect, they'll be wanting. they will have plenty of racial pride and prejudice, but that is not the same thing. that will make them angry when simians of one color mate with those of another. but a general deterioration in physique will cause much less excitement. they will _talk_ about improving the race--they will talk about everything--but they won't use their chances to _do_ it. whenever a new discovery makes life less hard, for example, these heedless beings will seldom preserve this advantage, or use their new wealth to take more time thereafter for thought, or to gain health and strength or do anything else to make the race better. instead, they will use the new ease just to increase in numbers; and they will keep on at this until misery once more has checked them. life will then be as hard as ever, naturally, and the chance will be gone. they will have a proverb, "the poor ye have always with you,"--said by one who knew simians. their ingenious minds will have an answer to this. they will argue it is well that life should be spartan and hard, because of the discipline and its strengthening effects on the character. but the good effects of this sort of discipline will be mixed with sad wreckage. and only creatures incapable of disciplining themselves could thus argue. it is an odd expedient to get yourself into trouble just for discipline's sake. the fact is, however, the argument won't be sincere. when their nations grow so over-populous and their families so large it means misery, that will not be a sign of their having felt ready for discipline. it will be a sign of their not having practised it in their sexual lives. _eleven_ the simians are always being stirred by desire and passion. it constantly excites them, constantly runs through their minds. wild or tame, primitive or cultured, this is a brand of the breed. other species have times and seasons for sexual matters, but the simian-folk are thus preoccupied all the year round. this super-abundance of desire is not necessarily good or bad, of itself. but to shape it for the best it will have to be studied--and faced. this they will not do. some of them won't like to study it, deeming it bad--deeming it bad yet yielding constantly to it. others will hesitate because they will deem it so sacred, or will secretly fear that study might show them it ought to be curbed. meantime, this part of their nature will be coloring all their activities. it will beautify their arts, and erotically confuse their religions. it will lend a little interest to even their dull social functions. it will keep alive degrading social evils in all their great towns. through these latter evils, too, their politics will be corrupted; especially their best and most democratic attempts at self-government. self-government works best among those who have learned to self-govern. * * * * * in the far distant ages that lie before us what will be the result of this constant preoccupation with desire? will it kill us or save us? will this trait and our insatiable curiosity interact on each other? that might further eugenics. that might give us a better chance to breed finely than all other species. * * * * * we already owe a great deal to passion: more than men ever realize. wasn't it darwin who once even risked the conjecture that the vocal organs themselves were developed for sexual purposes, the object being to call or charm one's mate. hence--perhaps--only animals that were continuously concerned with their matings would be at all likely to form an elaborate language. and without an elaborate language, growth is apt to be slow. if we owe this to passion, what follows? does it mean, for example, that the more different mates that each simian once learned to charm, the more rapidly language, and with it civilization, advanced? _twelve_ a doctor, who was making a study of monkeys, once told me that he was trying experiments that bore on the polygamy question. he had a young monkey named jack who had mated with a female named jill; and in another cage another newly-wedded pair, arabella and archer. each pair seemed absorbed in each other, and devoted and happy. they even hugged each other at mealtime and exchanged bits of food. after a time their transports grew less fiery, and their affections less fixed. archer got a bit bored. he was decent about it, though, and when arabella cuddled beside him he would more or less perfunctorily embrace her. but when he forgot, she grew cross. the same thing occurred a little later in the jack and jill cage, only there it was jill who became a little tired of jack. soon each pair was quarreling. they usually made up, pretty soon, and started loving again. but it petered out; each time more quickly. [illustration: archer felt bored] meanwhile the two families had become interested in watching each other. when jill had repulsed jack, and he had moped about it awhile, he would begin staring at arabella, over opposite, and trying to attract her attention. this got jack in trouble all around. arabella indignantly made faces at him and then turned her back; and as for jill, she grew furious, and tore out his fur. but in the next stage, they even stopped hating each other. each pair grew indifferent. then the doctor put jack in with arabella, and archer with jill. arabella promptly yielded to jack. new devotion. more transports. jill and archer were shocked. jill clung to the bars of her cage, quivering, and screaming remonstrance; and even blasé archer chattered angrily at some of the scenes. then the doctor hung curtains between the cages to shut out the view. jill and archer, left to each other, grew interested. they soon were inseparable. the four monkeys, thus re-distributed, were now happy once more, and full of new liveliness and spirit. but before very long, each pair quarreled--and made up--and quarreled--and then grew indifferent, and had cynical thoughts about life. at this point, the doctor put them back with their original mates. and--they met with a rush! gave cries of recognition and joy, like faithful souls reunited. and when they were tired, they affectionately curled up together; and hugged each other even at mealtime, and exchanged bits of food. * * * * * this was as far as the doctor had gotten, at the time that i met him; and as i have lost touch with him since, i don't know how things were afterward. his theory at the time was, that variety was good for fidelity. "so many of us feel this way, it may be in the blood," he concluded. "some creatures, such as wolves, are more serious; or perhaps more cold-blooded. never mate but once. well--we're not wolves. we can't make wolves our models. of course we are not monkeys either, but at any rate they are our cousins. perhaps wolves can be continent without any trouble at all, but it's harder for simians: it may affect their nervous systems injuriously. if we want to know how to behave, according to the way nature made us, i say that with all due allowances we should study the monkeys." to be sure, these particular monkeys were living in idleness. this corresponds to living in high social circles with us, where men do not have to work, and lack some of the common incentives to home-building. the experiment was not conclusive. still, even in low social circles-_thirteen_ are we or are we not simians? it is no use for any man to try to think anything else out until he has decided first of all where he stands on that question. it is not only in love affairs: let us lay all that aside for the moment. it is in ethics, economics, art, education, philosophy, what-not. if we are fallen angels, we should go this road: if we are super-apes, that. "our problem is not to discover what we ought to do if we were different, but what we ought to do, being what we are. there is no end to the beings we can imagine different from ourselves; but they do not exist," and we cannot be sure they would be better than we if they did. for, when we imagine them, we must imagine their entire environment; they would have to be a part of some whole that does not now exist. and that new whole, that new reality, being merely a figment of our little minds, "would probably be inferior to the reality that is. for there is this to be said in favor of reality: that we have nothing to compare it with. our fantasies are always incomplete, because they are fantasies. and reality is complete. we cannot compare their incompleteness with its completeness."[4] [4] from an anonymous article entitled "tolstoy and russia" in the _london times_, sept. 26, 1918. too many moralists begin with a dislike of reality: a dislike of men as they are. they are free to dislike them--but not at the same time to be moralists. their feeling leads them to ignore the obligation which should rest on all teachers, "to discover the best that man can do, not to set impossibilities before him and tell him that if he does not perform them he is damned." man is moldable; very; and it is desirable that he should aspire. but he is apt to be hasty about accepting any and all general ideals without figuring out whether they are suitable for simian use. one result of his habit of swallowing whole most of the ideals that occur to him, is that he has swallowed a number that strongly conflict. any ideal whatever strains our digestions if it is hard to assimilate: but when two at once act on us in different ways, it is unbearable. in such a case, the poets will prefer the ideal that's idealest: the hard-headed instinctively choose the one adapted to simians. whenever this is argued, extremists spring up on each side. one extremist will say that being mere simians we cannot transcend much, and will seem to think that having limitations we should preserve them forever. the other will declare that we are not merely simians, never were just plain animals; or, if we were, souls were somehow smuggled in to us, since which time we have been different. we have all been perfect at heart since that date, equipped with beautiful spirits, which only a strange perverse obstinacy leads us to soil. what this obstinacy is, is the problem that confronts theologians. they won't think of it as simian-ness; they call it original sin. they regard it as the voice of some devil, and say good men should not listen to it. the scientists say it isn't a devil, it is part of our nature, which should of course be civilized and guided, but should not be stamped out. (it might mutilate us dangerously to become under-simianized. look at mrs. humphry ward and george washington. worthy souls, but no flavor.) * * * * * in every field of thought then, two schools appear, that are divided on this: must we forever be at heart high-grade simians? or are we at heart something else? for example, in education, we have in the main two great systems. one depends upon discipline. the other on exciting the interest. the teacher who does not recognize or allow for our simian nature, keeps little children at work for long periods at dull and dry tasks. without some such discipline, he fears that his boys will lack strength. the other system believes they will learn more when their interest is roused; and when their minds, which are mobile by nature, are allowed to keep moving. or in politics: the best government for simians seems to be based on a parliament: a talk-room, where endless vague thoughts can be expressed. this is the natural child of those primeval sessions that gave pleasure to apes. it is neither an ideal nor a rational arrangement of course. small executive committees would be better. but not if we are simians. or in industry: why do factory workers produce more in eight hours a day than in ten? it is absurd. super-sheep could not do it. but that is the way men are made. to preach to such beings about the dignity of labor is futile. the dignity of labor is not a simian conception at all. true simians hate to have to work steadily: they call it grind and confinement. they are always ready to pity the toilers who are condemned to this fate, and to congratulate those who escape it, or who can do something else. when they see some performer in spangles risk his life, at a circus, swinging around on trapezes, high up in the air, and when they are told he must do it daily, do they pity _him_? no! super-elephants would say, and quite properly, "what a horrible life!" but it naturally seems stimulating to simians. boys envy the fellow. on the other hand whenever we are told about factory life, we instinctively shudder to think of enduring such evils. we see some old workman, filling cans with a whirring machine; and we hear the humanitarians telling us, indignant and grieving, that he actually must stand in that nice, warm, dry room every day, safe from storms and wild beasts, and with nothing to do but fill cans; and at once we groan: "how deadly! what monotonous toil! shorten his hours!" his work would seem blissful to super-spiders,--but to us it's intolerable. the factory system is meant for other species than ours. our monkey-blood is also apparent in our judgments of crime. if a crime is committed on impulse, we partly forgive it. why? because, being simians, with a weakness for yielding to impulses, we like to excuse ourselves by feeling not accountable for them. elephants would have probably taken an opposite stand. they aren't creatures of impulse, and would be shocked at crimes due to such causes; their fault is the opposite one of pondering too long over injuries, and becoming vindictive in the end, out of all due proportion. if a young super-elephant were to murder another on impulse, they would consider him a dangerous character and string him right up. but if he could prove that he had long thought of doing it, they would tend to forgive him. "poor fellow, he brooded," they would say. "that's upsetting to any one." as to modesty and decency, if we are simians we have done well, considering: but if we are something else--fallen angels--we have indeed fallen far. not being modest by instinct we invent artificial ideals, which are doubtless well-meaning but are inherently of course second-rate, so that even at our best we smell prudish. and as for our worst, when we as we say let ourselves go, we dirty the life-force unspeakably, with chuckles and leers. but a race so indecent by nature as the simians are would naturally have a hard time behaving as though they were not: and the strain of pretending that their thoughts were all pretty and sweet, would naturally send them to smutty extremes for relief. the standards of purity we have adopted are far too strict--for simians. _fourteen_ we were speaking a while ago of the fertility with which simians breed. this is partly due to the constant love interest they take in each other, but it is also reënforced by their reliance on numbers. that reliance will be deep, since, to their numbers, they will owe much success. it will be thus that they will drive out other species, and garrison the globe. such a race would naturally come to esteem fertility. it will seem profane not to. as time goes on, however, the advantage of numbers will end; and in their higher stages, large numbers will be a great drawback. the resources of a planet are limited, at each stage of the arts. also, there is only a limited space on a planet. yet it will come hard to them to think of ever checking their increase. they will bring more young into existence than they can either keep well or feed. the earth will be covered with them everywhere, as far as eye can see. north and south, east and west, there will always be simians huddling. their cities will be far more distressing than cities of vermin,--for vermin are healthy and calm and successful in life. ah, those masses of people--unintelligent, superstitious, uncivilized! what a dismal drain they will be on the race's strength! not merely will they lessen its ultimate chance of achievement; their hardships will always distress and preoccupy minds,--fine, generous minds,--that might have done great things if free: that might have done something constructive at least, for their era, instead of being burned out attacking mere anodyne-problems. nature will do what it can to lessen the strain, providing an appropriate remedy for their bad behavior in plagues. many epochs will pass before the simians will learn or dare to control them--for they won't think they can, any more than they dare control propagation. they will reverently call their propagation and plagues "acts of god." when they get tired of reverence and stop their plagues, it will be too soon. their inventiveness will be--as usual--ahead of their wisdom; and they will unfortunately end the good effects of plagues (as a check) before they are advanced enough to keep down their numbers themselves. meanwhile, when, owing to the pressure of other desires, any group of primates does happen to become less prolific, they will feel ashamed, talk of race suicide, and call themselves decadent. and they will often be right: for though some regulation of the birth-rate is an obvious good, and its diminution often desirable in any planet's history, yet among simians it will be apt to come from second-rate motives. greed, selfishness or fear-thoughts will be the incentives, the bribes. contrivances, rather than continence, will be the method. how audacious, and how disconcerting to nature, to baffle her thus! even into her shrine they must thrust their bold paws to control her. another race viewing them in the garlanded chambers of love, unpacking their singular devices, might think them grotesque: but the busy little simians will be blind to such quaint incongruities. still, there is a great gift that their excess of passion will bestow on this race: it will give them romance. it will teach them what little they ever will learn about love. other animals have little romance: there is none in the rut: that seasonal madness that drives them to mate with perhaps the first comer. but the simians will attain to a fine discrimination in love, and this will be their path to the only spiritual heights they can reach. for, in love, their inmost selves will draw near, in the silence of truth; learning little by little what the deepest sincerity means, and what clean hearts and minds and what crystal-clear sight it demands. such intercommunication of spirit with spirit is at the beginning of all true understanding. it is the beginning of silent cosmic wisdom: it may lead to knowing the ways of that power called god. _fifteen_ not content with the whole of a planet and themselves too, to study, this race's children will also study the heavens. how few kinds of creatures would ever have felt that impulse, and yet how natural it will seem to these! how boundless and magnificent is the curiosity of these tiny beings, who sit and peer out at the night from their small whirling globe, considering deeply the huge cold seas of space, and learning with wonderful skill to measure the stars. in studies so vast, however, they are tested to the core. in these great journeys the traveler must pay dear for his flaws. for it always is when you most finely are exerting your strength that every weakness you have most tells against you. one weakness of the primates is the character of their self-consciousness. this useful faculty, that can probe so deep, has one naïve defect--it relies too readily on its own findings. it doesn't suspect enough its own unconfessed predilections. it assumes that it can be completely impartial--but isn't. to instance an obvious way in which it will betray them: beings that are intensely self-conscious and aware of their selves, will also instinctively feel that their universe is. what active principle animates the world, they will ask. a great blind force? it is possible. but they will recoil from admitting any such possibility. a self-aware purposeful force then? that is better! (more simian.) "a blind force can't have been the creator of all. it's unthinkable." any theory _their_ brains find "unthinkable" cannot be true. (this is not to argue that it really is a blind force--or the opposite. it is merely an instance of how little impartial they are.) * * * * * a second typical weakness of this race will come from their fears. they are not either self-sufficing or gallant enough to travel great roads without cringing,--clear-eyed, unafraid. they are finely made, but not nobly made,--in that sense. they will therefore have a too urgent need of religion. few primates have the courage to face--alone--the still inner mysteries: infinity, space and time. they will think it too terrible, they will feel it would turn them to water, to live through unearthly moments of vision without creeds or beliefs. so they'll get beliefs first. ah, poor creatures! the cart before the horse! ah, the blasphemy (pitiful!) of their seeking high spiritual temples, with god-maps or bibles about them, made below in advance! think of their entering into the presence of truth, declaring so loudly and boldly they know her already, yet far from willing to stand or fall by her flames--to rise like a phoenix or die as an honorable cinder!--but creeping in, clad in their queer blindfolded beliefs, designed to shield them from her stern, bright tests! think of truth sadly--or merrily--eyeing such worms! _sixteen_ imagine you are watching the bandarlog at play in the forest. as you behold them and comprehend their natures, now hugely brave and boastful, now full of dread, the most weakly emotional of any intelligent species, ever trying to attract the notice of some greater animal, not happy indeed unless noticed,--is it not plain they are bound to invent things called gods? don't think for the moment of whether there are gods or not; think of how sure these beings would be to invent them. (not wait to find them.) having small self-reliance they can not bear to face life alone. with no self-sufficingness, they must have the countenance of others. it is these pressing needs that will hurry the primates to build, out of each shred of truth they can possibly twist to their purpose, and out of imaginings that will impress them because they are vast, deity after deity to prop up their souls. what a strange company they will be, these gods, in their day, each of them an old bearded simian up in the sky, who begins by fishing the universe out of a void, like a conjurer taking a rabbit out of a hat. (a hat which, if it resembled a void, wasn't there.) and after creating enormous suns and spheres, and filling the farthest heavens with vaster stars, one god will turn back and long for the smell of roast flesh, another will call desert tribes to "holy" wars, and a third will grieve about divorce or dancing. all gods that any groups of simians ever conceive of, from the woodenest little idol in the forest to the mightiest spirit, no matter how much they may differ, will have one trait in common: a readiness to drop any cosmic affair at short notice, focus their minds on the far-away pellet called earth, and become immediately wholly concerned, aye, engrossed, with any individual worshipper's woes or desires,--a readiness to notice a fellow when he is going to bed. this will bring indescribable comfort to simian hearts; and a god that neglects this duty won't last very long, no matter how competent he may be in other respects. but one must reciprocate. for the maker of the cosmos, as they see him, wants noticing too; he is fond of the deference and attention that simians pay him, and naturally he will be angry if it is withheld;--or if he is not, it will be most magnanimous of him. hence prayers and hymns. hence queer vague attempts at communing with this noble kinsman. to desire communion with gods is a lofty desire, but hard to attain through an ignobly definite creed. dealing with the highest, most wordless states of being, the simians will attempt to conceive them in material form. they will have beliefs, for example, as to the furnishings and occupations in heaven. and why? why, to help men to have religious conceptions without themselves being seers,--which in any true sense of "religious" is an impossible plan. * * * * * in their efforts to be concrete they will make their creeds amusingly simian. consider the simian amorousness of jupiter, and the brawls on olympus. again, in the old jewish bible, what tempts the first pair? the tree of knowledge, of course. it appealed to the curiosity of their nature, and who could control _that_! and satan in the bible is distinctly a simian's devil. the snake, it is known, is the animal monkeys most dread. hence when men give their devil a definite form they make him a snake. a race of super-chickens would have pictured their devil a hawk. _seventeen_ what are the handicaps this race will have in building religions? the greatest is this: they have such small psychic powers. the over-activity of their minds will choke the birth of such powers, or dull them. the race will be less in touch with nature, some day, than its dogs. it will substitute the compass for its once innate sense of direction. it will lose its gifts of natural intuition, premonition, and rest, by encouraging its use of the mind to be cheaply incessant. this lack of psychic power will cheat them of insight and poise; for minds that are wandering and active, not receptive and still, can seldom or never be hushed to a warm inner peace. one service these restless minds however will do: they eventually will see through the religions they themselves invented. but ages will be thrown away in repeating this process. a simian creed will not be very hard thus to pierce. when forming a religion, they will be in far too much haste, to wait to apply a strict test to their holy men's visions. furthermore they will have so few visions, that any will awe them; so naturally they will accept any vision as valid. then their rapid and fertile inventiveness will come into play, and spin the wildest creeds from each vision living dust ever dreamed. they will next expect everybody to believe whatever a few men have seen, on the slippery ground that if you simply try believing it, you will then feel it's true. such religions are vicarious; their prophets alone will see god, and the rest will be supposed to be introduced to him by the prophets. these "believers" will have no white insight at all of their own. now, a second-hand believer who is warmed at one remove--if at all--by the breath of the spirit, will want to have exact definitions in the beliefs he accepts. not having had a vision to go by, he needs plain commandments. he will always try to crystallize creeds. and that, plainly, is fatal. for as time goes on, new and remoter aspects of truth are discovered, which can seldom or never be fitted into creeds that are changeless. * * * * * over and over again, this will be the process: a spiritual personality will be born; see new truth; and be killed. his new truth not only will not fit into too rigid creeds, but whatever false finality is in them it must contradict. so, the seer will be killed. his truth being mighty, however, it will kill the creeds too. there will then be nothing left to believe in--except the dead seer. for a few generations he may then be understandingly honored. but his priests will feel that is not enough: he must be honored uncritically: so uncritically that, whatever his message, it must be deemed the whole truth. some of his message they themselves will have garbled; and it was not, at best, final; but still it will be made into a fixed creed and given his name. truth will be given his name. all men who thereafter seek truth must find only his kind, else they won't be his "followers." (to be his co-seekers won't do.) priests will always hate any new seers who seek further for truth. their feeling will be that their seer found it, and thus ended all that. just believe what he says. the job's over. no more truth need be sought. it's a comforting thing to believe cosmic search nicely settled. thus the mold will be hardened. so new truths, when they come, can but break it. then men will feel distraught and disillusioned, and civilizations will fall. thus each cycle will run. so long as men intertwine falsehoods with every seer's visions, both perish, and every civilization that is built on them must perish too. _eighteen_ if men can ever learn to accept all their truths as not final, and if they can ever learn to build on something better than dogma, they may not be found saying, discouragedly, every once in so often, that every civilization carries in it the seeds of decay. it will carry such seeds with great certainty, though, when they're put there, by the very race, too, that will later deplore the results. why shouldn't creeds totter when they are jerry-built creeds? on stars where creeds come late in the life of a race; where they spring from the riper, not cruder, reactions of spirit; where they grow out of nobly developed psychic powers that have put their possessors in tune with cosmic music; and where no cheap hallucinations discredit their truths; they perhaps run a finer, more beautiful course than the simians', and open the eyes of the soul to far loftier visions. _nineteen_ it has always been a serious matter for men when a civilization decayed. but it may at some future day prove far more serious still. our hold on the planet is not absolute. our descendants may lose it. germs may do them out of it. a chestnut fungus springs up, defies us, and kills all our chestnuts. the boll weevil very nearly baffles us. the fly seems unconquerable. only a strong civilization, when such foes are about, can preserve us. and our present efforts to cope with such beings are fumbling and slow. we haven't the habit of candidly facing this danger. we read our biological history but we don't take it in. we blandly assume we were always "intended" to rule, and that no other outcome could even be considered by nature. this is one of the remnants of ignorance certain religions have left: but it's odd that men who don't believe in easter should still believe this. for the facts are of course this is a hard and precarious world, where every mistake and infirmity must be paid for in full. * * * * * if mankind ever is swept aside as a failure however, what a brilliant and enterprising failure he at least will have been. i felt this with a kind of warm suddenness only today, as i finished these dreamings and drove through the gates of the park. i had been shutting my modern surroundings out of my thoughts, so completely, and living as it were in the wild world of ages ago, that when i let myself come back suddenly to the twentieth century, and stare at the park and the people, the change was tremendous. all around me were the well-dressed descendants of primitive animals, whizzing about in bright motors, past tall, soaring buildings. what gifted, energetic achievers they suddenly seemed! i thought of a photograph i had once seen, of a ship being torpedoed. there it was, the huge, finely made structure, awash in the sea, with tiny black spots hanging on to its side--crew and passengers. the great ship, even while sinking, was so mighty, and those atoms so helpless. yet, it was those tiny beings that had created that ship. they had planned it and built it and guided its bulk through the waves. they had also invented a torpedo that could rend it asunder. * * * * * it is possible that our race may be an accident, in a meaningless universe, living its brief life uncared-for, on this dark, cooling star: but even so--and all the more--what marvelous creatures we are! what fairy story, what tale from the arabian nights of the jinns, is a hundredth part as wonderful as this true fairy story of simians! it is so much more heartening, too, than the tales we invent. a universe capable of giving birth to many such accidents is--blind or not--a good world to live in, a promising universe. and if there are no other such accidents, if we stand alone, if all the uncountable armies of planets are empty, or peopled by animals only, with no keys to thought, then we have done something so mighty, what may it not lead to! what powers may we not develop before the sun dies! we once thought we lived on god's footstool: it may be a throne. this is no world for pessimists. an amoeba on the beach, blind and helpless, a mere bit of pulp,--that amoeba has grandsons today who read kant and play symphonies. will those grandsons in turn have descendants who will sail through the void, discover the foci of forces, the means to control them, and learn how to marshal the planets and grapple with space? would it after all be any more startling than our rise from the slime? no sensible amoeba would have ever believed for a minute that any of his most remote children would build and run dynamos. few sensible men of today stop to feel, in their hearts, that we live in the very same world where that miracle happened. this world, and our racial adventure, are magical still. _twenty_ yet although for high-spirited marchers the march is sufficient, there still is that other way of looking at it that we dare not forget. our adventure may satisfy _us_: does it satisfy nature? she is letting us camp for awhile here among the wrecked graveyards of mightier dynasties, not one of which met her tests. their bones are the message the epochs she murdered have left us: we have learned to decipher their sickening warning at last. * * * * * yes, and even if we are permitted to have a long reign, and are not laid away with the failures, are we a success? we need so much spiritual insight, and we have so little. our airships may some day float over the hills of arcturus, but how will that help us if we cannot find the soul of the world? is that soul alive and loving? or cruel? or callous? or dead? we have no sure vision. hopes, guesses, beliefs--that is all. there are sounds we are deaf to, there are strange sights invisible to us. there are whole realms of splendor, it may be, of which we are heedless; and which we are as blind to as ants to the call of the sea. life is enormously flexible--look at all that we've done to our dogs,--but we carry our hairy past with us wherever we go. the wise st. bernards and the selfish toy lap-dogs are brothers, and some things are possible for them and others are not. so with us. there are definite limits to simian civilizations, due in part to some primitive traits that help keep us alive, and in part to the mere fact that every being has to be something, and when one is a simian one is not also everything else. our main-springs are fixed, and our principal traits are deep-rooted. we cannot now re-live the ages whose imprint we bear. we have but to look back on our past to have hope in our future: but--it will be only _our_ future, not some other race's. we shall win our own triumphs, yet know that they would have been different, had we cared above all for creativeness, beauty, or love. * * * * * so we run about, busy and active, marooned on this star, always violently struggling, yet with no clearly seen goal before us. men, animals, insects--what tribe of us asks any object, except to keep trying to satisfy its own master appetite? if the ants were earth's lords they would make no more use of their lordship than to learn and enjoy every possible method of toiling. cats would spend their span of life, say, trying new kinds of guile. and we, who crave so much to know, crave so little but knowing. some of us wish to know nature most; those are the scientists. others, the saints and philosophers, wish to know god. both are alike in their hearts, yes, in spite of their quarrels. both seek to assuage, to no end, the old simian thirst. if we wanted to _be_ gods--but ah, can we grasp that ambition? a note on the type in which this book is set _the text of this book was set on the linotype in baskerville. the punches for this face were cut under the supervision of george w. jones, an eminent english printer. linotype baskerville is a facsimile cutting from type cast from the original matrices of a face designed by john baskerville. the original face was the forerunner of the "modern" group of type faces. ¶ john baskerville (1706-75), of birmingham, england, a writing-master, with a special renown for cutting inscriptions in stone, began experimenting about 1750 with punch-cutting and making typographical material. it was not until 1757 that he published his first work, a virgil in royal quarto, with great-primer letters. this was followed by his famous editions of milton, the bible, the book of common prayer, and several latin classic authors. his types, at first criticized as unnecessarily slender, delicate, and feminine, in time were recognized as both distinct and elegant, and both his types and his printing were greatly admired. printers, however, preferred the stronger types of caslon, and baskerville before his death repented of having attempted the business of printing. for four years after his death his widow continued to conduct his business. she then sold all his punches and matrices to the société littéraire-typographique, which used some of the types for the sumptuous kehl edition of voltaire's works in seventy volumes.--_ composed, printed and bound by h. wolff, new york. paper made by p. f. glatfelter & co., spring grove, pa. an expository outline of the "vestiges of the natural history of creation;" with a comprehensive and critical analysis of the arguments by which the extraordinary hypotheses of the author are supported and have been impugned, with their bearing upon the religious and moral interests of the community. with a notice of the author's "explanations:" a sequel to the vestiges. * * * * * _originally printed in a supplement of_ the atlas _newspaper of august 30 and december 20, 1845._ * * * * * london: effingham wilson, royal exchange. j. vincent, oxford; g. andrews, durham; j. teppell, norwich; brodie and co., salisbury. a. and c. black, edinburgh; d. robertson, glasgow; a. brown and co., aberdeen. w. curry, jun., and co., dublin. 1846. advertisement. * * * * * the following tractate first appeared in the form of a literary review in a supplement of the atlas; but two impressions of that journal having been long since exhausted, and inquiries still continuing numerous and urgent, the proprietor has granted permission for the article to be reprinted in a separate, more convenient, and perhaps enduring vehicle than that of a newspaper. few works of a scientific import have been published that so promptly and deeply fixed public attention as the _vestiges of creation_, or elicited more numerous replies and sharper critical analysis and disquisition. upon so vast a question as the evolution of universal creation differences of opinion were natural and unavoidable. many have disputed the accuracy of some of the author's facts, and the sequence and validity of his inductive inferences; but few can withhold from him the praise of a patient and intrepid spirit of inquiry, much occasional eloquence, and very considerable powers of analysis, systematic induction, arrangement and combination. in what follows the leading objects kept in view have been--first, an expository outline of the author's facts and argument; next, of the chief reasons by which they have been impugned by professor sedgwick, professor whewell, mr. bosanquet, and others who have entered the lists of controversy. these arrayed, the concluding purpose fitly followed of a brief exhibition of the relative strength of the main points in issue, with their bearing on the moral and religious interests of the community. it is the fourth and latest edition that has been submitted to investigation. in this impression the author has introduced several corrections and alterations, without, however, any infringement or mitigation of its original scope and character. more recently appeared his "explanations," a sequel to the "vestiges of the natural history of creation;" in which the author endeavours to elucidate and strengthen his former position. this had become necessary in consequence of the number of his opponents, and the inquiry and discussion to which the original publication had given rise. of this, also, a lengthened review was given in the atlas, which has been included; so that the reader will now have before him a succinct outline of a novel and interesting topic of philosophical investigation. in the present reprint a few corrections have been made, and the illustrative table at page 34, and some other additions, introduced. _london, january_ 1, 1846. an expository outline of the "vestiges of the natural history of creation." it rarely happens that speculative inquiries in england command much attention, and the _vestiges of creation_ would have probably formed no exception, had it not been from the unusual ability with which the work has been executed. the subject investigated is one of vast, almost universal, interest; for everyone--the low, in common with the high in intellect--find enigmas in creation that they would gladly have unriddled, and promptly gather round the oracle who has boldly stepped forth to cut the knot of their perplexities. the first impression made, too, is favourable. no very striking originality, eloquence, or genius, is displayed; yet there is ingenuity; and though the author betrays the zeal of an advocate, desirous of leading to a determinate and _material_ conclusion, his address, like that of the apostle of temperance, is mostly mild and equable, with occasionally a little gentlemanly fervour to give animation to his discourse. his style is mostly felicitous, sometimes beautiful, lucid, precise, and elevated. in tone and manner of execution, in quiet steadiness of purpose, in the firm, intrepid spirit with which truth, or that which is conceived to be true, is followed, regardless of startling presentments, the _vestiges_ call to mind the _mecanique celeste_, or _système du monde_. in caution, as in science, the author is immeasurably inferior to laplace; but in magnitude and boldness of design he transcends the illustrious frenchman. laplace sought no more than to subject the celestial movements to the formulas of analysis, and reconcile to common observation terrestrial appearances; but our author is far more ambitious--more venturesome in aim--which is nothing less than to lift the veil of isis, and solve the phenomena of universal nature. with what success remains to be considered. that great skill and cleverness, that a very superior mastery is evinced, we have conceded, and, we will also add, great show of fairness in treatment and conclusion. no partial opening is made; the great design, in all its extent, is manfully grappled with. the universe is first surveyed, next the mystery of its origin. after ranging through sidereal space, examining the bodies found there, their arrangement, formation, and evolution, the author selects our own planet for especial interrogation. he disembowels it, scrutinizing the internal evidences of its structure and history, and thence infers the causes of past vicissitudes, existing relations, and appearances. these disposed of, the surface is explored, the phenomena of animal and vegetable existence contemplated, and the sources of vital action, sexual differences, and diversities of species assigned. man, as the supreme head and last work of progressive creation, challenges a distinct consideration; his history and mental constitution are investigated, and the relation in which a sublime reason stands to the instinct of brutes discriminated. the end and purpose of all appropriately form the concluding theme, which finished, the curtain drops, and the last sounds heard are that the name of the great unknown will probably never be revealed; that "praise will elicit no response," nor any "word of censure" be parried or deprecated. "give me," exclaimed archimedes, "a fulcrum, and i will raise the earth." "give me," says the author of the _vestiges_, "gravitation and development, and i will create a universe." alexander's ambition was to conquer a world, our author's is to create one. but he is wrong in saying that his is the "first attempt to connect the natural sciences into a history of creation, and thence to eliminate a view of nature as one grand system of causation." the attempt has been often made, but utterly failed; its results have been found valueless, hurtful--to have occupied without enlarging the intellect, and the very effort has long been discountenanced. great advances, however, have been made in science since system-making began to be discredited; nature has been perseveringly ransacked in all her domains, and many extraordinary secrets drawn from her laboratory. astronomy and geology, chemistry and electricity, have greatly extended the bounds of knowledge; still, we apprehend, we are not yet sufficiently armed with facts to resolve into one consistent whole her infinite variety. efforts at generalization, however, and the systematic arrangement of natural phenomena, are seldom wholly fruitless. if false, they tend to provoke discussion--to lead to active thought and useful research. a solitary truth, though new and useful, rarely obtains higher distinction than to be quietly placed on the rolls of science, while a bold speculation, traversing the whole field of creation, and smoothing all its difficulties, satisfies for the moment, and fixes general attention. of this the _vestiges of creation_ are an example. without adding to our positive knowledge by a single new discovery, demonstration, or experiment, they have excited more interest than the _principia_ of newton. from this popular success, if good do not accrue, no great evil need be anticipated. hypotheses are most hurtful when accredited by an irreversible authority--when erected into a tribunal without appeal, they become the arbitrary dictator in lieu of the handmaid of science. discussion and invention, in place of being stimulated, are then fettered by them; the human mind is enslaved, as europe was for centuries by the _physics_ of aristotle, and still continues to be in some of the ancient retreats and conservatories of exploded errors. but these form the exceptions, not the rule of the age, which is free and equal inquiry. errors have ceased to have prescriptive immunities; and mere conjectures, however sanctioned or plausible, if inconsistent with science--with the ascertained facts of experiment and observation, are speedily passed into the region of dreams and chimeras. whether this will be the fate of our author remains to be proved. the moment selected for his appearance has at least been well chosen. the _vestiges_ have the air of novelty, a long time having elapsed since any one had the hardihood to propound a new system of nature. in common with most manifestations of our time, his effort exhibits a marked improvement on the crudities of his predecessors in the same line of architectural ambition. science has been called to his aid, and the patient ingenuity with which he has sought to make the latest discoveries subservient to his purpose challenges admiration, if not acquiescence. some of our contemporaries have been warmed into almost theological aversion by the boldness of his conclusions, but we see little cause for fear, and none for bitterness or apprehension. more closely nature is investigated and deeper the impression will become of her majesty and might. unlike earthly greatnesses, she loses no power--no grandeur--no fascination--no prestige, by familiarity. the greatest philosophers will always rank among her greatest admirers and most devout and fervent worshippers. had our author proved all he has assumed our faith would not be lessened, nor our wonder diminished. whether matter or spirit has been the world's architect, the astounding miracle of its creation is not the less. what does it import whether it resulted direct from the fiat of omnipotence, or intermediately from the properties he impressed, or the law of development he prescribed? he who gave the law, who infused the energies by which chaos was transmuted into an organized universe, remains great and inscrutable as ever. it is time, however, that we entered upon a more detailed and closer investigation of the _vestiges of creation_. our purpose is not hastily, and without examination, to deprecate, deny, or controvert; but patiently, and without prejudice, to inquire, to submit faithfully and intelligibly the outlines of a remarkable treatise; describe briefly its scope and bearing, the arguments by which they are supported, and the counter reasons by which they appear to be wholly or partially impugned. our readers will thus be enabled to appreciate the merits of a controversy, the most comprehensive and interesting that for a lengthened period has occupied the attention of the scientific and intellectual world. for greater clearness of exposition we shall endeavour to follow the order observed by the author in the division and treatment of his subjects, commencing first with the bodies of space. the author opens his subject with a brief but luminous outline of the arrangement and formation of the astral and planetary systems of the heavens. he first describes the solar system, of which our earth is a member, consisting of the sun, planets, and satellites with the less intelligible orbs termed comets, and taking as the uttermost bounds of this system the orbit of uranus, it occupies a portion of space not less than three thousand six hundred millions of miles in diameter. the mind cannot form an exact notion of so vast an expanse, but an idea of it may be obtained from the fact, that, if the swiftest racehorse ever known had began to traverse it at full speed at the time of the birth of moses, he would only yet have accomplished half his journey. vast as is the solar system, it is only one of an infinity of others which may be still more extensive. our sun is supposed to be a star belonging to a constellation of stars, each of which has its accompaniment of revolving planets; and the constellation itself with similar constellations to form revolving clusters round some mightier centre of attraction; and so on, each astral combination increasing in number, magnitude, and complexity, till the mind is utterly lost in the vain effort to grasp the limitless arrangement. of the stars astronomers can hardly be said to know anything with certainty. sirius, which is the most lustrous, was long supposed to be the nearest and most within the reach of observation, but all attempts to calculate the distance of that luminary have proved futile. of its inconceivable remoteness some notion may be formed by the fact, that the diameter of the earth's annual orbit, if viewed from it, would dwindle into an invisible point. this is what is meant by the stars not having, like the planets, a _parallax_; that is, the earths' orbit, as seen from them, does not subtend a measurable angle. with two other stars, however, astronomers have unexpectedly and recently been more fortunate than with sirius, and have been able to calculate their distances from the earth. the celebrated bessel, and soon afterwards, the late mr. henderson, astronomer royal for scotland, were the first to surmount the difficulty that had baffled the telescopic resources of the herschels. bessel detected a parallax of one-third of a second in the star 61 cygni, and in the constellation of the centaur henderson found another star whose parallax amounted to one second. of the million of fixed glittering points that adorn the sky, these are the only two whose distances have been calculated, and to express them, miles, leagues, or orbits seems inadequate. light, whose speed is known to be 192,000 miles per second, would be three years in reaching our earth from the star of henderson; and starting from bessel's star and moving at the same rate it could only reach us in ten years. these are the nearest stars, but there are others whose distances are immeasurably greater, and whose light, though starting from them at the beginning of creation, may not have reached our globe! the stars visible to the eye are about 3,000, but the number increases with every increase of telescopic power, and may be said to be innumerable. they are not of uniform lustre or form, but vary in figure and brightness. some of them have a _nebulous_ or cloudy appearance; and there are entire clusters with this dusky aspect, mostly pervaded, however, with luminous points of more brilliant hue. in the outer fields of astral space sir william herschel observed a multitude of nebulæ, one or two of which may be seen by the naked eye. all of them, when seen by instruments of low power, look like masses of luminous vapour; but some of them had brighter spots, suggesting to sir william the idea of a condensation of the nebulous matter round one or more centres. but when these luminous masses are examined by more powerful instruments many of them lose their cloudy form, and are resolved into shining points, "like spangles of diamond dust." it is in this way several nebulæ have yielded to the gigantic reflector of lord rosse, and others with still greater optical resources may follow. this brings us to the first questionable and controversial portion of the _vestiges_; namely,--the nebular hypothesis. it is among the gaseous bodies just described, in the outer boundary of nature, which neither telescope nor geometry can well reach, that speculation has laid its _venue_, and commenced its aerial castles. laplace was the first to suggest the nebular hypothesis, which he did with great diffidence, not as a theory proved, or hardly likely, but as a mathematical possibility or illustration. his range of creation, moreover, was not so vast as that of our author, which assumes to compass the entire universe, but was limited to the evolution of the solar system. the mode in which this might be evolved, laplace thus explains:-he conjectures that in the original condition of the solar system the sun revolved upon his axis, surrounded by an atmosphere which, in virtue of an excessive heat, extended far beyond the orbits of all the planets, the planets as yet having no existence. the heat gradually diminished, and as the solar atmosphere contracted by cooling, the rapidity of its rotation increased by the laws of rotatory motion, and an exterior zone of vapour was detached from the rest, the central attraction being no longer able to overcome the increased centrifugal force. the zone of vapour might in some cases retain its form, as we still see in saturn's ring; but more usually the ring of vapour would break into several masses, and these would generally coalesce into one mass, which would revolve about the sun. such portions of the solar atmosphere abandoned successively at different distances, would form planets in the state of vapour. these masses of vapour, it appears from mechanical laws, would have each its rotatory motion, and as the cooling of the vapour still went on, would each produce a planet that might have satellites and rings formed from the planet, in the same manner as the planets were formed from the atmosphere of the sun. all the known motions of the solar system are consistent and reconcileable with this theory of laplace, and upon it the author of the _vestiges_ has enlarged and founded his wider scheme of physical creation. he supposes the void of nature to have been originally filled with a universal fire mist (p. 30), out of which all the celestial orbs were made and put in motion. how this mist was put in activity, and resolved into the luminous and revolving bodies that we now see, and one of which we inhabit is the first urgent perplexity to surmount in the conjecture. it is manifest that if a mist filled the entire region of space, a mist it must for ever remain, unless acted upon by some cause adequate to give it new action and arrangement. no sun, no stars or planets could spontaneously emanate from an inert vapour any more than from nothing. to meet this, his first difficulty, the author supposes that there were certain _nuclei_, or centres of greater condensation, analogous to those still remarked in the nebulæ of the heavens, and that these nuclei, by their superior attractive force, consolidated into spheres the gaseous matter around them:- "of nebulous matter," says he, "in its original state we know too little to enable us to suggest _how nuclei should be established in it_. but supposing that from a _peculiarity_ in the constitution nuclei are formed, we know very well how, by the power of gravitation, the process of an aggregation of the neighbouring matter to these nuclei should proceed until masses more or less solid should be detached from the rest. it is a _well-known law in physics, that when fluid matter collects towards, or meets in a centre, it establishes a rotatory motion_. see minor results of this law in the whirlpool and the whirlwind--nay, on so humble a scale as the water sinking through the aperture of a funnel. it thus becomes certain, that when we arrive at the stage of a nebulous star we have a rotation on its axis commenced." up to this, however, the author has proved nothing. the existence of the fire-mist and nuclei are assumptions only, and the way by which he tries to account for rotatory motion is clearly erroneous. the aggregation of matter round the nuclei by gravitation would have no such tendency; no more than a perfect balance would of itself have a tendency to move about its fulcrum, or a falling stone to deviate from its vertical course. gravitation would indeed compress the particles of matter, but its tendency and entire action is towards the nucleus; it compresses them no more on one side of the line of their direction to the centre of force than on any other side; and hence no _lateral_ or _rotatory motion_ would ensue. rotation, therefore, is yet unaccounted for; though the author says _it is a well-known law in physics_ that when fluid matter collects towards, or meets in a centre, it establishes a rotatory motion; and then for illustration refers to a whirlwind or whirlpool. no such effect would follow the conditions stated, and an entire ignorance is betrayed of the laws of mechanical philosophy. in the whirlpool and the whirlwind the gyration is caused by the fluid passing, not _to_ the centre, but _through_ it and away from it; in the whirlpool downwards through the place of exit, in the whirlwind upwards to where the vacuum has caused the rapid aggregation. laplace was too able a mathematician to commit these elementary blunders; he did not assume to account for rotation by inapplicable laws, but took for granted that the sun revolved upon its axis, and thence communicated a corresponding motion to the bodies thrown from its surface. but our author has sought to advance beyond his teacher, and in this way has shown his ignorance of physics by an egregious mistake. at this point we might stop, without following the ulterior steps by which the solar system is made to evolve out of heated vapour. having got rotation, though by an impossible process, the author falls into the illustration already given of the theory of laplace. the rotation of each nucleus or sun round its axis produces centrifugal force; that force, by refrigeration, increases beyond the centripetal force of gravity; in consequence rings are formed and detached from the surface, whose unequal coherence of parts mostly causes them to break into separate masses or planets, partaking of the motion of the bodies from which they have been separated, and these primaries in their turn becoming centres of gravitation and centrifugal force, throw off their secondaries, or _moons_. in this way the solar system and other systems upon a similar plan of arrangement, it is conjectured, may have been formed. according to the author the generative process is still in progress, and new worlds are in course of being thrown off from new suns in the confines of creation. these nebulous stars on the outer bounds of space, of varying forms and brightness, are supposed to be the centres of new systems in different stages of development, like children of various ages and growth in a numerous family. this is the author's own illustration (p. 20), and after giving it he proceeds:- "precisely thus, seeing in our astral system many thousands of worlds in all stages of formation, from the most rudimental to that immediately preceding the present condition of those we deem perfect, it is unavoidable to conclude that all the perfect have gone through the various stages which we see in the rudimental. this leads us at once to the conclusion that the whole of our firmament was at one time a diffused mass of nebulous matter, extending through the space which it still occupies. so also, of _course_, must have been the other astral systems. indeed, we must presume the whole to have been originally in one connected mass, the astral systems being only the first division into parts, and solar systems the second. "the first idea which all this impresses upon us is, that the formation of bodies in space is _still and at present in progress_. we live at a time when many have been formed, and many are still forming. our own solar system is to be regarded as completed, supposing its perfection to consist in the formation of a series of planets, for there are mathematical reasons for concluding that mercury is the nearest planet to the sun, which can, according to the laws of the system, exist. but there are other solar systems within our astral systems, which are as yet in a less advanced state, and even some quantities of nebulous matter which have scarcely begun to advance towards the stellar form. on the other hand, there are vast numbers of stars which have all the appearance of being fully formed systems, if we are to judge from the complete and definite appearance which they present to our vision through the telescope. we have no means of judging of the _seniority of systems; but it is reasonable to suppose that among the many, some are older than ours_. there is, indeed, one piece of evidence for the probability of the comparative youth of our system, altogether apart from human traditions and the geognostic appearances of the surface of our planet. this consists in a thin nebulous matter, which is diffused around the sun to nearly the orbit of mercury, of a very oblately spheroidal shape. this matter, which sometimes appears to our naked eyes, at sunset, in the form of a cone projecting upwards in the line of the sun's path, and which bears the name of the zodiacal light, has been thought a residuum or last remnant of the concentrating matter of our system, and thus may be supposed to indicate the comparative recentness of the principal events of our cosmogony. _supposing the surmise and inference_ to be correct, and they may be held as so far supported by more familiar evidence, we might with the more confidence speak of our system as not amongst the elder born of heaven, but one whose various phenomena, physical and moral, as yet lay undeveloped, while myriads of others were fully fashioned, and in complete arrangement. thus, in the sublime chronology to which we are directing our inquiries, we first find ourselves called upon to consider the globe which we inhabit as a child of the sun, elder than venus and her younger brother mercury, but posterior in date of birth to mars, jupiter, saturn, and uranus; next to regard our whole system as probably of recent formation in comparison with many of the stars of our firmament. we must, however, be on our guard against supposing the earth as a recent globe in our ordinary conceptions of time. from evidence afterwards to be adduced, it will be seen that it cannot be presumed to be less than many hundreds of centuries old. how much older uranus may be, no one can tell, far less how much more aged may be many of the stars of our firmament, or the stars of other firmaments, than ours." all this is ingenious and fluently expressed. the author has an easy way of surmounting his difficulties by the use of such little auxiliary phrases, as "of course," "it may be surmised," "it is reasonable to suppose," and so on; which, though trifling in themselves, help him in their connecting inferences through many embarrassing perplexities. but his hypothesis is yet unproved; his fire-mist is only a conjecture; his nuclei, scattered like so many eggs in space out of which future suns and worlds are in process of incubation, is of the same description, and rotation, the first step in his process of creation, would not ensue under the conditions he has assigned. without dwelling on these shortcomings, we shall terminate this portion of the author's inquiry with a few general strictures. first, on its inconsistency with what we know of the solar system; and, secondly, on its inadequacy to explain the facts of which we are cognizant on our own globe. in the first place, for the hypothesis to be applicable to our system, it is requisite that the primary and secondary bodies should revolve, both in their orbits and round their axes, in one direction, and nearly in one plane. most of the bodies of the system observe these laws, their orbits are nearly circular, nearly in the plane of the original equator of the solar rotation, and in the direction of that rotation. but there are exceptions; the comets, which intersect the equatorial plane in every angle of direction form one, and the most distant of the planets forms another. the satellites of uranus are retrograde. they move from east to west in orbits highly inclined to that of their primary, and on both accounts are exceptions to the order of the other secondary bodies. our author is so perplexed by this inconsistency that he first doubts the fact, and next tries to explain it by alleging that "it may be owing to a _bouleversement_ of the primary." what is meant by the _bouleversement_ of a planet none of his critics seem to apprehend, nor do we. but that the moons of uranus are contrariwise to those of the other planets, sir john herschel has indubitably established; so that the author at any rate upon this point has sustained a bouleversement. our own moon forms a third exception to his theory. according to his system, this satellite is a slip or graft from our planet, and in constitution, it might be inferred, would partake of the elements of the parent. but the fact is otherwise. the moon has no atmosphere, no seas, or rivers, nor any water, and of course totally unfit for human inhabitants, or organic life of any kind. it must, then, have had a different origin, or be in some earlier stage of development than that through which our earth has passed. leaving these exceptions, we may next inquire into the relevant purposes of the nebular hypothesis, supposing its assumptions acquiesced in. like the fanciful theories of the ancient philosophers, it seems only to involve a profitless topic of controversy, without solving natural phenomena. it does not unravel the mystery of the beginning, brings us no nearer to the first creative force. like a good chemist, previous to analysis, the author first throws all matter into a state of solution; but granting him his fire-mist and nuclei in the midst, how or whence came this condition and arrangement of nature? what was its pre-existing state? or, if that be answered, how or whence was that preceding state educed, for it, too, must have had one prior to it? so that the mind makes no advances by such inquiries, is lost in a maze that can have no end, because it has no beginning; and, like noah's messenger, for want of a resting place, is compelled to return to the first starting point. easier, and quite as satisfactory, it seems to believe, as we have been taught to believe, that the celestial spheres were at once perfect and entire, projected into space from the hands of the maker, than that they were elaborated out of luminous vapour by gravity and condensation. hopeless inquiry is thus foreclosed, an inquisition that cannot be answered, silenced, and removed out of the pale of discussion. it is not from any attribute of the deity being impugned that the hypothesis is objectionable. design and intelligence in the creation are left paramount as before, and our impression of the skill exercised, and the means employed, only transferred to another part of the work. he who produced the primordial condition the author supposes, who filled space with such a mist, composed of such materials, subjected to such laws, such constitution, that sun, moon, and stars necessarily resulted from them, appears omnipotent as ever. but it does not advance inquiry, nor assist us in explaining the wonders we contemplate in our own globe. suppose a planet formed by the author's process, what kind of a body would it be? something, as professor whewell suggests, resembling a large meteoric stone. how after wards came this unformed mass to be like our earth, to be covered with motion and organization, with life and general felicity? what primitive cause stocked it with plants and animals, and produced all the surprising and subtle contrivances which we find in their structure, all the wide and profound mutual dependence which we trace in their economy? is it possible to conceive, as the _vestiges_ inculcate, that man, with his sentiment and intellect, his powers and passions, his will and conscience, were also produced as the ultimate result of vapourous condensation? one more conjecture of the author, in this division of his subject, we shall only notice. it is that "the formation of bodies in space _is still in progress_." what may be doing in the nebulæ, in the region scarcely within reach of telescopic vision, in what may be considered the yet uninclosed and commonable waste of the universe, is a subject, we suspect, of much obscurity, and respecting which no precise intelligence has been received; but limiting attention to the solar system, which is nearer home and more within cognizance, the work seems finished, perfect, and unchangeable, and, like the great architect, made to endure for ever. this was the conclusion of laplace; he proved that the state of our system is _stable_; that is, the ellipsis the planets describe will always remain nearly circular, and the axis of revolution of the earth will never deviate much from its present position. he also gave a mathematical proof that this stability is not accidental, but the result of design, of an arrangement by which the planets all move in the same direction, in orbits of small eccentricity and slightly inclined to each other. reasoning from analogy, as the author of the _vestiges_ is prone to do--extending our views from our solar system to other systems--other suns and revolving planets--it is fair to conclude that they are not less perfect in arrangement--subject to like conditions of permanency, and alike exempt from mutation, decay, collision, or extinction. descending from this high region, we accompany the author to his next and lower field--the earth and its geological history. our globe is somewhat less than 8,000 miles in diameter; it is of a spheroidal form, the equatorial exceeding the polar axis in the proportion of 300 to 299, and which slight inequality, in consequence of its diurnal revolution, is necessary to preserve the land near the equator from inundation by the sea. the mean density or average weight of the earth is, in proportion to that of distilled water, as 5.66 to 1. so that its specific gravity is considerably less than that of tin, the lightest of the metals, but exceeds that of granite, which is three times heavier than water. descending below the surface, the first sensation that strikes is the increase of temperature. this is so rapid, that for every one hundred feet of sinking we obtain an increase of more than one degree of fahrenheit's thermometer. if there be no interruption to this law, and no reason exists to conclude there is, it is manifest that at the depth of a few miles we must reach an intensity of heat utterly unbearable. hence it follows that by no improvements in machinery can mining operations be carried down to a great depth below the surface. the greatest depth yet penetrated does not exceed three thousand feet, and forms a very small advance towards the earth's centre, distant 4,000 miles. geologists, however, without penetrating far into the earth, have found means for obtaining an insight for several miles into its interior structure, and armed with hammer, chisel, and climbing hook, they explore the beetling sea-cliff, traverse the deepest valleys, and scale the highest mountains, carefully examining their formation, disposition, and substance, and are thus enabled to obtain some knowledge of the earth's stomach, as it were, by scrutinising the deposits and eruptive ejectments on its surface. for example, we come to a mountain composed of a particular substance with strata or beds of other rock lying against its sloped sides; we, of course, infer that the substance of the mountain dips away under the strata that we see lying against it. suppose that we walk away from the mountain across the turned-up edges of the stratified rocks, and that for many miles we continue to pass over other stratified rocks, all disposed in the same way, till we begin to cross the opposite edges of the same beds; after which we pass over these rocks all in reverse order, till we come to another extensive mountain composed of similar materials to the first, and shelving away under the strata in the same way; we should then infer that the stratified rocks occupied a basin formed by the rocks of these two mountains, and by calculating the thickness right through these strata could say to what depths the rock of the mountain extended below. in this way has the interior of the globe been examined, and its contents and arrangement, for several miles below the surface, ascertained. the result of such inspection we leave the author of the _vestiges_ to describe:- "it appears that the basis rock of the earth, as it may be called, is of hard texture, and crystalline in its constitution. of this rock, granite may be said to be the type, though it runs into many varieties. over this, except in the comparatively few places where it projects above the general level in mountains, other rocks are disposed in sheets or strata, with the appearance of having been deposited originally from water. but these last rocks have nowhere been allowed to rest in their original arrangement. uneasy movements from below have broken them up in great inclined masses, while in many cases there has been projected through the rents rocky matter more or less resembling the great inferior crystalline mass. this rocky matter must have been in a state of fusion from heat at the time of its projection, for it is often found to have run into and filled up lateral chinks in these rents. there are even instances where it has been rent again, and a newer melted matter of the same character sent through the opening. finally, in the crust as thus arranged, there are, in many places, chinks containing veins of metal. thus, there is first a great inferior mass, composed of crystalline rock, and probably resting immediately on the fused and expanded matter of the interior: next, layers or strata of aqueous origin; next, irregular masses of melted inferior rock that have been sent up volcanically and confusedly at various times amongst the aqueous rocks, breaking up these into masses, and tossing them out of their original levels." this, we believe, is a correct outline of the crust of the earth, so far as it has been possible to observe it. it exhibits extraordinary signs of commotion and vicissitude; the lowest rocks indicating a previous condition of igneous fusion; those above them of aqueous solution. fire and water have thus been the chief tellurian anarchists, and the shaking of continents and the constant shifting of level in sea and land still continue to attest their restless energies. that igneous matter has, during many periods, been protruded from below--that mountains have risen in succession from the sea, and injected their molten substance through cracks and fissures of superincumbent strata--are facts resting on indubitable evidence. many masses of granite became the solid bottom of some portions of the sea before the secondary strata were laid gradually upon them. the granite of mont blanc rose during a recent tertiary period. "we can prove," says professor sedgwick, "more than mere shiftings of level, and that many portions of sea and land have entirely changed their places. the rocks at the top of snowdon are full of petrified sea-shells; the same may be said of some high crests of the alps, pyrenees, and andes. we have proof demonstrative that many parts of scotland, and that all england, formed, during many ages, the solid bottom of the sea. it may be true that the antagonist powers of nature during the human period have reached a kind of balance. but during all geological periods there have been such long intervals of repose, or of such gradual movements, that we may trace the history of the earth in the successive deposits formed in the waters of the sea." this is the great business of geology. although at first sight the interior of the earth appears a confused scene, after careful observation we readily detect in it a regularity and order from which much instructive light is thrown on its past vicissitudes. the deposition of the aqueous rocks and the projection of the volcanic have unquestionably taken place since the settlement of the earth in its present form. they are, indeed, of an order of events which are going on under the agency of intelligible causes, down to the present day. we may therefore consider these generally as recent transactions. but advancing to the far distant antecedent era of its existence, we may consider it to have been a globe of its present size enveloped in the crystalline rock already described, with the waters of the present seas and the present atmosphere around it, though these were probably in considerably different conditions, both as to temperature and their constituent materials, from what they now are. we may thus presume that, without this primitive case of granitic texture, the great bulk of the matters of our earth were agglomerated, whether in a fluid or solid state is uncertain; but there cannot be any doubt that they continue to exist in a condition of great heat and compression, having a mean density of more than double that of the minerals on the surface. judging from the results and still observable conditions, it may be inferred that the heat retained in the interior of the globe was more intense, or had greater freedom to act, in some places than in others. these become the scenes of volcanic operations, and in time marked their situations by the extrusion from below of trap and basalts--rocks composed of the crystalline matter, fused by intense heat, and developed on the surface in various conditions, according to the particular circumstances under which it was sent up; some, for example, being thrown up under water, and some in the open air, which contingencies would make considerable difference in its texture and appearance. it would, however, be a mistake to infer that, previous to these eruptions, the earth was a smooth ball, with air and water playing round it. geology tells us plainly that there were great irregularities--lofty mountains, interspersed with deep seas--and by which, perhaps, the mountains were wholly or partially covered. but it is a fact worthy of observation that the solids of our globe cannot for a moment be exposed to water or the atmosphere without becoming liable to change. they instantly begin to wear down. the matter so worn off being carried into the neighbouring depths and there deposited, became the components of the successive series of stratified rocks, extending from the basal envelope of granite to the earth's surface, and which it will be proper briefly to describe. deposits or rock formations. the first of the series is the _gneis and mica slate system_, of which examples are exposed to view in the highlands of scotland and the west of england. these earliest stratified rocks contain no matters which are not to be found in the primitive granite. they are the same in material--silica, mica, quartz, or hornblende--but changed into new forms and combinations, and hence called by mr. lyell metamorphic rocks. some of them are composed exclusively of one of the materials of granite; the _mica schist_, for example, of mica; the _quartz rocks_, of quartz. in the metamorphic rocks no organic remains have been found, and they are geologically below all the rocks that do contain traces of animal life. from the primary rocks we pass into the next ascending series, called the _clay slate and grauwacke slate system_, which in some places is found resting immediately on the granite, the antecedent bed being there wanting. this deposit has been well examined, because some of its slate beds have been extensively quarried for domestic purposes. by some geologists it is called the _silurian system_, it being largely developed at the surface of a district of western england formerly occupied by the silures. it is found also in north wales and in the north of england, in beds of great thickness, and in scotland, but there the silurian rocks are more feebly represented. the _old red sandstone, or devonian system_, comes next. it forms the material of the grand and rugged mountains which fringe many parts of our highland coasts, and ranges, on the south flank of the grampians, from the eastern to the western sea of scotland. there is no part of geology and science more clear than that which refers to the ages of mountains. it is as certain that the grampian mountains are older than the alps and apennines, as it is that civilisation had reached italy and enabled her to subdue the world, while scotland was the abode of barbarism. the pyrenees, carpathians, and other ranges of continental europe are all younger than these scotch hills, or even the insignificant mendip hills of southern england. stratification tells this tale as plainly, and more truly, than livy tells the story of the roman republic. it tells us that at the time when the grampians sent streams and detritus to straits where now the valleys of the forth and clyde meet, the greater part of europe was a wide ocean. the last three series of strata contain the remains of the earliest occupants of the globe, and of which we shall soon speak. they are of enormous thickness--in england, not much less than 30,000 feet, or nearly six miles. we have now arrived at the secondary rocks, of which the lowest group is the _carboniferous formation_, so called from its remarkable feature of numerous interspersed beds of coal. it commences with beds of the mountain limestone, which in england attains a depth of 800 yards. coal is altogether composed of the matter of a terrestrial vegetation, transmuted by putrefaction of a peculiar kind beneath the surface of water, and in the absence of air. from examples seen at the present day at the mouths of such rivers as the mississippi, which traverse extensive sylvan regions, it is thought that the vegetation, the rubbish of decayed forests, was carried by rivers into estuaries, and there accumulated into vast natural rafts, until it sank to the bottom, where an overlayer of sand or mud would prepare it for becoming a stratum of coal. others conceive that the vegetation first went into the condition of peat moss, that a sink in a level then exposed it to be overrun by the sea and covered with a layer of sand or mud; that a subsequent uprise made the mud dry land, and fitted it to bear a new forest, which afterwards, like its predecessors, became a bed of peat--that, in short, by repetitions of this process the alternate layers of coal, sand and shell constituting the carboniferous group were formed. the _magnesian limestone_ deposits succeed the carboniferous, and sometimes pass into them by insensible gradations. in the south of england they are represented by conglomerates, and partly composed of the solid and more or less rounded fragments of the older strata. they afford a proof of what geologists have often occasion to remark of the long periods of time during which the ancient works of nature were perfected; for the older rocks were solid as they are now, and their organic remains petrified at the time these conglomerates were forming. we can only briefly glance at the remaining chapters of geological history. the _new red sandstone_ forms the base of the great central plains of england, and is surmounted by the oliferous marls and red arenaceous beds which pass under the succession of great oolitic terraces that stretch across england from the coasts of dorsetshire to the north-eastern coast of yorkshire. it marks the commencement of an important era, being the strata in which land animals are first found. the _oolte system_ which follows marks the beginning of mammalia, and in some of its beds in buckinghamshire are found the exuviæ of tropical trees. near weymouth, in the well-known dirt beds, are found trees with their silicified trunks growing up in the position of nature, and their roots embedded in the soil on which they grew. next we have the chalk or _cretaceous formation_, that makes such a conspicuous figure in england. the celebrated cliffs of dover are of this era. it forms a stripe from yorkshire to kent, and is found in france, germany, russia, and in north america. the english chalk beds are 1,200 feet thick, showing the considerable depth of the ocean in which they were formed. their origin has been a questionable topic; they were thought to be formed from the detritus of coral reefs, but professor ehrenberg has recently announced, as the result of his microscopical researches, that chalk is composed partly of inorganic particles and partly of shells of inconceivable minuteness, a cubic inch of the substance containing about ten millions of them. in the hollows of the chalk-beds have been formed series of strata--clay, limestone, marl alternating--to which the name of the _tertiary system_ has been given. it is irregularly distributed over vast surfaces of all our continents, and must be considered as the beds of estuaries left at the conclusion of the cretaceous period. london and paris rest on basins of this formation, and another such basin extends from near winchester under southampton, and reappears in the isle of wight. we hasten upward to the _diluvial system_, which brings us near to the present surface. to this era is referred the erratic blocks, or gigantic boulder stones, which have been driven by floods across our continents, or drifted in icebergs over valleys, and perched sometimes on mountain tops. to it also must be referred the _till_ of scotland and the great brown clay of england, and our vast beds of gravel and superficial rubbish, connected with the deluvium in the history of _ossiferous caverns_, of which that examined by dr. buckland at kirkdale is an example. they occur in the calcareous strata, as the great caverns generally do, and have in all instances been naturally closed up till the period of their discovery. at kirkdale the remains of twenty-four species of animals were found--namely, pigeon, lark, raven, duck, partridge, mouse, water-rat, rabbit, hare, hippopotamus, rhinoceros, elephant, weasel, fox, wolf, deer, ox, horse, bear, tiger, hyena. from many of the bones of the gentler of these animals being found in a broken state, it is supposed that the cave was the haunt of hyenas and other predaceous animals, by which the smaller ones had been consumed. we come last to the _modern_ or _superficial formation_, of which the best specimen is the great bedford level, that spreads over the lower lands of norfolk, cambridgeshire, and lincolnshire, consisting of accumulations of silt, drifted matter, and bog-earth, some of which began before the earliest periods of british history. when these accumulations are removed by artificial means, we find below sometimes shells of recent species, and the remains of an old estuary, sometimes sand-banks, gravel beds, stumps of trees, and masses of drifted wood. on this recent surface are found skulls of a living species of european bear, skeletons of the arctic wolf, european beaver and wild boar, and numerous horns and bones of the roebuck and red deer, and of the gigantic stag or irish elk. they testify to a zoology on the verge of that now prevailing or melting into it. in corresponding deposits of north america are found remains of the mammoth, mastadon, buffalo, and other animals of extinct or living species. considering it best not to interrupt the description of the successive formations, this is almost the only allusion that has been made to the fossils which constitute so important a part of geological science. it is now to be explained that from an early period, that is, from the metamorphic deposit to the close of the rock series, each formation is found to enclose remains of the organic beings, plants, and animals, which flourished upon earth during the time they were forming; and these organisms, or such parts of them as were of sufficient solidity, have been in many instances preserved with the utmost fidelity, although for the most part converted into the substance of the enclosing mineral. the rocks may be thus said to form a kind of history of the organic departments of nature apparently from near their beginning to the present time. it is upon the commencement and progress of life under these circumstances that the author of the _vestiges of creation_ has put forth some of his most startling and controversial propositions; but before noticing them it will be useful to prepare the way by shortly describing the gradations of organic existences, following the same order as observed in the rock series, by beginning with the lowest or humblest forms of organization. rise and progress of plants and animals. the interior of the earth reveals wonders not less impressive than those of the skies. we have seen in the last section how the crust of our globe is composed of successive layers or tiers of strata, rising upward, terrace upon terrace, till we reach the present vegetable mould or superficial platform of animated existence. in the aggregate these formations or systems, marking the several epochs in nature's development, may extend to a depth, as dr. buckland conjectures, of ten or fifteen miles below the surface, and each may be considered a vast cemetery or graveyard, entombing the remains of ages long anterior to human creation. we, in fact, live upon a pile of worlds, and anticipating the future from past records and from changes still manifest from the shallowing soundings of neighbouring seas, it is not improbable that the existing scene of bustle may have heaped upon it as many superincumbent masses as the lowest of the rocks enclosing the vestiges of life. if not with a kind of awe, it must have certainly been with intense curiosity that the first investigators of fossilology looked upon the earliest forms of animated being of which we have any traces as existing upon this globe. these first denizens, however, seem to have been of a simple structure and humble order, not fit to play high class characters. no land animals are found among them, none which could breathe the atmosphere, none but tenants of the water, and even animals so high in the scale as fish were wanting. in popular language, the earliest fossils are corals and shellfish. but to make the subject generally intelligible it will be necessary first to define the orders of the animal kingdom. cuvier was the first to give a philosophical view of the animal world in reference to the plan on which each animal is constructed. according to him there are four forms on which animals have been modelled, and of which ulterior divisions are only slight modifications founded on the development or addition of some parts that do not produce any essential change of structure. the four great branches of the animal world are the _vertebrata_, _mollusca_, _articulata_, and _radiata_. the _vertebrata_ are those animals which (as man and other sucklers, birds and fishes) have a backbone and a skull with lateral appendages, within which the viscera are excluded, and to which the muscles are attached. the _mollusca_ or soft animals have no bony skeleton; the muscles are attached to the skin, which often include stony plates called shells; such mollusca are shell-fish, others are cuttle-fish, and many pulpy sea animals. the _articulata_ consist of crustacea (lobsters, &c.), insects, spiders, and annulos worms, which, like the other classes of this branch, consist of a head and a number of successive portions of the body jointed together, whence the name. finally the _radiata_ include the animals known under the name of zoophytes. now it is fossils of the _radiata_ division of the animal kingdom that are found in the lowest stratified rocks, polypiaria and crinodia, the first including various forms of these extraordinary animals (corallines) which still abound in tropical seas, often obstructing the course of the mariner, and even laying the foundation of new continents. the crinoids are an early and simple form of the large family of star-fishes; the animal is little more than a stomach, surrounded by tentacula to provide itself with food, and mounted upon a many-jointed stalk, so as to resemble a flower upon its stem. along with these in the slate system are a few lowly genera of crustacea, and of a higher class, the mollusca, and the existence of these imply the contemporary existence of certain humbler forms of life, vegetable and animal, for their subsistence, forming a scene approaching to what is found in seas of the present day, excepting that fishes, nor any higher vertebrata, as yet roamed the marine wilds. the animal species of this era seem to have been few in number, and almost the whole had become extinct before the next group of strata had been formed. in the silurian deposit the vestiges of life become more abundant, the number of species extended, and important additions made in the traces of sea plants and fishes. remains of fishes have been detected in rocks immediately over the aymestry limestone, being apparently the first examples of vertebrated animals which breathed upon our planet. (p. 64). the cephaloda, represented in our era by the nautilus and cuttle-fish, pertain to the silurian formation, and are the most highly organised of the mollusca, possessing in some families an internal bony skeleton, together with a heart and a head with mandibles not unlike those of the parrot. in the old red sandstone the same marine specimens are continued with numerous additions. several of the strata are crowded with remains of fish, showing that the seas in which these beds were deposited had swarmed with that class of inhabitants. the predominating kinds are of an inferior model to the two orders which afterwards came into existence, and still are the principal fishes of our seas; the former are covered with integuments of a considerably different character from the true scales covering the latter, and which orders, from their form of organization, are named stenoid and cycloid. up to the present we find proofs of the general uniformity of organic life over the surface of the earth at the time when each particular system of rocks was formed. the types of being formed in the old red as in preceding deposits, are identical in species with the remains that occur in the corresponding class of rocks in brittany, the hartz, norway, russia, and north america; attesting the similarity and almost universality, if not contemporary character, of terrestrial changes. a few other geological facts may be here mentioned for recollection, and which throw light on the marine animal and vegetable forms of this and preceding eras. first there was comparatively an absence of salt in the early ocean; and next the temperature of the earth is conjectured to have been higher, and perhaps almost uniform throughout. the higher temperature of the primeval times is attributed to the greater proximity or intensity of the globe's internal heat, and which, poured through cracks and fissures of the lately concreted crust, m. brongniart supposes to have been sufficiently great to overpower the ordinary meteorological influences and spread a tropical climate all over its surface. it must be further borne in mind that as yet no _land animals or plants_ existed, and for this presumable reason, that dry land had not appeared. it is only in the next or carboniferous formation that evidence is traced of island or continent. as a consequence of this emergence there was fresh water; for rain, instead of returning to the sea, as formerly, was collected in channels of the earth and became springs, rivers, and lakes. it was made a receptacle for an advance in organism, and land plants became a conspicuous part of the new creation. according to the _vestiges of creation_, terrestrial botany began with classes of comparatively simple forms and structure. in the ranks of the vegetable kingdom the lowest place is taken by plants of cellular tissue, and which have no flowers, as lichens, mosses, fungi, ferns, and sea-weeds. above these stand plants with vascular tissue, bearing flowers, and of which there are two subdivisions: first, plants having one seed-lobe, and in which the new matter is added within, of which the cane and palm are examples; second, plants having two seed lobes, and in which the new matter is added on the outside under the bark, of which the pine, elm, oak, and all the british forest trees are examples. now the author of the _vestiges_ states that two-thirds of the plants of this era belong to the cellular kind, but to this one of his ablest critics (_edinburgh review_ for july) demurs, asserting that the carboniferous epoch shows a gorgeous _flora_--that the first fruits of vegetable nature were not rude, ill-fashioned forms, but in magnificence and complexity of structure equal to any living types, and that the forest approached the rank and complicated display of a tropical jungle, where the prevalence of great heat with great moisture, combined with the fact that the atmosphere contained a greater proportion of the natural food of plants, must undoubtedly have forcibly stimulated vegetation, and in quantity and luxuriance of growth, if not fineness of organization, produced it in rich abundance. the earth, it is likely, was one vast forest, which would perform a most important part for the good of its future inhabitants, helping to purge the air of its excess of carbonic acid, by which the earth's surface would be prepared for its new occupants. the animal remains of this era are not numerous in comparison with those that go before or follow. contrary to what the author of the _vestiges_ supposes (p. 111), insects were already buzzing in the air; there were, however, no crawling reptiles on the ground, and it is a doubtful point whether birds cheered the ancient forests with their song. but fishes reached their most perfect organic type. they were the lords of creation, and had a structure in conformity with their high office. since then the class has increased in its species, but has degenerated to a less noble type. in the next formation, the new red sandstone, reptiles make their appearance. they are considered next to fishes in the zoological scale. so nearly are they sometimes connected, that it is doubtful to which class they belong. many reptiles are also amphibious, adapted either to water or land. the surface of the globe abounded in large flat, muddy shores, and was suited to the new order of visitants called into existence. in the oolite system, mostly consisting of calcareous beds, mammals make their appearance. some additions were made to the reptile form. one animal (the behemite) appeared, but terminated in the next era. in the following series of rocks mammals increase in abundance. the advance in land animals is less marked, but considerable in the tertiary strata. the tapir forms a conspicuous type. one animal of the kind was eighteen feet long, and had a couple of tusks turning down from the lower jaw, by which it could attach itself, like the walrus, to a bank, while its body floated in the water. many animals of a former period disappear, and are replaced by others belonging to still existent families--elephant, hippopotamus, and rhinoceros--though extinct as species. some of these forms are startling from their size. the great mastadon was a species of elephant living on aquatic plants, and reaching the height of twelve feet. the mammoth was another elephant, and supposed to have survived till comparatively recent times. the megatherium is an incongruity of nature, of gigantic proportions, yet ranking in a much humbler order than the elephant, that of the edenta, to which the sloth, ant-eater, and armadilla belong. the megatherium had a skeleton of enormous solidity, with an armour-clad body, and five toes, terminating in huge claws to grasp the branches on which it fed. finally, beside the dog, cat, squirrel, and bear, we have offered to us, for the first time, oxen, deer, camel, and other specimens of the rumantia. traces of the quadrumane, or monkey, have been found in the older tertiaries of france, india, and england. so that we may now be said to have arrived at the zoological forms not long antecedent to the appearance of the chief of all, bimana, or man, and shall here pause to consider the conclusions of the author of the _vestiges of creation_ on the origin of the organic existences that have been successively exhibited. it will be convenient, however, first to introduce a synoptic view of the evolutions of the earth as set forth in this and the preceding section. for this purpose the author has introduced a parallel table, exhibiting on one side a scale of animal life beginning with the humblest and ascending to the highest species; and on the other side the successive series of rock formations, in which their fossiliferous remains have been found up to the present superficial deposits of the globe. objections have been made to the correctness of the author's analogies, scale, and his classification of animals, the chief of which will be adverted to in the next section; but the table is essential, as presenting at one view an outline of the hypothesis he has sought to establish. scale of animal kingdom. order of animals in ascending series foetal human brain of rocks. resembles, in _invertebrata._ 1 infusoria _traces of infusoria_(?) 1 gneiss and mica\ slate system \ 2 polypi polypiaria \ \ 5 echinodermata echinodermata \ \ { 7 brachiopoda {15-20 brachiopoda} crustacea } 2 clay slate system \ 1st month, typically, moll-{ 9 pteropoda artic-{crustacea pteropoda } / } that of an usca {10 gasteropoda ulata {12-14 gasteropoda} annelides / / avertebrated animal {11 cephalopoda {annelides cephalopoda} \ / } 3 silurian system / _vertebrata._ { _remains of fishes_ / / { fishes of low type; \ \ 32-36 fishes { heterocercal; allied } 4 old red sandstone } 2nd month, that of a fish; { to crustacea / / { sauroid fishes \ 37 batrachia (frogs, &c.) batrachia \ } 5 carboniferous 39 sauria (lizards, &c.) sauria / formation 40 chelonia (tortoises) chelonia / 3rd month, that of a turtle; 41-46 birds _footsteps of birds_ 6 new red sandstone 4th month, that of a bird; 47 cetacea (dolphins, whales, &c.) _bones of a \ cetaceous animal_ } 7 oolite _bones of a marsupial_ / 8 chalk 48 pachydermata (tapirs, &c.) pachydermata \ 49 edentata (sloths) edentata \ 50 rodentia (squirrels, hare, &c.) rodentia \ 5th month, that of a rodent; 51 marsupialia (opossums, &c.) marsupialia \ 52 ruminantia (oxen, stag, &c.) ruminantia \ 6th month, that of a ruminant; 53 amphibia (seals) } 9 tertiary 54 digitigrada (dog, cat, &c.) digitigrada / 7th month, that of a digitigrade animal; 55 plantigrada (bear, &c.) plantigrada / 56 insectivora (shrew, &c.) insectivora / 57 cheiroptera (bats) cheiroptera / 58 quadrumana (apes) quadrumana / 8th month, that of the quadrumana; 29 bimana (man) bimana 10 superficial deposits 9th month, attains full human character. transmutation of species. in the two last sections we have gone through the earth's geological history, first of the changes in its physical structure, next of the mutations in the organic forms that have, in serial order, appeared in the successive strata of its external envelope, from the period of that far distant crisis when it was a molten globe on which its primitive granitic covering was just beginning to concrete, in consequence of abating heat, until we have arrived at the first prognostic signs of approaching human existence. the rock upon rock of vast thickness, by which the earth's crust, through countless ages, has been formed, unquestionably constitutes a most extraordinary phenomenon of physical creation, but hardly so marvellous and incomprehensible as the beginning, progress, and end of the divers orders of marine and terrestrial beings that filled each world of life. it is to geologists, to playfair, hutton, lyell, buckland, sedgwick, owen, and other great names, native and foreign, to whom we are indebted for this singular revelation of nature's works. it is their unwearied research that has opened to us the surprising spectacle we have attempted briefly to describe of the diversified groups of species which have, in the course of the earth's history, succeeded each other at vast intervals of time; one set of animals and plants wholly or partly disappearing from the face of our planet, and others, which apparently did not before exist, becoming the only or predominant occupants of the globe. now the great question arises--whence, by what power, or by what law, were these reiterated transitions brought about? were the organized species of one geological epoch, by some long-continued agency of natural causes, transmuted into other and succeeding species? or were there an extinction of species, and a replacement of them by others, through special and miraculous acts of creation? or, lastly, did species gradually degenerate and die out from the influence of the altered and unfavourable physical conditions in which they were placed, and be supplanted by immigrants of different species, and to which the new conditions were more congenial? the last, we confess, is the view to which we are most inclined--first, because we think a transmutation of species, from a lower to a higher type, has not been satisfactorily proved; and second, because of the strong impression we entertain, that the universe, subject to certain cyclical and determinate mutations, was made complete at first, with self-subsisting provisions for its perpetual renewal and conservation. we shall advert to this matter hereafter; but at present it is the conclusions of the author of the _vestiges_ that claim consideration. he adopts the first interpretation of animal phenomena, namely, that there has been a transmutation of species, that the scale of creation has been gradually advancing in virtue of an inherent and organic law of development. nature, he contends, began humbly; her first works were of simple form, which were gradually meliorated by circumstances favourable to improvement, and that everywhere animals and plants exhibit traces of a parallel advance of the physical conditions and the organic structure. the general principle, he inculcates, is, that each animal of a higher kind, in the progress of its embryo state, passes through states which are the final condition of the lower kind; that the higher kinds of animals came later, and were developed from the lower kinds, which came earlier in the series of rock formations, by new peculiar conditions operating upon the embryo, and carrying it to a higher stage. these conclusions the author maintains geology has established, and of the results thence derived he gives the subjoined recapitulation:- "in pursuing the progress of the development of both plants and animals upon the globe, we have seen an advance in both cases, from simple to higher forms of organization. in the botanical department we have first sea, afterwards land plants; and amongst these the simpler (cellular and cryptogamic) before the more complex. in the department of zoology, we see, first, traces all but certain of infusoria [shelled animalculæ]; then polypiaria, crinoidea, and some humble forms of the articulata and mollusca; afterwards higher forms of the mollusca; and it appears that these existed for ages before there were any higher types of being. the first step forward gives fishes, the humblest class of the vertebrata; and, moreover, the earliest fishes partake of the character of the lower sub-kingdom, the articulata. afterwards come land animals, of which the first are reptiles, universally allowed to be the type next in advance from fishes, and to be connected with these by the links of an insensible gradation. from reptiles we advance to birds, and thence to mammalia, which are commenced by marsupialia, acknowledgedly low forms in their class. that there is thus a progress of some kind, the most superficial glance at the geological history is sufficient to convince us." now this appears plausible and conclusive, but the correctness of the recapitulation here made, and its conformity to actual nature, have been sharply disputed. it may be true that sea plants came first, but of this there is no proof; and of land plants there is not a shadow of evidence that the simpler forms came into being before the more complex: the simple and complex forms are found together in the more ancient _flora_. it is true that we first see polypiaria, crinoidea, articulata, and mollusca, but not exactly in the order stated by the author. it is true that the next step gives us fishes, but it is not true that the earliest fishes link on to the lower sub-kingdom, the articulata. it is true that we afterwards find reptiles, but those which first appear belong to the highest order of the class, and show no links of an insensible gradation into fishes. in the tertiary deposit of the london clay the evidence of concatenation entirely fails. among the millions of organic forms, from corals up to mammalia of the london and paris basins, hardly a single secondary species is found. in the south of france it is said that two or three secondary species struggle into the tertiary strata; but they form a rare and evanescent exception to the general rule. organic nature at this stage seems formed on a new pattern--plants as well as animals are changed. it might seem as if we had been transported to a new planet; for neither in the arrangement of the genera and the species, nor in their affinities with the types of a pre-existing world, is there any approach to a connected chain of organic development. for some discrepancies the author endeavours to account, and it is fair to give his explanation:- "fossil history has no doubt still some obscure passages; and these have been partially adverted to. fuci, the earliest vegetable fossils as yet detected, are not, it has been remarked, the lowest forms of aquatic vegetation; neither are the plants of the coal-measures the very lowest, though they are a low form, of land vegetation. there is here in reality no difficulty of the least importance. the humblest forms of marine and land vegetation are of a consistence to forbid all expectation of their being preserved in rocks. had we possessed, contemporaneously with the fuci of the silurians, or the ferns of the carboniferous formation, fossils of higher forms respectively, _equally unsubstantial_, but which had survived all contingencies, then the absence of mean forms of similar consistency might have been a stumbling-block in our course; but no such phenomena are presented. the blanks in the series are therefore no more than blanks; and when a candid mind further considers that the botanical fossils actually present are all in the order of their organic development, the whole phenomena appear exactly what might have been anticipated. it is also remarked, in objection, that the mollusca and articulata appear in the same group of rocks (the slate system) with polypiaria, crinoidea, and other specimens of the humblest sub-kingdom; some of the mollusca, moreover, being cephalopods, which are the highest of their division in point of organization. perhaps, in strict fact, the cephalopoda do not appear till a later time, that of the silurian rocks. but even though the cephalopoda could be shewn as pervading all the lowest fossiliferous strata, what more would the fact denote than that, in the first seas capable of sustaining any kind of animal life, the creative energy advanced it, in the space of one formation, (no one can say how long a time this might be,) to the highest forms possible in that element, excepting such as were of vertebrate structure. it may here be inquired if geologists are entitled to set so high a value as they do upon the point in the scale of organic life which is marked by the upper forms of the mollusca. it will afterwards be seen that this is a low point compared with the whole scale, if we are to take as a criterion that parity of development which has been observed in the embryo of one of the higher animals. _the human embryo passes through the whole space representing the invertebrate animals in the first month, a mere fraction of its course._ there is indeed a remarkably rapid change of forms in such an embryo at first: the rapidity, says professor owen, is 'in proportion to the proximity of the ovum to the commencement of its development;' and, conformable to this fact, we find the same zoologist stating that, in the lowest division of the animal kingdom, (the acrita of his arrangement,) there is a much quicker advance of forms towards the next above it, than is to be seen in subsequent departments. there is, indeed, to the most ordinary observation, a rapidity and force in the productive powers of the lowest animals, which might well suggest an explanation of that rush of life which seems to be indicated in the slate and silurian rocks. with regard to the so-called early occurrence of fishes partaking of the saurian character, i would say that their occurrence a full formation after the earliest and simplest fishes, is, considering how little we know of the space of time represented by a formation, not early: their being later in any degree is the fact mainly important. the subsequent rise of new orders of fishes, fully piscine in character, may be explained by the supposition of their having been developed, as is most likely, from a different portion of the inferior sub-kingdom. in short, all the objections which have been made to the great fact of a general progress of organic development throughout the geological ages, will be found, on close examination, to refer merely to doubtful appearances of small moment, which vanish into nothing when rightly understood." upon some of the chief points here involved, it may be remarked that the most eminent physiologists are not agreed; they are not agreed that animals can be arranged in a series, passing from lower to higher; nor that animals of a higher kind in the embryo state pass through the successive stages of the lower kinds; the character of these stages, in the asserted doctrine, being taken from the brain and heart, and man being the highest point of the series. there are physiologists too who deny that the brain of the human embryo at any period, however early, resembles the brain of any mollusk or of any articulata. it never, they assert, passes through a stage comparable or analogous to a permanent condition of the same organ in any invertebrate animal; and in like manner the spinal cord in the human vertebræ at no period agrees with the corresponding part of the lower kind of animals. the moment it becomes visible in the human embryo, it is entirely dorsal in position; while in mollusks and articulatas a great part, or nearly the whole, is ventral. the same is true of the heart, or centre of the vascular system, which has always a different relative position in the great nervous centre in the human embryo from what it has in any articulate animal, and in most mollusks. a second position in the _vestiges_ appears not to have been established--namely, as to the uniform geological arrangement of different organic structures. it is not true that _only_ the lowest forms of animal life are found in the lowest fossiliferous rocks, and that the more complicated structures are gradually and exclusively developed among the higher bands in what might be called a natural ascending scale. on the contrary, the predaceous cephalopods and the highly organized crustaceous are among the oldest fossils. such appears to be the order of nature as evidenced by facts, and it must be admitted, however repugnant to preconceived notions or mere mortal conjectural amendments. in the third place the evidence seems to preponderate in favour of _permanency of species_. there can be no doubt that both plants and animals may, by the influence of breeding, and of external agents operating upon their constitution, be greatly modified, so as to give rise to varieties and races different from what before existed. but there are limits to such modifications, as in the different kind and breed of dogs; and no organized beings can, by the mere working of natural causes, be made to pass from the type of one species to that of another. a wolf by domestication, for example, can never become a dog, nor the ourang-outang by the force of external circumstances be brought within the circle of the human species. in this opinion mr. lyell, dr. prichard, and mr. lawrence, concur. the general conclusion at which they have arrived is, that there is a capacity in all species to accommodate themselves to a certain extent to a change of external circumstances; this extent varying greatly according to the species. there may thus be changes of appearance or structure, and some of these changes are transmissible to the offspring; but the mutations thus superinduced are governed by certain laws, and confined within certain limits. indefinite divergence from the original type is not possible, and the extreme limit of possible variation may usually be reached in a short period of time; in short, professor whewell concludes (_indications of creation_, p. 56), _that every species has a real existence in nature_, and a transmutation from one to another does not exist. thus for example, cuvier remarks that, notwithstanding all the differences of age, appearance and habits, which we find in the dogs of various races and countries, and though we have (in the egyptian mummies) skeletons of this animal as it existed 3,000 years ago, the relation of the bones to each other remains essentially the same; and with all the varieties of their shape and size, there are characters which resist all the influences, both of external nature, of human intercourse, and of time. what varieties, again, in the forms of the different breeds of horses and horned cattle; racers, hunters, coach horses, dray horses, and ponies; short-horns and long-horns, devons and herefords, polled galloways and shetlands; how unlike are the unimproved breeds of cattle as they existed a century ago before the march of agricultural improvement began, and how different were most of these as then existing in what may be called the normal state from the wild cattle produced in chillington park. it has been found, however, when external and artificial conditions are removed, and these different breeds are allowed to run wild, as in the pampas and australia, no matter what the diversity of size, shape, and colour of the domestic breeds, they reverted in their wild state, in these respects, to their primitive types. so again with regard to cultivated vegetables and flowers. how different are the species of the red cabbage and the cauliflower; who would have expected them to be varieties of the wild _brassica oleracea_? yet from that they have been derived by cultivation. they have, however, a tendency like animals to revert to the original type, or, in the gardener's phrase, to degenerate, which it requires the utmost care on his part to counteract. when left to a state of nature, they speedily lose their acquired forms, properties and character, and regain those of the original species. if species be permanent--if no education or training can educe new kinds--if the higher classes of animals are not the results of meliorations of the lower--whence did they come? this question we are not bound to answer. it might be as reasonably asked, whence did the lower classes come? geology, like other sciences, does not conduct us to the _beginning_, it only takes up creation at certain ulterior stages of development. the changes and construction of the globe may have been different in different parts; it has not been proved that geological revolutions have been either universal or contemporary. there may have been climates and regions adapted to the existence of the higher class of land animals, while contemporarily therewith other portions of the globe might be undergoing changes beneath the ocean. it is not improbable that the human species dwelt nearly stationary for ages on the old continents of africa and asia, while europe and america were covered with water. supposing these new continents formed, either by the gradual subsidence of the sea or the rising of its bed, successive inhabitants would follow in the order presented by existing organic remains. while covered by the sea, what now form europe and america could only be peopled by marine animals; but as the land rose or the waters subsided into their ocean channels, and dry land appeared, reptiles and amphibiæ might become the occupants; next, as the earth became drier and more salubrious, the new continent would be resorted to by terrestrial animals; in a still more advanced stage of purification and salubrity, man himself, as the lord of all the preceding classes of immigrants, would take possession, and as he still continues the living occupant it is premature to look for his petrifaction. origin of the animated tribes. science has mastered many perplexities, but is almost powerless as ever in generation. all that lives, and still more all that moves, must have a pre-existing germ formed independently of the created being, but which is essential to its existence, and fixes the type of organization. the old adage--_omne animal ab ovo_--may be taken as generally true. but though every animal has its primordial egg or germ, all germs are not identical. in the beginning of life there are other organic elements besides the ovum. partly on direct proof and partly on good analogy, it may be inferred that these differ in different species--that each in the first stages of existence is bound by a different and immutable mode of development--and, if so, there can be no embryotic identity. "by no change of conditions," says dr. clarke, "can two ova of animals of the same species be developed into different animal species; neither by any provision of identical conditions can two ova of different species be developed into animals of the same kind." if these views be right, and we believe them to be so, there cannot be a transmutation of species under the influence of external circumstances. baffled in the effort either to create species or organically to change them, attempts have been made to approach nearer to the source of vitality, and explain the chemical, electric, or mechanical laws by which the vital principle is influenced. for this purpose various hypotheses have been put forth; one is the noted conjecture of lord monboddo, that man is only an advanced development of the chimpanzee or ourang-outang. a second explanation is that given by lamarck, who surmised, and with much ingenuity attempted to prove, that one being advanced in the course of generations into another, in consequence merely of the experience of wants calling for the exercise of faculties in a particular direction, by which exercise new developments of organs took place, ending in variations sufficient to constitute new species. in this way the swiftness of the antelope, the claws and teeth of the lion, the trunk of the elephant, the long neck of the giraffe have been produced, it is supposed, by a certain plastic character in the construction of animals, operated upon for a long course of ages by the attempts which these animals make to attain objects which their previous organization did not place within their reach. this is what is meant by the hypothesis of _progressive tendencies_, and which requires for its validity not only the assumption of a mere capacity for change, but of active principles conducive to improvement and the attainment of higher powers and faculties. more recently st. hilaire has published a paper in which he speaks of the immutability of species as a conviction that is on the decline, and that the age of cuvier is on the close. carried away by what professor phillips has called a poetical conjecture that cannot be proved, this writer propounded the speculation that the present crocodiles are really the offspring of crocodilian reptiles, the difference being merely the effect of physical conditions, especially operating during long geological periods upon one original race. the human species, he contends, are but an advanced development of the higher order of the monkey tribe, and that the negroes are degenerating towards that type again. according to him the sivatherium--a fossil animal that had been found in the himalaya mountains--was the primeval type that time had fined down into the giraffe from long-continued feeding on the branches of trees. dr. falconer and capt. cautley, however, have shown that anatomical proofs are all against this inference, but if any doubt remained it must yield to the fact, that among the _fauna_ of the sewalik hills the sivatherium and the giraffe were contemporaries. the author of the _vestiges of creation_ has put forth an hypothesis founded on the preceding conjectures, but more compact and conclusive. he is, as we have seen, in favour of the progressive change of species, adopting the notion that men once had tails, and that the rudiments of this condal appendage are found in an undeveloped state in the _os coccygis_ (p. 199.) his leading idea of the progress of organic life is that the "_simplest and most primitive type under a law to which that of like production is subordinate, gave birth to the type next above it; that this again produced the next higher, and so on to the very highest_, the stages of advance being in all cases very small--namely, from one species only to another; so that the phenomenon has always been of a modest and simple character." (p. 231.) the arguments by which the author endeavours to prove his hypothesis may be thus compressed. according to him foetal development is a science, illustrated by hunter's great collection of the royal college of surgeons, and established by the conclusions of st. hilaire and tiedmann. its primary positions are--1. that the embryos of all animals are not distinguishably different from each other; and, 2. that those of all animals pass through a series of phases of development, each of which is the type or analogue of the permanent configuration of tribes inferior to it in the scale. higher the order of animals, the more numerous its stages of progress. man himself is not exempt from this law. his first foetal form is that which is permanent in the animalcule; it next passes through ulterior stages, resembling successively a fish, a reptile, a bird, and the lower mammalia before it attains its specific maturity. the period of gestation determines the species; protract it, and the species is advanced to a higher class. this might be done by the force of certain conditions operating upon the system of the mother. give good conditions and the young she produces will improve in development; give bad conditions and it will recede. cases of monstrous birth in the human species are appealed to, in which the most important organs are left imperfectly developed; the heart, for instance, having sometimes advanced no further than the three-chambered or reptile form, while there are instances of that organ being left in the two-chambered or fish-like form. these defects arise from a failure of the power of development in the mother, occasioned by misery or bad health, and they are but the converse of those conditions that carry on species to species. the _differences of sexes_ is the result of foetal progress only one degree less marked than that of a change of species. sex is fully ascertained to be a matter of development. all beings are at one stage of the embryotic progress _female_. a certain number of them are afterwards advanced to the more powerful sex. for proof of this, the economy of bees is cited; when they wish to raise a queen-bee, or true female, they prepare for the larva a more commodious cell, and feed it with delicate food. but we shall here stop to remark on the author's argument up to this point. it is manifest, according to his hypothesis, that neither sex nor species depend on the ancestral germ, but simply on physical conditions and mechanical development. but eminent physiologists deny that the facts are such as he has stated; they deny, as we have stated in a former section, that the foetal progress is such as the _vestiges_ represent them to be; they deny that the human embryo, for example, exhibits in successive stages the form of fish, lizard, bird, beast: on the contrary, they contend that it is only in the earliest period of the organic germ, when the manifestations are almost too obscure for microscopic sense, that any resemblance exists; that immediately the organic germ becomes sensible to observation, sex and species are found to be fixed. take, for example, the vertebrata; in these, by some mysterious bond of union, the organic globules are seen to arrange themselves into two nearly parallel rows. we may then say that the keel of the animal is laid down, and in it we have the first rudiments of a backbone and a continuous spinal chord. but during the progress and completion of this first organic process no changes have been observed assimilating the nascent embryo to any of the inferior animals. the next series of changes in the germinal membrane are of two kinds--in one the nervous system, the organs of motion, the intestinal canal, the heart and blood-vessels are manifested; the other set of changes, which are subsequent, produce the perfection of the animal and determine its sex. all these manifestations result from germinal appendages that cannot be severed or changed without ruin to the embryo, and the conditions essential to life as the structure advances are due temperature, due nutriment of the nervous organs, and due access to the atmospheric air. without, therefore, pursuing further this part of the inquiry, we shall remark that the question at issue between the _vestiges_ and its opponents is one of facts--of conflicting evidence--to be tried by the jury of the public, or rather by those who, from science or professional pursuits, are competent to form an authoritative opinion. our own conclusion is, that in face of the testimony adduced against it, the author's hypothesis is not yet established. for proof that species do change, and that even new species have been actually and recently produced, the author has adduced statements certainly as questionable and little satisfactory as his representation of foetal phenomena. we can only briefly enumerate them. first we are told that oats sown at midsummer, if kept cropped down, so as to be prevented shooting into ear, and then allowed to remain in the ground over winter, will spring up next year in the form of rye (p. 226). this need not be disputed about; the experiment can be easily tried; but if rye were the result, it would be no conclusive proof of a translation of species. perhaps the oat-plants perished under the operation of repeated cuttings, and the rye seed was dormant in the earth and sprung up in its place; or, if not so, oats and rye may not be different species, only varieties of the same species. they are scarcely more dissimilar than the primrose, the cowslip, and the oxlip, which have all been raised from the seed of the same plant, and are now regarded by botanists as varieties instead of species. when lime is laid on waste ground we are told that white clover will spring up spontaneously, and in situations where no clover-seed could have been left dormant in the soil (p. 182). but how is this to be proved? it is certain that seeds will remain dormant in the soil for centuries, and then spring up the first year the soil is turned up by the plough. some seeds have retained their vitality for thousands of years in the old tombs of egypt; they have been repeatedly brought to england, sown, and produced good wheat. we are next told that wild pigs never have the measles, they are produced by a _hyatid_ and the result of domestication; that a _tinea_ is found in dressed wool that does not exist in its unwashed state; that a certain insect disdains all food but chocolate, and that the larva of _oinopota cellaris_ only lives in wine and beer. all these are articles manufactured by man, and are adduced as proofs of animal life, independent of any primordial egg. the entoza are dwelt upon; they are creatures living in the interior of other animals, of which the tape-worm that infests the human body is a melancholy instance. in these illustrations we think the author has some show of reason, for we feel convinced that there is such a thing as spontaneous generation from the inorganic substance, wisely provided for clearing the earth of noxious effluvia and putrid matter, and converting them into new elements conducive to health and life. we believe in this source of vitality from its wisdom and necessity, its necessity and wisdom, in our estimate, being strong presumptive proofs of its existence in harmony with the general forecast and economy of nature. of the self-originating spring of life, some of the examples adduced by the author are proofs, and of which we have familiar illustrations in cheese-mites, maggots in carrion, and the green fly that breeds so profusely in weak and decaying vegetation; in all which by some inscrutable law the organic germ, without an antecedent, appears to evolve from the dead or putrifying mass for its riddance and transmutation. conceding, however, thus far to the author, we are not prepared to admit that the creative powers of messrs. crosse and weekes has been established. these gentlemen are said (p. 190) to have introduced a stranger in the animal kingdom, a species of _acarus_ or mite amidst a solution of silica submitted to the electric current. the insects produced by the action of a galvanic battery continued for eleven months are represented as minute and semi-transparent, and furnished with long bristles. one of the creatures resulting from this elaborate term of gestation was observed in the very act of emerging, in its first-born nudity, and sought concealment in a corner of the apparatus. some of them were observed to go back into the parent fluid and occasionally they devoured each other; and soon after they were called to life, they were disposed to multiply their species in the common way! so much for the experiment; against its verity it is alleged, first, that the _acarus crossii_ are not a new species, or if new, that neither mr. crosse nor mr. weekes, who repeated mr. crosse's experiment, produced them, but only aided by the voltaic battery the development of the insects from their eggs. such a mode of generation is contrary to all human experience, and can only be believed in on the strongest corroborative proof. neither by chemistry nor galvanism can man, we apprehend, be more than instrumental and co-operative, not originally and independently creative. in almost every form of life, whether animal or vegetable, art can multiply varieties,--can train, direct--but cannot form new species. this is the mockery of science. with all its invention and resource, it cannot produce organic originals. it can rear a crab-apple into a golden-pippin, or wild sea-weed into a luxuriant cabbage; it can raise infinite varieties of roses, tulips, and pansies, but can create no new plant, fruit, or flower. man can make a steam-engine, or a watch, but he cannot make a fly, a midge, or blade of grass. he is an ingenious compiler, but not a creator; and his powers of manufacture and conversion are restricted within narrow boundaries. he cannot wander far in the indulgence of his fancies without being recalled, and compelled to return to the first models set by the great architect. the further he strays from primitive types in the effort to improve, by crossing, cutting, and grafting, and proportionably less becomes the procreative force. hybrids are notoriously sterile. garden fruit is not permanent, and requires to be renewed from seed. the law seems universal in plants and animals, that the vital energy or germ is less forcible and prolific in the pampered and artificial, than in the natural and wild races. hypothesis of the vital principle. it is ascertained that the basis of all vegetable and animal substances consists in nucleated cells--that is, cells having granules within them. nutriment is converted into these before being assimilated by the system. it has likewise been noted that the globules of the blood are reproduced by the expansion of contained granules; "they are, in short," says the _vestiges_, "_distinct organisms multiplied by the same fissiporous generation_. so that all animated nature may be said to be based on this mode of origin; _the fundamental form of organic being is a globule, having a new globule forming within itself_, by which it is in time discharged, and which is again followed by another and another, in endless succession. it is of course obvious, that if these globules could be produced by any process from inorganic elements, we should be entitled to say that the fact of a transit from the inorganic to the organic had been witnessed." (p. 176.) "globules," the author continues, "can be produced in albumen by electricity. _if_, therefore, these globules be identical with the cells which are now held to be reproductive, it _might_ be said that the production of albumen by artificial means is the only step in the process wanting. this has not yet been effected." (p. 177.) these are the advances towards generation by chemistry and electricity. the process, however, according to this detail, appears still far from complete. albumen is to be produced "by artificial means;" and even then we should doubt entire success. chemists have long commanded the power to resolve the seeds of animal and vegetable life into their elements; they have analysed them, and shown the exact weight and proportion of each constituent; but they never could put them together again, or, by any similar compound produce the primordial egg or organic germ, from which a living being would arise. a connecting link--a vital spark, or animating soul--is always wanting to complete the existence of the prometheus of the laboratory. mark, too, the "_if_," and the "_might_," in this most lame and impotent hypothesis:--"_if_, therefore, these globules be identical with the cells which are held to be reproductive, it _might_ be said," &c. globules can be easily produced; the passage of the electric fluid through water will produce aerial globules in rapid and expansive movement; boys can produce them with suds and a tobacco-pipe in rapid succession, each, for aught we know, containing a "granule" that multiplies by "fissiporous generation." but these are not organic globules, and the author has committed the great perversion in language or logic of confounding the organic globule of life with the inorganic globule of a chemist. his theory is more fanciful than that of lamarck, from whom it is derived, and who had, at least, his _petit corps gelatineux_ to begin with--to commence weaving organic tissue from--but our author's organic globule is not so substantive a conception; and as he does not pretend to be able to produce even this by physical means, he has not made a single step in generation. this we consider the least satisfactory and successful portion of the author's work. it assigns no intelligible cause for the origin of life--it only _begs the question_, by the substitution of one mystery for another. his law of development is of the same description,--without sense or significancy, unsupported by applicable facts, and is not so comprehensible a cause of vital changes as lamarck's assigned progressive tendencies of animals to master the appliances essential to their wants. animal affinities, instinct, and reason. the scheme of the _vestiges_ is uniformly and consistently worked out; all phenomena are resolved into gravitation and development--the first as the law of inorganic, the latter of organic matter. by the last, however, no new principle is revealed, only a new phrase devised, by the amplified application of which the author's entire system may be said to be _begged_ rather than proved; since development is used in a sense implying an indefinite power of animate and inanimate creation; so that at last we make no new discovery, only grasp a new nomenclature. but the author is always interesting, either by the novel display of facts or the ingenious concatenation of plausibilities. consistently with his fundamental notion of animal transmutation, he tries to prove a family likeness or affinity from the humblest to the highest species. in this way he seeks to explain the marvel with respect to the huge bulk of many of the tertiary mammalia--the mammoth, mastadon, and megatherium; they were in immediate descent from the cetacea, or whale and dolphin tribe. (p. 267.) again, human reason is considered no exclusive gift; it exists subordinately in the instinct of brutes, and is alleged to be nothing more than a mode of operation peculiar to the faculties in a humble state of endowment, or early stage of development. cuvier and newton are only intellectual expansions of a clown; and this notion is extended to moral obliquities, the wicked man being characterised as one "whose highest moral feelings are rudimental." (p. 358.) from a like principle the writer concurs with dr. prichard, that mankind may have had a common origin; that there exists no diversities of colour or osseous structure not referable to climatable or other plastic agencies influencing the development of the different races, commencing with the lowest, or negro tribe, and ascending upward through the intermediate aboriginal american, mongolian, and malay, to the last and most perfect stage of the caucasian type. into the verity of these conclusions we are not called upon to enter; they have been long in controversy, involve a great array of facts and inductive inferences, and we have only referred to them as corollaries or collaterals of the author's hypothetical fabric. religious and moral tendencies. we have no charge of impiety to bring against the _vestiges_. final causes, or to express ourselves more intelligibly, a _purpose_ in creation, is nowhere impugned. the deity is not degraded by impersonification in the form and frailties of mortality, but everywhere the author reverently bows to that august and unsearchable name, acknowledges the grand and benevolent design--the admirable adaptation of every created thing to its end and place, and finally concludes in a strain of grateful and exulting optimism, that we confess we have not fully arrived at--namely, that everything "is very good." (p. 387.) from this impression we have only one constructive drawback to notice in the author's mechanical but fanciful constitution of the universe, by which a special providence in the government of the world seems to be dispensed with, and the almighty is placed in the sinecure position of the grand elector of the abbe sieyes, with nothing to do. but no divine attribute is abscinded--no glory of omnipotence dimmed--whether it pleases him to rule by direct interpositions of power, or his own pre-ordained eternal laws. still less can we detect in the speculative inquiries of the _vestiges_ conclusions hostile to the moral and social interests of the community. men are formed to be what they are; vice and crime are the fruits of malorganization, and malorganization is the result of the unfavourable conditions in which the subject of it has been placed, prior or subsequent to birth. these are the author's leading metaphysical inculcations. they impose grave duties upon individuals and upon society, rightly understood and applied, but we cannot discern a hurtful tendency in them. they are useful knowledge, knowledge that it would be well for parents and rulers to master, by showing the importance of education, of favourable circumstances, and of good moral and physical training, for rearing happy, well-ordered, and virtuous members of the community. supreme in intelligence, man, we firmly believe, is not less supremely blessed in the means of felicity, provided his real nature and position in the scheme of creation were understood, recognised, and carried out. he has his place, his office, and his destiny; he is no enigma but as an individual; "in the mass," as the author emphatically remarks, "he is a mathematical problem." his conduct is uniform and consistent; the result of known and ascertainable causes--causes calculable and predicable in their consequences, as the statistics of crime have incontestibly established. general conclusions on the vestiges. the heavens are wonderful, and the earth is wonderful, and man, who, by force of intellect, has sought to comprehend the immensity of one and unravel the formation of the other, is hardly less wonderful than either. still the great mystery remains unriddled; our researches have brought us no nearer the beginning, and the first cause of all continues unapproachable and undefinable as ever. instead of explaining physical creation, we begin with it; we take the existence of matter for granted, and its attributes for granted, and forthwith begin to fabricate a universe, without first ascertaining whence was matter, or whence the laws by which it is impressed, and has been governed in its evolutions. nature's greatest phenomena are the celestial spaces and the bodies that fill them; our own planet and its living occupants. upon each of these, their commencement and subsequent vicissitudes, the _vestiges of creation_ have propounded an hypothesis, but one mystery is only sought to be explained by another still more mysterious. for the fiat of a creator chemical affinities and mechanical laws have been substituted, but aided by these the author has failed to produce a world such as we find it. hence we are again driven upon the old tradition, the old sacred authority, that the world was created out of nothing; and this is as easy to comprehend as the solution of the _vestiges_, that it sprang from that which is certainly next to nothing--a heated fog or universal fire-mist. when the author deals with the facts of science he interests and instructs, but when he speculates he only amuses or perplexes, without advancing knowledge. his terse and luminous description of the astral firmament deeply impresses with the might and the magnitude of the vast design; but when he attempts to account for the elimination of suns and worlds, their formation and arrangement, we are struck by the puerile folly of his conjectural presumptions. descending from this august and glittering canopy to our own planet, we are not less astonished by the exhibition of the extraordinary revolutions it has undergone. geology is the true historian of the earth. conducted by the lights it affords, we see an eternity of ages has rolled before us; we discover a series of worlds rising through the depths of ocean from the central sphere of heat, amidst boiling floods and volcanic fires, each new platform of existence, that countless periods of time had been requisite to form, peopled with its own congenial forms of organic life, mostly commencing with the simpler, and ascending by almost imperceptible gradations to the higher and more complex structures of being. we are struck by the correspondence, by the _pari passu_ development and formation of the earth's crust and organic existences, and we are apt hastily to conclude that a relation has subsisted between them, that contemporary changes have been cause and effect, and that the improvement of the earth produced the correlative improvement in animals and plants. this forms the author's second questionable hypothesis; it is plausible, but false--repugnant to fact and correct observation. we have no credible evidence that species have changed, or are changeable by the utmost efforts of art or favouring conditions; all we can effect is to improve them within definite limits, but not alter their characteristic types; and we have certain proof that neither man nor the animal nearly next to him in organization, has changed either in habits, disposition, form, or osseus structure during the last 3,000 years. resemblance is no proof of identity; and hence, though species run into each other by almost inappreciable shades of difference, it is no proof that they are derivative, or other than isolated and self-dependent creations. that they are such, and shall continue such, seems a fixed canon of nature, who, apparently, has prescribed to each its circle of amendment and range, that like shall beget like--that nought organic shall exist without ancestral germ--and that the variety of species which constitutes the beauty and order of nature shall by no chance, contrivance, or mingling of races, be confounded. geological facts are in favour of this conclusion. they attest the appearance of new species, not their improvement. in each species a gradation of improvement, approximating from a lower to the next higher organism, is not perceptible; but each seems to have been made perfect at first, and most suited to the co-existent state of the earth. the earliest reptiles were not reptiles of inferior structure; nor the earliest fishes, birds, or beasts. they were adapted, as we now find them, to their precise sphere of existence, without progressive aptitude, preparatory to a higher and translated condition of being. geology rather points to the extinction and degeneracy of species than their improvement; and the fossils of the old red sandstone, and of the carboniferous formation, attest a loftier and more magnificent creation of both marine and land products than any now subsisting. for these and other reasons before adduced, we dismiss the hypothesis of animal transmutation as unproved and untenable. it pleases and satisfies superficial views, but confronted with the facts of nature, it vanishes like a baseless vision. man is _sui generis_, sole and exclusive in organization, without pre-existing type or affinity to other species; and his alleged recent metamorphosis from a monkey, and his first and far more distant one from a snail or a tadpole, are paradoxes only worthy of idle debating clubs. having attempted to unfold the progression of species by his law of development, the author next essays to explain the commencement of the vital principle itself. but here, too, he must have a beginning, and his "organic globule" answers a similar purpose, in deducing the mystery of life, as his nuclei in the "nebular hypothesis." in both the perplexity and real difficulty is not solved or mastered, but evaded. but we have already remarked on the point, and shall only observe that when the author can elicit _thought_ from inorganic matter, either by chemistry or galvanism, we shall think he has made a step in creation. until then he does not advance, only deceives himself and readers by verbal subtleties and baseless suppositions. apart from its hypotheses, the _vestiges_ form a valuable and interesting work. it is the most complete, elaborate, and--with all its faults of detail, logic, and inference--the most scientific expositor of universal nature yet offered to the world. but its hypotheses are unwarranted, not inductively derived, and can have no hold on men of science, supported as they mostly are by fanciful analogies, facts misunderstood or misstated, and illustrations selected without discrimination or applicability. theories do sometimes conduce to the discovery of truth, but are often obstructive; occupy the mind, like theological controversy, without advancing science; and are viewed with the same aversion by the philosopher that the political abstractions tendered to the multitude by the demagogue are viewed by the patriotic legislator. the work, however, will live, and deserves to live. the temple of nature has been looked into, not profoundly, perhaps, nor always successfully; but in a fearless spirit, and with a highly-accomplished mind. had the divine cosmos been more fully dwelt upon and depicted--had the harmony, beauty, and beneficence of creation been more fully and exclusively displayed--we should have been more gratified; but we are thankful, in the main, for what we have received. an impulse has been given to popular inquiry, and a vast field for discussion opened, from which we can prospectively discern neither less love for man, nor reverence for god. who the author is we have no certain knowledge. it is not, we suspect, lord king, nor lord thurlow, nor lady byron; but it may be the author of the _essay on the formation of opinions_, and of the _principle of representation_. mr. bailey, of sheffield, though little known, possesses the fine reasoning powers, intellectual grasp, independence of research, abstract analysis, and attic style, that would qualify him to produce the _vestiges of creation_, though we never heard that he is a great natural philosopher. but, as just hinted, deep science is not evinced by the _vestiges_, only an able, systematic, and tasteful arrangement of its distant and recent advances. "explanations:" a sequel to the "vestiges of the natural history of creation." (_from the_ atlas _of december 20, 1845._) so many strong objections had been arrayed against the _vestiges of creation_, that the author was called upon to elucidate and reinforce his argument, or abandon the ground he had taken up. the more candid and equitable of his judges--those who were disposed to try him upon the merits, and independently test the claims of his inquiry, as in fairness it ought to be, as strictly a scientific speculation, regardless of any constructive bearings it might have on current opinions or prejudices--could not arrive at any more favourable conclusion than that he had failed to establish his hypotheses. indeed this was the only verdict that could be safely delivered in. the impugners of the work were in the same helpless predicament as its author, who had, however, more venturously presumed to unravel unsearchable mysteries, concerning which, in the existing state of science, men can only conjecture, wonder, and adore, utterly unable to affirm or deny aught respecting them. what, for instance, with the remotest semblance of certainty, can be predicated of the stellar orbs? is it not idle almost to speculate on the impenetrable secret of their origin when their very existence is undefinable--when their end, their glittering discs, and all but immeasurable distances are wholly unapproachable? nor hardly less beyond our grasp is the commencement of organic existences. we do pride ourselves on recent advances to the sources of entity; we tear up the dead, we torture the living, and sedulously chronicle every beat of the heart and vibration of the brain to slake an insatiable curiosity, yet how unsatisfactory our reach towards the hidden springs of life--how limited our attainments, when the creation of a single blade of grass, the humblest worm, a poor beetle, or gadfly, would baffle the utmost structural skill of the greatest philosopher! into the fathomless depths of our own globe we have also essayed to penetrate. poor beings! of three score and ten, whose utmost historical span extends only to some thousands of years, have sought to trammel up the terrene vicissitudes of millions of ages anterior to their own existence! does not this savour of a vain research, or of a laudable thirst for knowledge? over all these dark and solemn inscrutabilities, however, the _vestiges_ undertook to throw a glare of light, to reveal their beginning, progression, order, relations, and law of development. although daring in aim, the attempt was not to be wholly deprecated. while religious freedom had been secured, philosophy had become timid, official, and timeserving; retentive as fontenelle of the truths within its grasp, and fearful to give utterance to aught that might disturb the stillness of the temple, the lecture-room, or fashionable auditory. modern teachers had been used so long to the baconian go-cart, that they had become as apprehensive of losing the inductive clue as the palinuruses of old of the sight of the directing shore. but the time had arrived when it seemed expedient to relax the strictness of the investigative rule, and afford scope for a more systematic, if not speculative research. science had made great acquisitions, and it seemed desirable, if only for experiment sake, to see what kind of frankenstein would result from the architectural union of her scattered limbs. this formed the scope of the _vestiges of creation_; novelties were not propounded, only a portentous skeleton raised from the truths physical astronomy, geology, chemistry, physiology, and natural history had established. does the author recoil from his work? no; these _explanations_ attest that he is steadfast in the worship of the idol of his brain. he retracts nothing, he re-asserts, elucidates, and often dexterously turns the weapons of the most formidable and orthodox of his adversaries against them, by showing from their writings that they had, in detail at least, acquiesced in the truths that they now, in a generalised form, seek to controvert and repudiate. so much adroitness and pertinacity in the author can hardly fail to provoke resistance, if not asperity, despite of the imperturbable temper in which he maintains the combat. the learned have been disturbed in their daily routine, by the discharge from an unknown hand, of a massive pyrites, that has diffused as much consternation among the herd of modish elocutionists, college tutors, and chimpanzee professors, as jove's ligneous projectile among the lieges of the standing pool. for this commotion we have, on a former occasion, conceded that there existed valid reasons, and we hasten to see the way in which they have been met in the rejoinder before us; contenting ourselves, as we needs must, by briefly noticing some of the salient points of the controversy. first of the nebular hypothesis. the chief objection to this theory is, that the existence of nebulous matter in the heavens is disproved by the discoveries made by the telescope of the earl of rosse. by the reach of this wondrous tube, masses of light, rendered apparently nebulous by their vast distance, have been resolved into clusters of stars, and thence the assumption seemed unwarrantable that any luminous matter, different from the solid bodies composing planetary systems existed in the heavenly spaces. but to this the author replies, that there are two classes of nebulæ--one resolvable into constellations--another comparatively near, that remains unaffected by telescopic power, and that until this last description can be separated, the nebular hypothesis is not disproved. it is thus brought to an issue of facts, both as to the existence of nebulæ of this latter kind, and the optical power to resolve them into distinct stars. but the author can hardly claim this negative success in grappling with a second objection--namely, his assumed origin of _rotatory motion_. according to him, a confluence of atoms round a spherical centre of attraction, would cause the agglomerated mass to revolve upon its axis in the manner of our earth. this was denied by everybody the least acquainted with the laws of motion; and thus did one of his imaginary solutions of a great phenomenon of the universe fall dead to the ground. this he now seems to concede, but in a sentence unintelligible to us, in which an undoubted physical law is spoken of as only an _abstract truth_ (p. 20). he obviously still clings to his first mistaken inference, and calls to his aid professor nichol, whom he has also pressed into his service to help him over the last-mentioned difficulty by the professor's affirmation of a diversity of nebulous clusters. but the professor does not commit himself to the extent of the author; his aqueous whirlpool is cited from herschel, only in illustration, and correctly said to be produced by the unequal force of convergence of a fluid to a common centre. but the author's nuclei, disposed in his notable "fire-mist," did not act with unequal force on the ambient vapour, and whose central convergence in consequence, would not produce rotation or motion of any kind. this was the real matter in question, the author was taken up on his own premises, and the results he assumed to follow from them proved to be inconsistent with the unquestionable laws of gravitating matter. he has gone over the geological portion of his subject with much care, but if competent, it would be impossible within our narrow limits to accompany him; nor could the discussion be made either interesting or intelligible except to the scientific, who have devoted attention to an extremely curious, but still obscure and unsettled field of investigation. he has elaborately cleared up many points, and successfully, we think, answered some weighty objections, but we are not yet converts to his theory of organic development. one passage we shall extract; after adverting to the facts established by powerful evidence, that during the long term of the earth's existence, strata of various thickness were deposited in seas composed of matter worn away from the previous rocks; that these strata by volcanic agency were raised into continents, or projected into mountain chains, and that sea and land have been constantly interchanging conditions. he continues:- "the remains and traces of plants and animals found in the succession of strata show that, while these operations were going on, the earth gradually became the theatre of organic being, simple forms appearing first, and more complicated afterwards. _a time when there was no life_ is first seen. we then _see life begin, and go on_; but whole ages elapsed before man came to crown the work of nature. this is a wonderful revelation to have come upon the men of our time, and one which the philosophers of the days of newton could never have expected to be vouchsafed. the great fact established by it is, that the organic creation, as we now see it, was not placed upon the earth at once; it observed a progress. now we can _imagine_ the deity calling a young plant or animal into existence instantaneously; but we see that he does not usually do so. the young plant and also the young animal go through a series of conditions, advancing them from a mere germ to the fully developed repetition of the respective parental forms. so, also, we can _imagine_ divine power evoking a whole creation into being by one word; but we find that such had not been his mode of working in that instance, for geology fully proves that organic creation passed through a series of stages before the highest vegetable and animal forms appeared. here we have the first hint of organic creation having arisen in the manner of natural order. the analogy does not prove identity of causes, but it surely points very broadly to natural order or law having been the mode of procedure in both instances." to the allusion in the last sentence there can be no demur; that there is "natural order or law" in creation who will contest? but it is the author's law and the author's order that are in dispute--his transmutation of species, the higher classes emerging from and partly annihilating the lower, under meliorated conditions of being. that the simpler form of organic life should first appear; that remains of invertebrated animals should be first found; then, with these, fish, being the lowest of the vertebrated; next, reptiles and birds, which occupy higher grades; and finally, along with the rest, mammifers, the highest of all--all this appears natural enough. _how could it be otherwise?_ when the earth was a slimy bed, what but the lowest forms of life--the mollusca, and other soft animals, without bony structure--could possibly live in or occupy it? during the carboniferous era, when the earth was enveloped in an atmosphere of hydrogen, vegetation might thrive; but man, and animals like him, dependent on vital air, could not exist; nor are remains of them found in this epoch of the globe's vicissitudes. all this is comprehensible. but the perplexing inquiry is, whence did the successive grades of animals emerge? that they could not contemporaneously exist; when the whole earth was a shoreless sea, and that animals could not live is certain; but were they created in succession by the divine fiat, or did they emerge, as our author supposes and elaborately tries to prove, from the humblest primitive forms, by an inscrutable law of progression--evidenced, he contends, by geological facts--though by some his facts are disputed--and certainly not confirmed by any animal changes observable within the limits of human experience? there is another alternative offers, which would dispense both with the author's hypothesis and the need of successive organic creations by a special providence. is it a geological fact, since life began, that the earth has _simultaneously_ undergone throughout its entire surface the revolutions assigned to it? may it not always, from that period, have consisted, as it now does, of water and dry land, alternately changing their sites, but always apart, and allowing of the contemporary existence on some portion of its surface of all the varieties of tribes ever found upon it? the fossiliferous rocks that formed the primeval sea-beds could only be deposited by the abrasion from the anterior and higher rocks. it has always appeared to us that this conjecture is worthy of consideration, and, if found tenable, would reconcile many perplexities. upon subjects so obscure, and to which the human intellect has been only recently directed, it is not surprising that men of science have not arrived at uniformity of conclusion. unable to reconcile phenomena with positive knowledge, there are names of no mean repute who would reserve certain domains of creation as the fields of special interventions. to this class dr. whewell appears to belong, who assumes that "events not included in the _course of nature_ have formerly taken place." in the same way professor sedgwick, to account for the appearance of certain animals, says, "they were not called into being by any law of nature, but by a power above nature." he adds, "they were created by the hand of god, and adapted to the conditions of the period." to this the author of the _vestiges_ assents, with the explanation (p. 134) that their existence was not the result of a "special exertion of power to meet special conditions," but of an antecedent and primitive law of development suited to the new exigencies, and emanating from the creator. this, he contends, does not lower our estimate of the divine character; and, in proof, cites dr. doddridge, who cannot be suspected of irreverence. "when we assert," says the pious and amiable author, "a perpetual divine agency, we readily acknowledge that matters are so contrived as not to need a divine interposition in a different manner from that in which it had been constantly exerted. and it must be evident that an unremitting energy, displayed in such circumstances, _greatly exalts our idea of god, instead of depressing it_; and, therefore, by the way, is so much more likely to be true." against constructive inferences it is urged, in the _explanations_- "as to results which may flow from any particular view which reason may show as the best supported, i must firmly protest against any assumed title in an opponent to pronounce what these are. the first object is to ascertain truth. no truth can be derogatory to the presumed fountain of all truth. the derogation must lie in the erroneous construction which a weak human creature puts upon the truth. and practically it is the true infidel state of mind which prompts apprehension regarding any fact of nature, or any conclusion of sound argument." the writer then quotes sir john herschell as having some years ago announced views strictly conformable to those subsequently taken of organic creation in the _vestiges_:- "'for my part,' says sir john, 'i cannot but think it an inadequate conception of the creator, to assume it as granted that his combinations are exhausted upon any one of the theatres of their former exercise, though, in this, as in all his other works, we are led, by _all analogy_, to suppose that he operates through a series of intermediate causes, and that, in consequence, _the origination of fresh species, could it ever come under our cognizance, would be found to be a natural, in contradistinction to a miraculous process_,--although we perceive no indications of any process actually in progress which is likely to issue in such a result. in his address to the british association at cambridge, (1845), he said with respect to the author's hypothesis of the first step of organic creation--'the transition from an inanimate crystal to a globule capable of such endless organic and intellectual development, is as great a step--as unexplained a one--as unintelligible to us--and in any sense of the word as _miraculous_, as the immediate creation and introduction upon earth, of every species and every individual would be!'" the rev. dr. pye smith is next adduced:- "'our most deeply investigated views of the divine government,' says he, 'lead to the conviction that it is exercised in the way of _order_, or what we usually call _law_. god reigns according to immutable principles, that is _by law_, in _every part of his kingdom--the mechanical, the intellectual, and the moral_; and it appears to be most clearly a position arising out of that fact, that _a comprehensive germ which shall necessarily evolve all future developments_, down to the minutest atomic movements, is a more suitable attribution to the deity, than the idea of a necessity for irregular interferences.'" lastly, the reviewer of the _vestiges_ in _blackwood's magazine_, who is understood to be a naturalist of distinguished ability, expresses himself in an equally decided manner:- "to reduce to a system the acts of creation, or the development of the several forms of animal life, no more impeaches the authorship of creation, than to trace the laws by which the world is upheld, and its phenomena perpetually renewed. the presumption naturally rises in the mind, that the same great being would adopt the same mode of action in both cases.... to a mind accustomed, as is every educated mind, to regard the operations of deity as essentially differing from the limited, sudden, evanescent impulses of a human agent, it is distressing to be compelled to picture to itself, the power of god as put forth _in any other manner than in those slow, mysterious, universal laws, which have so plainly an eternity to work in;_ it pains the imagination to be obliged to assimilate those operations, for a moment, to the brief energy of a human will, or the manipulations of a human hand.... no, there is nothing atheistic, nothing irreligious, in the attempt to conceive creation, as well as reproduction, carried on by universal laws." we have dwelt so much upon this matter because it is one in which popular feelings are likely to be most deeply interested. we shall give the author, too, the benefit of his _explanations_ on another point, elucidating his former statement of the transmutation of a crop of oats into a crop of rye:- "'at the request,' says dr. lindley, 'of the marquis of bristol, the reverend lord arthur hervey, in the year 1843, sowed a handful of oats, treated them in the manner recommended, by continually stopping the flowering stems, and the produce, in 1844, has been for the most part ears of a very slender barley, having much the appearance of rye, with a little wheat, and some oats; samples of which are, by the favour of lord bristol, now before us.' the learned writer then adverts to the 'extraordinary, but certain fact, that in orchidaceous plants, forms just as different as wheat, barley, rye, and oats, have been proved by the most rigorous evidence, to be accidental variations of one common form, brought about no one knows how, but before our eyes, and rendered permanent by equally mysterious agency. then says reason, if they occur in orchidaceous plants, why should they not also occur in corn plants? for it is not likely that such vagaries will be confined to one little group in the vegetable kingdom; it is more rational to believe them to be a part of the _general system_ of creation.... how can we be _sure_, that wheat, rye, oats, and barley, are not all accidental off-sets from some unsuspected species?'" it may be so; but this would only prove that the "unsuspected species" included greater varieties, not that a really defined species was transmutable into another. but it is a point upon which no satisfactory result can be arrived at, since naturalists are not agreed in the classification of species, nor what attributes constitute one. the broomfield experiment is again brought forward, as decisive of the power to originate new life from inorganic elements. it will be remembered that mr. weekes, of sandwich, continued during three years to subject solutions to electric action, and invariably found insects produced in these instances, while they as invariably failed to appear where the electric action was not employed, but every other condition fulfilled. in a letter to the author of the _vestiges_--two are inserted, one on the independent generation of fungi--mr. weekes says- "one hundred and sixty-six days from the commencement of the experiment--the first acari seen in connexion therewith, six in number and nearly full-grown, were discovered on the outside of the open glass vessel. on removing two pieces of card which had been laid over the mouth of this vessel, several fine specimens were found inhabiting the under surfaces, and others completely developed and in active motion here and there within the glass. making my visit at an hour when a more favourable light entered the room, swarms of acari were found on the cards, about the glass tumbler, both within and without, and also on the platform of the apparatus. at this identical hour dr. j. black favoured me with a call, inspected the arrangements, and received six living specimens of the acarus produced from solution in the open vessel." specimens of the insect were sent to paris, when they set a whole conclave of philosophers a-laughing, because they were found to contain ova. other specimens were sent to london, but there their fate was sealed by their being found to be, not a new species, but one then abundant in the country. for ourselves we think the experiment not conclusive. we adopt hume's principle. all but universal experience having established that life is _ex ovo_ only, we must have a proportionate body of counter evidence to establish a different mode of generation. at all events, mr. weekes's protracted gestation of 166 days by his galvanic battery is not likely, in the existing rage for despatch, to supersede the existing routine of reproduction. london: printed by c. whiting, beaufort house, strand. the atlas, a general family newspaper and journal of literature. * * * * * this periodical, which may be justly called a weekly cyclopædia of politics, literature, arts, and science, is published every saturday afternoon, in time for the post, containing the news of saturday. * * * * * the atlas is divided into two principal departments, news and literature, and these are subdivided and classified with care and industry into heads of easy reference, so that each particular subject is preserved distinct and entire. the dimensions of the sheet, which folds into sixteen large quarto-sized pages, containing forty-eight columns, afford this classification facilities which 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things, embodying a lively commentary on passing events and men and manners. 2.--theatrical criticisms upon the written and acted drama, in which both are reviewed in a spirit of truth and perfect candour. 3.--reviews of all new works of ability, with numerous extracts. independent and free from all literary and personal prejudices, the opinions of the reviewers in the atlas may be consulted with confidence in their integrity. 4.--literary memoranda, notes of all novelties in literature abroad and at home, and summary criticisms on all works of minor importance. 5.--music and musicians, or scientific criticisms on vocal and instrumental performers, operas, and new music, on the continent as well as in england, with occasional engraved illustrations. 6.--fine arts, weekly notices of pictorial exhibitions, and critical descriptions of paintings, drawings, and engravings, with commentaries on all new works of art. 7.--scientific notices, or descriptions of improvements in mechanics and the experimental sciences, illustrated occasionally by diagrams, with an account of new patents, meteorological tables, proceedings of literary and scientific institutions, &c. the literary division of the atlas in the various branches has formed an era in the class of publications in which it ranks; and exhibits a remarkable union of the essential features of the more elaborate reviews, with the popular and practical objects of the general newspaper. * * * * * published for the proprietor, at the office, 6, southampton-street, strand, london.--price eight pence. orders received by all newsmen throughout the kingdom. _in one volume octavo, cloth lettered, price five shillings,_ national distress, its causes and remedies; a prize essay as originally published in "the atlas." * * * * * by samuel laing, esq., jun., _late fellow of st. john's, cambridge._ * * * * * part i. chap. i.--general considerations--absence of the usual historical symptoms of national decline--definition of the evils which threaten society. chap. ii.--official pauperism and unrecognised destitution--evidence respecting the condition of the lower classes in large towns. chap. iii.--extent of destitution in large towns--condition of hand-loom weavers and other classes of unskilled manufacturing operatives. chap. iv.--condition of class of agricultural labourers. chap. v.--condition of classes of labouring population employed in mines, fisheries, canals, railways, &c. chap. vi.--condition of classes superior to common labourers--general view of society in great britain. part ii. chap. i.--general views--modern theories of society--effect and paramount importance of moral causes. chap. ii.--economical causes--population--theory of malthus. chap. iii.--economical causes, continued--revolution in the course of industry effected by machinery--extension of manufactures--factory system, &c. chap. iv.--foreign competition. part iii. chap. i.--free trade, corn laws. chap. ii.--free trade, continued--new tariff, provisions, sugar, &c. reciprocity system--commercial treaties. chap. iii.--taxation. chap. iv.--currency and banking. chap. v.--emigration. chap. vi.--poor laws. chap. vii.--sanitary and building regulations, &c. chap. viii.--education. chap. ix.--conclusion. * * * * * london: published by longman and co.; simpkin and marshall; and whittaker and co. also, at the atlas office, 6, southampton-street, strand. public domain works from the university of michigan digital libraries) what is darwinism? by charles hodge, princeton, n. j. new york: scribner, armstrong, and company. 1874. entered according to act of congress, in the year 1874, by scribner, armstrong, & company, in the office of the librarian of congress, at washington. riverside, cambridge: stereotyped and printed by h. o. houghton and company. contents. page importance of the question 1 different theories as to the origin of the universe, and specially of vegetable and animal organisms. 1. the scriptural theory 3 2. the pantheistic theory 7 3. the epicurean theory 10 4. the doctrine of herbert spencer 11 5. hylozoic theory 21 6. unscriptural forms of theism 22 darwin's theory 26 natural selection 31 sense in which darwin uses the word natural 40 the three elements or darwinism 48 the exclusion of design in nature the formative idea of darwin's theory 49 proof of darwin's denial of teleology, from his own writings 53 proof from the expositions of his theory by its avowed advocates. mr. russell wallace 64 professor huxley 72 dr. büchner 84 carl vogt 85 prof. haeckel 87 strauss 147 proof from the objections urged by the opponents of mr. darwin's theory. duke of argyll 96 agassiz 101 professor janet 105 m. flourens 108 rev. walter mitchell 111 principal dawson 119 relation of darwinism to religion 125 causes of the antagonism between science and religion 126 the evolution theory contrary to facts and to scripture 141 sir william thomson on teleology 165 dr. asa gray 174 darwinism tantamount to atheism 177 what is darwinism? this is a question which needs an answer. great confusion and diversity of opinion prevail as to the real views of the man whose writings have agitated the whole world, scientific and religious. if a man says he is a darwinian, many understand him to avow himself virtually an atheist; while another understands him as saying that he adopts some harmless form of the doctrine of evolution. this is a great evil. it is obviously useless to discuss any theory until we are agreed as to what that theory is. the question, therefore, what is darwinism? must take precedence of all discussion of its merits. the great fact of experience is that the universe exists. the great problem which has ever pressed upon the human mind is to account for its existence. what was its origin? to what causes are the changes we witness around us to be referred? as we are a part of the universe, these questions concern ourselves. what are the origin, nature, and destiny of man? professor huxley is right in saying, "the question of questions for mankind--the problem which underlies all others, and is more interesting than any other--is the ascertainment of the place which man occupies in nature and of his relation to the universe of things. whence our race has come, what are the limits of our power over nature, and of nature's power over us, to what goal are we tending, are the problems which present themselves anew and with undiminished interest to every man born into the world."[1] mr. darwin undertakes to answer these questions. he proposes a solution of the problem which thus deeply concerns every living man. darwinism is, therefore, a theory of the universe, at least so far as the living organisms on this earth are concerned. this being the case, it may be well to state, in few words, the other prevalent theories on this great subject, that the points of agreement and of difference between them and the views of mr. darwin may be the more clearly seen. _the scriptural solution of the problem of the universe_. that solution is stated in words equally simple and sublime: "in the beginning god created the heavens and the earth." we have here, first, the idea of god. the word god has in the bible a definite meaning. it does not stand for an abstraction, for mere force, for law or ordered sequence. god is a spirit, and as we are spirits, we know from consciousness that god is, (1.) a substance; (2.) that he is a person; and, therefore, a self-conscious, intelligent, voluntary agent. he can say i; we can address him as thou; we can speak of him as he or him. this idea of god pervades the scriptures. it lies at the foundation of natural religion. it is involved in our religious consciousness. it enters essentially into our sense of moral obligation. it is inscribed ineffaceably, in letters more or less legible, on the heart of every human being. the man who is trying to be an atheist is trying to free himself from the laws of his being. he might as well try to free himself from liability to hunger or thirst. the god of the bible, then, is a spirit, infinite, eternal, and unchangeable in his being, wisdom, power, holiness, goodness, and truth. as every theory must begin with some postulate, this is the grand postulate with which the bible begins. this is the first point. the second point concerns the origin of the universe. it is not eternal either as to matter or form. it is not independent of god. it is not an evolution of his being, or his existence form. he is extramundane as well as antemundane. the universe owes its existence to his will. thirdly, as to the nature of the universe; it is not a mere phenomenon. it is an entity, having real objective existence, or actuality. this implies that matter is a substance endowed with certain properties, in virtue of which it is capable of acting and of being acted upon. these properties being uniform and constant, are physical laws to which, as their proximate causes, all the phenomena of nature are to be referred. fourthly, although god is extramundane, he is nevertheless everywhere present. that presence is not only a presence of essence, but also of knowledge and power. he upholds all things. he controls all physical causes, working through them, with them, and without them, as he sees fit. as we, in our limited spheres, can use physical causes to accomplish our purposes, so god everywhere and always coöperates with them to accomplish his infinitely wise and merciful designs. fifthly, man a part of the universe, is, according to the scriptures, as concerns his body, of the earth. so far, he belongs to the animal kingdom. as to his soul, he is a child of god, who is declared to be the father of the spirits of all men. god is a spirit, and we are spirits. we are, therefore, of the same nature with god. we are god-like; so that in knowing ourselves we know god. no man conscious of his manhood can be ignorant of his relationship to god as his father. the truth of this theory of the universe rests, in the first place, so far as it has been correctly stated, on the infallible authority of the word of god. in the second place, it is a satisfactory solution of the problem to be solved,--(1.) it accounts for the origin of the universe. (2.) it accounts for all the universe contains, and gives a satisfactory explanation of the marvellous contrivances which abound in living organisms, of the adaptations of these organisms to conditions external to themselves, and for those provisions for the future, which on any other assumption are utterly inexplicable. (3.) it is in conflict with no truth of reason and with no fact of experience.[2] (4.) the scriptural doctrine accounts for the spiritual nature of man, and meets all his spiritual necessities. it gives him an object of adoration, love, and confidence. it reveals the being on whom his indestructible sense of responsibility terminates. the truth of this doctrine, therefore, rests not only on the authority of the scriptures, but on the very constitution of our nature. the bible has little charity for those who reject it. it pronounces them to be either derationalized or demoralized, or both. footnotes: [1] _evidences of man's place in nature._ london, 1864, p. 57. [2] the two facts which are commonly urged as inconsistent with theism, are the existence of misery in the world, and the occurrence of undeveloped or useless organs, as teeth in the jaws of the whale and mammæ on the breast of a man. as to the former objection, sin, which is the only real evil, is accounted for by the voluntary apostasy of man; and as to undeveloped organs they are regarded as evidences of the great plan of structure which can be traced in the different orders of animals. these unused organs were--says professor joseph le conte, in his interesting volume on religion and science, new york, 1874, p. 54--regarded as blunders in nature, until it was discovered that use is not the only end of design. "by further patient study of nature," he says, "came the recognition of another law beside use,--a law of order underlying and conditioning the law of use. organisms are, indeed, contrived for use, but according to a preordained plan of structure, which must not be violated." it is of little moment whether this explanation be considered satisfactory or not. it would certainly be irrational to refuse to believe that the eye was made for the purpose of vision, because we cannot tell why a man has mammæ. a man might as well refuse to admit that there is any meaning in all the writings of plato, because there is a sentence in them which he cannot understand. _the pantheistic theory_. this has been one of the most widely diffused and persistent forms of human thought on this whole subject. it has been for thousands of years not only the philosophy, but the religion of india, and, to a great extent, of china. it underlies all the forms of greek philosophy. it crept into the church, concealed under the disguise of scriptural terminology, in the form of neo-platonism. it was constantly reappearing during the middle ages, sometimes in a philosophical, and sometimes a mystical form. it was revived by spinoza in the seventeenth century, and subsequently became dominant in the philosophy and literature of europe. it is coming up again. some distinguished naturalists are swinging round from one pole to the opposite; from saying there is no god, to teaching that everything is god. sometimes, one and the same book in one half teaches materialism, in the other half idealism: the one affirming that everything is matter, the other that matter is nothing, but that everything is mind, and mind is god. the leading principles of the pantheistic theory are,--(1.) that there is an infinite and absolute being. of this being nothing can be affirmed but actuality. it is denied that it is conscious, intelligent, or voluntary. (2.) it is subject to the blind necessity of self-evolution or development. (3.) this development being necessary is constant; from everlasting to everlasting. according to the braminical doctrine, indeed, there are successive cycles of activity and repose, each cycle being measured by countless milliards of centuries. according to the moderns, self-evolution being necessary, there can be no repose, so that ohne welt kein gott. (4.) the finite is, therefore, the existence form of the infinite; all that is in the latter for the time being is in the former. all that is possible is actual. (5.) the finite is the infinite, or, to use theistic language, the world is god, in the sense that all the world is and contains is the form in which god, at each successive moment, exists. there is no power, save only the power manifested in the world; no consciousness, intelligence, or voluntary activity, but in finite things, and the aggregate of these is the power, consciousness, intelligence, and activity of god. what we call sin is as much a form of god's activity as what we call virtue. in other words, there is no such thing as free agency in man, no such thing as sin or responsibility. when a man dies he sinks into the abyss of being as a drop of water is lost in the ocean. (6.) man is the highest form of god's existence. god is incarnate in the human race. strauss says, that what the church teaches of christ is not true of any individual man, but is true of mankind. or, as feuerbach more concisely expresses it, "man alone is our god." the blasphemy of some of the german philosophers on this subject is simply unutterable. in india we see the practical operation of this system when it takes hold on the people. there the personification of the infinite as evil (the goddess kala) is the most popular object of worship. _epicurean theory._ epicurus assumed the existence of matter, force and motion,--stoff und kraft. he held that all space was filled with molecules of matter in a state of rapid motion in every direction. these molecules were subject to gravity and endowed with properties or forces. one combination of molecules gave rise to unorganized matter, another to life, another to mind; and from the various combinations, guided by unintelligent physical laws, all the wonderful organisms of plants and animals have arisen. to these combinations also all the phenomena of life, instinct, and intelligence in the world are to be referred. this theory has been adopted in our day by a large class of scientific men, especially in germany. the modern advocates of the theory are immeasurably superior to the ancient epicureans in their knowledge of astronomy, botany, zoölogy, and biology; but in their theory of the universe, and in their mode of accounting for all the phenomena of life and intelligence, they are precisely on the same level. they have not added an idea to the system, which has ever been regarded as the opprobrium of human thought. büchner, moleschott, vogt, hold that matter is eternal and indestructible; that matter and force are inseparable: the one cannot exist without the other. what, it is asked, is motion without something moving? what is electricity without an electrified body? what is attraction without molecules attracting each other? what is contractibility without muscular fibre, or secretion without a secreting gland? one combination of molecules exhibits the phenomena of life, another combination exhibits the phenomena of mind. all this was taught by the old heathen philosopher more than two thousand years ago. that this system denies the existence of god, of mind as a thinking substance distinct from matter, and of the possibility of the conscious existence of man after death, are not inferences drawn by opponents, but conclusions openly avowed by its advocates. _herbert spencer's new philosophy._ mr. darwin calls spencer our "great philosopher." his is the speculating mind of the new school of science. this gives to his opinions special interest, although no one but himself is to be held responsible for his peculiar views, except so far as others see fit to avow them. mr. spencer postulates neither mind nor matter. he begins with force. force, however, is itself perfectly inscrutable. all we know about it is, that it is, that it is indestructible, and that it is persistent. as to the origin of the universe, he says there are three possible suppositions: 1st. that it is self-existent. 2d. that it is self-created. 3d. that it is created by an external agency.[3] all these he examines and rejects. the first is equivalent to atheism, by which spencer understands the doctrine which makes space, matter, and force eternal and the causes of all phenomena. this, he says, assumes the idea of self-existence, which is unthinkable. the second theory he makes equivalent to pantheism. "the precipitation of vapor," he says, "into cloud, aids us in forming a symbolic conception of a self-evolved universe;" but, he adds, "really to conceive self-creation, is to conceive potential existence passing into actual existence by some inherent necessity, which we cannot do." (p. 32). the theistic theory, he says, is equally untenable. "whoever agrees that the atheistic hypothesis is untenable because it involves the impossible idea of self-existence, must perforce admit that the theistic hypothesis is untenable if it contains the same impossible idea." (p. 38). the origin of the universe is, therefore, a fact which cannot be explained. it must have had a cause; and all we know is that its cause is unknowable and inscrutable. when we turn to nature the result is the same. everything is inscrutable. all we know is that there are certain appearances, and that where there is appearance there must be something that appears. but what that something is, what is the noumenon which underlies the phenomenon, it is impossible for us to know. in nature we find two orders of phenomena, or appearances; the one objective or external, the other subjective in our consciousness. there are an ego and a non-ego, a subject and object. these are not identical. "it is," he says, "rigorously impossible to conceive that our knowledge is a knowledge of appearances only, without at the same time conceiving a reality of which they are appearances, for appearance without reality is unthinkable." (p. 88). so far we can go. there is a reality which is the cause of phenomena. further than that, in that direction, our ignorance is profound. he proves that space cannot be an entity, an attribute, or a category of thought, or a nonentity. the same is true of time, of motion, of matter, of electricity, light, magnetism, etc., etc. they all resolve themselves into appearances produced by an unknown cause. as the question, what is matter? is a crucial one, he dwells upon it in various parts of his writings. newton's theory of ultimate atoms; leibnitz's doctrine of monads; and the dynamic theory of boscovich, which makes matter mere centres of force, are all dismissed as unthinkable. it is not very clear in what sense that word is to be taken. sometimes it seems to mean, meaningless; at others, self-contradictory or absurd; at others, inconceivable, _i. e._ that of which no conception or mental image can be formed; at any rate, it implies what is unknowable and untenable. the result is, so far as matter is concerned, that we know nothing about it. "our conception of matter," he says, "reduced to its simplest shape, is that of coexistent positions that offer resistance, as contrasted with our conception of space in which the coexistent positions offer no resistance." (p. 166). resistance, however, is a form of force; and, therefore, on the following page, spencer says, "that forces standing in certain correlations, form the whole contents of our idea of matter." when we turn from the objective to the subjective, from the external to the inward world, the result is still the same. he agrees with hume in saying that the contents of our consciousness is a series of impressions and ideas. he dissents, however, from that philosopher, in saying that that series is all we know. he admits that impressions necessarily imply that there is something that is impressed. he starts the question, what is it that thinks? and answers, we do not know. (p. 63). he admits that the reality of individual personal minds, the conviction of personal existence is universal, and perhaps indestructible. nevertheless that conviction cannot justify itself at the bar of reason; nay, reason is found to reject it. (p. 65). dean mansel says, that consciousness gives us a knowledge of self as a substance and not merely of its varying states. this, however, he says, "is absolutely negatived by the laws of thought. the fundamental condition to all consciousness, emphatically insisted upon by mr. mansel in common with sir william hamilton and others, is the antithesis of subject and object.... what is the corollary from this doctrine, as bearing on the consciousness of self? the mental act in which self is known implies, like every other mental act, a perceiving subject and a perceived object. if, then, the object perceived is self, what is the subject that perceives? or if it is the true self which thinks, what other self can it be that is thought of? clearly, a true cognition of self implies a state in which the knowing and the known are one--in which subject and object are identified; and this mr. mansel rightly holds to be the annihilation of both. so that the personality of which each is conscious, and of which the existence is to each a fact beyond all others the most certain, is yet a thing which cannot be known at all; knowledge of it is forbidden by the very nature of human thought." (pp. 65, 66). mr. spencer does not seem to expect that any man will be shaken in his conviction by any such argument as that. when a man is conscious of pain, he is not to be puzzled by telling him that the pain is one thing (the object perceived) and the self another thing (the perceiving subject). he knows that the pain is a state of the self of which he is conscious. consciousness is a form of knowledge; but knowledge of necessity supposes an intelligent reality which knows. a philosophy which cannot be received until men cease to believe in their own existence, must be in extremis. mr. spencer's conclusion is, that the universe--nature, or the external world with all its marvels and perpetual changes,--the world of consciousness with its ever varying states, are impressions or phenomena, due to an inscrutable, persistent force. as to the nature of this primal force or power, he quotes abundantly and approvingly from sir william hamilton and mr. mansel, to prove that it is unknowable, inconceivable, unthinkable. he, however, differs from those distinguished writers in two points. while admitting that we know no more of the first cause than we do of a geometrical figure which is at once a circle and a square, yet we do know that it is actual. for this conviction we are not dependent on faith. in the second place, hamilton and mansel taught that we know that the infinite cannot be a person, self-conscious, intelligent, and voluntary; yet we are forced by our moral constitution to believe it to be an intelligent person. this mr. spencer denies. "let those," he says, "who can, believe that there is eternal war between our intellectual faculties and our moral obligations. i, for one, admit of no such radical vice in the constitution of things." (p. 108). religion has always erred, he asserts, in that while it teaches that the infinite being cannot be known, it insists on ascribing to it such and such attributes, which of course assumes that so far forth it is known. we have no right, he contends, to ascribe personality to the "unknown reality," or anything else, except that it is the cause of all that we perceive or experience. there may be a mode of being, as much transcending intelligence and will, as these transcend mechanical motion. to show the folly of referring to the unknown the attributes of our own spirits, he makes "the grotesque supposition that the tickings and other movements of a watch constituted a kind of consciousness; and that a watch possessed of such a consciousness, insisted on regarding the watchmaker's actions as determined like its own by springs and escapements." (p. 111). the vast majority of men, instead of agreeing with mr. spencer in this matter, will doubtless heartily, each for himself, join the german philosopher jacobi, in saying, "i confess to anthropomorphism inseparable from the conviction that man bears the image of god; and maintain that besides this anthropomorphism, which has always been called theism, is nothing but atheism or fetichism."[4] mr. spencer, therefore, in accounting for the origin of the universe and all its phenomena, physical, vital, and mental, rejects theism, or the doctrine of a personal god, who is extramundane as well as antemundane, the creator and governor of all things; he rejects pantheism, which makes the finite the existence-form of the infinite; he rejects atheism, which he understands to be the doctrine of the eternity and self-existence of matter and force. he contents himself with saying we must acknowledge the reality of an unknown something which is the cause of all things,--the noumenon of all phenomena. "if science and religion are to be reconciled, the basis of the reconciliation must be this deepest, widest, and most certain of all facts,--that the power which the universe manifests is utterly inscrutable." (p. 46). "the ultimate of ultimates is force." "matter and motion, as we know them, are differently conditioned manifestations of force." "if, to use an algebraic illustration, we represent matter, motion, and force, by the symbols _x_, _y_, _z_; then we may ascertain the values of _x_ and _y_ in terms of _z_, but the value of _z_ can never be found; _z_ is the unknown quantity, which must forever remain unknown, for the obvious reason that there is nothing in which its value can be expressed." (pp. 169, 170). we have, then, no god but force. atheist is everywhere regarded as a term of reproach. every man instinctively recoils from it. even the philosophers of the time of the french revolution repudiated the charge of atheism, because they believed in motion; and motion being inscrutable, they believed in an inscrutable something, _i. e._ in force. we doubt not mr. spencer would indignantly reject the imputation of atheism; nevertheless, in the judgment of most men, the difference between antitheist and atheist is a mere matter of orthography. footnotes: [3] _first principles of a new system of philosophy._ by herbert spencer. second edition. new york, 1869, p. 30. [4] _von den göttlichen dingen_, _werke_, iii. pp. 422, 425. leipzig, 1816. _hylozoic theory._ this theory assumes the universe to be eternal. there is nothing extra, or antemundane. there is but one substance, and that substance is matter. matter, however, has an active and passive principle. life and rationality are among its attributes or functions. the universe, therefore, is a living whole pervaded by a principle not only of life but of intelligence. this hylozoic doctrine, some modern scientific men, as professor tyndall, seem inclined to adopt. they tell us that matter is not the dead and degraded thing it is commonly regarded. it is active and transcendental. what that means, we do not know. the word transcendental is like a parabola, in that there is no knowing where its meaning ends. to say that matter is transcendental, is saying there is no telling what it is up to. this habit of using words which have no definite meaning is very convenient to writers, but very much the reverse for readers. some of the ancient stoics distinguished between the active and passive principles in the world, calling the one mind, the other, matter. these however were as intimately united as matter and life in a plant or animal. _theism in unscriptural forms._ there are men who are constrained to admit the being of god, who depart from the scriptural doctrine as to his relation to the world. according to some, god created matter and endowed it with certain properties, and then left it to itself to work out, without any interference or control on his part, all possible results. according to others, he created not only matter, but life, or living germs, one or more, from which without any divine intervention all living organisms have been developed. others, again, refer not only matter and life, but mind also to the act of the creator; but with creation his agency ceases. he has no more to do with the world, than a ship-builder has with the ship he has constructed, when it is launched and far off upon the ocean. according to all these views a creator is a mere _deus ex machina_, an assumption to account for the origin of the universe. another general view of god's relation to the world goes to the opposite extreme. instead of god doing nothing, he does everything. second causes have no efficiency. the laws of nature are said to be the uniform modes of divine operation. gravitation does not flow from the nature of matter, but is a mode of god's uniform efficiency. what are called chemical affinities are not due to anything in different kinds of matter, but god always acts in one way in connection with an acid, and in another way in connection with an alkali. if a man places a particle of salt or sugar on his tongue, the sensation which he experiences is not to be referred to the salt or sugar, but to god's agency. when this theory is extended, as it generally is by its advocates, from the external to the internal world, the universe of matter and mind, with all their phenomena, is a constant effect of the omnipresent activity of god. the minds of some men, as remarked above, are so constituted that they can pass from the theory that god does nothing, to the doctrine that he does everything, without seeing the difference. mr. russel wallace, the companion and peer of mr. darwin, devotes a large part of his book on "natural selection," to prove that the organs of plants and animals are formed by blind physical causes. toward the close of the volume he teaches that there are no such causes. he asks the question, what is matter? and answers, nothing. we know, he says, nothing but force; and as the only force of which we have any immediate knowledge is mind-force, the inference is "that the whole universe is not merely dependent on, but actually _is_, the will of higher intelligences, or of one supreme intelligence."[5] this is a transition from virtual materialism to idealistic pantheism. the effect of this admission on the part of mr. wallace on the theory of natural selection, is what an explosion of its boiler would be to a steamer in mid-ocean, which should blow out its deck, sides, and bottom. nothing would remain above water. the duke of argyll seems at times inclined to lapse into the same doctrine. "science," he says, "in the modern doctrine of conservation of energy and the convertibility of forces, is already getting a firm hold of the idea, that all kinds of force are but forms of manifestations of one central force issuing from some one fountain-head of power. sir john herschel has not hesitated to say, 'that it is but reasonable to regard the force of gravitation as the direct or indirect result of a consciousness or will existing somewhere.' and even if we cannot certainly identify force in all its forms with the direct energies of the one omnipresent and all-pervading will, it is at least in the highest degree unphilosophical to assert the contrary,--to think or to speak, as if the forces of nature were either independent of, or even separate from the creator's power."[6] the duke, however, in the general tenor of his book, does not differ from the common doctrine, except in one point. he does not deny the efficiency of physical causes, or resolve them all into the efficiency of god; but he teaches that god, in this world at least, never acts except through those causes. he applies this doctrine even to miracles, which he regards as effects produced by second causes of which we are ignorant, that is, by some higher law of nature. the scriptures, however, teach that god is not thus bound; that he operates through second causes, with them, or without them, as he sees fit. it is a purely arbitrary assumption, that when christ raised the dead, healed the lepers, or gave sight to the blind, any second cause intervened between the effect and the efficiency of his will. what physical law, or uniformly acting force, operated to make the axe float at the command of the prophet? or, in that greatest of all miracles, the original creation of the world. footnotes: [5] _the theory of natural selection._ by alfred russel wallace. london, 1870, p. 368. [6] _reign of law._ by the duke of argyle. fifth edition, london, 1867, p. 123. _mr. darwin's theory._ we have not forgotten mr. darwin. it seemed desirable, in order to understand his theory, to see its relation to other theories of the universe and its phenomena, with which it is more or less connected. his work on the "origin of species" does not purport to be philosophical. in this aspect it is very different from the cognate works of mr. spencer. darwin does not speculate on the origin of the universe, on the nature of matter, or of force. he is simply a naturalist, a careful and laborious observer; skillful in his descriptions, and singularly candid in dealing with the difficulties in the way of his peculiar doctrine. he set before himself a single problem, namely, how are the fauna and flora of our earth to be accounted for? in the solution of this problem, he assumes:-1. the existence of matter, although he says little on the subject. its existence however, as a real entity, is everywhere taken for granted. 2. he assumes the efficiency of physical causes, showing no disposition to resolve them into mind-force, or into the efficiency of the first cause. 3. he assumes also the existence of life in the form of one or more primordial germs. he does not adopt the theory of spontaneous generation. what life is he does not attempt to explain, further than to quote (p. 326), with approbation, the definition of herbert spencer, who says, "life depends on, or consists in, the incessant action and reaction of various forces,"--which conveys no very definite idea. 4. to account for the existence of matter and life, mr. darwin admits a creator. this is done explicitly and repeatedly. nothing, however, is said of the nature of the creator and of his relation to the world, further than is implied in the meaning of the word. 5. from the primordial germ or germs (mr. darwin seems to have settled down to the assumption of only one primordial germ), all living organisms, vegetable and animal, including man, on our globe, through all the stages of its history, have descended. 6. as growth, organization, and reproduction are the functions of physical life, as soon as the primordial germ began to live, it began to grow, to fashion organs however simple, for its nourishment and increase, and for the reproduction, in some way, of living forms like itself. how all living things on earth, including the endless variety of plants, and all the diversity of animals--insects, fishes, birds, the ichthyosaurus, the mastodon, the mammoth, and man--have descended from the primordial animalcule, he thinks, may be accounted for by the operation of the following natural laws, viz.:-first, the law of heredity, or that by which like begets like. the offspring are like the parent. second, the law of variation, that is, while the offspring are, in all essential characteristics, like their immediate progenitor, they nevertheless vary more or less within narrow limits, from their parent and from each other. some of these variations are indifferent, some deteriorations, some improvements, that is, they are such as enable the plant or animal to exercise its functions to greater advantage. third, the law of over production. all plants and animals tend to increase in a geometrical ratio; and therefore tend to overrun enormously the means of support. if all the seeds of a plant, all the spawn of a fish, were to arrive at maturity, in a very short time the world could not contain them. hence of necessity arises a struggle for life. only a few of the myriads born can possibly live. fourth, here comes in the law of natural selection, or the survival of the fittest. that is, if any individual of a given species of plant or animal happens to have a slight deviation from the normal type, favorable to its success in the struggle for life, it will survive. this variation, by the law of heredity, will be transmitted to its offspring, and by them again to theirs. soon these favored ones gain the ascendency, and the less favored perish; and the modification becomes established in the species. after a time another and another of such favorable variations occur, with like results. thus very gradually, great changes of structure are introduced, and not only species, but genera, families, and orders in the vegetable and animal world, are produced. mr. darwin says he can set no limit to the changes of structure, habits, instincts, and intelligence, which these simple laws in the course of millions or milliards of centuries may bring into existence. he says, "we cannot comprehend what the figures 60,000,000 really imply, and during this, or perhaps a longer roll of years, the land and waters have everywhere teemed with living creatures, all exposed to the struggle for life, and undergoing change." (p. 354). "mr. croll," he tells us, "estimates that about sixty millions of years have elapsed since the cambrian period, but this, judging from the small amount of organic change since the commencement of the glacial period, seems a very short time for the many and the great mutations of life, which have certainly occurred since the cambrian formation; and the previous one hundred and forty million years can hardly be considered as sufficient for the development of the varied forms of life which certainly existed toward the close of the cambrian period." (p. 379). years in this connection have no meaning. we might as well try to give the distance of the fixed stars in inches. as astronomers are obliged to take the diameter of the earth's orbit as the unit of space, so darwinians are obliged to take a geological cycle as their unit of duration. _natural selection._ as natural selection which works so slowly is a main element in mr. darwin's theory, it is necessary to understand distinctly what he means by it. on this point he leaves us no room for doubt. on p. 92, he says: "this preservation of favorable variations, and the destruction of injurious variations, i call natural selection, or, the survival of the fittest." "owing to the struggle (for life) variations, however slight and from whatever cause proceeding, if they be in any degree profitable to the individuals of a species, in their infinitely complex relations to other organic beings and to their physical conditions of life, will tend to the preservation of such individuals, and will generally be inherited by their offspring. the offspring also will thus have a better chance of surviving, for, of the many individuals of any species which are periodically born, but a small number can survive. i have called this principle, by which each slight variation, if useful, is preserved, by the term natural selection, in order to mark its relation to man's power of selection. but the expression often used by mr. herbert spencer of the survival of the fittest, is more accurate, and sometimes is equally convenient." (p. 72). "slow though the progress of selection may be, if feeble man can do so much by artificial selection, i can see no limit to the amount of change, to the beauty and infinite complexity of the co-adaptations between all organic beings, one with another, and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection, or the survival of the fittest." (p. 125). "it may be objected that if organic beings thus tend to rise in the scale, how is it that throughout the world a multitude of the lowest forms still exist; and how is it that in each great class some forms are far more highly developed than others?... on our theory the continuous existence of lowly forms offers no difficulty; for natural selection, or the survival of the fittest, does not necessarily include progressive development, it only takes advantage of such variations as arise and are beneficial to each creature under its complex relations of life.... geology tells us that some of the lowest forms, the infusoria and rhizopods, have remained for an enormous period in nearly their present state." (p. 145). "the fact of little or no modification having been effected since the glacial period would be of some avail against those who believe in an innate and necessary law of development, but is powerless against the doctrine of natural selection, or the survival of the fittest, which implies only that variations or individual differences of a favorable nature occasionally arise in a few species and are then preserved." (p. 149) this process of improvement under the law of natural selection includes not only changes in the organic structure of animals, but also in their instincts and intelligence. on entering on this part of his subject, mr. darwin says, "i would premise that i have nothing to do with the origin of the primary mental powers, any more than i have with that of life itself. we are concerned only with the diversities of instinct and of other mental qualities within the same class." (p. 255) he shows that even in a state of nature the instincts of animals of the same species do in some degree vary, and that they are transmitted by inheritance. a mastiff has imparted courage to a greyhound, and a greyhound has transmitted to a shepherd-dog a disposition to hunt hares. among sporting dogs, the young of the pointer or retriever have been known to point or to retrieve without instruction. "if," he says, "it can be shown that instincts do vary ever so little, then i can see no difficulty in natural selection preserving and continually accumulating variations of instinct to any extent that was profitable. it is thus, as i believe, that all the most complex and wonderful instincts have arisen." (p. 257) he was rather unguarded in saying that he saw no difficulty in accounting for the most wonderful instincts of animals. he admits that he has found very great difficulty. he selects three cases which he found it specially hard to deal with: that of the cuckoo, that of the cell-building bee, and of the slave-making ant. he devotes much space and labor in endeavoring to show how the instinct of the bee, for example, in the construction of its cell, _might_ have been gradually acquired. it is clear, however, that he was not able fully to satisfy even his own mind; for he admits that "it will be thought that i have an over-weening confidence in the principle of natural selection, when i do not admit that such wonderful and well established facts do not annihilate the theory." (p. 290) this remark was made with special reference to the instincts of the ant, which he finds very hard to account for. he adds, "no doubt many instincts of very difficult explanation could be opposed to the theory of natural selection: cases in which we cannot see how an instinct could possibly have originated; cases in which no intermediate gradations are known to exist; cases of instinct of such trifling importance that they could hardly have been acted upon by natural selection; cases of instincts almost identically the same in animals so remote in the scale of nature, that we cannot account for their similarity by inheritance from a common progenitor, and consequently cannot believe that they were independently acquired through natural selection. i will not here enter on those cases, but will confine myself to one special difficulty which at first appeared to me insuperable, and actually fatal to the whole theory. i allude to neuters, or sterile females in insect communities; for these neuters often differ widely in instinct and structure from both the males and the fertile females, and yet, from being sterile, they cannot propagate their kind." (p. 289) he is candid enough to say, in conclusion, "i do not pretend that the facts given in this chapter (on instinct) strengthen in any great degree my theory; but none of the cases of difficulty, to the best of my judgment, annihilate it." (p. 297) when it is remembered that his theory is, that slight variations occurring in an individual advantageous to it (not to its associates), in the struggle for life, is perpetuated by inheritance, it is no wonder that the case of sterile ants gave him so much trouble. accidental sterility is not favorable to the individual, and its being made permanent by inheritance, is out of the question, for the sterile have no descendants. yet these sterile females are not degenerations, they are in general larger and more robust than their associates. we have thus seen that, according to mr. darwin, all the infinite variety of structure in plants and animals is due to the law of natural selection. "on the principle of natural selection with divergence of character," he says, "it does not seem incredible that, from some such low and intermediate form, both animals and plants have been developed, and if we admit this, we must likewise admit that all the organized beings which have ever lived on this earth may be descended from some one primordial form." (p. 573) we have seen also that he does not confine his theory to organic structure, but applies it to all the instincts and all the forms of intelligence manifested by irrational creatures. nor does he stop there; he includes man within the sweep of the same law. "in the distant future i see open fields for far more important researches. psychology will be based on a new foundation, that of the _necessary_ acquirement of each mental power and capacity by gradation. light will be thrown on the origin of man and his history." (p. 577) the "distant future" was near at hand. in his introduction to his work on the "descent of man," he says, he had determined not to publish on that subject, "as i thought that i should thus only add to the prejudices against my views. it seemed to me sufficient to indicate, in the first edition of my 'origin of species,' that by this work 'light would be thrown on the origin of man and his history;' and this implies that man must be included with other organic beings in any general conclusion respecting his manner of appearance on this earth. now the case wears a wholly different aspect. when a naturalist like carl vogt (we shall see in what follows what kind of a witness he is) ventures to say in his address as president of the national institution of geneva (1869), 'personne, en europe au moins, n'ose plus soutenir la création indépendante et de toutes piéces, des espéces,'--it is manifest that at least a large number of naturalists must admit that species are the modified descendants of other species; and this especially holds good of the younger and rising naturalists.... of the older and honored chiefs in natural science, many unfortunately are still opposed to evolution in every form." carl vogt would not write thus. to him no man is honored who does agree with him, and any man who believes in god he execrates. in 1871, mr. darwin ventured on the publication of his "descent of man." in that work, he endeavors to show that the proximate progenitor of man is the ape. he says "there is less difference of structure between the two, than between the higher and lower forms of apes themselves." not only so, but he attempts to show that the mental faculties of man are derived by slight variations, long continued, from the measure of intellect possessed by lower animals. he even says, that there is less difference in intelligence between man and the higher mammals, than there is between the intelligence of the ant and that of the coccus, insects of the same class.[7] in like manner he teaches that man's moral nature has been evolved by slow degrees from the social instincts common to many animals. (pp. 68, 94) the moral element, thus derived, he admits might lead to very different lines of conduct. "if men," he says, "were reared under the same conditions as hives-bees, there can hardly be a doubt, that our unmarried females would, like the worker-bees, think it a sacred duty to kill all their brothers, and mothers would strive to kill their fertile daughters; and no one would think of interfering. (vol. i. p. 70) "lower animals, especially the dog, manifest love, reverence, fidelity, and obedience; and it is from these elements that the religious sentiment in man has been slowly evolved by a process of natural selection." (vol. i. p. 65) the grand conclusion is, "man (body, soul, and spirit) is descended from a hairy quadruped, furnished with a tail and pointed ears, probably arboreal in its habits, and an inhabitant of the old world." (vol. ii. p. 372) mr. darwin adds: "he who denounces these views (as irreligious) is bound to explain why it is more irreligious to explain the origin of man as a distinct species by descent from some lower form, through the laws of variation and natural selection, than to explain the birth of the individual through the laws of ordinary reproduction." (vol. ii. p. 378) footnote: [7] _descent of man_, etc. by charles darwin, m. a., f. r. s., etc. new york, 1871, vol. i. p. 179. _the sense in which mr. darwin uses the word "natural."_ we have not yet reached the heart of mr. darwin's theory. the main idea of his system lies in the word "natural." he uses that word in two senses: first, as antithetical to the word artificial. men can produce very marked varieties as to structure and habits of animals. this is exemplified in the production of the different breeds of horses, cattle, sheep, and dogs; and specially, as mr. darwin seems to think, in the case of pigeons. of these, he says, "the diversity of breeds is something astonishing." some have long, and some very short bills; some have large feet, some small; some long necks, others long wings and tails, while others have singularly short tails; some have thirty, and even forty, tail-feathers, instead of the normal number of twelve or fourteen. they differ as much in instinct as they do in form. some are carriers, some pouters, some tumblers, some trumpeters; and yet all are descendants of the rock pigeon which is still extant. if, then, he argues, man, in a comparatively short time, has by artificial selection produced all these varieties, what might be accomplished on the boundless scale of nature, during the measureless ages of the geologic periods. secondly, he uses the word natural as antithetical to supernatural. natural selection is a selection made by natural laws, working without intention and design. it is, therefore, opposed not only to artificial selection, which is made by the wisdom and skill of man to accomplish a given purpose, but also to supernatural selection, which means either a selection originally intended by a power higher than nature; or which is carried out by such power. in using the expression natural selection, mr. darwin intends to exclude design, or final causes. all the changes in structure, instinct, or intelligence, in the plants or animals, including man, descended from the primordial germ, or animalcule, have been brought about by unintelligent physical causes. on this point he leaves us in no doubt. he defines nature to be "the aggregate action and product of natural laws; and laws are the sequence of events as ascertained by us." it had been objected that he often uses teleological language, speaking of purpose, intention, contrivance, adaptation, etc. in answer to this objection, he says: "it has been said, that i speak of natural selection as a power or deity; but who objects to an author speaking of the attraction of gravity as ruling the movements of the planet?" he admits that in the literal sense of the words, natural selection is a false term; but "who ever objected to chemists, speaking of the elective affinities of various elements?--and yet an acid cannot strictly be said to elect the base with which it in preference combines." (p. 93) we have here an affirmation and a negation. it is affirmed that natural selection is the operation of natural laws, analogous to the action of gravitation and of chemical affinities. it is denied that it is a process originally designed, or guided by intelligence, such as the activity which foresees an end and consciously selects and controls the means of its accomplishment. artificial selection, then, is an intelligent process; natural selection is not. there are in the animal and vegetable worlds innumerable instances of at least apparent contrivance, which have excited the admiration of men in all ages. there are three ways of accounting for them. the first is the scriptural doctrine, namely, that god is a spirit, a personal, self-conscious, intelligent agent; that he is infinite, eternal, and unchangeable in his being and perfections; that he is ever present; that this presence is a presence of knowledge and power. in the external world there is always and everywhere indisputable evidence of the activity of two kinds of force: the one physical, the other mental. the physical belongs to matter, and is due to the properties with which it has been endowed; the other is the everywhere present and ever acting mind of god. to the latter are to be referred all the manifestations of design in nature, and the ordering of events in providence. this doctrine does not ignore the efficiency of second causes; it simply asserts that god over-rules and controls them. thus the psalmist says, "i am fearfully and wonderfully made.... my substance was not hid from thee, when i was made in secret, and curiously wrought (or embroidered) in the lower parts of the earth. thine eyes did see my substance yet being imperfect; and in thy book all my members were written, which in continuance were fashioned, when as yet there were none of them." "he who fashioned the eye, shall not he see? he that formed the ear shall not he hear?" "god makes the grass to grow, and herbs for the children of men." he sends rain, frost, and snow. he controls the winds and the waves. he determines the casting of the lot, the flight of an arrow, and the falling of a sparrow. this universal and constant control of god is not only one of the most patent and pervading doctrines of the bible, but it is one of the fundamental principles of even natural religion. the second method of accounting for contrivances in nature admits that they were foreseen and purposed by god, and that he endowed matter with forces which he foresaw and intended should produce such results. but here his agency stops. he never interferes to guide the operation of physical causes. he does nothing to control the course of nature, or the events of history. on this theory it may be said, (1.) that it is utterly inconsistent with the scriptures. (2.) it does not meet the religious and moral necessities of our nature. it renders prayer irrational and inoperative. it makes it vain for a man in any emergency to look to god for help. (3.) it is inconsistent with obvious facts. we see around us innumerable evidences of the constant activity of mind. this evidence of mind and of its operations, according to lord brougham and dr. whewell, is far more clear than that of the existence of matter and of its forces. if one or the other is to be denied, it is the latter rather than the former. paley indeed says, that if the construction of a watch be an undeniable evidence of design it would be a still more wonderful manifestation of skill, if a watch could be made to produce other watches; and, it may be added, not only other watches, but all kinds of time-pieces in endless variety. so it has been asked, if man can make a telescope, why cannot god make a telescope which produces others like itself? this is simply asking, whether matter can be made to do the work of mind? the idea involves a contradiction. for a telescope to make a telescope, supposes it to select copper and zinc in due proportions and fuse them into brass; to fashion that brass into inter-entering tubes; to collect and combine the requisite materials for the different kinds of glass needed; to melt them, grind, fashion, and polish them; adjust their densities and focal distances, etc., etc. a man who can believe that brass can do all this, might as well believe in god. the most credulous men in the world are unbelievers. the great napoleon could not believe in providence; but he believed in his star, and in lucky and unlucky days. this banishing god from the world is simply intolerable, and, blessed be his name, impossible. an absent god who does nothing is, to us, no god. christ brings god constantly near to us. he said to his disciples, "consider the ravens, for they neither sow nor reap; which have neither store-house nor barn; and god feedeth them; how much better are ye than the fowls. and which of you by taking thought can add to his stature one cubit? consider the lilies how they grow; they toil not, neither do they spin; and yet i say unto you that solomon in all his glory was not arrayed like one of these. if then god so clothe the grass, which is to-day in the field, and to-morrow is cast into the oven; how much more will he clothe you, o ye of little faith." "and seek ye not what ye shall eat, or what ye shall drink, neither be ye of doubtful mind. for all these things do the nations of the world seek after; and your father knoweth that ye have need of these things." it may be said that christ did not teach science. true, but he taught truth; and science, so called, when it comes in conflict with truth, is what man is when he comes in conflict with god. the advocates of these extreme opinions protest against being considered irreligious. herbert spencer says, that his doctrine of an inscrutable, unintelligent, unknown force, as the cause of all things, is a much more religious doctrine than that of a personal, intelligent, and voluntary being of infinite power and goodness. matthew arnold holds that an unconscious "power which makes for right," is a higher idea of god than the jehovah of the bible. christ says, god is a spirit. holbach thought that he made a great advance on that definition, when he said, god is motion. the third method of accounting for the contrivances manifested in the organs of plants and animals, is that which refers them to the blind operation of natural causes. they are not due to the continued coöperation and control of the divine mind, nor to the original purpose of god in the constitution of the universe. this is the doctrine of the materialists, and to this doctrine, we are sorry to say, mr. darwin, although himself a theist, has given in his adhesion. it is on this account the materialists almost deify him. from what has been said, it appears that darwinism includes three distinct elements. first, evolution; or the assumption that all organic forms, vegetable and animal, have been evolved or developed from one, or a few, primordial living germs; second, that this evolution has been effected by natural selection, or the survival of the fittest; and third, and by far the most important and only distinctive element of his theory, that this natural selection is without design, being conducted by unintelligent physical causes. neither the first nor the second of these elements constitute darwinism; nor do the two combined. as to the first, namely, evolution, mr. darwin himself, in the historical sketch prefixed to the fifth edition of his "origin of species," says, that lamarck, in 1811 and more fully in 1815, "taught that all species, including man, are descended from other species." he refers to some six or eight other scientists, as teaching the same doctrine. this idea of evolution was prominently presented and elaborated in the "vestiges of creation," first published in 1844. ulrici, professor in the university of halle, germany, in his work "gott und die natur," says that the doctrine of evolution took no hold on the minds of scientific men, but was positively rejected by the most eminent physiologists, among whom he mentions j. müller, k. wagner, bischoff, hoffmann, and others.[8] the rev. george henslow, lecturer on botany at st. bartholomew's hospital, london, himself a pronounced evolutionist, says the theories of lamarck and of the "vestiges of creation" have given place to that of mr. darwin; "and there are not wanting many symptoms of decay in the acceptance even of his. not only has he considerably modified his views in later editions of the 'origin of species,' distinctly expressing the opinion that he attributed too great influence to natural selection, but even men of science, owen, huxley,--and at least in its application to man, wallace himself,--are either opposed to it in great measure, or else give it but a qualified assent. thus, it has been the fate of all theories of the development of living things to lapse into oblivion. _evolution_ itself, however, will stand the same."[9] we find in the "transactions of the victoria institute," a still more decided repudiation of darwinism on the part of mr. henslow. he there says: "i do not believe in darwin's theory; and have endeavored to refute it by showing its utter impossibility."[10] he defines evolution by saying, "it supposes all animals and plants that exist now, or have ever existed, to have been produced through laws of generation from preëxisting animals and plants respectively; that affinity amongst organic beings implies, or is due to community of descent; and that the degree of affinity between organisms is in proportion to their nearness of generation, or, at least, to the persistence of common characters, they being the products of originally the same parentage."[11] a man, therefore, may be an evolutionist, without being a darwinian. it should be mentioned that mr. henslow expressly excludes man, both as to body and soul, from the law of evolution. nor is the theory of natural selection the vital principle of mr. darwin's theory, unless the word natural be taken in a sense antithetical to supernatural. in the historical sketch just referred to, mr. darwin not only says that he had been anticipated in teaching the doctrine of evolution by lamarck and the author of the "vestiges of creation;" but that the theory of natural selection, as the means of accounting for evolution, was not original with him. he tells us that as early as 1813, dr. w. c. wells "distinctly recognizes the principle of natural selection;" and that mr. patrick matthew, in 1831, "gives precisely the same view of the origin of species as that propounded by mr. wallace and myself." ideas are like seed: they are often cast forth, and not finding a congenial soil produce no fruit. to mr. darwin is undoubtedly due the elaboration and thoroughly scientific defence of the theory of natural selection, and to him is to be referred the deep and widespread interest which it has excited. footnotes: [8] _gott und die natur_. von d. hermann ulrici. zweite auflage. leipzig, 1866, p. 394. [9] _the theory of evolution of living things and the application of the principles of evolution to religion_. by rev. george henslow, m. a., f. l. s., f. g. s. london, 1873, pp. 27, 28. [10] _journal of the transactions of the victoria institute, or philosophical society of great britain_. vol. iv. london, 1870, p. 278. [11] _evolution and religion_, p. 29. _darwinism excludes teleology._ it is however neither evolution nor natural selection, which give darwinism its peculiar character and importance. it is that darwin rejects all teleology, or the doctrine of final causes. he denies design in any of the organisms in the vegetable or animal world. he teaches that the eye was formed without any purpose of producing an organ of vision. although evidence on this point has already been adduced, yet as it is often overlooked, at least in this country, so that many men speak favorably of mr. darwin's theory, who are no more darwinians than they are mussulmans; and as it is this feature of his system which brings it into conflict not only with christianity, but with the fundamental principles of natural religion, it should be clearly established. the sources of proof on this point are,--1st. mr. darwin's own writings. 2d. the expositions of his theory given by its advocates. 3d. the character of the objections urged by its opponents. the point to be proved is that it is the distinctive doctrine of mr. darwin, that species owe their origin, not to the original intention of the divine mind; not to special acts of creation calling new forms into existence at certain epochs; not to the constant and everywhere operative efficiency of god, guiding physical causes in the production of intended effects; but to the gradual accumulation of unintended variations of structure and instinct, securing some advantage to their subjects. _darwin's own testimony._ that such is mr. darwin's doctrine we prove from his own writings. and the first proof from that source is found in express declarations. when an idea pervades a book and constitutes its character, detached passages constitute a very small part of the evidence of its being inculcated. in the present case, however, such passages are sufficient to satisfy even those who have not had occasion to read mr. darwin's books. in referring to the similarity of structure in animals of the same class, he says, "nothing can be more hopeless than to attempt to explain this similarity of pattern in members of the same class, by utility or the doctrine of final causes."[12] on the last page of his work, he says: "it is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. these laws, taken in the largest sense, being growth with reproduction; variability from the indirect and direct action of the conditions of life, and from use and disuse; a ratio of increase so high as to lead to a struggle for life, and as a consequence to natural selection, entailing divergence of character and extinction of less improved forms. thus from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, the production of the higher animals directly follows. there is a grandeur in this view of life, with its several powers, having been originally breathed by the creator into a few forms or into one; and that whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved." (p. 579) in another of his works, he asks, "did he (god) ordain that crop and tail-feathers of the pigeon should vary, in order that the fancier might make his grotesque pouter and fan-tail breeds? did he cause the frame and mental qualities of the dog to vary, in order that a breed might be formed of indomitable ferocity, with jaws fitted to pin down the bull, for man's brutal sport? but if we give up the principle in one case; if we do not admit that the variations of the primeval dog were intentionally guided in order, for instance, that the greyhound, that perfect image of symmetry and vigor, might be formed; no shadow of reason can be assigned for the belief that variations, alike in nature and the results of the same general laws, which have been the groundwork through natural selection of the most perfectly adapted animals in the world, man included, were intentionally and specially guided. however much we may wish it, we can hardly follow professor asa gray, in his belief 'that variations have been led along certain beneficial lines, as a stream is led along useful lines of irrigation.'"[13] variations, which by their gradual accumulation give rise to new species, genera, families, and orders, are themselves, step by step, accidental. mr. darwin sometimes says they happen by chance; sometimes he says they happen of necessity; at others he says, "we are profoundly ignorant of their causes." these are only different ways of saying that they are not intentional. when a man lets anything fall from his hands, and says it was accidental, he does not mean that it was causeless, he only means that it was not intentional. and that is precisely what darwin means when he says that species arise out of accidental variations. his whole book is an argument against teleology. the whole question is, how are we to account for the innumerable varieties, kinds, and genera of plants and animals, including man? were they intended? or, did they arise from the gradual accumulations of unintentional variations? his answer to these questions is plain. on page 245, he says: "nothing at first can appear more difficult to believe than that the more complex organs and instincts have been perfected not by means superior to, though analogous with, human reason, but by innumerable slight variations, each good for the individual possessor. nevertheless, this difficulty, though appearing to our imagination[14] insuperably great, cannot be considered real, if we admit the following propositions, namely, that all parts of the organizations and instincts offer, at least, individual differences; that there is a struggle for existence, which leads to the preservation of profitable deviations of structure or instinct; and, lastly, that gradations in the state of perfection of each organ may have existed, each good of its kind." he says, over and over, that if beauty or any variation of structure can be shown to be intended, it would "annihilate his theory." his doctrine is that such unintended variations, which happen to be useful in the struggle for life, are preserved, on the principle of the survival of the fittest. he urges the usual objections to teleology derived from undeveloped or useless organs, as web-feet in the upland goose and frigate-bird, which never swim. what, however, perhaps more than anything, makes clear his rejection of design is the manner in which he deals with the complicated organs of plants and animals. why don't he say, they are the product of the divine intelligence? if god made them, it makes no difference, so far as the question of design is concerned, how he made them: whether at once or by a process of evolution. but instead of referring them to the purpose of god, he laboriously endeavors to prove that they may be accounted for without any design or purpose whatever. "to suppose," he says, "that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different degrees of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, i freely confess, absurd in the highest degree." (p. 222) nevertheless he attempts to explain the process. "it is scarcely possible," he says, "to avoid comparing the eye with the telescope. we know that this instrument has been perfected by the long continued efforts of the highest of human intellects; and we naturally infer that the eye has been formed by a somewhat analogous process. but may not this inference be presumptuous? have we any right to assume that the creator works by intellectual powers like those of man? if we must compare the eye to an optical instrument, we ought in imagination to take a thick layer of transparent tissue, with spaces filled with fluid, and with a nerve sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different densities and thicknesses, placed at different distances from each other, and with the surfaces of each layer slowly changing in form. further, we must suppose that there is a power represented by natural selection, or the survival of the fittest, always intently watching each slight alteration in the transparent layers, and carefully preserving each, which, under varied circumstances, tends to produce a distinct image. we must suppose each new state of the instrument to be multiplied by the million; each to be preserved until a better is produced, and the old ones to be all destroyed. in living bodies, variations will cause the slight alterations, generation will multiply them almost infinitely, and natural selection will pick out with unerring skill each improvement."[15] (p. 226) "let this process," he says, "go on for millions of years," and we shall at last have a perfect eye. it would be absurd to say anything disrespectful of such a man as mr. darwin, and scarcely less absurd to indulge in any mere extravagance of language; yet we are expressing our own experience, when we say that we regard mr. darwin's books the best refutation of mr. darwin's theory. he constantly shuts us up to the alternative of believing that the eye is a work of design or the product of the unintended action of blind physical causes. to any ordinarily constituted mind, it is absolutely impossible to believe that it is not a work of design. darwin himself, it is evident, dear as his theory is, can hardly believe it. "it is indispensable," he says, "to arrive at a just conclusion as to the formation of the eye, that the reason should conquer the imagination; but i have felt the difficulty far too keenly to be surprised at any degree of hesitation in extending the principle of natural selection to so startling an extent." (p. 225) it will be observed that every step in his account of the formation of the eye is an arbitrary assumption. we must first assume a thick layer of tissue; then that the tissue is transparent; then that it has cavities filled with fluid; that beneath the tissue is a nerve sensitive to light; then that the fluid is constantly varying in density and thickness; that its surfaces are constantly changing their contour; that its different portions are ever shifting their relative distances; that every favorable change is seized upon and rendered permanent,--thus after millions of years we may get an eye as perfect as that of an eagle. in like manner we may suppose a man to sit down to account for the origin and contents of the bible, assuming as his "working hypothesis," that it is not the product of mind either human or divine, but that it was made by a type-setting machine worked by steam, and picking out type hap-hazard. in this way in a thousand years one sentence might be produced, in another thousand a second, and in ten thousand more, the two might get together in the right position. thus in the course of "millions of years" the bible might have been produced, with all its historical details, all its elevated truths, all its devout and sublime poetry, and above all with the delineation of the character of christ, the [greek: idea tôn ideôn], the ideal of majesty and loveliness, before which the whole world, believing and unbelieving, perforce bows down in reverence. and when reason has sufficiently subdued the imagination to admit all this, then by the same theory we may account for all the books in all languages in all the libraries in the world. thus we should have darwinism applied in the sphere of literature. this is the theory which we are told is to sweep away christianity and the church! mr. darwin gives the same unsatisfactory account of the marvellous "contrivances" in the vegetable world. in one species of orchids, the labellum or lower lip is hollowed into a great bucket continually filled with water, secreted from two horns which stand above it; when the bucket is sufficiently filled, the water flows out through a pipe or spout on one side. the bees, which crowd into the flower for sake of the nectar, jostle each other, so that some fall into the water; and their wings becoming wet they are unable to fly, and are obliged to crawl through the spout. in doing this they come in contact with the pollen, which, adhering to their backs, is carried off to other flowers. this complicated contrivance by which the female plants are fertilized has, according to the theory, been brought about by the slow process of natural selection or survival of the fittest. still more wonderful is the arrangement in another species of orchids. when the bee begins to gnaw the labellum, he unavoidably touches a tapering projection, which, when touched, transmits a vibration which ruptures a membrane, which sets free a spring by which a mass of pollen is shot, with unerring aim, over the back of the bee, who then departs on his errand of fertilization. a very large class of plants are fertilized by means of insects. these flowers are beautiful, not for the sake of beauty,--for that mr. darwin says would annihilate his theory,--but those which happen to be beautiful attract insects, and thus become fertilized and perpetuated, while the plainer ones are neglected and perish. so with regard to birds. the females are generally plain, because those of bright colors are so exposed during the period of incubation that they are destroyed by their enemies. in like manner male birds are usually adorned with brilliant plumage. this is accounted for on the ground that they are more attractive, and thus they propagate their race, while the plainer ones have few or no descendants. thus all design is studiously and laboriously excluded from every department of nature. the preceding pages contain only a small part of the evidence furnished by mr. darwin's own writings, that his doctrine involves the denial of all final causes. the whole drift of his books is to prove that all the organs of plants and animals, all their instincts and mental endowments, may be accounted for by the blind operation of natural causes, without any intention, purpose, or coöperation of god. this is what professor huxley and others call "the creative idea," to which the widespread influence of his writings is to be referred. footnotes: [12] _origin of species_, p. 517. [13] _the variations of animals and plants under domestication._ by charles darwin, f. r. s., etc. new york, 1868, vol. ii. pp. 515, 516. [14] what can the word "imagination" mean in this sentence, if it does not mean "common sense?" [15] mr. darwin's habit of personifying nature has given, as his friend mr. wallace says, his readers a good deal of trouble. he defines nature to be the aggregate of physical forces; and in the single passage quoted, he speaks of natural selection "as intently watching" "picking out with unerring skill," and "carefully preserving." it is true, he tells us this is all to be understood metaphorically. _testimony of the advocates of the theory._ it is time to turn to the exposition of darwinism by its avowed advocates, in proof of the assertion that it excludes all teleology. the first of these witnesses is mr. alfred russel wallace, himself a distinguished naturalist. mr. darwin informs his readers that as early as 1844, he had collected his material and worked out his theory, but had not published it to the world, although it had been communicated to some of his friends. in 1858 he received a memoir from mr. wallace, who was then studying the natural history of the malay archipelago. from that memoir he learnt that mr. wallace had "arrived at almost exactly the same conclusions as i (he himself) have on the origin of species." this led to the publishing his book on that subject contemporaneously with mr. wallace's memoir. there has been no jealousy or rivalry between these gentlemen. mr. wallace gracefully acknowledges the priority of mr. darwin's claim, and attributes to him the credit of having elaborated and sustained it in a way to secure for it universal attention. these facts are mentioned in order to show the competency of mr. wallace as a witness as to the true character of darwinism. mr. wallace, in "the theory of natural selection," devotes a chapter to the consideration of the objections urged by the duke of argyll, in his work on the "reign of law," against that theory. those objections are principally two: first, that design necessarily implies an intelligent designer; and second, that beauty not being an advantage to its possessor in the struggle for life, cannot be accounted for on the principle of the survival of the fittest. the duke, he says, maintains that contrivance and beauty indicate "the constant supervision and interference of the creator, and cannot possibly be explained by the unassisted action of any combination of laws. now, mr. darwin's work," he adds, "has for its main object to show that all the phenomena of living things--all their wonderful organs and complicated structures, their infinite variety of form, size, and color, their intricate and involved relations to each other--may have been produced by the action of a few general laws of the simplest kind, laws which are in most cases mere statements of admitted facts." (p. 265) those laws are those with which we are familiar: heredity, variations, over production, struggle for life, survival of the fittest. "it is probable," he says, "that these primary facts or laws are but results of the very nature of life, and of the essential properties of organized and unorganized matter. mr. herbert spencer, in his 'first principles' and in his 'biology,' has, i think, made us able to understand how this may be; but at present we may accept these simple laws, without going further back, and the question then is, whether the variety, the harmony, the contrivance, and the beauty we perceive, can have been produced by the action of these laws alone, or whether we are required to believe in the incessant interference and direct action of the mind and will of the creator." (p. 267)[16] mr. wallace says, that the duke of argyll maintains that god "has personally applied general laws to produce effects which those laws are not in themselves capable of producing; that the universe alone with all its laws intact, would be a sort of chaos, without variety, without harmony, without design, without beauty; that there is not (and therefore we may presume that there could not be) any self-developing power in the universe. i believe, on the contrary, that the universe is so constituted as to be self-regulating; that as long it contains life, the forms under which that life is manifested have an inherent power of adjustment to each other and to their surroundings; and that this adjustment necessarily leads to the greatest amount of variety and beauty and enjoyment, because it does depend on general laws, and not on a continual supervision and rearrangement of details." (p. 268) "the strange springs and traps and pitfalls found in the flowers of orchids, cannot," he says, "be necessary _per se_, since exactly the same end is gained in ten thousand other flowers which do not possess them. is it not then an extraordinary idea, to imagine the creator of the universe contriving the various complicated parts of these flowers, as a mechanic might contrive an ingenious toy or a difficult puzzle? is it not a more worthy conception, that they are the results of those general laws which were so coördinated at the first introduction of life upon the earth as to result necessarily in the utmost possible development of varied forms." (p. 270) "i for one," he says, "cannot believe that the world would come to chaos if left to law alone.... if any modification of structure could be the result of law, why not all? if some self-adaptations should arise, why not others? if any varieties of color, why not all the varieties we see? no attempt is made to explain this except by reference to the fact that 'purpose' and 'contrivance' are everywhere visible, and by an illogical deduction they could only have arisen by the direct action of some mind, because the direct action of our minds produce similar 'contrivances;' but it is forgotten that adaptation, however produced, must have the appearance of design." (p. 280)[17] after referring to the fact that florists and breeders can produce varieties in plants and animals, so that, "whether they wanted a bull-dog to torture another animal, a greyhound to catch a hare, or a bloodhound to hunt down their oppressed fellow-creatures, the required variations have always appeared," he adds: "to be consistent, our opponents must maintain that every one of the variations that have rendered possible the changes produced by man, have been determined at the right time and place by the creator. every race produced by the florist or breeder, the dog or the pigeon fancier, the rat-catcher, the sporting man, or the slave-hunter, must have been provided for by varieties occurring when wanted; and as these variations were never withheld, it would prove that the sanction of an all-wise and all powerful being has been given to that which the highest human minds consider to be trivial, mean, or debasing." (p. 290)[18] the nebular hypothesis, as propounded by la place, proposed to account for the origin of the universe, by a process of evolution under the control of mere physical forces. that hypothesis has, so far as evolution is concerned, been adopted by men who sincerely believe in god and in the bible. but they hold not only that god created matter and endowed it with its properties, but that he designed the universe, and so controlled the operation of physical laws that they accomplished his purpose. so there are christian men who believe in the evolution of one kind of plants and animals out of earlier and simpler forms; but they believe that everything was designed by god, and that it is due to his purpose and power that all the forms of vegetable and animal life are what they are. but this is not the question. what darwin and the advocates of his theory deny, is all design. the organs, even the most complicated and wonderful, were not intended. they are said to be due to the undirected and unintended operation of physical laws. this is mr. wallace's argument. he endeavors to show that it is unworthy of god that he should be supposed to have contrived the mechanism of the orchids, as a mechanist contrives a curious puzzle. we recently heard prof. joseph henry, in a brief address, say substantially: "if i take brass, glass, and other materials, and fuse them, the product is a slag. this is what physical laws do. if i take those same materials, and form them into a telescope, that is what mind does." this is the whole question in a nutshell. that design implies an intelligent designer, is a self evident truth. every man believes it; and no man can practically disbelieve it. even those naturalists who theoretically deny it, if they find in a cave so simple a thing as a flint arrow-head, are as sure that it was made by a man as they are of their own existence. and yet they want us to believe that an eagle's eye is the product of blind natural causes. no combination of physical forces ever made a ship or a locomotive. it may, indeed, be said that they are dead matter, whereas plants and animals live. but what is life but one form of the organizing efficiency of god? mr. wallace does not go as far as mr. darwin. he recoils from regarding man either as to body or soul as the product of mere natural causes. he insists that "a superior intelligence is necessary to account for man." (p. 359) this of course implies that the agency of no such higher intelligence is admitted in the production of plants or of animals lower than man. footnotes: [16] the question is not, as mr. wallace says, "how has the creator worked?" but it is, as he himself states, whether the essential properties of matter have alone worked out all the wonders of creation; or, whether they are to be referred to the mind and will of god. it is worthy of remark how messrs. darwin and wallace refer to mr. spencer as their philosopher. we have seen what spencer's philosophy is. [17] it is, therefore, clear that design is what mr. darwin and mr. wallace repudiate. [18] that god permits men in the use of the laws of nature to distil alcohol and brew poisons, does not prove that he approves of drunkenness or murder. _professor huxley._ the second witness as to the character of mr. darwin's theory is professor huxley. we have some hesitation in including the name of this distinguished naturalist among the advocates of darwinism.[19] on the one hand, in his essay on the origin of species, printed in the "westminster review," in 1860, and reprinted in his "lay sermons," etc., in 1870, he says: "there is no fault to be found with mr. darwin's method, but it is another thing whether he has fulfilled all the conditions imposed by that method. is it satisfactorily proved that species may[20] be originated by selection? that none of the phenomena exhibited by species are inconsistent with the origin of species in this way? if these questions can be answered in the affirmative, mr. darwin's view steps out of the rank of hypotheses into that of theories; but so long as the evidence at present adduced falls short of enforcing that affirmative, so long, to our minds, the new doctrine must be content to remain among the former,--an extremely valuable, and in the highest degree probable, doctrine; indeed, the only extant hypothesis which is worth anything in a scientific point of view; but still a hypothesis, and not yet a theory of species. after much consideration," he adds, "and assuredly with no bias against mr. darwin's views, it is our clear conviction that, as the evidence now stands, it is not absolutely proven that a group of animals, having all the characters exhibited by species in nature, has ever been originated by selection, whether artificial or natural."[21] again, in his work on "man's place in nature," he expresses himself much to the same effect: "a true physical cause is admitted to be such only on one condition, that it shall account for all the phenomena which come within the range of its operation. if it is inconsistent with any one phenomenon it must be rejected; if it fails to explain any one phenomenon it is so far to be suspected, though it may have a perfect right to provisional acceptance.... our acceptance, therefore, of the darwinian hypothesis must be provisional so long as one link in the chain of evidence is wanting; and so long as all the animals and plants certainly produced by selective breeding from a common stock are fertile, and their progeny are fertile one with another, that link will be wanting. for so long selective breeding will not be proved to be competent to all that is required if it produce natural species."[22] in immediate connection with the above passage, there is another which throws a clear light on professor huxley's cosmical views. "the whole analogy of natural operations furnish so complete and crushing an argument against the intervention of any but what are called secondary causes, in the production of all the phenomena of the universe; that, in view of the intimate relations of man and the rest of the living world, and between the forces exerted by the latter and all other forces, i can see no reason for doubting that all are coördinate terms of nature's great progression, from formless to formed, from the inorganic to the organic, from blind force to conscious intellect and will."[23] ought not this to settle the matter? are we to give up the bible and all our hopes for the sake of an hypothesis that all living things, including man, on the face of the earth, are descended from a primordial animalcule, by natural selection, when such a man as huxley, who (as voltaire said of the prophet habbakuk) is _capable de tout_, says that it has not been proved that any one species has thus originated? but on the other hand, while he honestly admits that darwin's doctrine is a mere hypothesis and not a theory, he has nevertheless written at least three essays or reviews in its exposition and vindication. he is freely referred to on the continent of europe, at least, as an ardent advocate of the doctrine; and he quotes without protest such designations of himself. at any rate, as he assures his readers that he has no bias against mr. darwin's views, as he has devoted much time and attention to the subject, and as he is one of the most prominent naturalists of the age, there can be no question as to his competency as a witness as to what darwinism is. his testimony that mr. darwin's doctrine excludes all teleology, or final causes, is explicit. in his review of the "criticisms on the origin of species," he says, "that when he first read mr. darwin's book, that which struck him most forcibly was the conviction that teleology, as commonly understood, had received its death-blow at mr. darwin's hands. for the teleological argument runs thus: an organ is precisely fitted to perform a function or purpose; therefore, it was specially constructed to perform that function. in paley's famous illustration, the adaptation of all the parts of a watch to the function or purpose of showing the time, is held to be evidence that the watch was specially contrived to that end; on the ground that the only cause we know of competent to produce such an effect as a watch which shall keep time, is a contriving intelligence adapting the means directly to that end."[24] this, mr. huxley tells us, is precisely what darwin denies with reference to the organs of plants and animals. the eye was not formed for the purpose of seeing, or the ear for hearing. it so happened that a nerve became sensitive to light; then in course of time, it happened that a transparent tissue came over it; and thus in "millions of years" an eye, as we have seen above, happened to be formed. no such organ was ever intended or designed by god or man. "an apparatus," says professor huxley, "thoroughly adapted to a particular purpose, might be the result of a method of trial and error worked by unintelligent agents, as well as by the application of means appropriate to the end by an intelligent agent." "for the notion that every organism has been created as it is and launched straight at a purpose, mr. darwin substitutes the conception of something, which may fairly be termed a method of trial and error. organisms vary incessantly; of these variations the few meet with surrounding conditions which suit them, and thrive; the many are unsuited, and become extinguished." "for the teleologist an organism exists, because it was made for the conditions in which it is found; for the darwinian an organism exists, because, out of many of its kind, it is the only one which has been able to persist in the conditions in which it is found." "if we apprehend," huxley further says, "the spirit of the 'origin of species' rightly, then, nothing can be more entirely and absolutely opposed to teleology, as it is commonly understood, than the darwinian theory." (p. 303) it has already been stated that mr. wallace does not apply the doctrine of evolution to man; neither does mr. mivart, a distinguished naturalist, who is a member of the latin church. the manner in which professor huxley speaks of these gentlemen shows how thoroughly, in his judgment, mr. darwin banishes god from his works: "mr. wallace and mr. mivart are as stout evolutionists as mr. darwin himself; but mr. wallace denies that man can have been evolved from a lower animal by that process of natural selection, which he, with mr. darwin, holds to be sufficient for the evolution of all animals below man; while mr. mivart, admitting that natural selection has been one of the conditions of the animals below man, maintains that natural selection must, even in their case, have been supplemented by some other cause,--of the nature of which, unfortunately, he does not give us any idea. thus mr. mivart is less of a darwinian than mr. wallace, for he has faith in the power of natural selection. but he is more of an evolutionist than mr. wallace, because mr. wallace thinks it necessary to call in an intelligent agent, a sort of supernatural sir john sebright, to produce even the animal frame of man; while mr. mivart requires no divine assistance till he comes to man's soul."[25] in the "academy" for october, 1869, there is a review by professor huxley of dr. haeckel's "natürlische schöpfungsgeschichte," in which he says: "professor haeckel enlarges on the service which the 'origin of species' has done in favoring what he terms 'the causal or mechanical' view of living nature as opposed to the 'teleological or vitalistic' view. and no doubt it is quite true the doctrine of evolution is the most formidable of all the commoner and coarser forms of teleology. perhaps the most remarkable service to the philosophy of biology rendered by mr. darwin is the reconciliation of teleology and morphology, and the explanation of the facts of both which his view offers. "the teleology which supposes that the eye, such as we see it in man or in the higher vertebrata, was made with the precise structure which it exhibits, to make the animal which possesses it to see, has undoubtedly received its death-blow. but it is necessary to remember that there is a higher teleology, which is not touched by the doctrine of evolution, but is actually based on the fundamental proposition of evolution. that proposition is, that the whole world, living and not living, is the result of the mutual interaction, according to definite laws, of forces possessed by the molecules of which the primitive nebulosity of the universe was composed. if this be true, it is no less certain that the existing world lay potentially in the cosmic vapor; and that a sufficient intelligence could, from a knowledge of the properties of that vapor, have predicted, say, the state of fauna of great britain in 1869, with as much certainty as one can say what will happen to the vapor of the breath on a cold winter's day." this is the doctrine of the self-evolution of the universe. we know not what may lie behind this in mr. huxley's mind; but we are very sure that there is not an idea in the above paragraph which epicurus of old, and büchner, vogt, haeckel, and other "materialisten von profession," would not cheerfully adopt. his distinction between a higher and lower teleology is of no account in this discussion. what is the teleology to which, he says, mr. darwin has given the death-blow, the extracts given above clearly show. the eye, huxley says, was not made for the purpose of seeing, or the ear for the purpose of hearing. "according to teleology," he says, "each organism is like a rifle bullet fired straight at a mark; according to darwin, organisms are like grapeshot, of which one hits something and the rest fall wide."[26] footnotes: [19] mr. huxley, if we may judge from what he says of himself, is somewhat liable to be misunderstood. he says he was fourteen years laboring to resist the charge of positivism made against the class of scientific men to which he belongs. he also tells us in his letter to professor tyndall, prefixed to his volume of _lay sermons and addresses_, that the "essay on the physical basis of life," included in that volume, was intended as a protest, from the philosophical side, against what is commonly called materialism. it turned out, however, that the public regarded it as an argument in favor of materialism. this we think was a very natural, if not an unavoidable mistake, on the part of the public. for in that essay, he says that protoplasm, or the physical basis of life, "is a kind of matter common to all living beings, that the powers or faculties of all kinds of living matter, diverse as they may be in degree, are substantially of the same kind." protoplasm as far as examined contains the four elements,--carbon, hydrogen, oxygen, and nitrogen. these are lifeless bodies, "but when brought together under certain conditions, they give rise to the still more complex body protoplasm; and this protoplasm exhibits the phenomena of life." there is no more reason, he teaches, for assuming the existence of a mysterious something called vitality to account for vital phenomena, than there is for the assumption of something called aquasity to account for the phenomena of water. life is said to be "the product of a certain disposition of material molecules." the matter of life is "composed of ordinary matter, differing from it only in the manner in which its atoms are aggregated. i take it," he says, "to be demonstrable that it is utterly impossible to prove that anything whatever may not be the effect of a material and necessary cause, and that human logic is equally incompetent to prove that any act is really spontaneous. a really spontaneous act is one, which, by the assumption, has no cause; and the attempt to prove such a negative as this, is on the face of the matter absurd. and while it is thus a philosophical impossibility to demonstrate that any given phenomenon is not the effect of a material cause, any one who is acquainted with the history of science will admit that its progress has, in all ages, meant, and now more than ever means, the extension of what we call matter and causation, and the concomitant gradual banishment from all regions of human thought of what we call spirit and spontaneity." [20] it cannot escape the attention of any one that mr. darwin, mr. wallace, professor huxley, and all the other advocates or defenders of darwinism, do not pretend to prove anything more than that species _may_ be originated by selection, not that there is no other satisfactory account of their origin. mr. darwin admits that referring them to the intention and efficiency of god, accounts for everything, but, he says, that is not science. [21] _lay sermons, addresses, and reviews_. by thomas henry huxley, ll. d., f. r. s. london, 1870, p. 323. [22] _evidence of man's place in nature_. london, 1864, p. 107. [23] since writing the above paragraph our eye fell on the following note on the 89th page of the duke of argyle's _reign of law_, which it gives us pleasure to quote. it seems that a writer in the _spectator_ had charged professor huxley with atheism. in the number of that paper for february 10, 1866, the professor replies: "i do not know that i care very much about popular odium, so there is no great merit in saying that if i really saw fit to deny the existence of a god i should certainly do so, for the sake of my own intellectual freedom, and be the honest atheist you are pleased to say i am. as it happens, however, i cannot take this position with honesty, inasmuch as it is, and always has been, a favorite tenet, that atheism is as absurd, logically speaking, as polytheism." in the same paper he says, "the denying the possibility of miracles seems to me quite as unjustifiable as speculative atheism." how this can be reconciled with the passages quoted above, we are unable to see. [24] _lay sermons_, etc., p. 330. [25] _contemporary review_, vol. xviii. 1871, p. 444. in this same article mr. huxley says: "elijah's great question, will ye serve god or baal? choose ye, is uttered audibly enough in the ears of every one of us as we come to manhood. let every man who tries to answer it seriously ask himself whether he can be satisfied with the baal of authority, and with all the good things his worshippers are promised in this world and the next. if he can, let him, if he be so inclined, amuse himself with such scientific implements as authority tells him are safe and will not cut his fingers; but let him not imagine that he is, or can be, both a true son of the church and a loyal soldier of science." "and, on the other hand, if the blind acceptance of authority appear to him in its true colors, as mere private judgment _in excelsis_, and if he have courage to stand alone face to face with the abyss of the eternal and unknowable, let him be content, once for all, not only to renounce the good things promised by 'infallibility,' but even to bear the bad things which it prophesies; content to follow reason and fact in singleness and honesty of purpose, wherever they may lead, in the sure faith that a hell of honest men will to him be more endurable than a paradise full of angelic shams." there can be no doubt that the apostle paul believed in the infallibility of the scriptures. imagine professor huxley calling st. paul to his face, a sham! what are all the huxleys who have ever lived or ever can live, to that one paul in power for good over human thought, character, and destiny! professor huxley goes on in the next paragraph to say: "mr. mivart asserts that 'without belief in a personal god there is no religion worthy of the name.' this is a matter of opinion. but it may be asserted, with less reason to fear contradiction, that the worship of a personal god, who, on mr. mivart's hypothesis, must have used words studiously calculated to deceive his creatures and worshippers, is 'no religion worthy of the name.' 'incredibile est, deum illis verbis ad populum fuisse locutum quibis deciperetur,' is a verdict in which for once jesuit casuistry concurs with the healthy moral sense of all mankind." (p. 458). mr. huxley calls believers in the scriptures, and (apparently) believers in a personal god, bigots, old ladies of both sexes, bibliolators, fools, etc., etc. [26] _lay sermons_, etc. p. 331. _büchner._ dr. louis büchner, president of the medical association of hessen-darmstadt, etc., etc., is not only a man of science but a popular writer. perhaps no book of its class, in our day, has been so widely circulated as his volume on "kraft und stoff," matter and force. it has been translated into all the languages of europe. he holds that matter and force are inseparable; there cannot be the one without the other; both are eternal and imperishable; neither can be either increased or diminished; life originated spontaneously by the combination of molecules of matter under favorable conditions; all the phenomena of the universe, inorganic and organic, whether physical, vital, or mental, are due to matter and its forces. consequently there is no god, no creation, no mind distinct from matter, no conscious existence of man after death. all this is asserted in the most explicit terms. dr. büchner has published a work on darwinism in two volumes. darwin's theory, he says, "is the most thoroughly naturalistic that can be imagined, and far more atheistic than that of his decried predecessor lamarck, who admitted at least a general law of progress and development; whereas, according to darwin, the whole development is due to the gradual summation of innumerable minute and accidental operations."[27] footnote: [27] _sechs vorlesungen über die darwinische theorie_. von ludwig büchner. zweite auflage, leipzig, 1848, vol. i. p. 125. _carl vogt._ in his preface to his work on the "descent of man," mr. darwin quotes this author as a high authority. we see him elsewhere referred to as one of the first physiologists of germany. vogt devotes the concluding lecture of the second volume of his work on man, to the consideration of darwinism. he expresses his opinion of it, after high commendation, in the following terms. he says that it cannot be doubted that darwin's "theory turns the creator--and his occasional intervention in the revolutions of the earth and in the production of species--without any hesitation out of doors, inasmuch as it does not leave the smallest room for the agency of such a being. the first living germ being granted, out of it the creation develops itself progressively by natural selection, through all the geological periods of our planets, by the simple law of descent--no new species arises by creation and none perishes by divine annihilation--the natural course of things, the process of evolution of all organisms and of the earth itself, is of itself sufficient for the production of all we see. thus man is not a special creation, produced in a different way, and distinct from other animals, endowed with an individual soul and animated by the breath of god; on the contrary, man is only the highest product of the progressive evolution of animal life springing from the group of apes next below him."[28] after this no one can be surprised to hear him say, that "the pulpits of the orthodox, the confessionals of the priests, the platforms of the interior missions, the presidential chairs of the consistories, resound with protestations against the assaults made by materialism and darwinism against the very foundations of society." (p. 286) this he calls "das wehgeschrei der moralisten" (the wail of the moralists). the designation moralists is a felicitous one, as applied to the opponents of vogt and his associates. it distinguishes them as men who have not lost their moral sense; who refuse to limit their faith to what can be proved by the five senses; who bow to the authority of the law written by the finger of god, on the hearts of men, which neither sophistry nor wickedness can effectually erase. all vogt thinks it necessary to reply to these moralists is, "lasst sie bellen, bis sie ausgebellt haben" (let them bark till they are tired). "ende." footnote: [28] _vorlesungen über den menschen, seine stellung in der schoepfung und in der geschichte der erde_. von carl vogt. giessen, 1863, vol. ii. p. 260. _haeckel._ dr. ernst haeckel, professor in the university of jena, is said to stand at the head of the living naturalists of germany. his work on "natural history of creation" contains a course of lectures delivered to the professors, students, and citizens of jena. it is, therefore, somewhat popular in its character. the ability of the writer is manifest on every page. the distinctness of his perceptions, precision of language, perspicuity of style, and the strength of his convictions, give the impression of a man fully master of his subject, who has thought himself through, and is perfectly satisfied with the conclusions at which he has arrived. at the same time it is the impression of a man who is developed only on one side; who never looks within; who takes no cognizance of the wonders revealed in consciousness; to whom the intuitions of reason and of the conscience, the sense of dependence on a will higher than our own--the sense of obligation and responsibility are of no account,--in short a man to whom the image of god enstamped on the soul of man is invisible. this being the case, he that is least in the kingdom of heaven is greater than he. haeckel admits that the title of his book, "natural creation," _i. e._ creation by natural laws, is a contradiction. he distinguishes, however, between the creation of substance and the creation of form. of the former he says science knows nothing. to the scientist matter is eternal. if any one chooses to assume that it was created by an extramundane power, haeckel says he will not object. but that is a matter of faith; and "where faith begins, science ends." the very reverse of this is true. science must begin with faith. it cannot take a single step without it. how does haeckel know that his senses do not deceive him? how does he know that he can trust to the operations of his intellect? how does he know that things are as they appear? how does he know that the universe is not a great phantasmagoria, as so many men have regarded it, and man the mere sport of chimeras? he must believe in the laws of belief impressed on his nature. knowledge implies a mind that knows, and confidence in the act of knowing implies belief in the laws of mind. "an inductive science of nature," says president porter, "presupposes a science of induction, and a science of induction presupposes a science of man."[29] haeckel, however, says faith is the mere product of the poetic imagination; science, of the understanding; if its conclusions come into conflict with the creations of the imagination, the latter, of course, must give way.[30] he says, there have ever been two conflicting theories of the universe: the one, monistic; the other, dualistic. the one admits of only one substance, matter; the other of two, matter and mind. he prefers to call the former monism rather than materialism, because the latter term often includes the idea of moral materialism, _i. e._ the doctrine that sensual pleasure is the end of life; a doctrine, he says, much more frequently held by princely church-men than by men of science. he maintains, however, that "all knowable nature is one; that the same eternal, immutable (ehernen, brazen) laws are active in the life of animals and plants, in the formation of crystals, and the power of steam; in the whole sphere of biology, zoölogy, and botany. we have, therefore, the right to hold fast the monistic and mechanical view, whether men choose to brand the system as materialism or not. in this sense, all natural science, with the law of causation at its head, is thoroughly materialistic." (p. 32) the monistic theory he calls "mechanical or causal," as distinguished from the dualistic theory, which he calls "teleological or vitalistic." according to the latter, "the vegetable and animal kingdoms are considered as the products of a creative agency, working with a definite design. in looking on an organism, the conviction seems unavoidable that so skilfully constructed a machine, such a complicated working apparatus, as an organism is, could be produced only by an agency analogous to, although far more perfect than the agency of man." "this," he says, "supposes the creator to be an organism analogous to man, although infinitely more perfect; who contemplates his formative powers, lays the plan of the machine, and then, by the use of appropriate means, produces an effect answering to the preconceived plan.... however highly the creator may be exalted, this view involves the ascription to him of human attributes, in virtue of which he can form a plan, and construct organisms to correspond with it. that is the view to which darwin's doctrine is directly opposed, and of which agassiz is, among naturalists, the most important advocate. the famous work of agassiz, 'essay on classification,' which is in direct opposition to darwin's, and appeared about the same time, has carried out logically to the utmost the absurd anthropomorphic doctrine of a creator." (p. 17) the monistic theory is called "mechanical and causal," because it supposes that all the phenomena of the universe, organic and inorganic, vegetable and animal, vital and mental, are due to mechanical or necessarily operating causes (causæ efficientes); just as the dualistic theory is called "teleological or vitalistic," because it refers natural organisms to causes working for the accomplishment of a given end (causæ finales). (p. 67) the grand difficulty in the way of the mechanical or monistic theory was the occurrence of innumerable organisms, apparently at least, indicative of design. to get over this difficulty, haeckel says, some who could not believe in a creative and controlling mind adopted the idea of a metaphysical ghost called vitality. the grand service rendered by darwin to science is, that his theory enables us to account for the appearances of design in nature without assuming final causes, or, a mind working for a foreseen and intended end. "all that had appeared before darwin," he says, "failed to secure success, and to meet with general acceptance of the doctrine of the mechanical production of vegetable and animal organisms. this was accomplished by darwin's theory." (p. 20) the precise difficulty which mr. darwin's doctrine has, according to haeckel, enabled men of science to surmount, is thus clearly stated on p. 633. it is, "that organs for a definite end should be produced by undesigning or mechanical causes." this difficulty is overcome by the doctrine of evolution. "through the theory of descent, we are for the first time able to establish the monistic doctrine of the unity of nature, that a mechanic-causal explanation of the most complicated organisms, _e. g._ the formation and constitution of the organs of sense, have no more difficulty for the common understanding, than the mechanical explanation of any physical process, as, for example, earthquakes, the direction of the winds, or the currents of the sea. we thus arrive at the conviction of the last importance, that all natural bodies with which we are acquainted are equally endowed with life (gleichmässig belebt sind); that the distinction between living and dead matter does not exist. when a stone is thrown into the air and falls by certain laws to the ground, or when a solution of salt forms a crystal, the result is neither more nor less a mechanical manifestation of life, than the flowering of a plant, the generation or sensibility of animals, or the feelings or the mental activity of man. in thus establishing the monistic theory of nature lies the highest and most comprehensive merit of the doctrine of descent, as reformed by darwin." (p. 21) "as to the much vaunted design in nature, it is a reality only for those whose views of animal and vegetable life are to the last degree superficial. any one who has gone deeper into the organization and vital activity of animals and plants, who has made himself familiar with the action and reaction of vital phenomena, and the so-called economy of nature, comes of necessity to the conclusion, that design does not exist, any more than the vaunted goodness of the creator" (die vielgerühmte allgüte des schöpfers). (p. 17) professor huxley, in his review of this work of haeckel, already quoted, says: "i do not like to conclude without reminding the reader of my entire concurrence with the general tenor and spirit of the work, and of my high estimate of its value." if you take out of haeckel's book its doctrine of monism, which he himself says means materialism, it has no "tenor or spirit" in it. it is not, however, for us to say how far professor huxley intended his indorsement to go. haeckel says that darwin's theory of evolution leads inevitably to atheism and materialism. in this we think he is correct. but we have nothing to do with haeckel's logic or with our own. we make no charge against mr. darwin. we cite haeckel merely as a witness to the fact that darwinism involves the denial of final causes; that it excludes all intelligent design in the production of the organs of plants and animals, and even in the production of the soul and body of man. this first of german naturalists would occupy a strange position in the sight of all europe, if, after lauding a book to the skies because it teaches a certain doctrine, it should turn out that the book taught no such doctrine at all. footnotes: [29] _the science of nature versus the science of man_. by noah porter, president of yale college. new york, 1871, p. 29. [30] _natürlische schöpfungsgeschichte_. von dr. ernst haeckel, professor in der universität jena. zweite auflage, berlin, 1873, pp. 8, and 9. _the opponents of darwinism._ _the duke of argyll._ when cultivated men undertake to refute a certain system, it is to be presumed that they give themselves the trouble to ascertain what that system is. as the advocates of mr. darwin's theory defend and applaud it because it excludes design, and as its opponents make that the main ground of their objection to it, there can be no reasonable doubt as to its real character. the question is, how are the contrivances in nature to be accounted for? one answer is, they are due to the purpose of god. mr. darwin says, they are due to the gradual and undesigned accumulation of slight variations. the duke's first objection to that doctrine is, that the evidence of design in the organs of plants and animals is so clear that mr. darwin himself cannot avoid using teleological language. "he exhausts," he says, "every form of words and of illustration by which intention or mental purpose can be described. 'contrivance,' 'beautiful contrivance,' 'curious contrivance,' are expressions which occur over and over again. here is one sentence describing a particular species (of orchids): 'the labellum is developed _in order_ to attract the lepidoptera; and we shall soon see reason for supposing that the nectar is purposely so lodged, that it can be sucked only slowly _in order_ to give time for the curious chemical quality of the matter setting hard and dry.'"[31] we have already seen that mr. darwin's answer to this objection is, that it is hard to keep from personifying nature, and that these expressions as used by him mean no more than chemists mean when they speak of affinities, and one element preferring another. a second objection is, that a variation would not be useful to the individual in which it happens to occur, unless other variations should occur at the right time and in the right order; and that the concurrence of so many accidents as are required to account for the infinite diversity of forms in plants and animals, is altogether inconceivable. a third objection is, that the variations often have no reference to the organism of the animal itself but to other organisms. "take one instance," he says, "out of millions. the poison of a deadly snake,--let us for a moment consider what that is. it is a secretion of definite chemical properties with reference not only--not even mainly--to the organism of the animal in which it is developed, but specially to another animal which it is intended to destroy." "how," he asks, "will the law of growth adjust a poison in one animal with such subtle knowledge of the organization of the other, that the deadly virus shall in a few minutes curdle the blood, benumb the nerves, and rush in upon the citadel of life? there is but one explanation: a mind having minute and perfect knowledge of the structure of both has designed the one to be capable of inflicting death upon the other. this mental purpose and resolve is the one thing which our intelligence perceives with direct and intuitive recognition. the method of creation by which this purpose has been carried into effect is utterly unknown."[32] a fourth objection has reference to beauty. according to mr. darwin, flowers are not intentionally made beautiful, but those which happen to be beautiful attract insects, and by their agency are fertilized and survive. male birds are not intentionally arrayed in bright colors, but those which happen to be so arrayed are attractive, and thus become the progenitors of their race. against this explanation the duke earnestly protests. he refers to the gorgeous adorned class of hummingbirds, of which naturalists enumerate no less than four hundred and thirty different species, distinguished one from the other, in general, only by their plumage. "now," he asks, "what explanation does the law of natural selection give,--i will not say of the origin, but even of the continuance of such specific varieties as these? none whatever. a crest of topaz is no better in the struggle of existence than a crest of sapphire. a frill ending in spangles of the emerald is no better in the battle of life than a frill ending in spangles of the ruby. a tail is not affected for the purposes of flight, whether its marginal, or its central feathers are decorated with white. it is impossible to bring such varieties into any physical law known to us. it has relation however to a purpose, which stands in close analogy with our knowledge of purpose in the works of men. mere beauty and mere variety, for their own sake, are objects which we ourselves seek, when we can make the forces of nature subordinate to the attainment of them. there seems to be no conceivable reason why we should doubt or question that these are ends and aims also in the forms given to living organisms, when the facts correspond with this view and with no other."[33] it will be observed that all these objections have reference to the denial of teleology on the part of mr. darwin. if his theory admitted that the organisms in nature were due to a divine purpose, the objections would be void of all meaning. there is a fifth objection. according to darwin's theory organs are formed by the slow accumulation of unintended variations, which happen to be favorable to the subject of them in the struggle for life. but in many cases these organs, instead of being favorable, are injurious or cumbersome until fully developed. take the wing of a bird, for example. in its rudimental state, it is useful neither for swimming, walking, nor flying. now, as darwin says it took millions of years to bring the eye to perfection, how long did it take to render a rudimental wing useful? it is no sufficient answer to say that these rudimental organs might have been suited to the condition in which the animal existed, during the formative process. this is perfectly arbitrary. it has no basis of fact. there are but three kinds of locomotion that we know of: in the water, on the ground, and through the air; for all these purposes a half-formed wing would be an impediment. the duke devotes almost a whole chapter of his interesting book to the consideration of "contrivance in the machinery for flight." the conditions to secure regulated movement through the atmosphere are so numerous, so complicated, and so conflicting, that the problem never has been solved by human ingenuity. in the structure of the bird it is solved to perfection. as we are not writing a teleological argument, but only producing evidence that darwinism excludes teleology, we cannot follow the details which prove that the wing of the gannet or swift is almost as wonderful and beautiful a specimen of contrivance as the eye of the eagle. footnotes: [31] _reign of law_. london, 1867, p. 40. [32] _reign of law_. london, 1867, p. 37. [33] _reign of law_, pp. 247, 248. _agassiz._ every one knows that the illustrious agassiz, over whose recent grave the world stands weeping, was from the beginning a pronounced and earnest opponent of mr. darwin's theory. he wrote as a naturalist, and therefore his objections are principally directed against the theory of evolution, which he regarded as not only destitute of any scientific basis, but as subversive of the best established facts in zoölogy. nevertheless it is evident that his zeal was greatly intensified by his apprehension that a theory which obliterates all evidence of the being of god from the works of nature, endangered faith in that great doctrine itself. the rev. dr. peabody, in the discourse delivered on the occasion of professor agassiz's funeral, said: "i cannot close this hasty and inadequate, yet fervent and hearty tribute, without recalling to your memory the reverent spirit in which he pursued his scientific labors. nearly forty years ago, in his first great work on fossil fishes, in developing principles of classification, he wrote in quotations, 'an invisible thread in all ages runs through this immense diversity, exhibiting as a general result that there is a continual progress in development ending in man, the four classes of vertebrates presenting the intermediate steps, and the invertebrates the constant accessory accompaniment. have we not here the manifestation of a mind as powerful as prolific? an act of intelligence as sublime as provident? the marks of goodness as infinite as wise? the most palpable demonstration of the existence of a personal god, author of all this; ruler of the universe, and the dispenser of all good? this at least is what i read in the works of creation.' and it was what he ever read, and with profound awe and adoration. to this exalted faith he was inflexibly loyal. the laws of nature were to him the eternal word of god. "his repugnance to darwinism grew in great part from his apprehension of its atheistical tendency,--an apprehension which i confess i cannot share; for i forget not that these theories, now in the ascendent, are maintained by not a few devout christian men, and while they appear to me unproved and incapable of demonstration, i could admit them without parting with one iota of my faith in god and christ. yet i cannot but sympathize most strongly with him in the spirit in which he resisted what seemed to him lese-majesty against the sovereign of the universe. nor was his a theoretical faith. his whole life, in its broad philanthropy, in its pervading spirit of service, in its fidelity to arduous trusts and duties, and in its simplicity and truthfulness, bespoke one who was consciously fulfilling a mission from god to his fellow-men." the words "evolution" and "darwinism" are so often in this country, but not in europe, used interchangeably, that it is conceivable that dr. peabody could retain his faith in god, and yet admit the doctrine of evolution. but it is not conceivable that any man should adopt the main element of mr. darwin's theory, viz., the denial of all final causes, and the assertion, that since the first creation of matter and life, god has left the universe to the control of unintelligent physical causes, so that all the phenomena of the plants and animals, all that is in man, and all that has ever happened on the earth, is due to physical force, and yet retain his faith in christ. on that theory, there have been no supernatural revelation, no miracles; christ is not risen, and we are yet in our sins. it is not thus that this matter is regarded abroad. the christians of germany say that the only alternative these theories leave us, is heathenism or christianity; "heidenthum oder christenthum, die frage der zeit." _janet._ janet, a professor of philosophy, is the author of a book on the materialism of büchner.[34] the greater part of the last chapter of his work is devoted to darwinism. he says, "dr. büchner invoked (darwin's book) as a striking confirmation of his doctrine." (p. 154) what büchner's doctrine is has been shown on a previous page. the points of coincidence between darwin's system and his are, that both regard mind as a mere function of living matter; and both refer all the organs and organisms of living things to the unconscious, unintelligent operation of physical causes. büchner's way of accounting for complicated organs was, "that the energy of the elements and forces of matter, which in their fated and accidental occurrence must have produced innumerable forms, which must needs limit each other mutually, and correspond, apparently, the one with the other, as if they were made for that purpose. out of all those forms, they only have survived which were adapted, in some manner, to the conditions of the medium in which they were placed." (p. 30) this is very clumsy. no wonder büchner preferred darwin's method. the two systems are, indeed, exactly the same, but mr. darwin has a much more winning way of presenting it. professor janet does not seem to have much objection to the doctrine of evolution in itself; it is the denial of teleology that he regards as the fatal element of mr. darwin's theory. "according to us," he says, "the true stumbling-block of mr. darwin's theory, the perilous and slippery point, is the passage from artificial to natural selection; it is when he wants to establish that a blind and designless nature has been able to obtain, by the occurrence of circumstances, the same results which man obtains by thoughtful and well calculated industry." (p. 174) towards the end of his volume he says: "we shall conclude by a general observation. notwithstanding the numerous objections we have raised against mr. darwin's theory, we do not declare ourselves hostile to a system of which zoölogists are the only competent judges. we are neither for nor against the transmutation of species, neither for nor against the principle of natural selection. the only positive conclusion of our debate is this: no principle hitherto known, neither the action of media, nor habit, nor natural selection, can account for organic adaptations without the intervention of the principle of finality. natural selection, unguided, submitted to the laws of a pure mechanism, and exclusively determined by accidents, seems to me, under another name, the chance proclaimed by epicurus, equally barren, equally incomprehensible; on the other hand, natural selection guided beforehand by a provident will, directed towards a precise end by intentional laws, might be the means which nature has selected to pass from one stage of being to another, from one form to another, to bring to perfection life throughout the universe, and to rise by a continuous process from the monad to man. now, i ask mr. darwin himself, what interest has he in maintaining that natural selection is not guided--not directed? what interest has he in substituting accidental causes for every final cause? i cannot see. let him admit that in natural, as well as in artificial selection, there may be a choice and direction; his principle immediately becomes much more fruitful than it was before. his hypothesis, then, whilst having the advantage of exempting science from the necessity of introducing the personal and miraculous intervention of god in the creation of each species, yet would be free from the banishing out of the universe an all-provident thought, and of submitting everything to blind and brute chance." (pp. 198, 199) professor janet asks far too much of mr. darwin. to ask him to give up his denial of final causes is like asking the romanists to give up the pope. that principle is the life and soul of his system. footnote: [34] _the materialism of the present day: a critique of dr. büchner's system_. by paul janet, member of the institute of france, professor of philosophy at the paris faculté des lettres. translated from the french, by gustave masson, b. a. london and paris, 1867. _m. flourens._ m. flourens, recently dead, was one of the earliest and most pronounced opponents of darwinism. he published in 1864 his "examen du livre de m. darwin sur l'origine des espèces." his position as member of the académie française, and perpetual secretary of the académie des sciences, or institut de france, vouch for his high rank among the french naturalists. his connection with the jardin des plantes gave him enlarged opportunities for biological experiments. the result of his own experience, as well as the experience of other observers, was, as he expresses it, his solemn conviction that species are fixed and not transmutable. no ingenuity of device could render hybrids fertile. "they never establish an intermediate species." it is, therefore, to the doctrine of evolution his attention is principally directed. nevertheless, he is no less struck by darwin's way of excluding all intelligence and design in his manner of speaking of nature. on this point he quotes the language of cuvier, who says: "nature has been personified. living beings have been called the works of nature. the general bearing of these creatures to each other has become the laws of nature. it is thus while considering nature as a being endowed with intelligence and will, but in its power limited and secondary, that it may be said that she watches incessantly over the maintenance of her work; that she does nothing in vain, and always acts by the most simple means.... it is easy to see how puerile are those who give nature a species of individual existence distinct from the creator, and from the law which he has impressed upon the movements and peculiarities of the forms given by him to living things, and which he makes to act upon their bodies with a peculiar force and reason." older writers, says flourens, in speaking of nature, "gave to her inclinations, intentions, and views, and horrors (of a vacuum), and sports," etc. he says that one of the principal objects of his book is to show how mr. darwin "has deluded himself, and perhaps others, by a constant abuse of figurative language." "he plays with nature as he pleases, and makes her do whatsoever he wishes." when we remember that mr. darwin defines nature to be the aggregate of physical forces, we see how, in attributing everything to nature, he effectually excludes the supernatural. in his volume of "lay sermons, reviews," etc., professor huxley has a very severe critique on m. flourens's book. he says little, however, in reference to teleology, except in one paragraph, in which we read: "m. flourens cannot imagine an unconscious selection; it is for him a contradiction in terms." huxley's answer is, "the winds and waves of the bay of biscay have not much consciousness, and yet they have with great care 'selected,' from an infinity of masses of silex, all grains of sand below a certain size and have heaped them by themselves over a great area.... a frosty night selects the hardy plants in a plantation from among the tender ones as effectually as if the intelligence of the gardener had been operative in cutting the weaker ones down."[35] if this means anything, it means that as the winds and waves of the bay of biscay can make heaps of sand, so similar unconscious agencies can, if you only give them time enough, make an elephant or a man; for this is what mr. darwin says natural selection has done. footnote: [35] _lay sermons_, p. 347. _rev. walter mitchell, m. a., vice-president of the victoria institute._ the victoria institute, or philosophical society of great britain, under the presidency of the earl of shaftesbury, includes among its members many of the dignitaries of the church of england, and a large number of distinguished men of different professions and denominations. its principal object is, "to investigate fully and impartially the most important questions of philosophy and science, but more especially those that bear on the great truths revealed in holy scripture, with the view of defending these truths against the opposition of science, falsely so called." the institute holds bi-monthly meetings, at which papers are read on some important topic, and then submitted to criticism and discussion. these papers, many of which are very elaborate, are published in the transactions of the institute, together with a full report of the discussions to which they gave rise. six volumes, replete with valuable and varied information, have already been published. very considerable latitude of opinion is allowed. hence we find in the transactions, papers for and against evolution,--for and against darwinism. it would be easy to quote extracts, pertinent to our subject, more than enough to fill a volume much larger than the present. we must content ourselves with a few citations from the discussion on a paper in favor of the credibility of darwinism,[36] and another in favor of the doctrine of evolution.[37] in summing up the debates on these two topics, the chairman, rev. walter mitchell, presented with great clearness and force his reasons for regarding darwinism as incredible and impossible. in his protracted remarks he contrasts the scriptural doctrine, that of the vestiges of creation, and that of darwin on the origin of species. he thus states the doctrine of the bible on the subject: "if," he says, "science be another name for real knowledge; if science be the pursuit of sound wisdom; if science be the pursuit of truth itself; i say that man has no right to reject anything that is true because it savors of god. well, what is this hypothesis--older than that of darwin--which does, and does alone, account for all the observed facts, or all that which we can read, recorded in the book of nature? it is, that god created all things very good; that he made every vegetable after its own kind; that he made every animal after its own kind; that he allowed certain laws of variation, but that he has ordained strict, though invisible and invincible barriers, which prevent that variation from running riot, and which includes it within strict and well defined limits. this is a hypothesis which will account for all that we have learnt from the works of nature. it admits an intelligent being as the author of all the works of creation, animate as well as inanimate; it leaves no mysteries in the animate world unaccounted for. there is one thing which the animate, as well as the inanimate world declares to man, one thing everywhere plainly recorded, if we will only read it, and that is the impress of design, the design of infinite wisdom. any theory which comes in with an attempt to ignore design as manifested in god's creation, is a theory, i say, which attempts to dethrone god. this the theory of darwin does endeavor to do. if asked how our old theory accounts for such uniformity of design in the midst of such perplexing variety as we find in nature, we reply, that this can only be accounted for on one admission, that the whole is the work of one author, built according, as it were, to one style; that it represents the unity of one mind with the infinite power of adapting all its works in the most perfect manner for the uses for which they were created." "whewell has boldly maintained, and he has never been controverted, that all real advances in the sciences of physiology and comparative anatomy,--such as that made by harvey in discovering the circulation of the blood,--have been made by those who not only believed in the existence of design everywhere manifested in the animate world, but were led by that belief to make their discoveries." when discussing the paper of mr. henslow on evolution, he says: "in speaking of this paper i must commend the exceeding reverent tone in which the author has discussed the subject, and i should like to see all such subjects discussed in a similar tone. the view which mr. henslow brings forward, however, does not appear to be a very original one. it was the first view ever brought forward on the doctrine of evolution, and i was the first one to point out that the whole doctrine was one of retrograde character. the whole tone and character of this paper, except that which relates to the attributes and moral government of god,[38] is nothing more or less than the same view of the doctrine of evolution which created such a sensation in this country when that famous book came out, 'the vestiges of creation.' so far as i can understand the arguments of mr. darwin, they have simply been an endeavor to eject out of the idea of evolution the personal work of the deity. his whole endeavor has been to push the creator farther and farther back out of view. the most laborious part of darwin's attempt at reasoning,--for it is not true reasoning,--the most laborious part of his logic and reasoning, is intended to eliminate, as perfectly as any of the atheistical authors have endeavored to do, the idea of design. now, setting revelation aside, the manner in which the unknown author of the 'vestiges of creation' treated this subject, satisfactorily showed that the doctrine of evolution was not in itself an atheistical doctrine, nor did it deny the existence of design. so far as i could understand and make out, having carefully read the book at the time it came out and afterwards, and having carefully analyzed and compared it and mr. darwin's book with each other, so far as i could understand it, the doctrine of the author of the 'vestiges of creation' was simply, that god created all things, and that when he created matter he impressed on it certain laws; that matter, being evolved according to those laws, should produce beings and organs mutually adapted to one another and to the world; and that every successive development which should be produced was essentially foreseen, foreknown, and predetermined by the deity. his idea, for instance, of the evolution of an eye from a more simple organ was that the ultimate eye--man's eye, for instance--was to be a perfect optical instrument, and that its perfection depended on the previous design by the creator, that at a certain period it should appear in a body quite adapted for its purposes. there is one question,--and not the only one, but we must consider it as an important question,--whether you can maintain a doctrine of evolution which shall not be atheistical, and which shall admit the great argument of design? that is one thing; but the next thing is, does such a doctrine as that accord either with revelation or with the facts of science? i do not believe that it can be made to agree with what we believe to be the revealed word of god, and i do not believe that it has in the least degree been proved that the doctrine is consistent with sound science." as to mr. darwin's theory, it is obvious from the passages already quoted that he considers its characteristic feature is not evolution, nor even natural selection, but the denial of teleology, or of intelligent control. mr. darwin admits the original creation of one or a few forms of life; and mr. mitchell, in his comments on mr. warington's defence of his theory, asks, "why am i to limit the work of the creator to the simultaneous or successive creations of ten or twelve commencements of the animate creation? why, simply for the purpose of evading the evidence of design as manifested in the adaptation of all the organs of every animate creature to its wants, which can only be done by so incredible an hypothesis as that of mr. darwin. i say fearlessly, that any hypothesis which requires us to admit that the formation of such complex organs as the eye, the ear, the heart, the brain, with all their marvellous structures and mechanical adaptations to the wants of the creatures possessing them, so perfectly in harmony, too, with the laws of inorganic matter, affords no evidence of design; that such structures could be built up by gradual chance improvements, perpetuated by the law of transmission, and perfected by the destruction of creatures less favorably endowed, is so incredible, that i marvel to find any thinking man capable of adopting it for a single moment." it is useless to multiply quotations. darwinism is never brought up either formally or incidentally, that its exclusion of design in the formation of living organisms is not urged as the main objection against the whole theory. footnotes: [36] _the credibility of darwinism_. by george warington, esq., f. c. s., m. v. i. [37] _on certain analogies between the methods of deity in nature and revelation_. by rev. g. e. henslow, m. a., f. l. s., m. v. i. [38] the second part of mr. henslow's paper concerns "the methods of the deity as revealed to us in the bible." the same is substantially true of his work, _the theory of evolution_. _principal dawson._ dr. dawson, as we are informed, is regarded as the first palæontologist, and among the first geologists, in america. in his "story of earth and man,"[39] he passes in review the several geological periods recognized by geologists; describes as far as knowable the distribution of land and water during each period, and the vegetable and animal productions by which they were distinguished. his book from beginning to end is anti-darwinian. in common with other naturalists, his attention is directed principally to the doctrine of evolution, which he endeavors to prove is utterly untenable. that mr. darwin's theory excludes teleology is everywhere assumed as an uncontroverted and uncontrovertible fact. "the evolutionist doctrine," he says, "is itself one of the strangest phenomena of humanity. it existed, and most naturally, in the oldest philosophy and poetry, in connection with the crudest and most uncritical attempts of the human mind to grasp the system of nature; but that in our day a system destitute of any shadow of proof, and supported merely by vague analogies and figures of speech, and by the arbitrary and artificial coherence of its own parts, should be accepted as philosophy, and should find able adherents to string on its thread of hypotheses our vast and weighty stores of knowledge, is surpassingly strange.... in many respects these speculations are important, and worthy the attention of thinking men. they seek to revolutionize the religious belief of the world, and if accepted would destroy most of the existing theology and philosophy. they indicate tendencies among scientific thinkers, which, though probably temporary, must, before they disappear, descend to lower strata, and reproduce themselves in grosser forms, and with most serious effects on the whole structure of society. with one class of minds they constitute a sort of religion, which so far satisfies the craving for truth higher than those which relate to immediate wants and pleasures. with another and perhaps larger class, they are accepted as affording a welcome deliverance from all scruples of conscience and fears of a hereafter. in the domain of science evolutionism has like tendencies. it reduces the position of man, who becomes a descendant of inferior animals, and a mere term in a series whose end is unknown. it removes from the study of nature the ideas of final cause and purpose; and the evolutionist, instead of regarding the world as a work of consummate plan, skill, and adjustment, approaches nature as he would a chaos of fallen rocks, which may present forms of castles, and grotesque profiles of men and animals, but they are all fortuitous and without significance." (pp. 317, 318) "taking, then, this broad view of the subject, two great leading alternatives are presented to us. either man is an independent product of the will of a higher intelligence, acting directly or through the laws and materials of his own institution and production, or he has been produced by an unconscious evolution from lower things. it is true that many evolutionists, either unwilling to offend, or not perceiving the logical consequences of their own hypothesis, endeavor to steer a middle course, and to maintain that the creator has proceeded by way of evolution. but the bare, hard logic of spencer, the greatest english authority on evolution, leaves no place for this compromise, and shows that the theory, carried out to its legitimate consequences, excludes the knowledge of a creator and the possibility of his work. we have, therefore, to choose between evolution and creation, bearing in mind, however, that there may be a place in nature for evolution, properly limited, as well as for other things, and that the idea of creation by no means excludes law and second causes." (p. 321) "it may be said, that evolution may be held as a scientific doctrine in connection with a modified belief in creation. the work of actual creation may have been limited to a few elementary types, and evolution may have done the rest. evolutionists may still be theists. we have already seen that the doctrine, as carried out to its logical consequences, excludes creation and theism. it may, however, be shown that even in its more modified form, and when held by men who maintain that they are not atheists, it is practically atheistic, because excluding the idea of plan and design, and resolving all things into the action of unintelligent forces. it is necessary to observe this, because it is the half-way-evolutionism, which professes to have a creator somewhere behind it, that is most popular; though it is, if possible, more unphilosophical than that which professes to set out with absolute and determined nonentity, or from self-existing stardust containing all the possibilities of the universe." in reference to the objection of evolutionists, that the origin of every new species, on the theistic doctrine, supposes "a miracle," an intervention of the divine efficiency without the agency of second causes, principal dawson asks, "what is the actual statement of the theory of creation as it may be held by a modern man of science? simply this: that all things have been produced by the supreme creative will, acting either directly, or through the agency of the forces and material of his own production." (p. 340) he thus sums up his argument against the doctrine of evolution, specially in its application to man: "finally, the evolutionist picture wants some of the fairest lineaments of humanity, and cheats us with the semblance of man without the reality. shave and paint your ape as you may, clothe him and set him up upon his feet, still he fails greatly of the 'human form divine;' and so it is with him morally and spiritually as well. we have seen that he wants the instinct of immortality, the love of god, the mental and spiritual power of exercising dominion over the earth. the very agency by which he is evolved is of itself subversive of all these higher properties; the struggle for existence is essentially selfish, and, therefore, degrading. even in the lower animals, it is a false assumption that its tendency is to elevate; for animals, when driven to the utmost verge of the struggle for life, become depauperated and degraded. the dog which spends its life in snarling contention with its fellow curs for insufficient food, will not be a noble specimen of its race. god does not so treat his creatures. there is far more truth to nature in the doctrine which represents him as listening to the young ravens when they cry for food. but as applied to man, the theory of the struggle for existence, and survival of the fittest, though the most popular phase of evolutionism at present, is nothing less than the basest and most horrible of superstitions. it makes man not merely carnal but devilish. it takes his lowest appetites and propensities, and makes them his god and creator. his higher sentiments and aspirations, his self-denying philanthropy, his enthusiasm for the good and true, all the struggles and sufferings of heroes and martyrs, not to speak of that self-sacrifice which is the foundation of christianity, are, in the view of the evolutionist, mere loss and waste, failure in the struggle of life. what does he give us in exchange? an endless pedigree of bestial ancestors, without one gleam of high and holy tradition to enliven the procession; and for the future, the prospect that the poor mass of protoplasm, which constitutes the sum of our being, and which is the sole gain of an indefinite struggle in the past, must soon be resolved again into inferior animals or dead matter. that men of thought and culture should advocate such a philosophy, argues either a strange mental hallucination, or that the higher spiritual nature has been wholly quenched within them. it is one of the saddest of many sad spectacles which our age presents." (p. 395) footnote: [39] _the story of earth and man_. by j. w. dawson, ll. d., f. r. s., f. g. s., principal and vice-chancellor of mcgill university, montreal. author of _archaia, acadian geology_, etc. second edition. london, 1873, pp. 397. _relation of darwinism to religion._ the consideration of that subject would lead into the wide field of the relation between science and religion. into that field we lack competency and time to enter; a few remarks, however, on the subject may not be out of place. those remarks, we would fain make in a humble way irenical. there is need of an irenicum, for the fact is painfully notorious that there is an antagonism between scientific men as a class, and religious men as a class. of course this opposition is neither felt nor expressed by all on either side. nevertheless, whatever may be the cause of this antagonism, or whoever are to be blamed for it, there can be no doubt that it exists and that it is an evil. the first cause of the alienation in question is, that the two parties, so to speak, adopt different rules of evidence, and thus can hardly avoid arriving at different conclusions. to understand this we must determine what is meant by science, and by scientific evidence. science, according to its etymology, is simply knowledge. but usage has limited its meaning, in the first place, not to the knowledge of facts or phenomena, merely, but to their causes and relations. it was said of old, "[greek: hoti] scientiæ fundamentum, [greek: dioti] fastigium." no amount of materials would constitute a building. they must be duly arranged so as to make a symmetrical whole. no amount of disconnected data can constitute a science. those data must be systematized in their relation to each other and to other things. in the second place, the word is becoming more and more restricted to the knowledge of a particular class of facts, and of their relations, namely, the facts of nature or of the external world. this usage is not universal, nor is it fixed. in germany, especially, the word _wissenschaft_ is used of all kinds of ordered knowledge, whether transcendental or empirical. so we are accustomed to speak of mental, moral, social, as well as of natural science. nevertheless, the more restricted use of the word is very common and very influential. it is important that this fact should be recognized. in common usage, a scientific man is distinguished specially from a metaphysician. the one investigates the phenomena of matter, the other studies the phenomena of mind, according to the old distinction between physics and metaphysics. science, therefore, is the ordered knowledge of the phenomena which we recognize through the senses. a scientific fact is a fact perceived by the senses. scientific evidence is evidence addressed to the senses. at one of the meetings of the victoria institute, a visitor avowed his disbelief in the existence of god. when asked, what kind of evidence would satisfy him? he answered, just such evidence as i have of the existence of this tumbler which i now hold in my hand. the rev. mr. henslow says, "by science is meant the investigation of facts and phenomena recognizable by the senses, and of the causes which have brought them into existence."[40] this is the main root of the trouble. if science be the knowledge of the facts perceived by the senses, and scientific evidence, evidence addressed to the senses, then the senses are the only sources of knowledge. any conviction resting on any other ground than the testimony of the senses, must be faith. darwin admits that the contrivances in nature may be accounted for by assuming that they are due to design on the part of god. but, he says, that would not be science. haeckel says that to science matter is eternal. if any man chooses to say, it was created, well and good; but that is a matter of faith, and faith is imagination. ulrici quotes a distinguished german physiologist who believes in vital, as distinguished from physical forces; but he holds to spontaneous generation, not, as he admits, because it has been proved, but because the admission of any higher power than nature is unscientific.[41] it is inevitable that minds addicted to scientific investigation should receive a strong bias to undervalue any other kind of evidence except that of the senses, _i. e._, scientific evidence. we have seen that those who give themselves up to this tendency come to deny god, to deny mind, to deny even self. it is true that the great majority of men, scientific as well as others, are so much under the control of the laws of their nature, that they cannot go to this extreme. the tendency, however, of a mind addicted to the consideration of one kind of evidence, to become more or less insensible to other kinds of proof, is undeniable. thus even agassiz, as a zoölogist and simply on zoölogical grounds, assumed that there were several zones between the ganges and the atlantic ocean, each having its own flora and fauna, and inhabited by races of men, the same in kind, but of different origins. when told by the comparative philologists that this was impossible, because the languages spoken through that wide region, demonstrated that its inhabitants must have had a common descent, he could only answer that as ducks quack everywhere, he could not see why men should not everywhere speak the same language. a still more striking illustration is furnished by dr. lionel beale, the distinguished english physiologist. he has written a book of three hundred and eighty-eight pages for the express purpose of proving that the phenomena of life, instinct, and intellect cannot be referred to any known natural forces. he avows his belief that in nature "mind governs matter," and "in the existence of a never-changing, all-seeing, power-directing and matter-guiding omnipotence." he avows his faith in miracles, and "those miracles on which christianity is founded." nevertheless, his faith in all these points is provisional. he says that a truly scientific man, "if the maintenance, continuity, and nature of life on our planet should at some future time be fully explained without supposing the existence of any such supernatural omnipotent influence, would be bound to receive the new explanation, and might abandon the old conviction."[42] that is, all evidence of the truths of religion not founded on nature and perceived by the senses, amounts to nothing. now as religion does not rest on the testimony of the senses, that is on scientific evidence, the tendency of scientific men is to ignore its claims. we speak only of tendency. we rejoice to know or believe that in hundreds or thousands of scientific men, this tendency is counteracted by their consciousness of manhood--the conviction that the body is not the man,--by the intuitions of the reason and the conscience, and by the grace of god. no class of men stands deservedly higher in public estimation than men of science, who, while remaining faithful to their higher nature, have enlarged our knowledge of the wonderful works of god. a second cause of the alienation between science and religion, is the failure to make the due distinction between facts and the explanation of those facts, or the theories deduced from them. no sound minded man disputes any scientific fact. religious men believe with agassiz that facts are sacred. they are revelations from god. christians sacrifice to them, when duly authenticated, their most cherished convictions. that the earth moves, no religious man doubts. when galileo made that great discovery, the church was right in not yielding at once to the evidence of an experiment which it did not understand. but when the fact was clearly established, no man sets up his interpretation of the bible in opposition to it. religious men admit all the facts connected with our solar system; all the facts of geology, and of comparative anatomy, and of biology. ought not this to satisfy scientific men? must we also admit their explanations and inferences? if we admit that the human embryo passes through various phases, must we admit that man was once a fish, then a bird, then a dog, then an ape, and finally what he now is? if we admit the similarity of structure in all vertebrates, must we admit the evolution of one from another, and all from a primordial germ? it is to be remembered that the facts are from god, the explanation from men; and the two are often as far apart as heaven and its antipode. these human explanations are not only without authority, but they are very mutable. they change not only from generation to generation, but almost as often as the phases of the moon. it is a fact that the planets move. once it was said that they were moved by spirits, then by vortexes, now by self-evolved forces. it is hard that we should be called upon to change our faith with every new moon. the same man sometimes propounds theories almost as rapidly as the changes of the kaleidoscope. the amiable sir charles lyell, england's most distinguished geologist, has published ten editions of his "principles of geology," which so differ as to make it hard to believe that it is the work of the same mind. "in all the editions up to the tenth, he looked upon geological facts and geological phenomena as proving the fixity of species and their special creation in time. in the tenth edition, just published, he announces his change of opinion on this subject and his conversion to the doctrine of development by law."[43] "in the eighth edition of his work," says dr. bree, "sir charles lyell, the nestor of geologists, to whom the present generation is more indebted than to any other for all that is known of geology in its advanced stage, teaches that species have a real existence in nature, and that each was endowed at the time of its creation with the attributes and organization by which it is now distinguished." the change on the part of this eminent geologist, it is to be observed, is a mere change of opinion. there was no change of the facts of geology between the publication of the eighth and of the tenth edition of his work, neither was there any change in his knowledge of those facts. all the facts relied upon by evolutionists, have long been familiar to scientific men. the whole change is a subjective one. one year the veteran geologist thinks the facts teach one thing, another year he thinks they teach another. it is now the fact, and it is feared it will continue to be a fact, that scientific men give the name of science to their explanations as well as to the facts. nay, they are often, and naturally, more zealous for their explanations than they are for the facts. the facts are god's, the explanations are their own. the third cause of the alienation between religion and science, is the bearing of scientific men towards the men of culture who do not belong to their own class. when we, in such connections, speak of scientific men, we do not mean men of science as such, but those only who avow or manifest their hostility to religion. there is an assumption of superiority, and often a manifestation of contempt. those who call their logic or their conjectures into question, are stigmatized as narrow-minded, bigots, old women, bible worshippers, etc. professor huxley's advice to metaphysicians and theologians is, to let science alone. this is his irenicum. but do he and his associates let metaphysics and religion alone? they tell the metaphysician that his vocation is gone; there is no such thing as mind, and of course no mental laws to be established. metaphysics are merged into physics. professor huxley tells the religious world that there is over-whelming and crushing evidence (scientific evidence, of course) that no event has ever occurred on this earth which was not the effect of natural causes. hence there have been no miracles, and christ is not risen.[44] he says that the doctrine that belief in a personal god is necessary to any religion worthy of the name, is a mere matter of opinion. tyndall, carpenter, and henry thompson, teach that prayer is a superstitious absurdity; herbert spencer, whom they call their "great philosopher," _i. e._, the man who does their thinking, labors to prove that there cannot be a personal god, or human soul or self; that moral laws are mere "generalizations of utility," or, as carl vogt says, that self respect, and not the will of god, is the ground and rule of moral obligation. if any protest be made against such doctrines, we are told that scientific truth cannot be put down by denunciation (or as vogt says, by barking). so doubtless the pharisees, when our blessed lord called them hypocrites and a generation of vipers, and said: "ye compass sea and land to make one proselyte; and when he is made, ye make him twofold more the child of hell than yourselves," doubtless thought that that was a poor way to refute their theory, that holiness and salvation were to be secured by church-membership and church-rites. nevertheless, as those words were the words of christ, they were a thunderbolt which reverberates through all time and space, and still makes pharisees of every name and nation tremble. huxley's irenicum will not do. men who are assiduously poisoning the fountains of religion, morality, and social order, cannot be let alone. haeckel's irenicum amounts to much the same as that of professor huxley. he forbids the right to speak on these vital subjects, to all who are not thoroughly versed in biology, and who are not entirely emancipated from the trammels of their long cherished traditional beliefs.[45] this, as the whole context shows, means that a man in order to be entitled to be heard on the evolution theory, must be willing to renounce his faith not only in the bible, but in god, in the soul, in a future life, and become a monistic materialist.[46] it is very reasonable that scientific men, in common with lawyers and physicians and other professional men, should feel themselves entitled to be heard with special deference on subjects belonging to their respective departments. this deference no one is disposed to deny to men of science. but it is to be remembered that no department of human knowledge is isolated. one runs into and overlaps another. we have abundant evidence that the devotees of natural science are not willing to confine themselves to the department of nature, in the common sense of that word. they not only speculate, but dogmatize, on the highest questions of philosophy, morality, and religion. and further, admitting the special claims to deference on the part of scientific men, other men have their rights. they have the right to judge of the consistency of the assertions of men of science and of the logic of their reasoning. they have the right to set off the testimony of one or more experts against the testimony of others; and especially, they have the right to reject all speculations, hypotheses, and theories, which come in conflict with well established truths. it is ground of profound gratitude to god that he has given to the human mind intuitions which are infallible, laws of belief which men cannot disregard any more than the laws of nature, and also convictions produced by the spirit of god which no sophistry of man can weaken. these are barriers which no man can pass without plunging into the abyss of outer darkness. if there be any truth in the preceding remarks, then it is obvious that there can be no harmony between science and religion until the evils referred to be removed. scientific men must come to recognize practically, and not merely in words, that there are other kinds of evidence of truth than the testimony of the senses. they must come to give due weight to the testimony of consciousness, and to the intuitions of the reason and conscience. they must cease to require the deference due to established facts to be paid to their speculations and explanations. and they must treat their fellow-men with due respect. the pharisees said to the man whose sight had been restored by christ, "thou wast altogether born in sin, and dost thou teach us!" men of science must not speak thus. they must not say to every objector, thou art not scientific, and therefore hast no right to speak. the true irenicum is for all parties to give due heed to such words as these, "if any man would be wise, let him become a fool, that he may be wise;" or these, "be converted, and become as little children;" or these, "the spirit of truth shall guide you in all truth." we are willing to hear this called cant. nevertheless, these latter words fell from the lips of him who spake as never man spake. so much, and it is very little, on the general question of the relation of science to religion. but what is to be thought of the special relation of mr. darwin's theory to the truths of natural and revealed religion? we have already seen that darwinism includes the three elements, evolution, natural selection, and the denial of design in nature. these points, however, cannot now be considered separately. it is conceded that a man may be an evolutionist and yet not be an atheist and may admit of design in nature. but we cannot see how the theory of evolution can be reconciled with the declarations of the scriptures. others may see it, and be able to reconcile their allegiance to science with their allegiance to the bible. professor huxley, as we have seen, pronounces the thing impossible. as all error is antagonistic to truth, if the evolution theory be false, it must be opposed to the truths of religion so far as the two come into contact. mr. henslow, indeed, says science and religion are not antagonistic because they are in different spheres of thought. this is often said by men who do not admit that there is any thought at all in religion; that it is merely a matter of feeling. the fact, however, is that religion is a system of knowledge, as well as a state of feeling. the truths on which all religion is founded are drawn within the domain of science, the nature of the first cause, its relation to the world, the nature of second causes, the origin of life, anthropology, including the origin, nature, and destiny of man. religion has to fight for its life against a large class of scientific men. all attempts to prevent her exercising her right to be heard are unreasonable and vain. it should be premised that this paper was written for the single purpose of answering the question, what is darwinism? the discussion of the merits of the theory was not within the scope of the writer. what follows, therefore, is to be considered only in the light of a practical conclusion. 1. the first objection to the theory is its _primâ facie_ incredibility. that a single plant or animal should be developed from a mere cell, is such a wonder, that nothing but daily observation of the fact could induce any man to believe it. let any one ask himself, suppose this fact was not thus familiar, what amount of speculation, of arguments from analogies, possibilities, and probabilities, could avail to produce conviction of its truth. but who can believe that all the plants and animals which have ever existed upon the face of the earth, have been evolved from one such germ? this is darwin's doctrine. we are aware that this apparent impossibility is evaded by the believers in spontaneous generation, who hold that such germ cells may be produced anywhere and at all times. but this is not darwinism. darwin wants us to believe that all living things, from the lowly violet to the giant redwoods of california, from the microscopic animalcule to the mastodon, the dinotherium,--monsters the very description of which fill us with horror,--bats with wings twenty feet in breadth, flying dragons, tortoises ten feet high and eighteen feet long, etc., etc., came one and all from the same primordial germ. this demand is the more unreasonable when we remember that these living creatures are not only so different, but are, as to plants and animals, directly opposed in their functions. the function of the plant, as biologists express it, is to produce force, that of the animal to expend it. the plant, in virtue of a power peculiar to itself, which no art or skill of man can imitate, transmutes dead inorganic matter into organic matter, suited to the sustenance of animal life, and without which animals cannot live. the gulf, therefore, between the plant and animal would seem to be impassable. further, the variations by which the change of species is effected are so trifling as often to be imperceptible, and their accumulation of them so slow as to evade notice,--the time requisite to accomplish any marked change must be counted by millions, or milliards of years. here is another demand on our credulity. the apex is reached when we are told that all these transmutations are effected by chance, that is, without purpose or intention. taking all these things into consideration, we think it may, with moderation, be said, that a more absolutely incredible theory was never propounded for acceptance among men. 2. there is no pretence that the theory can be proved. mr. darwin does not pretend to prove it. he admits that all the facts in the case can be accounted for on the assumption of divine purpose and control. all that he claims for his theory is that it is possible. his mode of arguing is that if we suppose this and that, then it may have happened thus and so. amiable and attractive as the man presents himself in his writings, it rouses indignation, in one class at least of his readers, to see him by such a mode of arguing reaching conclusions which are subversive of the fundamental truths of religion. 3. another fact cannot fail to attract attention. when the theory of evolution was propounded in 1844 in the "vestiges of creation," it was universally rejected; when proposed by mr. darwin, less than twenty years afterward, it was received with acclamation. why is this? the facts are now what they were then. they were as well known then as they are now. the theory, so far as evolution is concerned, was then just what it is now. how then is it, that what was scientifically false in 1844 is scientifically true in 1864? when a drama is introduced in a theatre and universally condemned, and a little while afterward, with a little change in the scenery, it is received with rapturous applause, the natural conclusion is, that the change is in the audience and not in the drama. there is only one cause for the fact referred to, that we can think of. the "vestiges of creation" did not expressly or effectually exclude design. darwin does. this is a reason assigned by the most zealous advocates of his theory for their adoption of it. this is the reason given by büchner, by haeckel, and by vogt. it is assigned also in express terms by strauss, the announcement of whose death has diffused a feeling of sadness over all who were acquainted with his antecedents. in his last work, "the old faith and the new," he admits "that darwin's doctrine is a mere hypothesis; that it leaves the main points unexplained (die hupt und cardinal-punkte noch unerklärt sind); nevertheless, as he has shown how miracles may be excluded, he is to be applauded as one of the greatest benefactors of the human race." (p. 177) by "wunder," or miracle, strauss means any event for which natural causes are insufficient to account. "we philosophers and critical theologians," he says, "have spoken well when we decreed the abolition of miracles; but our decree (macht-spruch) remained without effect, because we could not show them to be unnecessary, inasmuch as we were unable to indicate any natural force to take their place. darwin has provided or indicated this natural force, this process of nature; he has opened the door through which a happier posterity may eject miracles forever." then follows the sentence just quoted, "he who knows what hangs on miracle, will applaud darwin as one of the greatest benefactors of the human race." with strauss and others of his class, miracles and design are identical, because one as well as the other assumes supernatural agency. he quotes helmholtz, who says, "darwin's theory, that adaptation in the formation of organisms may arise without the intervention of intelligence, by the blind operation of natural law;" and then adds, "as helmholtz distinguishes the english naturalist as the man who has banished design from nature, so we have praised him as the man who has done away with miracles. both mean the same thing.[47] design is the miracle-worker in nature, which has put the world upside down; or as spinoza says, has placed the last first, the effect for the cause, and thus destroyed the very idea of nature. design in nature, especially in the department of living organisms, has ever been appealed to by those who desire to prove that the world is not self-evolved, but the work of an intelligent creator." (p. 211) on page 175, he refers to those who ridicule darwin, and yet are so far under the influence of the spirit of the age as to deny miracles or the intervention of the creator in the course of nature, and says: "very well; how do they account for the origin of man, and in general the development of the organic out of the inorganic? would they assume that the original man as such, no matter how rough and unformed, but still a man, sprang immediately out of the inorganic, out of the sea or the slime of the nile? they would hardly venture to say that; then they must know that there is only the choice between miracle, the divine hand of the creator, and darwin." what an alternative; the creator or darwin! in this, however, strauss is right. to banish design from nature, as is done by darwin's theory, is, in the language of the rev. walter mitchell, virtually "to dethrone the creator." ludwig weis, m. d., of darmstadt, says it is at present "the mode" in germany (and of course in a measure here), to glorify buddhism. strauss, he adds, says, "nature knows itself in man, and in that he expresses the thought which all idealism and all materialism make the grand end. to the same effect it is said, 'in man the all comprehends itself as conscious being (comes to self-consciousness); or, in man the absolute knowledge (wissen, the act of knowing) appears in the limits of personality.' this was the doctrine of the buddhist and of the ancient chinese." thus, as dr. weis says, "in the nineteenth century of the christian era, philosophers and scientists have reached the point where the chinese were two thousand years ago." the only way that is apparent for accounting for evolution being rejected in 1844, and for its becoming a popular doctrine in 1866, is, that it happens to suit a prevailing state of mind. it is a fact, so far as our limited knowledge extends, that no one is willing to acknowledge himself, not simply an evolutionist, but an evolutionist of the darwinian school, who is not either a materialist by profession, or a disciple of herbert spencer, or an advocate of the philosophy of hume. there is another significant fact which goes to prove that the denial of design, which is the "creative idea" of darwinism, is the main cause of its popularity and success. professor owen, england's greatest naturalist, is a derivationist. derivation and evolution are convertible terms. both include the denial that species are primordial, or have each a different origin; and both imply that one species is formed out of another and simpler form. professor owen, however, although a derivationist, or evolutionist, is a very strenuous anti-darwinian. he differs from darwin as to two points. first, as to natural selection, or the survival of the fittest. he says that is inconsistent with facts and utterly insufficient to account for the origin of species. he refers the origin of species to an inherent tendency to change impressed on them from the beginning. and second, he admits design. he denies that the succession and origin of species are due to chance, and expresses his belief in the constant operation of creative power in the formation of species from the varied descendants of more generalized forms.[48] he believes "that all living things have been produced by such law (of variation) in time, their position and uses in the world having been preordained by the creator."[49] professor owen says he has taught the doctrine of derivation (evolution) for thirty years, but it attracted little attention. as soon, however, as darwin leaves out design, we have a prairie-fire. a prairie-fire, happily, does not continue very long; and while it lasts, it burns up little else than stubble. 4. all the evidence we have in favor of the fixedness of species is, of course, evidence not only against darwinism, but against evolution in all its forms. it would seem idle to discuss the question of the mutability of species, until satisfied what species is. this, unhappily, is a question which it is exceedingly difficult to answer. not only do the definitions given by scientific men differ almost indefinitely, but there is endless diversity in classification. think of four hundred and eighty species of humming-birds. haeckel says that one naturalist makes ten, another forty, another two hundred, and another one, species of a certain fossil; and we have just heard that agassiz had collected eight hundred species of the same fossil animal. haeckel also says (p. 246), that there are no two zoölogists or any two botanists who agree altogether in their classification. mr. darwin says, "no clear line of demarcation has yet been drawn between species and sub-species, and varieties." (p. 61) it is absolutely necessary, therefore, that a distinction should be made between artificial and natural species. no man asserts the immutability of all those varieties of plants and animals, which naturalists, for the convenience of classification, may call distinct species. haeckel, for example, gives a list of twelve species of man. so any one may make fifty species of dogs, or of horses. this is a mere artificial distinction, which amounts to nothing. there is far greater difference between a pouter and a carrier pigeon, than between a caucasian and a mongolian. to call the former varieties of the same species, and the latter distinct species, is altogether arbitrary. nevertheless, notwithstanding the arbitrary classifications of naturalists, it remains true that there are what professor dana calls "units" of the organic world. "when individuals multiply from generation to generation, it is but a repetition of the primordial type-idea, and the true notion of the species is not in the resulting group, but in the idea or potential element which is the basis of every individual of the group."[50] dr. morton's definition of species as "primordial organic forms," agrees with that given by professor dana; and both agree with the bible, which says that god created plants and animals each after its kind. a primordial form is a form which was not evolved out of some other form, but which began to be in the form--subject to such varieties as we see in the dog, horse, and man--in which it continued during the whole period of its existence. the criteria of these primordial forms or species of nature, are, (1.) morphological. animals, however, may approach very nearly in their structure, and yet belong to different species. it is only when the peculiarities of structure are indicative of specialty of design, that they form a safe ground of classification. if the teeth of one animal are formed to fit it to feed on flesh, and those of another to fit it to feed on plants; if one has webbed feet and another not; then, in all such cases, difference of structure proves difference of kind. (2.) physiological; that is, the internal nature, indicated by habits and instincts, furnishes another safe criterion. (3.) permanent fecundity. the progenitors of the same species reproduce their kind from generation to generation; the progeny of different species, although nearly allied, do not. it is a fixed law of nature that species never can be annihilated, except by all the individuals included in them dying out; and that new species cannot be produced. every true species is primordial. it is this fact, that is, that no variety, with the essential characteristics of species, has ever been produced, that forces, as we saw above, professor huxley to pronounce mr. darwin's doctrine to be an unproved hypothesis. species continue; varieties, if let alone, always revert to the normal type. it requires the skill and constant attention of man to keep them distinct. now that there are such forms in nature, is proved not only from the testimony of the great body of the most distinguished naturalists, but by all the facts in the case. first, the fact that such species are known to have existed unchanged, through what geologists consider almost immeasurable periods of time. palæontologists tell us that trilobites abounded from the primordial age down to the carboniferous period, that is, as they suppose, through millions of years. more wonderful still, the little animals whose remains constitute the chalk formations which are spread over large areas of country, and are sometimes a hundred feet thick, are now at work at the bottom of the atlantic. principal dawson tells us, with regard to mollusks existing in a sub-fossil state in the post-pliocene clays of canada, that "after carefully studying about two hundred species, and of some of these, many hundreds of specimens, i have arrived at the conclusion that they are absolutely unchanged.... here again we have an absolute refusal, on the part of all these animals, to admit that they are derived, or have tended to sport into new species."[51] on the previous page he says, "pictet catalogues ninety-eight species of mammals which inhabited europe in the post-glacial period. of these fifty-seven still exist unchanged, and the remainder have disappeared. not one can be shown to have been modified into a new form, though some of them have been obliged, by changes of temperature and other conditions, to remove into distant and now widely separated regions." a second fact which attests the primordial character and fixedness of species is, that every species as it first appears, is not in a transition state between one form and another, but in the perfection of its kind. science has indeed discovered an ascending order in creation, which agrees marvellously with that given in the book of genesis: first, vegetable productions; then the moving creatures in the sea; then terrestrial animals; and finally man. naturalists, who utterly reject the scriptures as a divine revelation, speak with the highest admiration of the mosaic account of the creation, as compared with any other cosmogony of the ancient world. while there is in general an ascending series in these living forms, each was perfect in its kind. agassiz says that fishes existed contemporaneously with species of all the invertebrate sub-kingdoms in the taconic, or sub-cambrian strata. this is the extreme limit of known geological strata in which life is found to have existed. as the evolution of one species out of another requires, according to darwin, millions of years, it is out of the question to trace these animals beyond the strata in which their remains are now found. yet "crabs or lobsters, worms, cuttle-fish, snails, jelly-fish, star-fish, oysters, the polyps lived contemporaneously with the first known vertebrate animals that ever came into being--all as clearly defined by unmistakable ordinal or special characters as they are at the present moment."[52] the foot of the horse is considered by zoölogists as "one of the most beautiful contrivances in nature." the remains of this animal found in what is called the pliocene period, show the foot to have been as perfect then as it is now. mr. wallace says that man has existed on the earth a hundred thousand years, and that it is probable that he existed four hundred thousand years ago. of course we do not believe this. we have little faith in the chronology of science. it gives no sure data for the calculation of time, hence we find them differing from four thousand to four hundred thousand years as to the time required for certain formations. the most trustworthy geologists teach that all that is known of the antiquity of man falls within the limits of biblical chronology. the further, however, darwinians push back the origin of man, the stronger, as against them, becomes the argument for the immutability of species. the earliest remains of man show that at his first appearance, he was in perfection. the oldest known human skull is that called the "engis," because found in the cave of engis in belgium. of this skull professor huxley says it may have belonged to an individual of one of the existing races of men. principal dawson, who has a cast of it, on the same shelf with the skulls of some algonquin indians, says it might be taken for the skull of an american indian. indeed, dawson seems to think that these fossil human remains go to show that the earliest men were better developed than any of the extant races. thirdly. the historical evidence accessible all goes to prove the immutability of species. the earliest historical records and the oldest monuments prove that all extant animals were what they now are thousands of years ago. fourthly. the fact that hybrids cannot be perpetuated, that no device of man can produce a new species, is proof that god has fixed limits which cannot be passed. this huxley himself admits to be an insuperable objection. so long as it exists, he says, darwin's doctrine must be content to remain a hypothesis; it cannot pretend to the dignity of a theory. another fact of like import is that varieties artificially produced, if let alone, uniformly revert to the simple typical form. it is only by the utmost care they can be kept distinct. all the highly prized varieties of horses, cattle, sheep, pigeons, etc., without human control, would be merged each class into one, with only the slight differences occasioned by diversities of climate and other external conditions. if in the sight of man it is important that the words of a book should be kept distinct, it is equally evident that in the sight of god it is no less important that the "units of nature" should not be mixed in inextricable and indistinguishable confusion. fifthly. the sudden appearance of new kinds of animals is another fact which palæontologists urge against the doctrine of evolution. according to the view of geologists great changes have, at remote periods, occurred in the state of the earth. continents have been submerged and the bottom of the sea raised above the surface of the waters. corresponding changes have occurred in the state of the atmosphere surrounding the globe, and in the temperature of the earth. accompanying or following these revolutions new classes of plants and animals appear, adapted to the new condition of the earth's surface. whence do they come? they have, as dawson expresses it, neither fathers nor mothers. nothing precedes them from which they could be derived; and nothing of the same kind follows them. they live through their appointed period; and then, in a multitude of cases, finally disappear, and are in their turn followed by new orders or kinds. in other words, the links or connecting forms of this assumed regular succession or derivation are not to be found. this fact is so patent, that hugh miller, when arguing against the doctrine of evolution as proposed in the "vestiges of creation," says, that the record in the rocks seems to have been written for the very purpose of proving that such evolution is impossible. we have the explicit testimony of agassiz, as a palæontologist, that the facts of geology contradict the theory of the transmutation of species. this testimony has been repeatedly given and in various forms. in the last production of his pen, he says: "as a palæontologist i have from the beginning stood aloof from this new theory of transmutation, now so widely admitted by the scientific world. its doctrines, in fact, contradict what the animal forms buried in the rocky strata of our earth tell us of their own introduction and succession upon the surface of the globe." "let us look now at the earliest vertebrates, as known and recorded in geological surveys. they should, of course, if there is any truth in the transmutation theory, correspond with the lowest in rank or standing. what then are the earliest known vertebrates? they are selachians (sharks and their allies) and ganoids (garpikes and the like), the highest of all living fishes, structurally speaking." he closes the article from which these quotations are taken with the assertion, "that there is no evidence of a direct descent of later from earlier species in the geological succession of animals."[53] it will be observed that agassiz is quoted, not as to matters of theory, but as to matters of fact. the only answer which evolutionists can make to this argument, is the imperfection of the geological record. when asked, where are the immediate predecessors of these new species? they answer, they have disappeared, or, have not yet been found. when asked, where are their immediate successors? the answer again is, they have disappeared.[54] this is an objection which mr. darwin, with his usual candor, virtually admits to be unanswerable. we have already seen, that he says, "every one will admit that the geological record is imperfect; but very few can believe that it is so very imperfect as my theory demands." such are some of the grounds on which geologists and palæontologists of the highest rank assert that the theory of evolution has not the slightest scientific basis; and they support their assertion with an amount of evidence of which the above items are a miserable pittance. sixthly. there is another consideration of decisive importance. strauss says, there are three things which have been stumbling-blocks in the way of science. first, the origin of life; second, the origin of consciousness; third, the origin of reason. these are equivalent to the gaps which, principal dawson says, exist in the theory of evolution. he states them thus: 1. that between dead and living matter. 2. that between vegetable and animal life. "these are necessarily the converse of each other: the one deoxidizes and accumulates, the other oxidizes and expends." 3. that "between any species of plant or animal, and any other species. it was this gap, and this only, which darwin undertook to fill up by his great work on the origin of species, but, notwithstanding the immense amount of material thus expended, it yawns as wide as ever, since it must be admitted that no case has been ascertained in which an individual of one species has transgressed the limits between it and another species." 4. "another gap is between the nature of the animal and the self-conscious, reasoning, and moral nature of man." (pp. 325-328) first, as to the gap between death and life; this is what dr. stirling calls the "gulf of all gulfs, which mr. huxley's protoplasm is as powerless to efface as any other material expedient that has ever been suggested."[55] this gulf mr. darwin does not attempt to bridge over. he admits that life owes its origin to the act of the creator. this, however, the most prominent of the advocates of darwinism say, is giving up the whole controversy. if you admit the intervention of creative power at one point, you may as well admit it in any other. if life owes its origin to creative power, why not species? if the stupendous miracle of creation be admitted, there is no show of reason for denying supernatural intervention in the operations of nature. most darwinians attempt to pass this gulf on the imaginary bridge of spontaneous generation. in other words, they say there is no gulf there. the molecules of matter, in one combination, may as well exhibit the phenomena of life, as in other combinations, any other kind of phenomena. the distinguished sir william thomson cannot trust himself to that bridge. "dead matter," he says, "cannot become living matter without coming under the influence of matter previously alive. this seems to me as sure a teaching of science as the law of gravitation.... i am ready to adopt, as an article of scientific faith, true through all space and through all time, that life proceeds from life, and nothing but life."[56] he refers the origin of life on this earth to falling meteors, which bring with them from other planets the germs of living organisms; and from those germs all the plants and animals with which our world is now covered have been derived. principal dawson thinks that this was intended as irony. but the whole tone of the address, and specially of the closing portion of it, in which this idea is advanced, is far too serious to admit of such an explanation. no one can read the address referred to without being impressed, and even awed, by the immensity and grandeur of the field of knowledge which falls legitimately within the domain of science. the perusal of that discourse produces a feeling of humility analogous to the sense of insignificance which every man experiences when he thinks of himself as a speck on the surface of the earth, which itself is but a speck in the immensity of the universe. and when a man of mere ordinary culture sees sir william thomson surveying that field with a mastery of its details and familiarity with all the recondite methods of its investigation, he feels as nothing in his presence. yet this great man, whom we cannot help regarding with wonder, is so carried away by the spirit of his class as to say, "science is bound, by the everlasting law of honor, to face fearlessly every problem which can fairly be brought before it. if a probable solution, consistent with the ordinary course of nature, can be found, we must not invoke an abnormal act of creative power." and, therefore, instead of invoking creative power, he accounts for the origin of life on earth by falling meteors. how he accounts for its origin in the places whence the meteors came, he does not say. yet sir william thomson believes in creative power; and in a subsequent page, we shall quote his explicit repudiation of the atheistic element in the darwinian theory. strauss quotes dubois-reymond, a distinguished naturalist, as teaching that the first of these great problems, viz. the origin of life, admits of explanation on scientific (i. e., in his sense, materialistic) principles; and even the third, viz. the origin of reason; but the second, or the origin of consciousness, he says, "is perfectly inscrutable." dubois-reymond holds that "the most accurate knowledge of the essential organism reveals to us only matter in motion; but between this material movement and my feeling pain or pleasure, experiencing a sweet taste, seeing red, with the conclusion 'therefore i exist,' there is a profound gulf; and it 'remains utterly and forever inconceivable why to a number of atoms of carbon, hydrogen, etc., it should not be a matter of indifference how they lie or how they move; nor, can we in any wise tell how consciousness should result from their concurrent action.' whether," adds strauss, "these _verba magistri_ are indeed the last word on the subject, time only can tell."[57] but if it is inconceivable, not to say absurd, that sense-consciousness should consist in the motion of molecules of matter, or be a function of such molecules, it can hardly be less absurd to account for thought, conscience, and religious feeling and belief on any such hypothesis. it may be said that mr. darwin is not responsible for these extreme opinions. that is very true. mr. darwin is not a monist, for in admitting creation, he admits a dualism as between god and the world. neither is he a materialist, inasmuch as he assumes a supernatural origin for the infinitesimal modicum of life and intelligence in the primordial animalcule, from which without divine purpose or agency, all living things in the whole history of our earth have descended. all the innumerable varieties of plants, all the countless forms of animals, with all their instincts and faculties, all the varieties of men with their intellectual endowments, and their moral and religious nature, have, according to darwin, been evolved by the agency of the blind, unconscious laws of nature. this infinitesimal spark of supernaturalism in mr. darwin's theory, would inevitably have gone out of itself, had it not been rudely and contemptuously trodden out by his bolder, and more logical successors. the grand and fatal objection to darwinism is this exclusion of design in the origin of species, or the production of living organisms. by design is meant the intelligent and voluntary selection of an end, and the intelligent and voluntary choice, application, and control of means appropriate to the accomplishment of that end. that design, therefore, implies intelligence, is involved in its very nature. no man can perceive this adaptation of means to the accomplishment of a preconceived end, without experiencing an irresistible conviction that it is the work of mind. no man does doubt it, and no man can doubt it. darwin does not deny it. haeckel does not deny it. no darwinian denies it. what they do is to deny that there is any design in nature. it is merely apparent, as when the wind of the bay of biscay, as huxley says, "selects the right kind of sand and spreads it in heaps upon the plains." but in thus denying design in nature, these writers array against themselves the intuitive perceptions and irresistible convictions of all mankind,--a barrier which no man has ever been able to surmount. sir william thomson, in the address already referred to, says: "i feel profoundly convinced that the argument of design has been greatly too much lost sight of in recent zoölogical speculations. reaction against the frivolities of teleology, such as are to be found, not rarely, in the notes of the learned commentators on 'paley's natural theology,' has, i believe, had a temporary effect of turning attention from the solid irrefragable argument so well put forward in that excellent old book. but overpowering proof of intelligence and benevolent design lie all around us, and if ever perplexities, whether metaphysical or scientific, turn us away from them for a time, they come back upon us with irresistible force, showing to us through nature the influence of a free will, and teaching us that all living beings depend upon one ever-acting creator and ruler." it is impossible for even mr. darwin, inconsistent as it is with his whole theory, to deny all design in the constitution of nature. what is his law of heredity? why should like beget like? take two germ cells, one of a plant, another of an animal; no man by microscope or by chemical analysis, or by the magic power of the spectroscope, can detect the slightest difference between them, yet the one infallibly develops into a plant and the other into an animal. take the germ of a fish and of a bird, and they are equally indistinguishable; yet the one always under all conditions develops into a fish and the other into a bird. why is this? there is no physical force, whether light, heat, electricity, or anything else, which makes the slightest approximation to accounting for that fact. to say, as stuart mill would say, that it is an ultimate fact, and needs no explanation, is to say that there may be an effect without an adequate cause. the venerable r. e. von baer, the first naturalist in russia, of whom agassiz speaks in terms of such affectionate veneration in the "atlantic monthly" for january, 1874, has written a volume dated dorpat, 1873, and entitled "zum streit über den darwinismus." in that volume, as we learn from a german periodical, the author says: "the darwinians lay great stress on heredity; but what is the law of heredity but a determination of something future? is it not in its nature in the highest degree teleological? indeed, is not the whole faculty of reproduction intended to introduce a new life-process? when a man looks at a dissected insect and examines its strings of eggs, and asks, whence are they? the naturalist of our day has no answer to give, but that they were of necessity gradually produced by the changes in matter. when it is further asked, why are they there? is it wrong to say, it is _in order that_ when the eggs are mature and fertilized, new individuals of the same form should be produced." it is further to be considered that there are innumerable cases of contrivance, or evidence of design in nature, to which the principle of natural selection, or the purposeless changes effected by unconscious force, cannot apply; as for example, the distinction of sex, with all that is therein involved. but passing by such cases, it may be asked, what would it avail to get rid of design in the vegetable and animal kingdom, while the whole universe is full of it? that this ordered cosmos is not from necessity or chance, is almost a self-evident fact. not one man in a million of those who ever heard of god, either does doubt or can doubt it. besides how are the cosmical relations of light, heat, electricity, to the constituent parts of the universe, and especially, so far as this earth is concerned, to vegetable and animal life, to be accounted for? is this all chance work? is it by chance that light and heat cause plants to carry on their wonderful operations, transmuting the inorganic into the organic, dead matter into living and life sustaining matter? is it without a purpose that water instead of contracting, expands at the freezing point?--a fact to which is due that the earth north of the tropic is habitable for man or beast. it is no answer to this question to say that a few other substances have the same peculiarity, when no good end, that we can see, is thereby accomplished. no man is so foolish as to deny that his eye was intended to enable him to see, because he cannot tell what the spleen was made for. it is, however, useless to dwell upon this subject. if a man denies that there is design in nature, he can with quite as good reason deny that there is any design in any or in all the works ever executed by man. the conclusion of the whole matter is, that the denial of design in nature is virtually the denial of god. mr. darwin's theory does deny all design in nature, therefore, his theory is virtually atheistical; his theory, not he himself. he believes in a creator. but when that creator, millions on millions of ages ago, did something,--called matter and a living germ into existence,--and then abandoned the universe to itself to be controlled by chance and necessity, without any purpose on his part as to the result, or any intervention or guidance, then he is virtually consigned, so far as we are concerned, to non-existence. it has already been said that the most extreme of mr. darwin's admirers adopt and laud his theory, for the special reason that it banishes god from the world; that it enables them to account for design without referring it to the purpose or agency of god. this is done expressly by büchner, haeckel, vogt, and strauss. the opponents of darwinism direct their objections principally against this element of the doctrine. this, as was stated by rev. dr. peabody, was the main ground of the earnest opposition of agassiz to the theory. america's great botanist, dr. asa gray, avows himself an evolutionist; but he is not a darwinian. of that point we have the clearest possible proof. mr. darwin, after explicitly denying that the variations which have resulted in "the formation of the most perfectly adapted animals in the world, man included, were intentionally and specially guided," adds: "however much we may wish it, we can hardly follow professor asa gray in his belief 'that variation has been led along certain beneficial lines' like a stream 'along definite and useful lines of irrigation.'"[58] if mr. darwin does not agree with dr. gray, dr. gray does not agree with mr. darwin. it is as to the exclusion of design from the operations of nature that our american, differs from the english, naturalist. this is the vital point. the denial of final causes is the formative idea of darwin's theory, and therefore no teleologist can be a darwinian. dr. gray quotes from another writer the sentence, "it is a singular fact, that when we can find how anything is done, our first conclusion seems to be that god did not do it;" and then adds, "i agree with the writer that this first conclusion is premature and unworthy; i will add, deplorable. through what faults of dogmatism on the one hand, and skepticism on the other, it came to be so thought, we need not here consider. let us hope, and i confidently expect, that it is not to last; that the religious faith which survived without a shock the notion of the fixedness of the earth itself, may equally outlast the notion of the absolute fixedness of the species which inhabit it; that in the future, even more than in the past, faith in an _order_, which is the basis of science, will not--as it cannot reasonably--be dissevered from faith in an _ordainer_, which is the basis of religion."[59] we thank god for that sentence. it is the concluding sentence of dr. gray's address as ex-president of "the american association for the advancement of science," delivered august, 1872. dr. gray goes further. he says, "the proposition that the things and events in nature were not designed to be so, if logically carried out, is doubtless tantamount to atheism." again, "to us, a fortuitous cosmos is simply inconceivable. the alternative is a designed cosmos.... if mr. darwin believes that the events which he supposes to have occurred and the results we behold around us were undirected and undesigned; or if the physicist believes that the natural forces to which he refers phenomena are uncaused and undirected, no argument is needed to show that such belief is atheistic."[60] we have thus arrived at the answer to our question, what is darwinism? it is atheism. this does not mean, as before said, that mr. darwin himself and all who adopt his views are atheists; but it means that his theory is atheistic; that the exclusion of design from nature is, as dr. gray says, tantamount to atheism. among the last words of strauss were these: "we demand for our universe the same piety which the devout man of old demanded for his god." "in the enormous machine of the universe, amid the incessant whirl and hiss of its jagged iron wheels, amid the deafening crash of its ponderous stamps and hammers, in the midst of this whole terrific commotion, man, a helpless and defenceless creature, finds himself placed, not secure for a moment that on an imprudent motion a wheel may not seize and rend him, or a hammer crush him to a powder. this sense of abandonment is at first something awful."[61] among the last words of paul were these: "i know whom i have believed, and am persuaded that he is able to keep that which i have committed unto him against that day.... the time of my departure is at hand. i have fought a good fight, i have finished my course, i have kept the faith: henceforth there is laid up for me a crown of righteousness, which the lord, the righteous judge, shall give me at that day: and not to me only, but unto all them also that love his appearing." footnotes: [40] _science and scripture not antagonistic, because distinct in their spheres of thought_. a lecture, by rev. george henslow, m. a., f. l. s., f. g. s. london, 1873, p. 1. [41] _gott und natur_, p. 200. [42] _protoplasm; or, matter and life._ by lionel s. beale, m. b., f. r. s. third edition. london & philadelphia, 1874, p. 345; and the whole chapter on design. [43] _fallacies in the hypothesis of mr. darwin_, by c. r. bree, m. d., f. z. s. london, 1872, p. 290. [44] when professor huxley says, as quoted above, that he does not deny the possibility of miracles, he must use the word miracle in a sense peculiar to himself. [45] _jenaer literaturzeitung_, january 3, 1874. in this number there is a notice by doctor haeckel of two books,--_descendenzlehre und darwinismus_, von oscar schmidt, leipzig, 1873; and _die fortschritte des darwinismus_, von j. w. spengel, cöln and leipzig, 1874; in which he says: "erstens, um in sachen der descendenz-theorie mitreden zu können, ein gewisser grad von tieferer biologischer (sowohl morphologischer als physiologischer) bildung unentbehrlich, den die meistzen von jenen auctoren (the opposers of the theory) nicht besitzen. zweitens ist für ein klares und zutreffendes urtheil in diesem sachen eine rücksichtslose hingabe an vernunftgemässe erkenntniss und eine dadurch bedingte resignation auf uralte, liebgewordene und tief vererbte vorurtheile erforderlich, zu welcher sich die wenigsten entschliesen können." [46] in his _natürlische schöpfungsgeschichte_, haeckel is still more exclusive. when he comes to answer the objections to the evolution, or, as he commonly calls it, the descendence theory, he dismisses the objections derived from religion, as unworthy of notice, with the remark that all glaube ist aberglaube; all faith is superstition. the objections from _a priori_, or intuitive truths, are disposed of in an equally summary manner, by denying that there are any such truths, and asserting that all our knowledge is from the senses. the objection that so many distinguished naturalists reject the theory, he considers more at length. first, many have grown old in another way of thinking and cannot be expected to change. second, many are collectors of facts, without studying their relations, or are destitute of the genius for generalization. no amount of material makes a building. others, again, are specialists. it is not enough that a man should be versed in one department; he must be at home in all: in botany, zoölogy, comparative anatomy, biology, geology, and palæontology. he must be able to survey the whole field. fourthly, and mainly, naturalists are generally lamentably deficient in philosophical culture and in a philosophical spirit. "the immovable edifice of the true, monistic science, or what is the same thing, natural science, can only arise through the most intimate interaction and mutual interpenetration of philosophy and observation (philosophie und empirie)." pp. 638-641. it is only a select few, therefore, of learned and philosophical monistic materialists, who are entitled to be heard on questions of the highest moment to every individual man, and to human society. [47] this short but significant sentence is omitted in the excellent translation of strauss's book, by mathilde blind, republished in new york, by henry holt & company, 1873. [48] _the fallacies of darwinism_, by c. r. bree, m. d., p. 308. [49] _the fallacies of darwinism_, p. 305. [50] _bibliotheca sacra_, 1857, p. 861. [51] _the story of earth and man_, p. 358. [52] dr. bree, p. 275. we presume geologists differ in the terms which they use to designate strata. agassiz calls the oldest containing fossil, the sub-cambrian. principal dawson calls the oldest the laurentian, and places the first vertebrates in the silurian. this is of no moment as to the argument. the important fact is that each species is distinct as soon as it appears; and that many have remained to the present time. [53] _atlantic monthly_, january, 1874. [54] we have heard a story of a gentleman who gave an artist a commission for a historical painting, and suggested as the subject, the passage of the israelites over the red sea. in due time he was informed that his picture was finished, and was shown by the artist a large canvas painted red. "what is that?" he asked. "why," says the artist, "that is the red sea." "but where are the israelites?" "oh, they have passed over." "and where are the egyptians?" "they are under the sea." [55] _as regards protoplasm in relation to professor huxley's essay an the physical basis of life_. by dr. james h. stirling. see, also, _physiological anatomy and physiology of man_, by l. s. beale; also, _the mystery of life in reply to dr. gull's attack on the theory of vitality_. by l. s. beale, m. d., 1871. [56] the address delivered by sir william thomson, as president of the british association at its meeting in edinburgh, 1871. [57] _the old faith and the new_. prefatory postscript, xxi. [58] _variation of plants and animals under domestication_. new york, 1868, vol. ii. pp. 515, 516. [59] _proceedings of the american association for the advancement of science_. cambridge, 1873, p. 20. [60] the _atlantic monthly_ for october, 1860. the three articles in the july, august, and october numbers of the _atlantic_, on this subject, have been reprinted with the name of dr. asa gray as their author. [61] strauss says that as he has arrived at the conclusion that there is no personal god, and no life after death, it would seem to follow that the question, have we still a religion? "must be answered in the negative." but as he makes the essence of religion to consist in a sense of dependence, and as he felt himself to be helpless in the midst of this whirling universe, he had that much religion left. advertisements _the great theological work of the age._ dr. hodge's theology. systematic theology. by charles hodge, d.d., ll.d., of princeton theological seminary. _complete in three volumes 8vo, tinted paper. price, vols. i. and ii._, $4.50. _vol. iii._, $5. in these volumes are comprised the results of the life-long labors and investigations of one of the most eminent theologians of the age. the work covers the ground usually occupied by treatises on systematic theology, and adopts the commonly received divisions of the subject,--theology, vol. i.; anthropology, vol. ii.; soteriology and eschatology, vol. iii. the introduction is devoted to the consideration of preliminary matters, such as method, or the principles which should guide the student of theology, and the different theories as to the source and standard of our knowledge of divine things, rationalism, mysticism, the roman catholic doctrine of the rule of faith, and the protestant doctrine on that subject. the department of theology proper includes the origin of the idea of god, the being of god, the anti-theistic systems of atheism, polytheism, materialism, and pantheism; the nature of god, the divine attributes, the doctrines of the trinity, the divinity of christ, and of the holy spirit; the decrees of god, creation, providence, and miracles. the department of anthropology includes the nature, origin, and antiquity of man, his primitive state and probation; the fall; the effect of adam's sin upon himself and upon his posterity; the nature of sin; the different philosophical and theological theories on that subject. soteriology includes the plan or purpose of god in reference to the salvation of men; the person and work of the redeemer; his offices as prophet, priest, and king, the work of the holy spirit in applying the redemption purchased by christ; common and efficacious grace, regeneration, faith, justification, sanctification, the law or rule of life, and the means of grace. eschatology includes the state of the soul after death; the second coming of christ; the resurrection of the body; the general judgment and end of the world, and the doctrine concerning heaven and hell. the plan of the author is to state and vindicate the teachings of the bible on these various subjects, and to examine the antagonistic doctrines of different classes of theologians. his book, therefore, is intended to be both didactic and elenchtic. the various topics are discussed with that close and keen analytical and logical power combined with that simplicity, lucidity, and strength of style which have already given dr. hodge a world-wide reputation as a controversialist and writer, and as an investigator of the great theological problems of the day. _single copies, sent post-paid on receipt of the price._ scribner, armstrong & co., 654 broadway, new york edinburgh review.--"the best history of the roman republic." london times.--"by far the best history of the decline and fall of the roman commonwealth." the history of rome, from the earliest time to the period of its decline. by dr. theodor mommsen. translated, with the author's sanction and additions, by the rev. w. p. dickson, regius professor of biblical criticism in the university of glasgow, late classical examiner in the university of st. andrews. with an introduction by dr. leonhard schmitz, and a copious index of the whole four volumes, prepared especially for this edition. reprinted from the revised london edition four volumes crown 8vo. price per volume, $2.00. dr. mommsen has long been known and appreciated through his researches into the languages, laws, and institutions of ancient rome and italy, as the most thoroughly versed scholar now living in these departments of historical investigation. to a wonderfully exact and exhaustive knowledge of these subjects, he unites great powers of generalization, a vigorous, spirited, and exceedingly graphic style and keen analytical powers, which give this history a degree of interest and a permanent value possessed by no other record of the decline and fall of the roman commonwealth. "dr. mommsen's work," as dr. schmitz remarks in the introduction, "though the production of a man of most profound and extensive learning and knowledge of the world, is not as much designed for the professional scholar as for intelligent readers of all classes who take an interest in the history of by-gone ages, and are inclined there to seek information that may guide them safely through the perplexing mazes of modern history." critical notices. "a work of the very highest merit; its learning is exact and profound; its narrative full of genius and skill; its descriptions of men are admirably vivid. we wish to place on record our opinion that dr. mommsen's is by far the best history of the decline and fall of the roman commonwealth."--_london times_. "since the days of niebuhr, no work on roman history has appeared that combines so much to attract, instruct, and charm the reader. its style--a rare quality in a german author--is vigorous, spirited, and animated. professor mommsen's work can stand a comparison with the noblest productions of modern history."--_dr. schmitz._ "this is the best history of the roman republic, taking the work on the whole--the author's complete mastery of his subject, the variety of his gifts and acquirements, his graphic power in the delineation of national and individual character, and the vivid interest which he inspires in every portion of his book. he is without an equal in his own sphere."--_edinburgh review_. "a book of deepest interest."--_dean trench_. another great historical work. _the history of greece,_ by prof. dr. ernst curtius. translated by adolphus william ward, m.a., fellow of st. peter's college, cambridge, prof. of history in owen's college, manchester. to be completed in four or five vols., crown 8vo, at $2.50 per volume. printed upon tinted paper, uniform with mommsen's history of rome, and the library edition of froude's history of england. vols. i., ii., iii., and iv., now ready. curtius' _history of greece_ is similar in plan and purpose to mommsen's _history of rome_, with which it deserves to rank in every respect as one of the great masterpieces of historical literature. avoiding the minute details which overburden other similar works, it groups together in a very picturesque manner all the important events in the history of this kingdom, which has exercised such a wonderful influence upon the world's civilization. the narrative of prof. curtius' work is flowing and animated, and the generalizations, although bold, are philosophical and sound. critical notices. "professor curtius' eminent scholarship is a sufficient guarantee for the trustworthiness of his history, while the skill with which he groups his facts, and his effective mode of narrating them, combine to render it no less readable than sound. professor curtius everywhere maintains the true dignity and impartiality of history, and it is evident his sympathies are on the side of justice, humanity, and progress."--_london athenæum_. "we can not express our opinion of dr. curtius' book better than by saying that it may be fitly ranked with theodor mommsen's great work."--_london spectator_. "as an introduction to the study of grecian history, no previous work is comparable to the present for vivacity and picturesque beauty, while in sound learning and accuracy of statement it is not inferior to the elaborate productions which enrich the literature of the age."--_n. y. daily tribune_. "the history of greece is treated by dr. curtius so broadly and freely in the spirit of the nineteenth century, that it becomes in his hands one of the worthiest and most instructive branches of study for all who desire something more than a knowledge of isolated facts for their education. this translation ought to become a regular part of the accepted course of reading for young men at college, and for all who are in training for the free political life of our country."--_n. y. evening post_. _this book sent post-paid, upon receipt of the price, by the publishers,_ scribner, armstrong & co., 654 broadway, new york. prospectus of a theological & philosophical library edited by henry b. smith, d.d., and philip schaff, d.d., _professors in the union theological seminary, new york._ the undersigned propose to publish a select and compact library of text-books upon all the main departments of theology and philosophy, adapted to the wants especially of ministers and students in all denominations. some of the works will be translated from the german and other languages; others will be based upon treatises by various authors; some will be written for the library by english or american scholars. the aim will be to furnish at least one condensed standard work on each of the scientific divisions of theology and philosophy, giving the result of the best critical investigations, excluding, however, such histories and commentaries as extend through many volumes. this scheme is not presented as final, but as indicating the aim of the editors. if sufficient encouragement be given, no pains will be spared to make the project complete, and thus to meet a great and acknowledged desideratum in the apparatus for study. on all these topics every student needs, at least, one good work. to supply this will be the aim of our library. the various volumes will be published in the best style, on reasonable terms, and as rapidly as the nature of the work and the encouragement of the public will allow. the editors will be assisted by eminent scholars of various denominations, who will respectively assume the literary responsibility for the volumes prepared by themselves within the general plan and aim of the library. now ready, in the theological and philosophical library. ueberweg's history of philosophy. vol. i.--_history of the ancient and mediæval philosophy_. by dr. friedrich ueberweg. translated from the fourth german edition by george s. morris, a.m., with additions by noah porter, d.d., ll.d., president of yale college, and a general introduction by the editor of the philosophical library. one vol. 8vo, cloth, $3.50. vol. ii.--_history of modern philosophy_. with an essay on english philosophy, by dr. noah porter, president of yale college; and on italian philosophy, by professor v. botta. one vol. 8vo, cloth. $4.00. _sent, post-paid, upon receipt of the price by the publishers,_ scribner, armstrong & co., 654 broadway, new york. lange's commentary. now ready: the minor prophets. _edited by_ rev. dr. philip schaff, _and including_ hosea.--by otto schmoller, ph. d., urach, wurtemberg. translated, with additions, by james e. mccurdy. joel.--by otto schmoller, ph. d. translated, with additional notes and a new version of the hebrew text, by john forsyth, d.d., ll.d. amos.--by otto schmoller, ph. d. translated and enlarged by talbot w. chambers, d.d. obadiah.--by paul kleinert, of berlin. translated, with additions, by george r. bliss, d.d. jonah.--by paul kleinert. translated and enlarged by charles elliott, d.d. micah.--by paul kleinert. translated, with additions, by george r. bliss, d.d. nahum, habakkuk, and zephaniah.--by paul kleinert. translated and enlarged by charles elliott, d.d. haggai.--by james f. mccurdy, princeton, n. y. zechariah.--by talbot w. chambers, d.d., new york. malachi.--by joseph packard, d.d. alexandria, va. one vol. royal 8vo, cloth $5.00 _the volumes previously published are_: old testament.--i. genesis. ii. joshua, judges, and ruth. iii. first and second kings. iv. psalms. v. proverbs, song of solomon, ecclesiastes. vi. jeremiah and lamentations. new testament.--i. matthew. ii. mark and luke. iii. john. iv. acts. v. the epistle of paul to the romans. vi. corinthians. vii. galatians, ephesians, philippians, colossians. viii. thessalonians, timothy, titus, philemon, and hebrews. ix. the epistles general of james, peter, john, and jude. each one vol. 8vo. price per vol., in half calf, $7.50: in sheep, $6.50: in cloth, $5.00. names and denominations of contributors. w. g. t. shedd, d.d., presbyterian. e. a. washburne, d.d., episcopal. a. c. kendrick, d.d., baptist. w. h. green, d.d., presbyterian. j. f. hurst, d.d., methodist. tayler lewis, ll.d., dutch reformed. rev. ch. f. shaffer, d.d., lutheran. r. d. hitchcock, d.d., presbyterian. e. harwood, d.d., episcopal. h. b. hackett, d.d., baptist. john lillie, d.d., presbyterian. rev. w. g. sumner, episcopal. prof. charles elliott, presbyterian. thos. c. conant, d.d., baptist. e. d. yeomans, d.d., presbyterian. rev. c. c. starbuck, congregational. j. isidor mombert, d.d., episcopal. d. w. poor, d.d., presbyterian. c. p. wing, d.d., presbyterian. george e. day. d.d., congregational. rev. p. h. steenstra, episcopal. a. gosman, d.d., presbyterian. pres. chas. a. aiken, d.d., presbyt'n. m. b. riddle, d.d., dutch reformed. prof. wm. wells, d.d., methodist. w. h. hornblower, d.d., presbyt'n. prof. george bliss, baptist. t. w. chambers, d.d., reformed. *** each volume of "lange's commentary" is complete in itself, and can be purchased separately. sent, post-paid, to any address upon receipt of the price ($5 per volume) by the publishers. scribner, armstrong & co., 654 broadway, new york. manuals of political economy, _published by_ scribner, armstrong & co. perry's elements of political economy. new edition, revised by the author. this treatise presents views favorable to the utmost freedom of commerce, compatible with legitimate revenue from tariff taxes. it is a standard text-book in all our colleges throughout the country. by arthur latham perry, professor of political economy and history in williams college. 487 _pages, price_ $2.50. "your book interests students more than any other i have ever instructed from,"--_pres. t. d. woolsey, yale college._ "as a manual for general reading and popular instruction, prof. perry's book is far superior to any work on the subject before issued in the united states."--_n. y. times._ "we cordially recommend this book to all, of whatever school of political economy, who enjoy candid statement and full and logical discussion."--_n. y. nation._ "there is more common sense in this book than in any of the more elaborate works on the same subject that have preceded it."--_n. y. independent._ "in all the portions of the book which we have read, the author shows himself to be a clear, strong, bold, and generally sound thinker."--_new englander_. bowen's american political economy. this treatise presents views compatible with the idea that "every country has a political economy of its own, suitable to its own physical circumstances of position on the globe, and to the character, habits, and institutions of the people." by francis bowen, professor of political economy and civil polity in harvard college. 495 _pages, price_ $2.50 "if our members of congress would vote themselves a copy of this book, and read it, fewer wild schemes would be concocted by them, and a great saving of time and the people's money would be secured."--_the philadelphia age._ "his arguments are worth considering, and his whole book is of high value to any american to study economical questions."--_springfield republican._ "a solid and well-reasoned treatise.... mr. bowen's views are clearly stated and thoroughly reasoned."--_boston congregationalist_. ... "there are hundreds going wrong to-day whom a careful perusal of this volume would set right."--_n. y. daily tribune_. ***_sent, post-paid, on receipt of price by the publishers._ prices and styles of the different editions of froude's history of england. the chelsea edition. in half roan, gilt top, per set of twelve vols. 12mo $21.00 elegance and cheapness are combined in a remarkable degree in this edition. it takes its name from the place of mr. froude's residence in london, also famous as the home of thomas carlyle. the popular edition. in cloth, at the rate of $1.25 per volume. the set (12 vols.), in a neat box. $15.00 the same, in half calf extra 36.00 this edition is printed from the same plates as the other editions, and on firm, white paper. it is, without exception, the cheapest set of books of its class ever issued in this country. the library edition. in twelve vols. crown 8vo, cloth $30.00 the same, in half calf extra 50.00 the edition is printed on laid and tinted paper, at the riverside press, and is in every respect worthy a place in the most carefully selected library. short studies on great subjects. by james anthony froude, m.a., _"history of england," "the english in ireland during the eighteenth century," etc._ popular edition. two vols. 12mo, cloth, $1.50 per vol. the set $3.00 chelsea edition. two vols. 12mo, half roan, gilt top, $2.00 per volume. per set 4.00 the complete works of james anthony froude, m.a. history of england and short studies. fourteen vols., in a neat box. popular edition $18.00 chelsea edition 25.00 _the above works sent, post-paid, by the publishers, on receipt of the price_ scribner, armstrong & co., 654 broadway, new york. popular and standard works published by scribner, armstrong & co., 654 broadway, new york, in 1873. 1. bagehot's (w.) lombard street. 12mo $1 75 2. bible commentary. vol. ii. 8vo 5 00 3. 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centre of the earth. _illustrated_. 12mo 2 00 28. very young couple (a). 12mo 1 25 ***_any of the above books sent postpaid to any address upon receipt of the price by the publishers._ little masterpieces of science [illustration: charles r. darwin.] little masterpieces of science edited by george iles the naturalist as interpreter and seer _by_ charles darwin alfred r. wallace thomas h. huxley leland o. howard george iles new york doubleday, page & company 1902 copyright, 1902, by doubleday, page & co. copyright, 1877, by d. appleton & co. copyright, 1901, by john wanamaker copyright, 1895, by g. h. buek & co. transcriber's notes: obvious printer's errors have been silently corrected. hyphenated and accented words have been standardized. see the end of this file for more information. preface to gather stones and fallen boughs is soon to ask, what may be done with them, can they be piled and fastened together for shelter? so begins architecture, with the hut as its first step, with the alhambra, st. peter's, the capitol at washington, as its last. in like fashion the amassing of fact suggests the ordering of fact: when observation is sufficiently full and varied it comes to the reasons for what it sees. the geologist delves from layer to layer of the earth beneath his tread, he finds as he compares their fossils that the more recent forms of life stand highest in the scale of being, that in the main the animals and plants of one era are more allied to those immediately next than to those of remoter times. he thus divines that he is but exploring the proofs of lineal descent, and with this thought in his mind he finds that the collections not only of his own district, but of every other, take on a new meaning. the great seers of science do not await every jot and tittle of evidence in such a case as this. they discern the drift of a fact here, a disclosure there, and with both wisdom and boldness assume that what they see is but a promise of what shall duly be revealed. thus it was that darwin early in his studies became convinced of the truth of organic evolution: the labours of a lifetime of all but superhuman effort, a judicial faculty never exceeded among men, served only to confirm his confidence that all the varied forms of life upon earth have come to be what they are through an intelligible process, mainly by "natural selection." the present volume offers from the classic pages of darwin his summary of the argument of "the origin of species," his account of how that book came to be written, and his recapitulation of "the descent of man." all this affords a supreme lesson as to the value of observation with a purpose. when darwin was confronted with an organ or trait which puzzled him, he was wont to ask, what use can it have had? and always the answer was that every new peculiarity of plant, or beast, is seized upon and held whenever it confers advantage in the unceasing conflict for place and food. no hue of scale or plume, no curve of beak or note of song, but has served a purpose in the plot of life, or advanced the action in a drama where the penalty for failure is extinction. as charles darwin stood first among the naturalists of the nineteenth century, his advocacy of evolution soon wrought conviction among the thinkers competent to follow his evidence and weigh his arguments. the opposition to his theories though short was sharp, and here he found a lieutenant of unflinching courage, of the highest expository power, in professor huxley. this great teacher came to america in 1876, and discoursed on the ancestry of the horse, as disclosed in fossils then recently discovered in the far west, maintaining that they afforded unimpeachable proof of organic evolution. his principal lecture is here given. in a remarkable field of "natural selection" bates, wallace and poulton have explained the value of "mimicry" as an aid to beasts, birds, insects, as they elude their enemies or lie unsuspected on the watch for prey. the resemblances thus worked out through successive generations attest the astonishing plasticity of bodily forms, a plasticity which would be incredible were not its evidence under our eyes in every quarter of the globe. insects have high economic importance as agents of destruction: we are learning how to pit one of them against another, so as to leave a clear field to the farmer and the fruit grower. in this department a leader is professor howard, who contributes a noteworthy chapter on the successful fight against the pest which threatened with ruin the orange groves of california. to the every-day observer the most enticing field of natural history is that in which common flowers and common insects work out their unending co-partnery. a blossom by its scent, its beauty of tint, allures a moth or bee and thus, in effect, is able to take flight and find a mate across a county so as to perpetuate its race a hundred miles from home. our volume closes with a sketch of the singular ties which thus bind together the fortunes of blossom and insect, so that at last the very form of a flower may be cast in the mould of its winged ally. a word is also spoken regarding the singular relations of late detected between the world of vegetation and minute forms once deemed parasitic. the pea and its kindred harbor on their rootlets certain tiny lodgers; the tenants pay a liberal rent in the form of nitrogen compounds, a striking interlacement of interests! george iles. contents darwin, charles the origin of species in summary varieties merge gradually into species. animals tend to increase in geometrical ratio. varieties diverge in consonance with diversity of opportunity for life. in the struggle for existence those which best accord with their surroundings will survive and propagate their kind. sexual selection has put a premium on beauty. the causes which in brief periods produce varieties, in long periods give rise to species. instincts, as of the hive bee, are slowly developed. geology supports the theory of evolution: the changes in time in the fossil record are gradual. geographical distribution lends its corroboration: in each region most of the inhabitants in every great class are plainly related. a common ancestor is suggested when we see the similarity of hand, wing and fin. embryos of birds, reptiles and fish are closely similar and unlike adult forms. slight changes in the course of millions of years produce wide divergences. 3 darwin, charles how "the origin of species" came to be written during his voyage on the _beagle_ darwin saw fossil armadillos like existing species, and on the islands of the galapagos group a gradually increased diversity of species of every kind. all this suggested that species gradually become modified. notes gathered of facts bearing on the question. observes that it is the variation between one animal and another which gives the breeder his opportunity. reads malthus on population, a work which points out the keen struggle for existence and that favourable variations tend to be preserved. in 1842 draws up a brief abstract of the theory of "natural selection." in 1856 begins an elaborate work on the same theme, but in 1858, hearing that wallace has written an essay advancing an independent theory of natural selection, offers a summary of his argument to the linnean society of london. writes "the origin of species," which is published most successfully, november, 1859. 35 darwin, charles the descent of man: the argument in brief since evolution is probable for all other animals, it is probable for man. the human form has so much in common with the forms of other animals that community of descent is strongly suggested. man, like other creatures, is subject to the struggle for existence. evidence shows that it is likely that man is descended from a tailed and hairy quadruped that dwelt in trees. man's mental power has been the chief factor in his advance, especially in his development of language. conscience is due to social instincts, love of approbation, memory, imagination and religious feeling. sexual selection in its effects upon human advancement. 45 wallace, alfred r. mimicry and other protective resemblances among animals the colours of animals are useful for concealment from their prey, from the creatures upon which they prey. the lion is scarcely visible as he crouches on the sand or among desert rocks and stones. larks, quails and many other birds are so tinted and mottled that their detection is difficult. the polar bear, living amid ice and snow, is white. reptiles and fish are so coloured as to be almost invisible in the grass or gravel where they rest. many beetles and other insects are so like the leaves or bark on which they feed that when motionless they cannot be discerned. some butterflies resemble dead, dry or decaying leaves so closely as to elude discovery. every individual better protected by colour than others, has a better chance for life, and of transmitting his hues. harmless beetles and flies are so like wasps and bees as to be left alone. 71 huxley, thomas h. evolution of the horse the hoof of the horse is simply a greatly enlarged and thickened nail: four of his five toes are reduced to mere vestiges. his teeth are built of substances of varying hardness: they wear away at different rates presenting uneven grinding surfaces. probable descent of the horse, link by link, especially as traced in the fossils of north america. evolution has taken a long time: how long the physicist and the astronomer must decide. 101 howard, leland o. fighting pests with insect allies a scale insect threatened with ruin the orchards of california. professor c. v. riley decided that the pest was a native of australia. mr. a. hoebele observes in australia that the pest is kept down by ladybirds. these are accordingly sent to california where they destroy the scale insect and restore prosperity among the fruit-growers. another pest, of olive trees, is devoured by an imported ladybird of another species. this plan extended to portugal and egypt with success. grasshoppers killed by a fungus cultivated for the purpose. introduction into the united states of the insect which fertilizes the smyrna fig. 123 iles, george the strange story of the flowers: a chapter in modern botany dress is important, whether natural or artificial. because they catch dust on their clothes, bees, moths and butterflies have brought about myriad espousals of flower with flower. colours and scents of blossoms attract insects. a flower which in form, scent or hue varies gainfully is likely to survive while others perish. all the parts of a flower are leaves in disguise. floral modes of repulsion and defence. plants which devour insects, a habit gradually acquired. the mesquit tree tells of water. plants believed to indicate mineral veins. seeds as emigrants equipped with wings or hooks. parasitic plants and their degradation. tenants that pay a liberal rent. the gardener as a creator of new flowers. the modern sugar beet due to mons. vilmorin. 139 the naturalist as interpreter and seer the origin of species: the argument in summary charles darwin [charles darwin, one of the greatest men of all time, did more to advance and prove the theory of evolution than anybody else who ever lived. this he accomplished by virtue of the highest gifts of observation, experiment, and generalization. his truthfulness, patience, and calmness of judgment have never been exceeded by mortal. his works are published by d. appleton & co., new york, together with his "life and letters," edited by his son francis. from "the origin of species" the argument in summary is here given.] on the view that species are only strongly marked and permanent varieties, and that each species first existed as a variety, we can see why it is that no line of demarcation can be drawn between species, commonly supposed to have been produced by special acts of creation, and varieties which are acknowledged to have been produced by secondary laws. on this same view we can understand how it is that in a region where many species of a genus have been produced, and where they now flourish, these same species should present many varieties; for where the manufactory of species has been active, we might expect, as a general rule, to find it still in action; and this is the case if varieties be incipient species. moreover, the species of the larger genera, which afford the greater number of varieties or incipient species, retain to a certain degree the character of varieties; for they differ from each other by a less amount of difference than do the species of smaller genera. the closely allied species also of a larger genera apparently have restricted ranges, and in their affinities they are clustered in little groups round other species--in both respects resembling varieties. these are strange relations on the view that each species was independently created, but are intelligible if each existed first as a variety. as each species tends by its geometrical rate of reproduction to increase inordinately in number; and as the modified descendants of each species will be enabled to increase by as much as they become more diversified in habits and structure, so as to be able to seize on many and widely different places in the economy of nature, there will be a constant tendency in natural selection to preserve the most divergent offspring of any one species. hence, during a long-continued course of modification, the slight differences of characteristic of varieties of the same species, tend to be augmented into the greater differences characteristic of the species of the same genus. new and improved varieties will inevitably supplant and exterminate the older, less improved, and intermediate varieties; and thus species are rendered to a large extent defined and distinct objects. dominant species belonging to the larger groups within each class tend to give birth to new and dominant forms; so that each large group tends to become still larger, and at the same time more divergent in character. but as all groups cannot thus go on increasing in size, for the world would not hold them, the more dominant groups beat the less dominant. this tendency in the large groups to go on increasing in size and diverging in character, together with the inevitable contingency of much extinction, explains the arrangement of all the forms of life in groups subordinate to groups, all within a few great classes, which has prevailed throughout all time. this grand fact of the grouping of all organic beings under what is called the natural system, is utterly inexplicable on the theory of creation. as natural selection acts solely by accumulating slight, successive, favourable variations, it can produce no great or sudden modifications; it can act only by short and slow steps. hence, the canon of "nature makes no leaps," which every fresh addition to our knowledge tends to confirm, is on this theory intelligible. we can see why throughout nature the same general end is gained by an almost infinite diversity of means, for every peculiarity when once acquired is long inherited, and structures already modified in many different ways have to be adapted for the same general purpose. we can, in short, see why nature is prodigal in variety, though niggard in innovation. but why this should be a law of nature if each species has been independently created no man can explain. many other facts are, as it seems to me, explicable on this theory. how strange it is that a bird, under the form of a woodpecker, should prey on insects on the ground; that upland geese which rarely or never swim, would possess webbed feet; that a thrush-like bird should dive and feed on sub-aquatic insects; and that a petrel should have the habits and structure fitting it for the life of an auk! and so in endless other cases. but on the view of each species constantly trying to increase in number, with natural selection always ready to adapt the slowly varying descendants of each to any unoccupied or ill-occupied place in nature, these facts cease to be strange, or might even have been anticipated. we can to a certain extent understand how it is that there is so much beauty throughout nature; for this may be largely attributed to the agency of selection. that beauty, according to our sense of it, is not universal, must be admitted by every one who will look at some venomous snakes, at some fishes, and at certain hideous bats with a distorted resemblance to the human face. sexual selection has given the most brilliant colours, elegant patterns, and other ornaments to the males, and sometimes to both sexes of many birds, butterflies and other animals. with birds it has often rendered the voice of the male musical to the female, as well as to our ears. flowers and fruit have been rendered conspicuous by brilliant colours in contrast with the green foliage, in order that the flowers may be easily seen, visited and fertilized by insects, and the seeds disseminated by birds. how it comes that certain colours, sounds and forms should give pleasure to man and the lower animals, that is, how the sense of beauty in its simplest form was first acquired, we do not know any more than how certain odours and flavours were first rendered agreeable. as natural selection acts by competition, it adopts and improves the inhabitants of each country only in relation to their co-inhabitants; so that we need feel no surprise at the species of any one country, although on the ordinary view supposed to have been created and specially adapted for that country, being beaten and supplanted by the naturalized productions from another land. nor ought we marvel if all the contrivances in nature be not, as far as we can judge, absolutely perfect, as in the case even of the human eye; or if some of them be abhorrent to our ideas of fitness. we need not marvel at the sting of the bee, when used against an enemy, causing the bee's own death; at drones being produced in such great numbers for one single act, and being then slaughtered by their sterile sisters; at the astonishing waste of pollen by our fir trees; at the instinctive hatred of the queen bee for her own fertile daughters; at ichneumonid㦠feeding within the living bodies of caterpillars; or at other such cases. the wonder indeed, is, on the theory of natural selection, that more cases of the want of absolute perfection have not been detected. the complex and little known laws governing production of varieties are the same, as far as we can judge, with the laws which have governed the production of distinct species. in both cases physical conditions seem to have produced some direct and definite effect, but how much we cannot say. thus, when varieties enter any new station, they occasionally assume some of the characters proper to the species of that station. with both varieties and species, use and disuse seem to have produced a considerable effect; for it is impossible to resist this conclusion when we look, for instance, at the logger-headed duck, which has wings incapable of flight, in nearly the same condition as in the domestic duck; or when we look at the burrowing tucu-tucu, which is occasionally blind, and then at certain moles, which are habitually blind and have their eyes covered with skin; or when we look at the blind animals inhabiting the dark caves of america and europe. with varieties and species, correlated variation seems to have played an important part, so that when one part has been modified other parts have been necessarily modified. with both varieties and species, reversions to long-lost characters occasionally occur. how inexplicable on the theory of creation is the occasional appearance of stripes on the shoulders and legs of the several species of the horse-genus and of their hybrids! how simply is this fact explained if we believe that these species are all descended from a striped progenitor, in the same manner as the several domestic breeds of the pigeon are descended from the blue and barred rock pigeon! on the ordinary view of each species having been independently created, why should specific characters, or those by which the species of the same genus differ from each other, be more variable than generic characters in which they all agree? why, for instance, should the colour of a flower be more likely to vary in any one species of genus, if the other species possess differently coloured flowers, than if all possessed the same coloured flowers? if species are only well-marked varieties, of which the characters have become in a high degree permanent, we can understand this fact; for they have already varied since they branched off from a common progenitor in certain characters, by which they have come to be specifically different from each other; therefore these same characters would be more likely again to vary than the generic characters which have been inherited without change for an immense period. it is inexplicable on the theory of creation why a part developed in a very unusual manner in one species alone of a genus, and therefore, as we may naturally infer, of great importance to that species, should be eminently liable to variation; but, on our view, this part has undergone, since the several species branched off from a common progenitor, an unusual amount of variability and modification, and therefore we might expect the part generally to be still variable. but a part may be developed in the most unusual manner, like the wing of a bat, and yet not be more variable than any other structure, if the part be common to many subordinate forms, that is, if it has been inherited for a very long period; for in this case it will have been rendered constant by long-continued natural selection. glancing at instincts, marvellous as some are, they offer no greater difficulty than do corporeal structures on the theory of the natural selection of successive, slight, but profitable modifications. we can thus understand why nature moves by graduated steps in endowing certain animals of the same class with their several instincts. i have attempted to show how much light the principle of gradation throws on the admirable architectural powers of the hive-bee. habit no doubt often comes into play in modifying instincts; but it certainly is not indispensable, as we see in the case of neuter insects, which leave no progeny to inherit the effects of long-continued habit. on the view of all the species of the same genus having descended from a common parent, and having inherited much in common, we can understand how it is that allied species, when placed under widely different conditions of life, yet follow nearly the same instincts; why the thrushes of temperate and tropical south america, for instance, line their nests with mud like our british species. on the view of instincts having been slowly acquired through natural selection, we need not marvel at some instincts being not perfect and liable to mistakes, and at many instincts causing other animals to suffer. if species be only well-marked and permanent varieties, we can see at once why their crossed offspring should follow the same complex laws in their degrees and kinds of resemblance to their parents--in being absorbed into each other by successive crosses, and in other such points--as do the crossed offspring of acknowledged varieties. this similarity would be a strange fact, if species had been independently created and varieties had been produced through secondary laws. if we admit that the geological record is imperfect to an extreme degree, then the facts, which the record does give, strongly support the theory of descent with modification. new species have come on the stage slowly and at successive intervals; and the amount of change after equal intervals of time, is widely different in different groups. the extinction of species and of whole groups of species, which has played so conspicuous a part in the history of the organic world, almost inevitably follows from the principle of natural selection; for old forms are supplanted by new and improved forms. neither single species nor groups of species reappear when the chain of ordinary generation is once broken. the gradual diffusion of dominant forms, with the slow modification of their descendants, causes the forms of life, after long intervals of time, to appear as if they had changed simultaneously throughout the world. the fact of the fossil remains of each formation being in some degree intermediate in character between the fossils in the formations above and below, is simply explained by their intermediate position in the chain of descent. the grand fact that all extinct beings can be classed with all recent beings, naturally follows from the living and the extinct being the offspring of common parents. as species have generally diverged in character during their long course of descent and modification, we can understand why it is that the more ancient forms, or early progenitors of each group, so often occupy a position in some degree intermediate between existing groups. recent forms are generally looked upon as being, on the whole, higher in the scale of organization than ancient forms; and they must be higher, in so far as the later and more improved forms have conquered the older and less improved forms in the struggle for life; they have also generally had their organs more specialized for different functions. this fact is perfectly compatible with numerous beings still retaining simple but little improved structures, fitted for simple conditions of life; it is likewise compatible with some forms having retrograded in organization, by having become at each stage of descent better fitted for new and degraded habits of life. lastly, the wonderful law of the long endurance of allied forms on the same continent--of marsupials [as kangaroos] in australia, of edentata [as armadillos, sloths, and anteaters] in america, and other such cases--is intelligible, for within the same country the existing and the extinct will be closely allied by descent. looking to geographical distribution, if we admit that there has been during the long course of ages much migration from one part of the world to another, owing to former climatical and geographical changes and to the many occasional and unknown means of dispersal, then we can understand, on the theory of descent with modification, most of the great leading facts in distribution. we can see why there should be so striking a parallelism in the distribution of organic beings throughout space, and in their geological succession throughout time; for in both cases the beings have been connected by the bond of ordinary generation, and the means of modification have been the same. we see the full meaning of the wonderful fact, which has struck every traveller, namely, that on the same continent, under the most diverse conditions, under heat and cold, on mountain and lowland, on deserts and marshes, most of the inhabitants within each great class are plainly related; for they are the descendants of the same progenitors and early colonists. on this same principle of former migration, combined in most cases with modification, we can understand by the aid of the glacial period, the identity of some few plants and the close alliance of many others, on the most distant mountains, and in the northern and southern temperate zones; and likewise the close alliance of some of the inhabitants of the sea in the northern and southern temperate latitudes, though separated by the whole inter-tropical ocean. although two countries may present physical conditions as closely similar as the same species ever acquire, we need feel no surprise at their inhabitants being widely different, if they have been for a long period completely sundered from each other; for as the relation of organism to organism is the most important of all relations, and as the two countries will have received colonists at various periods and in different proportions, from some other country or from each other, the course of modification in the two areas will inevitably have been different. on this view of migration, with subsequent modification, we see why oceanic islands are inhabited by only few species, but of these, why many are peculiar or endemic forms. we clearly see why species belonging to those groups of animals which cannot cross wide spaces of the ocean, as frogs and terrestrial mammals, do not inhabit oceanic islands; and why, on the other hand, new and peculiar species of bats, animals which can traverse the ocean, are often found on islands far distant from any continent. such cases as the presence of peculiar species of bats on oceanic islands and the absence of all other terrestrial mammals, are facts utterly inexplicable on the theory of independent acts of creation. the existence of closely allied representative species in any two areas, implies on the theory of descent with modification, that the same parent-forms formerly inhabited both areas: and we almost invariably find that wherever many closely allied species inhabit two areas, some identical species are still common to both. wherever many closely allied yet distant species occur, doubtful forms and varieties belonging to the same groups likewise occur. it is a rule of high generality that the inhabitants of each area are related to the inhabitants of the nearest source whence immigrants might have been derived. we see this in the striking relation of nearly all the plants and animals of the galapagos archipelago, of juan fernandez, and of the other american islands, to the plants and animals of the neighbouring american mainland; and of those of the cape verde archipelago, and of the other african islands to the african mainland. it must be admitted that these facts receive no explanation on the theory of creation. the fact, as we have seen, that all past and present organic beings can be arranged within a few great classes, in groups subordinate to groups, and with the extinct groups often falling in between the recent groups, is intelligible on the theory of natural selection with its contingencies of extinction and divergence of character. on these same principles we see how it is that the mutual affinities of the forms within each class are so complex and circuitous. we see why certain characters are far more serviceable than others for classification; why adaptive characters derived from rudimentary parts, though of no service to the beings, are often of high classificatory value; and why embryological characters are often the most valuable of all. the real affinities of all organic beings, in contradistinction to their adaptive resemblances, are due to inheritance or community of descent. the natural system is a genealogical arrangement, with the acquired grades of difference, marked by the terms, varieties, species, genera, families, etc.; and we have to discover the lines of descent by the most permanent characters, whatever they may be, and of however slight vital importance. the similar framework of bones in the hand of a man, wing of a bat, fin of the porpoise, and leg of the horse--the same number of vertebr㦠forming the neck of the giraffe and of the elephant--and innumerable other such facts, at once explain themselves on the theory of descent with slow and slight successive modifications. the similarity of pattern in the wing and in the leg of a bat, though used for such different purpose--in the jaws and legs of a crab--in the petals, stamens, and pistils of a flower, is likewise, to a large extent, intelligible on the view of the gradual modification of parts or organs, which were aboriginally alike in an early progenitor in each of these classes. on the principle of successive variations not always supervening at an early age, and being inherited at a corresponding not early period of life, we clearly see why the embryos of mammals, birds, reptiles, and fishes should be so closely similar, and so unlike the adult forms. we may cease marvelling at the embryo of an air-breathing mammal or bird having branchial slits and arteries running in loops, like those of a fish which has to breathe the air dissolved in water by the aid of well-developed branchi㦠[gills]. disuse, aided sometimes by natural selection, will often have reduced organs when rendered useless under changed habits or conditions of life; and we can understand on this view the meaning of rudimentary organs. but disuse and selection will generally act on each creature, when it has come to maturity and has to play its full part in the struggle for existence, and will thus have little power in an organ during early life; hence the organ will not be reduced or rendered rudimentary at this early age. the calf, for instance, has inherited teeth, which never cut through the gums of the upper jaw, from an early progenitor having well-developed teeth; and we may believe, that the teeth in the mature animal were formerly reduced by disuse, owing to the tongue and palate, or lips, having become excellently fitted through natural selection to browse without their aid; whereas in the calf, the teeth have been left unaffected, and on the principle of inheritance at corresponding ages have been inherited from a remote period to the present day. on the view of each organism with all its separate parts having been specially created, how utterly inexplicable is it that organs bearing the plain stamp of inutility, such as the teeth in the embryonic calf or the shrivelled wings under the soldered wing covers of many beetles, should so frequently occur. nature may be said to have taken pains to reveal her scheme of modification, by means of rudimentary organs, of embryological and homologous [corresponding] structures, but we are too blind to understand her meaning. i have now recapitulated the facts and considerations which have thoroughly convinced me that species have been modified, during a long course of descent. this has been effected chiefly through the natural selection of numerous successive, slight, favourable variations; aided in an important manner by the inherited effects of the use and disuse of parts; and in an unimportant manner, that is, in relation to adaptive structures, whether past or present, by the direct action of external conditions, and by variations which seem to us in our ignorance to arise spontaneously. it appears that i formerly underrated the frequency and value of these latter forms of variation, as leading to permanent modifications of structure independently of natural selection. but as my conclusions have lately been much misrepresented, and it has been stated that i attribute the modification of species exclusively to natural selection, i may be permitted to remark that in the first edition of this work, and subsequently, i placed in a most conspicuous, position--namely, at the close of the introduction--the following words: "i am convinced that natural selection has been the main but not the exclusive means of modification." this has been of no avail. great is the power of steady misrepresentation; but the history of science shows that fortunately this power does not long endure. it can hardly be supposed that a false theory would explain, in so satisfactory a manner as does the theory of natural selection, the several large classes of facts above specified. it has recently been objected that this is an unsafe method of arguing; but it is a method used in judging the common events of life, and has often been used by the greatest natural philosophers. the undulatory theory of light has thus been arrived at; and the belief in the revolution of the earth on its own axis was until lately supported by hardly any direct evidence. it is no valid objection that science as yet throws no light on the far higher problems of the essence of the origin of life. who can explain what is the essence of the attraction of gravity? no one now objects to following out the results consequent on this unknown element of attraction; notwithstanding that leibnitz formerly accused newton of introducing "occult qualities and miracles into philosophy." i see no good reasons why the views given in this volume should shock the religious feelings of any one. it is satisfactory, as showing how transient such impressions are, to remember that the greatest discovery ever made by man, namely, the law of the attraction of gravity, was also attacked by leibnitz, "as subversive of natural, and inferentially of revealed religion." a celebrated author and divine has written to me that "he has gradually learned to see that it is just as noble a conception of the deity to believe that he created a few original forms capable of self-development into other and needful forms, as to believe that he required a fresh act of creation to supply the voids caused by the action of his laws." why, it may be asked, until recently did nearly all the most eminent living naturalists and geologists disbelieve in the mutability of species? it cannot be asserted that organic beings in a state of nature are subject to no variation; it cannot be proved that the amount of variation in the course of long ages is a limited quantity; no clear distinction has been, or can be, drawn between species and well-marked varieties. it cannot be maintained that species when intercrossed are invariably sterile and varieties invariably fertile; or that sterility is a special endowment and sign of creation. the belief that species were immutable productions was almost unavoidable as long as the history of the world was thought to be of short duration; and now that we have acquired some idea of the lapse of time, we are too apt to assume, without proof, that the geological record is so perfect that it would have afforded us plain evidence of the mutation of species, if they had undergone mutation. but the chief cause of our natural unwillingness to admit that one species has given birth to other and distinct species, is that we are always slow in admitting great changes of which we do not see the steps. the difficulty is the same as that felt by so many geologists, when lyell first insisted that long lines of inland cliffs had been formed, and great valleys excavated, by the agencies which we still see at work. the mind cannot possibly grasp the full meaning of the term of even a million years; it cannot add up and perceive the full effects of many slight variations, accumulated during an almost infinite number of generations. although i am fully convinced of the truth of the views given in this volume under the form of an abstract, i by no means expect to convince experienced naturalists whose minds are stocked with a multitude of facts all viewed, during a long course of years, from a point of view directly opposite to mine. it is so easy to hide our ignorance under such expressions as the "plan of creation," "unity of design," etc., and to think that we give an explanation when we only restate a fact. any one whose disposition leads him to attach more weight to unexplained difficulties than to the explanation of a certain number of facts will certainly reject the theory. a few naturalists, endowed with much flexibility of mind, and who have already begun to doubt the immutability of species, may be influenced by this volume; but i look with confidence to the future, to young and rising naturalists, who will be able to view both sides of the question with impartiality. whoever is led to believe that species are mutable will do good service by conscientiously expressing his conviction; for thus only can the load of prejudice by which this subject is overwhelmed be removed. several eminent naturalists have of late published their belief that a multitude of reputed species in each genus are not real species; but that other species are real, that is, have been independently created. this seems to me a strange conclusion to arrive at. they admit that a multitude of forms, which till lately they themselves thought were special creations, and which are still thus looked at by the majority of naturalists, and which consequently have all the external characteristic features of true species--they admit that these have been produced by variation, but they refuse to extend the same view to other and slightly different forms. nevertheless, they do not pretend that they can define, or even conjecture, which are the created forms of life, and which are those produced by secondary laws. they admit variation as a true cause in one case, they arbitrarily reject it in another, without assigning any distinction in the two cases. the day will come when this will be given as a curious illustration of the blindness of preconceived opinion. these authors seem no more startled at a miraculous act of creation than at an ordinary birth. but do they really believe that at innumerable periods in the earth's history certain elemental atoms have been commanded suddenly to flash into living tissues? do they believe that at each supposed act of creation one individual or many were produced? were all the infinite numerous kinds of animals and plants created as eggs or seed, or as full grown? and in the case of mammals, were they created bearing the false marks of nourishment from the mother's womb? undoubtedly some of these same questions cannot be answered by those who believe in the appearance or creation of only a few forms of life, or of some one form alone. it has been maintained by several authors that it is as easy to believe in the creation of a million beings as of one; but maupertuis's philosophical axiom "of least action" leads the mind more willingly to admit the smaller number; and certainly we ought not to believe that innumerable beings within each great class have been created with plain, but deceptive, marks of descent from a single parent. as a record of a former state of things, i have retained in the foregoing paragraphs, and elsewhere, several sentences which imply that naturalists believe in the separate creation of each species; and i have been much censured for having thus expressed myself. but undoubtedly this was the general belief when the first edition of the present work appeared. i formerly spoke to very many naturalists on the subject of evolution, and never once met with any sympathetic agreement. it is probable that some did then believe in evolution, but they were either silent or expressed themselves so ambiguously that it was not easy to understand their meaning. now, things are wholly changed, and almost every naturalist admits the great principle of evolution. there are, however, some who still think that species have suddenly given birth, through quite unexplained means, to new and totally different forms. but, as i have attempted to show, weighty evidence can be opposed to the admission of great and abrupt modifications. under a scientific point of view, and as leading to further investigation, but little advantage is gained by believing that new forms are suddenly developed in an inexplicable manner from old and widely different forms, over the old belief in the creation of species from the dust of the earth. it may be asked how far i extend the doctrine of the modification of species. the question is difficult to answer, because the more distinct the forms are which we consider, by so much the arguments in favour of community of descent become fewer in number and less in force. but some arguments of the greatest weight extend very far. all the members of whole classes are connected together by a chain of affinities, and all can be classed on the same principle, in groups subordinate to groups. fossil remains sometimes tend to fill up very wide intervals between existing orders. organs in a rudimentary condition plainly show that an early progenitor had the organ in a fully developed condition, and this in some cases implies an enormous amount of modification in the descendants. throughout whole classes various structures are formed on the same pattern, and at a very early age the embryos closely resemble each other. therefore i cannot doubt that the theory of descent with modification embraces all the members of the same great class or kingdom. i believe that animals are descended from at most only four or five progenitors, and plants from an equal or lesser number. analogy would lead me one step further, namely, to the belief that all animals and plants are descended from some one prototype. but analogy may be a deceitful guide. nevertheless all living things have much in common, in their chemical composition, their cellular structure, their laws of growth, and their liability to injurious influences. we see this even in so trifling a fact as that the same poison often similarly affects plants and animals; or that the poison secreted by the gall-fly produces monstrous growths on the wild rose or oak tree. with all organic beings, excepting perhaps some of the very lowest, sexual reproduction seems to be essentially similar. with all, as far as is at present known, the germinal vesicle is the same; so that all organisms start from a common origin. if we look even to the two main divisions--namely, to the animal and vegetable kingdoms--certain low forms are so far intermediate in character that naturalists have disputed to which kingdom they should be referred. as professor asa gray has remarked, "the spores and other reproductive bodies of many of the lower alg㦠may claim to have first a characteristically animal, and then an unequivocally vegetable existence." therefore, on the principle of natural selection with divergence of character, it does not seem incredible that, from some such low and intermediate form, both animals and plants may have been developed; and, if we admit this, we must likewise admit that all the organic beings which have ever lived on this earth may be descended from some one primordial form. but this inference is chiefly grounded on analogy, and it is immaterial whether or not it is accepted. no doubt it is possible, as mr. g. h. lewes has urged, that at the first commencement of life many different forms were evolved; but if so, we may conclude that only a very few have left modified descendants. for, as i have recently remarked in regard to the members of each great kingdom, such as the vertebrata, articulata, etc., we have distinct evidence in their embryological, homologous, and rudimentary structures, that within each kingdom all the members are descended from a single progenitor. when the views advanced by me in this volume, and by mr. wallace, or when analogous views on the origin of species are generally admitted, we can dimly foresee that there will be a considerable revolution in natural history. systematists will be able to pursue their labours as at present; but they will not be incessantly haunted by the shadowy doubt whether this or that form be a true species. this, i feel sure and i speak after experience, will be no slight relief. the endless disputes whether or not some fifty species of british brambles are good species will cease. systematists will have only to decide (not that this will be easy) whether any form be sufficiently constant and distinct from other forms, to be capable of definition; and if definable, whether the differences be sufficiently important to deserve a specific name. this latter point will become a far more essential consideration than it is at present; for differences, however slight, between any two forms, if not blended by intermediate gradations, are looked at by most naturalists as sufficient to raise both forms to the rank of species. hereafter we shall be compelled to acknowledge that the only distinction between species and well-marked varieties is, that the latter are known, or believed to be connected at the present day by intermediate gradations, whereas species were formerly thus connected. hence, without rejecting the considerations of the present existence of intermediate gradations between any two forms, we shall be led to weigh more carefully and to value higher the actual amount of difference between them. it is quite possible that forms now generally acknowledged to be merely varieties may hereafter be thought worthy of specific names; and in this case scientific and common language will come into accordance. in short, we shall have to treat species in the same manner as those naturalists treat genera, who admit that genera are merely artificial combinations made for convenience. this may not be a cheering prospect; but we shall at least be freed from the vain search for the undiscovered and undiscoverable essence of the term species. the other and more general departments of natural history will rise greatly in interest. the terms used by naturalists, of affinity, relationship, community of type, paternity, morphology [the science of organic form], adaptive characters, rudimentary and aborted organs, etc., will cease to be metaphorical and will have a plain signification. when we no longer look at an organic being as a savage looks at a ship, as something wholly beyond his comprehension; when we regard every production of nature as one which has had a long history; when we contemplate every complex structure and instinct as the summing up of many contrivances, each useful to the possessor, in the same way as any great mechanical invention is the summing up of the labour, the experience, the reason, and even the blunders of numerous workmen; when we thus view each organic being, how far more interesting--i speak from experience--does the study of natural history become! a grand and almost untrodden field of inquiry will be opened, on the causes and laws of variation, on correlation, on the effects of use and disuse, on the direct action of external conditions, and so forth. the study of domestic productions will rise immensely in value. a new variety raised by man will be a more important and interesting subject for study than one more species added to the infinitude of already recorded species. our classifications will come to be, as far as they can be so made, genealogies; and will then truly give what may be called the plan of creation. the rules for classifying will no doubt become simpler when we have a definite object in view. we possess no pedigree or armorial bearings; and we have to discover and trace the many diverging lines of descent in our natural genealogies, by characters of any kind which have long been inherited. rudimentary[1] organs will speak infallibly with respect to the nature of long-lost structures. species and groups of species which are called aberrant, and which may fancifully be called living fossils, will aid us in forming a picture of the ancient forms of life. embryology will often reveal to us the structure, in some degree obscured, of the prototypes of each great class. when we can feel assured that all the individuals of the same species, and all the closely allied species of most genera, have, within a not very remote period descended from one parent, and have migrated from some one birth-place; and when we better know the many means of migration, then, by the light which geology now throws, and will continue to throw, on former changes of climate and of the level of the land, we shall surely be enabled to trace in an admirable manner the former migrations of the inhabitants of the whole world. even at present, by comparing the differences between the inhabitants of the sea on the opposite sides of a continent, and the nature of the various inhabitants on that continent in relation to their apparent means of immigration, some light can be thrown on ancient geography. the noble science of geology loses glory from the extreme imperfection of the record. the crust of the earth, with its imbedded remains, must not be looked at as a well-filled museum, but as a poor collection made at hazard and at rare intervals. the accumulation of each great fossiliferous formation will be recognized as having depended on an unusual occurrence of favourable circumstances, and the blank intervals between the successive stages as having been of vast duration. but we shall be able to gauge with some security the duration of these intervals by a comparison of the preceding and succeeding organic forms. we must be cautious in attempting to correlate as strictly contemporaneous two formations, which do not include many identical species, by the general succession of the forms of life. as species are produced and exterminated by slowly acting and still existing causes, and not by miraculous acts of creation; and as the most important of all causes of organic change is one which is almost independent of altered and perhaps suddenly altered physical conditions, namely, the mutual relation of organism to organism--the improvement of one organism entailing the improvement or the extermination of others; it follows, that the amount of organic change in the fossils of consecutive formations probably serves as a fair measure of the relative, though not actual lapse of time. a number of species, however, keeping in a body might remain for a long period unchanged, while within the same period, several of these species, by migrating into new countries and coming into competition with foreign associates, might become modified; so that we must not overrate the accuracy of organic change as a measure of time. in the future i see open fields for far more important researches. psychology will be securely based on the foundation already well laid by mr. herbert spencer, that of the necessary acquirement of each mental power and capacity by gradation. much light will be thrown on the origin of man and his history. authors of the highest eminence seem to be fully satisfied with the view that each species has been independently created. to my mind it accords better with what we know of the laws impressed on matter by the creator, that the production and extinction of the past and present inhabitants of the world should have been due to secondary causes, like those determining the birth and death of the individual. when i view all beings as not special creations, but as the lineal descendants of some few beings which lived long before the first bed of the cambrian system was deposited, they seem to me to become ennobled. judging from the past, we may safely infer that not one living species will transmit its unaltered likeness to a distant futurity. and of the species now living very few will transmit progeny of any kind to a far distant futurity; for the manner in which all organic beings are grouped, shows that the greater number of species in each genus, and all the species in many genera, have left no descendants, but have become utterly extinct. we can so far take a prophetic glance into futurity as to foretell that it will be the common and widely spread species, belonging to the larger and dominant groups within each class, which will ultimately prevail and procreate new and dominant species. as all the living forms of life are the lineal descendants of those which lived long before the cambrian epoch, we may feel certain that the ordinary succession by generation has never once been broken, and that no cataclysm has desolated the whole world. hence, we may look with some confidence to a secure future of great length. and as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress toward perfection. it is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us. these laws taken in the largest sense, being growth with reproduction; inheritance which is almost implied by reproduction; variability from the indirect and direct action of the conditions of life, and from use and disuse: a ratio of increase so high as to lead to a struggle for life, and as a consequence to natural selection, entailing divergence of character and the extinction of less improved forms. thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. there is grandeur in this view of life, with its several powers, having been originally breathed by the creator into a few forms or into one; and that, while this planet has gone circling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved. footnotes: [1] _vestigial_ is now preferred to _rudimentary_ as a term.--ed. how "the origin of species" came to be written. [an extract from the autobiography of charles darwin, in "the life and letters of charles darwin," new york, d. appleton & co.] from september, 1854, i devoted my whole time to arranging my huge pile of notes, to observing and to experimenting in relation to the transmutation of species. during the voyage of the _beagle_ i had been deeply impressed by discovering in the pampean formation great fossil animals covered with armour like that on the existing armadillos; secondly, by the manner in which closely allied animals replace one another in proceeding southwards over the continent; and, thirdly, by the south american character of most of the productions of the galapagos archipelago, and more especially by the manner in which these differ slightly on each island of the group, none of these islands appearing to be very ancient in a geological sense. it was evident that such facts as these, as well as many others, could only be explained on the supposition that species gradually become modified; and the subject haunted me. but it was equally evident that neither the action of the surrounding conditions, nor the will of the organisms (especially in the case of plants) could account for the innumerable cases in which organisms of every kind are beautifully adapted to their habits of life--for instance, a woodpecker or a tree-frog to climb trees, or a seed for dispersal by hooks or plumes. i had always been much struck by such adaptations, and until these could be explained it seemed to me almost useless to endeavour to prove by indirect evidence that species have been modified. after my return to england it appeared to me that by following the example of lyell in geology,[2] and by collecting all facts that bore in any way on the variation of animals and plants under domestication and nature, some light might perhaps be thrown on the whole subject. my first note-book was opened in july, 1837. i worked on true baconian principles, and without any theory collected facts on a wholesale scale, more especially with respect to domesticated productions, by printed enquiries, by conversation with skilful breeders and gardeners and by extensive reading. when i see the list of books of all kinds which i read and abstracted, including whole series of journals and translations, i am surprised at my industry. i soon perceived that selection was the keystone of man's success in making useful races of animals and plants. but how selection could be applied to organisms living in a state of nature remained for some time a mystery to me. in october, 1838, that is fifteen months after i had begun my systematic enquiry, i happened to read for amusement "malthus on population," and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved and unfavourable ones to be destroyed. the result of this would be the formation of a new species. here then i had at last got a theory by which to work; but i was so anxious to avoid prejudice that i determined not for some time to write even the briefest sketch of it. in june, 1842, i first allowed myself the satisfaction of writing a very brief abstract of my theory in pencil in 35 pages; and this was enlarged during the summer of 1844 into one of 230 pages, which i had fairly copied out and still possess. but at that time i overlooked one problem of great importance; and it is astonishing to me, except on the principle of columbus and his egg, how i could have overlooked it and its solution. this problem is the tendency in organic beings descended from the same stock to diverge in character as they become, modified. that they have diverged greatly is obvious from the manner in which species of all kinds can be classed under genera, genera under families, families under sub-orders and so forth; and i can remember the very spot on the road, whilst in my carriage, when to my joy the solution occurred to me; and this was long after i had come to down. this solution, as i believe, is that the modified offspring of all dominant and increasing forms tend to become adapted to many and highly diversified places in the economy of nature. early in 1856 lyell advised me to write out my views pretty fully, and i began at once to do so on a scale three or four times as extensive as that which was afterwards followed in my "origin of species;" yet it was only an abstract of the materials which i had collected and i got through about half the work on this scale. but my plans were overthrown, for early in the summer of 1858 mr. wallace, who was then in the malay archipelago, sent me an essay "on the tendency of varieties to depart indefinitely from the original type;" and this essay contained exactly the same theory as mine.[3] mr. wallace expressed the wish that if i thought well of his essay i should send it to lyell for perusal. the circumstances under which i consented at the request of lyell and hooker to allow of an abstract from my ms., together with a letter to asa gray, dated september 5, 1857, to be published at the same time with wallace's essay, are given in the "journal of the proceedings of the linnean society," 1858, p. 45. i was at first very unwilling to consent, as i thought mr. wallace might consider my doing so unjustifiable, for i did not then know how generous and noble was his disposition. the extract from my ms. and the letter to asa gray had neither been intended for publication, and were badly written. mr. wallace's essay, on the other hand, was admirably expressed and quite clear. nevertheless, our joint productions excited very little attention, and the only published notice of them which i can remember was by professor haughton of dublin, whose verdict was that all that was new in them was false, and what was true was old. this shows how necessary it is that any new idea should be explained at considerable length in order to arouse public attention. in september, 1858, i set to work by the strong advice of lyell and hooker to prepare a volume on the transmutation of species, but was often interrupted by ill health and short visits to dr. lane's delightful hydropathic establishment at moor park. i abstracted the ms. begun on a much larger scale in 1856, and completed the volume on the same reduced scale. it cost me thirteen months and ten days' hard labor. it was published under the title of the "origin of species," in november, 1859. though considerably added to and corrected in the later editions, it has remained substantially the same book. it is no doubt the chief work of my life. it was from the first highly successful. the first small edition of 1,250 copies was sold on the day of publication, and a second edition of 3,000 copies soon afterwards. sixteen thousand copies have now (1876) been sold in england; and considering how stiff a book it is, this is a large sale. it has been translated into almost every european tongue, even into such languages as spanish, bohemian, polish and russian. even an essay in hebrew has appeared on it, showing that the theory is contained in the old testament! the reviews were very numerous; for some time all that appeared on the "origin" and on my related books, and these amount (excluding newspaper reviews) to 265; but after a time i gave up the attempt in despair. many separate essays and books on the subject have appeared; and in germany a catalogue or bibliography on "darwinismus" has appeared every year or two. the success of the "origin" may, i think, be attributed in large part to my having long before written two condensed sketches and to my having abstracted a much larger manuscript, which was itself an abstract. by this means i was enabled to select the more striking facts and conclusions. i had also, during many years followed a golden rule, namely, that whenever a published fact, a new observation or thought came across me, which was opposed to my general results, to make a memorandum of it without fail and at once; for i had found by experience that such facts and thoughts were far more apt to escape from the memory than favourable ones. owing to this habit very few objections were raised against my views which i had not at least noticed and attempted to answer. it has sometimes been said that the success of the "origin" proved "that the subject was in the air," or "that men's minds were prepared for it." i do not think that this is strictly true, for i occasionally sounded not a few naturalists, and never happened to come across a single one who seemed to doubt about the permanence of species. even lyell and hooker, though they listened with interest to me, never seemed to agree. i tried once or twice to explain to able men what i meant by natural selection, but signally failed. what i believe was strictly true is that innumerable well-observed facts were stored in the minds of naturalists ready to take their proper places as soon as any theory which would receive them was sufficiently explained. another element in the success of the book was its moderate size; and this i owe to the appearance of mr. wallace's essay; had i published on the scale on which i began to write in 1856, the book would have been four or five times as large as the "origin," and very few would have had the patience to read it. i gained much by my delay an publishing from about, 1839, when the theory was clearly conceived, to 1859; and i lost nothing by it, for i cared very little whether men attributed most originality to me or wallace; and his essay no doubt aided in the reception of the theory. i was forestalled in only one important point, which my vanity has always made me regret, namely, the explanation by means of the glacial period of the presence of the same species of plants and of some few animals on distant mountain summits and in the arctic regions. this view pleased me so much that i wrote it out _in extenso_, and i believe that it was read by hooker some years before e. forbes published in 1846 his celebrated memoir on the subject. in the very few points in which we differed, i still think that i was in the right. i have never, of course, alluded in print to my having independently worked out this view. hardly any point gave me so much satisfaction when i was at work on the "origin," as the explanation of the wide difference in many classes between the embryo and the adult animal, and of the close resemblance of the embryos within the same class. no notice of this point was taken, as far as i remember, in the early reviews of the "origin," and i recollect expressing my surprise on this head in a letter to asa gray. within late years several reviewers have given the whole credit to fritz muller and haeckel, who undoubtedly have worked it out much more fully and in some respects more correctly than i did. i had materials for a whole chapter on the subject, and i ought to have made the discussion longer; for it is clear that i failed to impress my readers; and he who succeeds in doing so deserves, in my opinion, all the credit. this leads me to remark that i have almost always been treated honestly by my reviewers, passing over those without scientific knowledge as not worthy of notice. my views have been grossly misrepresented, bitterly opposed and ridiculed, but this has been generally done as, i believe, in good faith. on the whole, i do not doubt that my works have been over and over again greatly overpraised. i rejoice that i have avoided controversies, and this i owe to lyell, who many years ago, in reference to my geological works, strongly advised me never to get entangled in a controversy, as it rarely did any good and caused a miserable loss of time and temper. whenever i have found out that i have blundered, or that my work has been imperfect, and when i have been contemptuously criticised, and even when i have been overpraised, so that i have felt mortified, it has been my greatest comfort to say hundreds of times to myself that "i have worked as hard and as well as i could, and no man can do more than this." i remember when in good success bay, in tierra del fuego, thinking (and, i believe, that i wrote home to the effect) that i could not employ my life better than in adding a little to natural science. this i have done to the best of my abilities, and critics may say what they like, but they can not destroy this conviction. footnotes: [2] see masterpieces of science, vol. i, "earth and sky," sir charles lyell on uniformity in geological change. [3] the essay appears in "natural selection," london, 1870. the descent of man charles darwin [concluding chapter of "the descent of man," new york, d. appleton & co.] a brief summary will be sufficient to recall to the reader's mind the more salient points in this work. many of the views which have been advanced are highly speculative, and some, no doubt, will prove erroneous; but i have in every case given the reasons which have led me to one view rather than to another. it seemed worth while to try how far the principle of evolution would throw light on some of the more complex problems in the natural history of man. false facts are highly injurious to the progress of science, for they often endure long; but false views, if supported by some evidence, do little harm, for every one takes a salutary pleasure in proving their falseness; and, when this is done, one path toward error is closed and the road to truth is often at the same time opened. the main conclusion arrived at in this work, and now held by many naturalists who are well competent to form a sound judgment, is that man is descended from some less highly organized form. the grounds upon which this conclusion rests will never be shaken, for the close similarity between man and the lower animals in embryonic development, as well as in innumerable points of structure and constitution, both of high and of the most trifling importance--the rudiments which he retains, and the abnormal reversions to which he is occasionally liable--are facts which cannot be disputed. they have long been known, but, until recently, they told us nothing with respect to the origin of man. now, when viewed by the light of our knowledge of the whole organic world, their meaning is unmistakable. the great principle of evolution stands up clear and firm when these groups of facts are considered in connection with others, such as the mutual affinities of the members of the same group, their geographical distribution in past and present times, and their geological succession. it is incredible that all these facts should speak falsely. he who is not content to look, like a savage, at the phenomena of nature as disconnected, cannot any longer believe that man is the work of a separate act of creation. he will be forced to admit that the close resemblance of the embryo of man to that, for instance, of a dog--the construction of his skull, limbs and whole frame on the same plan with that of other mammals--the occasional appearance of various structures, for instance, of several distinct muscles, which man does not normally possess, but which are common to the quadrumana--and a crowd of analogous facts--all point in the plainest manner to the conclusion that man is the co-descendant of other mammals of a common progenitor. we have seen that man incessantly presents individual differences in all parts of his body and in his mental faculties. these differences or variations seem to be induced by the same general causes, and to obey the same laws as with the lower animals. in both cases similar laws of inheritance prevail. man tends to increase at a greater rate than his means of subsistence; consequently he is occasionally subjected to a severe struggle for existence, and natural selection will have effected whatever lies within its scope. a succession of strongly marked variations of a similar nature is by no means requisite; slight fluctuating differences in the individual suffice in the work of natural selection. we may feel assured that the inherited effects of the long-continued use or disuse of parts will have done much in the same direction with natural selection. modifications formerly of importance, though no longer of any special use, are long-inherited. when one part is modified other parts change through the principle of correlation, of which we have instances in many curious cases of correlated monstrosities. something may be attributed to the direct and definite action of the surrounding conditions of life, such as abundant food, heat or moisture; and, lastly, many characters of slight physiological importance, some indeed of considerable importance, have been gained through sexual selection. no doubt man, as well as every other animal, presents structures, which, as far as we can judge with our little knowledge, are not now of any service to him, nor to have been so during any former period of his existence, either in relation to his general conditions of life, or of one sex to the other. such structures cannot be accounted for by any form of selection, or by the inherited effects of the use and disuse of parts. we know, however, that many strange and strongly marked peculiarities of structure occasionally appear in our domesticated productions, and if the unknown causes which produce them were to act more uniformly, they would probably become common to all the individuals of the species. we may hope hereafter to understand something about the causes of such occasional modifications, especially through the study of monstrosities; hence, the labours of experimentalists, such as those of m. camille dareste, are full of promise for the future. in general we can only say that the cause of each slight variation and of each monstrosity lies much more in the constitution of the organism than in the nature of the surrounding conditions; though new and changed conditions certainly play an important part in exciting organic changes of many kinds. through the means just specified, aided perhaps by others as yet undiscovered, man has been raised to his present state. but since he attained to the rank of manhood, he has diverged into distinct races, or, as they may be more fitly called, subspecies. some of these, such as the negro and european, are so distinct that, if specimens had been brought to a naturalist without any further information, they would undoubtedly have been considered by him as good and true species. nevertheless, all the races agree in so many unimportant details of structure and in so many mental peculiarities, that these can be accounted for only by inheritance from a common progenitor; and a progenitor thus characterized would probably deserve to rank as man. it must not be supposed that the divergence of each race from the other races, and of all from a common stock, can be traced back to any one pair of progenitors. on the contrary, at every stage in the process of modification, all the individuals which were in any way best fitted for their conditions of life, though in different degrees, would have survived in greater numbers than the less well-fitted. the process would have been like that followed by man, when he does not intentionally select particular individuals, but breeds from all the superior individuals and neglects all the inferior individuals. he thus slowly but surely modifies his stock and unconsciously forms a new strain. so with respect to modifications acquired independently of selection, and due to variations arising from the nature of the organism and the action of the surrounding conditions, or from changed habits of life, no single pair will have been modified in a much greater degree than the other pairs which inhabit the same country, for all will have been continually blended through free intercrossing. by considering the embryological structure of man--the homologies [parallels] which he presents with the lower animals--the rudiments which he retains--and the reversions to which he is liable, we can partly recall in imagination the former condition of our early progenitors; and can approximately place them in their proper place in the zoological series. we thus learn that man is descended from a hairy, tailed quadruped, probably arboreal in its habits [living on or among trees] and an inhabitant of the old world. this creature, if its whole structure had been examined by a naturalist, would have been classed among the quadrumana, as surely as the still more ancient progenitor of the old and new world monkeys. the quadrumana and all the higher mammals are probably derived from an ancient marsupial animal [usually provided with a pouch for the reception and nourishment of the young, as in the case of the kangaroo] and this through a long line of diversified forms, from some reptile-like or some amphibian-like creature, and this again from some fish-like animal. in the dim obscurity of the past we can see that the early progenitor of all the vertebrata must have been an aquatic animal, provided with branchi㦠[gills], with the two sexes united in the same individual, and with the most important organs of the body (such as the brain and heart) imperfectly or not at all developed. this animal seems to have been more like the larv㦠of the existing marine ascidians than any other known form. the greatest difficulty which presents itself when we are driven to the above conclusion on the origin of man is the high standard of intellectual power and of moral disposition which he has attained. but every one who admits the principle of evolution must see that the mental powers of the higher animals, which are the same in kind with those of man, though so different in degree, are capable of advancement. thus the interval between the mental powers of one of the higher apes and of a fish, or between those of an ant and scale-insect, is immense; yet their development does not offer any special difficulty; for with our domesticated animals the mental faculties are certainly variable, and the variations are inherited. no one doubts that they are of the utmost importance to animals in a state of nature. therefore, the conditions are favourable for their development through natural selection. the same conclusion may be extended to man; the intellect must have been all-important to him, even at a very remote period, as enabling him to invent and use language, to make weapons, tools, traps, etc., whereby with the aid of his social habits he long ago became the most dominant of all living creatures. a great stride in the development of the intellect will have followed, as soon as the half-art and half-instinct of language came into use; for the continued use of language will have reacted on the brain and produced an inherited effect; and this again will have reacted on the improvement of language. as mr. chauncey wright has well remarked, the largeness of the brain in man relatively to his body, compared with the lower animals, may be attributed in chief part to the early use of some simple form of language--that wonderful engine which affixes signs to all sorts of objects and qualities, and excites trains of thought which would never arise from the mere impression of the senses, or if they did arise could not be followed out. the higher intellectual powers of man, such as those of ratiocination, abstraction, self-consciousness, etc., will have followed from the continued improvement of other mental faculties; but without considerable culture of the mind, both in the race and in the individual, it is doubtful whether these high powers would be exercised and thus fully attained. the development of the moral qualities is a more interesting problem. the foundation lies in the social instincts, including under this term the family ties. these instincts are highly complex, and in the case of the lower animals give special tendencies toward certain definite actions; but the more important elements are love and the distinct emotion of sympathy. animals endowed with the social instincts take pleasure in one another's company, warn one another of danger, defend and aid one another in many ways. these instincts do not extend to all the individuals of the species, but only to those of the same community. as they are highly beneficial to the species they have in all probability been acquired through natural selection. a moral being is one who is capable of reflecting on his past actions and their motives--of approving of some and disapproving of others; and the fact that man is the one being who certainly deserves this designation is the greatest of all distinctions between him and the lower animals. but in the fourth chapter i have endeavoured to show that the moral sense follows, firstly, from the enduring and ever-present nature of the social instincts; secondly, from man's appreciation of the approbation and disapprobation of his fellows; and, thirdly, from the high activity of his mental faculties, with past impressions extremely vivid; and in these latter respects he differs from the lower animals. owing to this condition of mind, man cannot avoid looking both backward and forward and comparing past impressions. hence, after some temporary desire or passion has mastered his social instincts, he reflects and compares the now weakened impression of such past impulses with the ever-present social instincts; and he then feels that sense of dissatisfaction which all unsatisfied instincts leave behind them, he therefore resolves to act differently for the future--and this is conscience. any instinct permanently stronger or more enduring than another gives rise to a feeling which we express by saying that it ought to be obeyed. a pointer dog if able to reflect on his past conduct would say to himself, i ought (as indeed we say of him) to have pointed at that hare and not have yielded to the passing temptation of hunting it. social animals are impelled partly by a wish to aid the members of their community in a general manner, but more commonly to perform certain definite actions. man is impelled by the same general wish to aid his fellows; but has few or no special instincts. he differs also from the lower animals in the power of expressing his desires by words, which thus become a guide to the aid required and bestowed. the motive to give aid is likewise much modified in man; it no longer consists solely of a blind instinctive impulse, but is much influenced by the praise or blame of his fellows. the appreciation and bestowal of praise and blame both rest on sympathy; and this emotion, as we have seen, is one of the most important elements of the social instincts. sympathy, though gained as an instinct, is also much strengthened by exercise or habit. as all men desire their own happiness, praise or blame is bestowed on actions or motives according as they lead to this end; and as happiness is an essential part of the general good the greatest-happiness principle indirectly serves as a nearly safe standard of right and wrong. as the reasoning powers advance and experience is gained the remoter effects of certain lines of conduct on the character of the individual and on the general good are perceived; and then the self-regarding virtues come within the scope of public opinion and receive praise and their opposites blame. but with the less civilized nations reason often errs, and many bad customs and base superstitions come within the same scope and are then esteemed as high virtues and their breach as heavy crimes. the moral faculties are generally and justly esteemed as of higher value than the intellectual powers. but we should bear in mind that the activity of the mind in vividly recalling past impressions is one of the fundamental though secondary bases of conscience. this affords the strongest argument for educating and stimulating in all possible ways the intellectual faculties of every human being. no doubt, a man with a torpid mind, if his social affections and sympathies are well developed, will be led to good actions and may have a fairly sensitive conscience. but whatever renders the imagination more vivid and strengthens the habit of recalling and comparing past impressions will make the conscience more sensitive, and may even somewhat compensate for weak social affections and sympathies. the moral nature of man has reached its present standard partly through the advancement of his reasoning powers and consequently of a just public opinion, but especially from his sympathies having been rendered more tender and widely diffused through the effects of habit, example, instruction and reflection. it is not improbable that after long practice virtuous tendencies may be inherited. with the more civilized races the conviction of the existence of an all-seeing deity has had a potent influence on the advance of morality. ultimately man does not accept the praise or blame of his fellows as his sole guide, though few escape this influence, but his habitual convictions, controlled by reason, afford him the safest rule. his conscience then becomes the supreme judge and monitor. nevertheless, the first foundation or origin of the moral sense lies in the social instincts, including sympathy; and these instincts, no doubt, were primarily gained, as in the case of the lower animals, through natural selection. the belief in god has often been advanced as not only the greatest but the most complete of all the distinctions between man and the lower animals. it is, however, impossible, as we have seen, to maintain that this belief is innate or instinctive in man. on the other hand, a belief in all-pervading spiritual agencies seems to be universal, and apparently follows from a considerable advance in man's reason and from a still greater advance in his faculties of imagination, curiosity and wonder. i am aware that the assumed instinctive belief in god has been used by many persons as an argument for his existence. but this is a rash judgment, as we should thus be compelled to believe in the existence of many cruel and malignant spirits, only a little more powerful than man; for the belief in them is far more general than in a beneficent deity. the idea of a universal and beneficent creator does not seem to arise in the mind of man until he has been elevated by long-continued culture. he who believes in the advancement of man from some low organized form will naturally ask, how does this bear on the belief in the immortality of the soul? the barbarous races of man, as sir j. lubbock has shown, possess no clear belief of this kind; but arguments derived from the primeval beliefs of savages are, as we have just seen, of little or no avail. few persons feel any anxiety from the impossibility of determining at what precise period in the development of the individual, from the first trace of a minute germinal vesicle, man becomes an immortal being; and there is no greater cause for anxiety because the period in the gradually ascending organic scale cannot possibly be determined. i am aware that the conclusions arrived at in this work will be denounced by some as highly irreligious; but he who denounces them is bound to show why it is more irreligious to explain the origin of man as a distinct species by descent from some lower form, through the laws of variation and natural selection, than to explain the birth of the individual through the laws of ordinary reproduction. the birth both of the species and of the individual are equally parts of that grand sequence of events, which our minds refuse to accept as the result of blind chance. the understanding revolts at such a conclusion, whether or not we are able to believe that every slight variation of structure, the union of each pair in marriage, the dissemination of each seed, and other such events have all been ordained for some special purpose. sexual selection has been treated at great length in this work; for, as i have attempted to show, it has played an important part in the history of the organic world. i am aware that much remains doubtful, but i have endeavoured to give a fair view of the whole case. in the lower divisions of the animal kingdom sexual selection seems to have done nothing; such animals are often affixed for life to the same spot, or have the sexes combined in the same individual, or, what is still more important, their perceptive and intellectual faculties are not sufficiently advanced to allow of the feelings of love and jealousy, or of the exertion of choice. when, however, we come to the arthropoda and vertebrata, even to the lowest classes in these two great sub-kingdoms, sexual selection has effected much; and it deserves notice that we here find the intellectual faculties developed, but in two very distinct lines, to the highest standard, namely in the hymenoptera [ants, bees, etc.], among the arthropoda [many insects, spiders, etc.], and in the mammalia, including man, among the vertebrata. in the most distinct classes of the animal kingdom--in mammals, birds, fishes, insects and even crustaceans--the differences between the sexes follow almost exactly the same rules. the males are almost always the wooers; and they alone are armed with special weapons for fighting with their rivals. they are generally stronger and larger than the females, and are endowed with the requisite qualities of courage and pugnacity. they are provided, either exclusively or in a much higher degree than the females, with organs for vocal or instrumental music, and with odoriferous glands. they are ornamented with infinitely diversified appendages and with the most brilliant or conspicuous colors, often arranged in elegant patterns, while the females are unadorned. when the sexes differ in more important structures it is the male which is provided with special sense-organs for discovering the female, with locomotive organs for reaching her, and often with prehensile organs for holding her. these various structures for charming or securing the female are often developed in the male during only part of the year; namely, the breeding season. they have in many cases been transferred in a greater or less degree to the females; and in the latter case they often appear in her as mere rudiments. they are lost or never gained by the males after emasculation. generally they are not developed in the male during early youth, but appear a short time before the age for reproduction. hence, in most cases the young of both sexes resemble each other; and the female somewhat resembles her young offspring throughout life. in almost every great class a few anomalous cases occur, where there has been an almost complete transposition of the characters proper to the two sexes; the females assuming characters which properly belong to the males. this surprisingly uniformity in the laws regulating the differences between the sexes in so many and such widely separated classes is intelligible if we admit the action throughout all the higher divisions of the animal kingdom of one common cause; namely, sexual selection. sexual selection depends on the success of certain individuals over others of the same sex, in relation to the propagation of the species; while natural selection depends on the success of both sexes, at all ages, in relation to the general conditions of life. the sexual struggle is of two kinds; in the one it is between the individuals of the same sex, generally the males, in order to drive away or kill their rivals, the females remaining passive; while in the other, the struggle is likewise between the individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners. this latter kind of selection is closely analogous to that which man unintentionally, yet effectually, brings to bear on his domesticated productions, when he preserves during a long period the most pleasing or useful individuals, without any wish to modify the breed. the laws of inheritance determine whether characters gained through sexual selection by either sex shall be transmitted to the same sex, or to both; as well as the age at which they shall be developed. it appears that variations arising late in life are commonly transmitted to one and the same sex. variability is the necessary basis for the action of selection and is wholly independent of it. it follows from this that variations of the same general nature have often been taken advantage of and accumulated through sexual selection in relation to the propagation of the species, as well as through natural selection in relation to the general purposes of life. hence secondary sexual characters, when equally transmitted to both sexes, can be distinguished from ordinary specific characters only by the light of analogy. the modifications acquired through sexual selection are often so strongly pronounced that the two sexes have frequently been ranked as distinct species, or even as distinct genera. such strongly marked differences must be in some manner highly important; and we know that they have been acquired in some instances at the cost not only of inconvenience, but of exposure to actual danger. the belief in the power of sexual selection rests chiefly on the following considerations: the characters which we have the best reasons for supposing to have been thus acquired are confined to one sex; and this alone renders it probable that in most cases they are connected with the act of reproduction. these characters in innumerable instances are fully developed only at maturity; and often during only a part of the year, which is always the breeding season. the males (passing over a few exceptional cases) are the more active in courtship; they are the best armed, and are rendered the most attractive in various ways. it is to be especially observed that the males display their attractions with elaborate care in the presence of the females; and that they rarely or never display them excepting during the season of love. it is incredible that all this should be purposeless. lastly, we have distinct evidence with some quadrupeds and birds that the individuals of one sex are capable of feeling a strong antipathy or preference for certain individuals of the other sex. bearing in mind these facts and not forgetting the marked results of man's unconscious selection, it seems to me almost certain that if the individuals of one sex were during a long series of generations to prefer pairing with certain individuals of the other sex, characterized in some peculiar manner, the offspring would slowly but surely become modified in this same manner. i have not attempted to conceal that, excepting when the males are more numerous than the females, or when polygamy prevails, it is doubtful how the more attractive males succeed in leaving a larger number of offspring to inherit their superiority in ornaments or other charms than the less attractive males; but i have shown that this would probably follow from the females--especially the more vigorous ones, which would be the first to breed--preferring not only the more attractive but at the same time the more vigorous and victorious males. although we have some positive evidence that birds appreciate bright and beautiful objects, as with the bower-birds of australia, and although they certainly appreciate the power of song, yet i fully admit that it is astonishing that the females of many birds and some mammals should be endowed with sufficient taste to appreciate ornaments, which we have reason to attribute to sexual selection; and this is even more astonishing in the case of reptiles, fish and insects. but we really know little about the minds of the lower animals. it cannot be supposed, for instance, that male birds of paradise or peacocks should take such pains in erecting, spreading and vibrating their beautiful plumes before the males for no purpose. we should remember the fact given on excellent authority in a former chapter that several peahens, when debarred from an admired male, remained widows during a whole season rather than pair with another bird. nevertheless, i know of no fact in natural history more wonderful than that the female argus pheasant should appreciate the exquisite shading of the ball-and-socket ornaments and the elegant patterns on the wing feathers of the male. he who thinks that the male was created as he now exists must admit that the great plumes, which prevent the wings from being used for flight and which, as well as the primary feathers, are displayed in a manner quite peculiar to this one species during the act of courtship, and at no other time, were given to him as an ornament. if so, he must likewise admit that the female was created and endowed with the capacity of appreciating such ornaments. i differ only in the conviction that the male argus pheasant acquired his beauty gradually, through the females having preferred during many generations the more highly ornamented males; the esthetic capacity of the females having been advanced through exercise or habit just as our own taste is gradually improved. in the male, through the fortunate chance of a few feathers not having been modified, we can distinctly see how simple spots with a little fulvous [tawny] shading on one side may have been developed by small steps into the wonderful ball-and-socket ornaments; and it is probable that they were actually thus developed. every one who admits the principle of evolution, and yet feels great difficulty in admitting that female mammals, birds, reptiles and fish, could have acquired the high taste implied by the beauty of the males, and which generally coincides with our own standard, should reflect that the nerve-cells of the brain in the highest as well as in the lowest members of the vertebrate series, are derived from those of the common progenitor of the whole group. it thus becomes intelligible that the brain and mental faculties should be capable under similar conditions of nearly the same course of development, and consequently of performing nearly the same functions. the reader who has taken the trouble to go through the several chapters devoted to sexual selection will be able to judge how far the conclusions at which i have arrived are supported by sufficient evidence. if he accepts these conclusions he may, i think, safely extend them to mankind; but it would be superfluous here to repeat what i have so lately said on the manner in which sexual selection apparently has acted on man, both on the male and female side, causing the two sexes of man to differ in body and mind, and the several races to differ from each other in various characters, as well as from their ancient and lowly organized progenitors. he who admits the principle of sexual selection will be led to the remarkable conclusion that the cerebral system not only regulates most of the existing functions of the body, but has indirectly influenced the progressive development of various bodily structures and of certain mental qualities. courage, pugnacity, perseverance, strength and size of body, weapons of all kinds, musical organs, both vocal and instrumental, bright colours, stripes and marks, and ornamental appendages, have all been indirectly gained by the one sex or the other, through the influence of love and jealousy, through the appreciation of the beautiful in sound, colour or form, and through the exertion of a choice; and those powers of the mind manifestly depend on the development of the cerebral system. man scans with scrupulous care the character and pedigree of his horses, cattle and dogs before he matches them; but when he comes to his own marriage he rarely, or never takes any such care. he is impelled by nearly the same motives as the lower animals when left to their own free choice, though he is in so far superior to them that he highly values mental charms and virtues. on the other hand he is strongly attracted by mere wealth or rank. yet he might by selection do something not only for the bodily constitution and frame of his offspring, but for their intellectual and moral qualities. both sexes ought to refrain from marriage if they are in any marked degree inferior in body or mind; but such hopes are utopian and will never be even partially realized until the laws of inheritance are thoroughly known. all do good service who aid toward this end. when the principles of breeding and inheritance are better understood, we shall not hear ignorant members of our legislature rejecting with scorn a plan for ascertaining whether or not consanguineous marriages are injurious to man. the advancement of the welfare of mankind is a most intricate problem; all ought to refrain from marriage who cannot avoid abject poverty for their children; for poverty is not only a great evil, but tends to its own increase by leading to recklessness in marriage. on the other hand, as mr. galton has remarked, if the prudent avoid marriage, while the reckless marry, the inferior members tend to supplant the better members of society. man, like every other animal, has no doubt advanced to his present high condition through a struggle for existence consequent on his rapid multiplication; and if he is to advance still higher, he must remain subject to a severe struggle. otherwise he would sink into indolence, and the more gifted men would not be more successful in the battle of life than the less gifted. hence our natural rate of increase, though leading to many and obvious evils, must not be greatly diminished by any means. there should be open competition for all men; and the most able should not be prevented by laws or customs from succeeding best and rearing the largest number of offspring. important as the struggle for existence has been and even still is, yet as far as the highest part of man's nature is concerned there are other agencies more important. for the moral qualities are advanced, either directly or indirectly, much more through the effects of habit, the reasoning powers, instruction, religion, etc., than through natural selection; though to this latter agency the social instincts, which afforded the basis for the development of the moral sense, may be safely attributed. the main conclusion arrived at in this work, namely, that man is descended from some lowly organized form, will, i regret to think, be highly distasteful to many. but there can hardly be a doubt that we are descended from barbarians. the astonishment i felt on first seeing a party of fuegians on a wild and broken shore will never be forgotten by me, for the reflection at once rushed into my mind--such were our ancestors. these men were absolutely naked and bedaubed with paint, their long hair was tangled, their mouths frothed with excitement, and their expression was wild, startled and distrustful. they possessed hardly any arts, and like wild animals lived on what they could catch; they had no government, and were merciless to every one not of their own small tribe. he who has seen a savage in his native land will not feel much shame, if forced to acknowledge that the blood of some more humble creature flows in his veins. for my own part i would as soon be descended from that heroic little monkey who braved his dreaded enemy in order to save the life of his keeper; or from that old baboon, who, descending from the mountains, carried away in triumph his young comrade from a crowd of astonished dogs--as from a savage who delights to torture his enemies, offers up bloody sacrifices, practises infanticide without remorse, treats his wives like slaves, knows no decency, and is haunted by the grossest superstitions. man may be excused for feeling some pride at having risen, though not through his own exertions, to the very summit of the organic scale; and the fact of his having thus risen, instead of having been aboriginally placed there, may give him hope for a still higher destiny in the distant future. but we are not here concerned with hopes or fears, only with the truth as far as our reason permits us to discover it. i have given the evidence to the best of my ability, and we must acknowledge, as it seems to me, that man, with all his noble qualities, with sympathy which feels for the most debased, with benevolence which extends not only to other men but to the humblest living creature, with his godlike intellect which has penetrated into the movements and constitution of the solar system--with all these exalted powers--man still bears in his bodily frame the indelible stamp of his lowly origin. mimicry and other protective resemblances among animals alfred russel wallace [mr. wallace, one of the greatest naturalists of the age, discovered the law of natural selection independently of darwin, and about the same time. among his works are "the malay archipelago," "island life," and "darwinism." from "natural selection," which was published by macmillan & co., 1871, the following extracts are taken. the theme has received important development at the hands of professor e. b. poulton, in his "the colours of animals," international scientific series, 1890: and in f. e. beddard's "animal colouration"; london, swan sonnenschein; n. y., macmillan, 1892.] there is no more convincing proof of the truth of a comprehensive theory, than its power of absorbing and finding a place for new facts, and its capability of interpreting phenomena which had been previously looked upon as unaccountable anomalies. it is thus that the law of universal gravitation and the undulatory theory of light have become established and universally accepted by men of science. fact after fact has been brought forward as being apparently inconsistent with them, and one after another these very facts have been shown to be the consequences of the laws they were at first supposed to disprove. a false theory will never stand this test. advancing knowledge brings to light whole groups of facts which it cannot deal with, and its advocates steadily decrease in numbers, notwithstanding the ability and scientific skill with which it has been supported. the course of a true theory is very different, as may be well seen by the progress of opinion on the subject of natural selection. in less than eight years "the origin of species" has produced conviction in the minds of a majority of the most eminent living men of science. new facts, new problems, new difficulties as they arise are accepted, solved or removed by this theory; and its principles are illustrated by the progress and conclusions of every well established branch of human knowledge. it is the object of the present essay to show how it has recently been applied to connect together and explain a variety of curious facts which had long been considered as inexplicable anomalies. perhaps no principle has ever been announced so fertile in results as that which mr. darwin so earnestly impresses upon us, and which is indeed a necessary deduction from the theory of natural selection, namely--that none of the definite facts of organic nature, no special organ, no characteristic form or marking, no peculiarities of instinct or of habit, no relations between species or between groups of species--can exist, but which must now be or once have been _useful_ to the individuals or races which possess them. this great principle gives us a clue which we can follow out in the study of many recondite phenomena, and leads us to seek a meaning and a purpose of some definite character in minuti㦠which we should be otherwise almost sure to pass over as insignificant or unimportant. the adaptation of the external colouring of animals to their conditions of life has long been recognized, and has been imputed either to an originally created specific peculiarity, or to the direct action of climate, soil, or food. where the former explanation has been accepted, it has completely checked inquiry, since we could never get any further than the fact of the adaptation. there was nothing more to be known about the matter. the second explanation was soon found to be quite inadequate to deal with all the varied phases of the phenomena, and to be contradicted by many well-known facts. for example, wild rabbits are always of gray or brown tints well suited for concealment among grass and fern. but when these rabbits are domesticated, without any change of climate or food, they vary into white or black, and these varieties may be multiplied to any extent, forming white or black races. exactly the same thing has occurred with pigeons; and in the case of rats and mice, the white variety has not been shown to be at all dependent on alteration of climate, food or other external conditions. in many cases the wings of an insect not only assume the exact tint of the bark or leaf it is accustomed to rest on, but the form and veining of the leaf or the exact rugosity of the bark is imitated; and these detailed modifications cannot be reasonably imputed to climate or food, since in many cases the species does not feed on the substance it resembles, and when it does, no reasonable connection can be shown to exist between the supposed cause and the effect produced. it was reserved for the theory of natural selection to solve all these problems, and many others which were not at first supposed to be directly connected with them. to make these latter intelligible, it will be necessary to give a sketch of the whole series of phenomena which may be classed under the head of useful or protective resemblances. concealment, more or less complete, is useful to many animals, and absolutely essential to some. those which have numerous enemies from which they cannot escape by rapidity of motion, find safety in concealment. those which prey upon others must also be so constituted as not to alarm them by their presence or their approach, or they would soon die of hunger. now, it is remarkable in how many cases nature gives this boon to the animal, by colouring it with such tints as may best serve to enable it to escape from its enemies or to entrap its prey. desert animals as a rule are desert-coloured. the lion is a typical example of this, and must be almost invisible when crouched upon the sand or among desert rocks and stones. antelopes are all more or less sandy-coloured. the camel is pre-eminently so. the egyptian cat and the pampas cat are sandy or earth-coloured. the australian kangaroos are of the same tints, and the original colour of the wild horse is supposed to have been a sandy or clay-colour. the desert birds are still more remarkably protected by their assimilative hues. the stone-chats, the larks, the quails, the goatsuckers and the grouse, which abound in the north african and asiatic deserts, are all tinted and mottled so as to resemble with wonderful accuracy the average colour and aspect of the soil in the district they inhabit. the rev. h. tristram, in his account of the ornithology of north africa in the first volume of the "ibis," says: "in the desert, where neither trees, brushwood, nor even undulation of the surface afford the slightest protection to its foes, a modification of colour which shall be assimilated to that of the surrounding country is absolutely necessary. hence _without exception_ the upper plumage of _every bird_, whether lark, chat, sylvain, or sand-grouse, and also the fur of _all the smaller mammals_, and the skin of _all the snakes and lizards_, is of one uniform isabelline or sand colour." after the testimony of so able an observer it is unnecessary to adduce further examples of the protective colours of desert animals. almost equally striking are the cases of arctic animals possessing the white colour that best conceals them upon snowfields and icebergs. the polar bear is the only bear that is white, and it lives constantly among snow and ice. the arctic fox, the ermine and the alpine hare change to white in winter only, because in summer white would be more conspicuous than any other colour, and therefore a danger rather than a protection; but the american polar hare, inhabiting regions of almost perpetual snow, is white all the year round. other animals inhabiting the same northern regions do not, however, change colour. the sable is a good example, for throughout the severity of a siberian winter it retains its rich brown fur. but its habits are such that it does not need the protection of colour, for it is said to be able to subsist on fruits and berries in winter, and to be so active upon the trees as to catch small birds among the branches. so also the woodchuck of canada has a dark-brown fur; but then it lives in burrows and frequents river banks, catching fish and small animals that live in or near the water. among birds, the ptarmigan is a fine example of protective colouring. its summer plumage so exactly harmonizes with the lichen-coloured stones among which it delights to sit, that a person may walk through a flock of them without seeing a single bird; while in winter its white plumage is an almost equal protection. the snow-bunting, the jerfalcon, and the snowy owl are also white-coloured birds inhabiting the arctic regions, and there can be little doubt but that their colouring is to some extent protective. nocturnal animals supply us with equally good illustrations. mice, rats, bats, and moles possess the least conspicuous of hues, and must be quite invisible at times when any light colour would be instantly seen. owls and goatsuckers are of those dark mottled tints that will assimilate with bark and lichen, and thus protect them during the day, and at the same time be inconspicuous in the dusk. it is only in the tropics, among forests which never lose their foliage, that we find whole groups of birds whose chief colour is green. the parrots are the most striking example, but we have also a group of green pigeons in the east; and the barbets, leaf-thrushes, bee-eaters, white-eyes, turacos, and several smaller groups, have so much green in their plumage as to tend greatly to conceal them among the foliage. the conformity of tint which has been so far shown to exist between animals and their habitations is of somewhat general character; we will now consider the cases of more special adaptation. if the lion is enabled by his sandy colour readily to conceal himself by merely crouching down in the desert, how, it may be asked, do the elegant markings of the tiger, the jaguar, and the other large cats agree with this theory? we reply that these are generally cases of more or less special adaptation. the tiger is a jungle animal, and hides himself among tufts of grass or of bamboos, and in these positions the vertical stripes with which his body is adorned must so assimilate with the vertical stems of the bamboo, as to assist greatly in concealing him from his approaching prey. how remarkable it is that besides the lion and tiger, almost all the other large cats are arboreal in their habits, and almost all have ocellated or spotted skins, which must certainly tend to blend them with the background of foliage; while the one exception, the puma, has an ashy-brown uniform fur, and has the habit of clinging so closely to a limb of a tree while waiting for his prey to pass beneath as to be hardly distinguishable from the bark. among birds, the ptarmigan, already mentioned, must be considered a remarkable case of special adaptation. another is a south american goatsucker (caprimulgus rupestris) which rests in the bright sunshine on little bare rocky islets in the upper rio negro, where its unusually light colours so closely resemble those of the rock and sand, that it can scarcely be detected until trodden upon. the duke of argyll, in his "reign of law," has pointed out the admirable adaptation of the colours of the woodcock to its protection. the various browns and yellows and pale ash-colour that occur on fallen leaves are all reproduced in its plumage, so that when according to its habit it rests upon the ground under trees, it is almost impossible to detect it. in snipes the colours are modified so as to be equally in harmony with the prevalent forms and colours of marshy vegetation. mr. j. m. lester, in a paper read before the rugby school natural history society observes:--"the wood-dove, when perched amongst the branches of its favourite _fir_, is scarcely discernible; whereas, were it among some lighter foliage the blue and purple tints in its plumage would far sooner betray it. the robin redbreast, too, although it might be thought that the red on its breast made it much easier to be seen, is in reality not at all endangered by it, since it generally contrives to get among some russet or yellow fading leaves, where the red matches very well with the autumn tints, and the brown of the rest of the body with the bare branches." reptiles offer us many similar examples. the most arboreal lizards, the iguanas, are as green as the leaves they feed upon, and the slender whip-snakes are rendered almost invisible as they glide among the foliage by a similar colouration. how difficult it is sometimes to catch sight of the little green tree-frogs sitting on the leaves of a small plant enclosed in a glass case in the zoological gardens; yet how much better concealed they must be among the fresh green damp foliage of a marshy forest. there is a north american frog found on lichen-covered rocks and walls, which is so coloured as exactly to resemble them, and as long as it remains quiet would certainly escape detection. some of the geckos which cling motionless on the trunks of trees in the tropics, are of such curiously marbled colours as to match exactly with the bark they rest upon. in every part of the tropics there are tree snakes that twist among boughs and shrubs, or lie coiled up in the dense masses of foliage. these are of many distinct groups, and comprise both venomous and harmless genera; but almost all of them are of a beautiful green colour, sometimes more or less adorned with white or dusky bands and spots. there can be little doubt that this colour is doubly useful to them, since it will tend to conceal them from their enemies, and will lead their prey to approach them unconscious of danger. dr. gunthner informs me that there is only one genus of true arboreal snakes (dipsas) whose colours are rarely green, but are of various shades of black, brown, and olive, and these are all nocturnal reptiles, and there can be little doubt conceal themselves during the day in holes, so that the green protective tint would be useless to them, and they accordingly retain the more usual reptilian hues. fishes present similar instances. many flat fish, as, for example, the flounder and the skate, are exactly the colour of the gravel or sand on which they habitually rest. among the marine flower gardens of an eastern coral reef the fishes present every variety of gorgeous colour, while the river fish even of the tropics rarely if ever have gay or conspicuous markings. a very curious case of this kind of adaptation occurs in the sea-horse (hippocampus) of australia, some of which bear long foliaceous appendages resembling seaweed, and are of a brilliant red colour; and they are known to live among seaweed of the same hue, so that when at rest they must be quite invisible. there are now in the aquarium of the zoological society some slender green pipe-fish which fasten themselves to any object at the bottom by their prehensile tails, and float about with the current, looking exactly like some cylindrical algã¦. it is, however, in the insect world that this principle of the adaptation of animals to their environment is most fully and strikingly developed. in order to understand how general this is, it is necessary to enter somewhat into details, as we shall thereby be better able to appreciate the significance of the still more remarkable phenomena we shall presently have to discuss. it seems to be in proportion to their sluggish motions or the absence of other means of defence, that insects possess the protective colouring. in the tropics there are thousands of species of insects which rest during the day clinging to the bark of dead or fallen trees; and the greater portion of these are delicately mottled with gray and brown tints, which though symmetrically disposed and infinitely varied, yet blend so completely with the usual colours of the bark that at two or three feet distance they are quite undistinguishable. in some cases a species is known to frequent only one species of tree. this is the case with the common south american long-horned beetle (onychocerus scorpio) which, mr. bates informed me, is found only on a rough-barked tree, called tapiriba, on the amazon. it is very abundant, but so exactly does it resemble the bark in colour and rugosity, and so closely does it cling to the branches, that until it moves it is absolutely invisible! an allied species (o. concentricus) is found only at para, on a distinct species of tree, the bark of which it resembles with equal accuracy. both these insects are abundant, and we may fairly conclude that the protection they derive from this strange concealment is at least one of the causes that enable the race to flourish. many of the species of cicindela, or tiger beetle, will illustrate this mode of protection. our common cicindela campestris frequents grassy banks and is of a beautiful green colour, while c. maritima, which is found only on sandy sea-shores, is of a pale bronzy yellow, so as to be almost invisible. a great number of the species found by myself in the malay islands are similarly protected. the beautiful cicindela gloriosa, of a very deep velvety green colour, was only taken upon wet mossy stones in the bed of a mountain stream, where it was with the greatest difficulty detected. a large brown species (c. heros) was found chiefly on dead leaves in forest paths; and one which was never seen except on the wet mud of salt marshes was of a glossy olive so exactly the colour of the mud as only to be distinguished when the sun shone, by its shadow! where the sandy beach was coralline and nearly white, i found a very pale cicindela; wherever it was volcanic and black, a dark species of the same genus was sure to be met with. there are in the east small beetles of the family buprestid㦠which generally rest on the midrib of a leaf, and the naturalist often hesitates before picking them off, so closely do they resemble pieces of bird's dung. kirby and spence mention the small beetle onthophilus sulcatus as being like the seed of an umbelliferous plant; and another small weevil, which is much persecuted by predatory beetles of the genus harpalus, is of the exact colour of loamy soil, and was found to be particularly abundant in loam pits. mr. bates mentions a small beetle (chlamys pilula) which was undistinguishable by the eye from the dung of caterpillars, while some of the cassidã¦, from their hemispherical forms and pearly gold-colour, resemble glittering dew-drops upon the leaves. a number of our small brown and speckled weevils at the approach of any object roll off the leaf they are sitting on, at the same time drawing in their legs and antennã¦, which fit so perfectly into cavities for their reception that the insect becomes a mere oval brownish lump, which it is hopeless to look for among the similarly coloured little stones and earth pellets among which it lies motionless. the distribution of colour in butterflies and moths respectively is very instructive from this point of view. the former have all their brilliant colouring on the upper surface of all four wings, while the under surface is almost always soberly coloured, and often very dark and obscure. the moths on the contrary have generally their chief colour on the hind wings only, the upper wings being of dull, sombre, and often imitative tints, and these generally conceal the hind wings when the insects are in repose. this arrangement of the colours is therefore eminently protective, because the butterfly always rests with his wings raised so as to conceal the dangerous brilliancy of his upper surface. it is probable that if we watched their habits sufficiently we should find the under surface of the wings of butterflies very frequently imitative and protective. mr. t. w. wood has pointed out that the little orange-tip butterfly often rests in the evening on the green and white flower heads of an umbelliferous plant, and that when observed in this position the beautiful green and white mottling of the under surface completely assimilates with the flower heads and renders the creature very difficult to be seen. it is probable that the rich dark colouring of the under side of our peacock, tortoiseshell, and red-admiral butterflies answers a similar purpose. two curious south american butterflies that always settle on the trunks of trees (gynecia dirce and callizona acesta) have the under surface curiously striped and mottled, and when viewed obliquely must closely assimilate with the appearance of the furrowed bark of many kinds of trees. but the most wonderful and undoubted case of protective resemblance in a butterfly which i have ever seen, is that of the common indian kallima inachis, and its malayan ally, kallima paralekta. the upper surface of these insects is very striking and showy, as they are of a large size, and are adorned with a broad band of rich orange on a deep bluish ground. the under side is very variable in colour, so that out of fifty specimens no two can be found exactly alike, but every one of them will be of some shade of ash or brown or ochre, such as are found among dead, dry or decaying leaves. the apex of the upper wings is produced into an acute point, a very common form in the leaves of tropical shrubs and trees, and the lower wings are also produced into a short, narrow tail. between these two points runs a dark curved line exactly representing the midrib of a leaf, and from this radiate on each side a few oblique lines, which serve to indicate the lateral veins of a leaf. these marks are more clearly seen on the outer portion of the base of the wings, and on the inner side towards the middle and apex, and it is very curious to observe how the usual marginal and transverse stri㦠of the group are here modified and strengthened so as to become adapted for an imitation of the venation of a leaf. we come now to a still more extraordinary part of the imitation, for we find representations of leaves in every stage of decay, variously blotched and mildewed and pierced with powdery black dots gathered into patches and spots, so closely resembling the various kinds of minute fungi that grow on dead leaves that is it impossible to avoid thinking at first sight that the butterflies themselves have been attacked by real fungi. but this resemblance, close as it is, would be little use if the habits of the insect did not accord with it. if the butterfly sat upon leaves or upon flowers, or opened its wings so as to expose the upper surface, or exposed and moved its head and antenn㦠as many other butterflies do, its disguise would be of little avail. we might be sure, however, from the analogy of many other cases, that the habits of the insect are such as still further to aid its deceptive garb; but we are not obliged to make any such supposition, since i myself had the good fortune to observe scores of kallima paralekta, in sumatra, and to capture many of them, and can vouch for the accuracy of the following details: these butterflies frequent dry forests and fly very swiftly. they were never seen to settle on a flower or a green leaf, but were many times lost sight of in a bush or tree of dead leaves. on such occasions they were generally searched for in vain, for while gazing intently at the very spot where one had disappeared, it would often suddenly dart out and again vanish twenty or fifty yards further on. on one or two occasions the insect was detected reposing, and it could then be seen how completely it assimilates itself to the surrounding leaves. it sits on a nearly upright twig, the wings fitting closely back to back, concealing the antenn㦠and head, which are drawn up between their bases. the little tails of the hind wings touch the branch and form a perfect stalk to the leaf, which is supported in its place by the claws of the middle pair of feet, which are slender and inconspicuous. the irregular outline of the wings gives exactly the perspective effect of a shrivelled leaf. we thus have size, colour, form, markings, and habits, all combining together to produce a disguise which may be said to be absolutely perfect; and the protection which it affords is sufficiently indicated by the abundance of the individuals that possess it.... we will now endeavour to show how these wonderful resemblances have most probably been brought about. returning to the higher animals, let us consider the remarkable fact of the rarity of white colouring in the mammalia or birds of the temperate or tropical zones in a state of nature. there is not a single white land-bird or quadruped in europe, except the few arctic or alpine species to which white is a protective colour. yet in many of these creatures there seems to be no inherent tendency to avoid white, for directly they are domesticated white varieties arise, and appear to thrive as well as others. we have white mice and rats, white cats, horses, dogs, and cattle, white poultry, pigeons, turkeys, and ducks, and white rabbits. some of these animals have been domesticated for a long period, others only for a few centuries; but in almost every case in which an animal has been thoroughly domesticated, parti-coloured and white varieties are produced and become permanent. it is also well known that animals in a state of nature produce white varieties occasionally. blackbirds, starlings, and crows are occasionally seen white, as well as elephants, deer, tigers, hares, moles, and many other animals; but in no case is a permanent white race produced. now there are no statistics to show that the normal-coloured parents produce white offspring oftener under domestication than in a state of nature, and we have no right to make such an assumption if the facts can be accounted for without it. but if the colours of animals do really, in the various instances already adduced, serve for their concealment and preservation, then white or any other conspicuous colour must be hurtful, and must in most cases shorten an animal's life. a white rabbit would be more surely the prey of hawk or buzzard, and the white mole, or field mouse, could not long escape from the vigilant owl. so, also, any deviation from those tints best adapted to conceal a carnivorous animal would render the pursuit of its prey much more difficult, would place it at a disadvantage among its fellows and in a time of scarcity would probably cause it to starve to death. on the other hand, if an animal spreads from a temperate into an arctic district, the conditions are changed. during a large portion of the year, and just when the struggle for existence is most severe, white is the prevailing tint of nature, and dark colours will be the most conspicuous. the white varieties will now have an advantage; they will escape from their enemies or will secure food, while their brown companions will be devoured or will starve; and "as like produces like" is the established rule in nature, the white race will become permanently established, and dark varieties, when they occasionally appear, will soon die out from their want of adaptation to their environment. in each case the fittest will survive, and a race will be eventually produced adapted to the conditions in which it lives. we have here an illustration of the simple and effectual means by which animals are brought into harmony with the rest of nature. that slight amount of variability in every species, which we often look upon as something accidental or abnormal, or so insignificant as to be hardly worthy of notice, is yet the foundation of all those wonderful and harmonious resemblances which play such an important part in the economy of nature. variation is generally very small in amount, but it is all that is required, because the change in the external conditions to which an animal is subject is generally very slow and intermittent. when these changes have taken place too rapidly, the result has often been the extinction of species; but the general rule is, that climatal and geological changes go on slowly, and the slight but continual variations in the colour, form and structure of all animals, has furnished individuals adapted to these changes, and who have become the progenitors of modified races. rapid multiplication, incessant slight variation, and survival of the fittest--these are the laws which ever keep the organic world in harmony with the inorganic and with itself. these are the laws which we believe have produced all the cases of protective resemblance already adduced, as well as those still more curious examples we have yet to bring before our readers. it must always be borne in mind that the more wonderful examples, in which there is not only a general but a special resemblance as in the walking leaf, the mossy phasma, and the leaf-winged butterfly--represent those few instances in which the process of modification has been going on during an immense series of generations. they all occur in the tropics, where the conditions of existence are the most favourable, and where climatic changes have for long periods been hardly perceptible. in most of them favourable variations both of colour, form, structure, and instinct or habit, must have occurred to produce the perfect adaptation we now behold. all these are known to vary, and favourable variations when not accompanied by others that are unfavourable, would certainly survive. at one time a little step might be made in this direction, at another time in that--a change of conditions might sometimes render useless that which it had taken ages to produce--great and sudden physical modifications might often produce the extinction of a race just as it was approaching perfection, and a hundred checks of which we can know nothing may have retarded the progress towards perfect adaptation; so that we can hardly wonder at there being so few cases in which a completely successful result has been attained as shown by the abundance and wide diffusion of the creatures so protected. [here are given many detailed examples of insects which gainfully mimic one another.] we will now adduce a few cases in which beetles imitate other insects, and insects of other orders imitate beetles. charis melipona, a south american longicorn of the family necydalidã¦, has been so named from its resemblance to a small bee of the genus melipona. it is one of the most remarkable cases of mimicry, since the beetle has the thorax and body densely hairy like the bee, and the legs are tufted in a manner most unusual in the order coleoptera. another longicorn, odontocera odyneroides, has the abdomen banded with yellow, and constricted at the base, and is altogether so exactly like a small common wasp of the genus odynerus, that mr. bates informs us he was afraid to take it out of his net with his fingers for fear of being stung. had mr. bates's taste for insects been less omnivorous than it was, the beetle's disguise might have saved it from his pin, as it had no doubt often done from the beak of hungry birds. a larger insect, sphecomorpha chalybea, is exactly like one of the large metallic blue wasps, and like them has the abdomen connected with the thorax by a pedicle, rendering the deception most complete and striking. many eastern species of longicorns of the genus oberea, when on the wing exactly resemble tenthredinidã¦, and many of the small species of hesthesis run about on timber, and cannot be distinguished from ants. there is one genus of south american longicorns that appears to mimic the shielded bugs of the genus scutellera. the gymnocerous capucinus is one of these, and is very like pachyotris fabricii, one of the scutelleridã¦. the beautiful gymnocerous dulcissimus is also very like the same group of insects, though there is no known species that exactly corresponds to it; but this is not to be wondered at, as the tropical hemiptera have been comparatively so little cared for by collectors. the most remarkable case of an insect of another order mimicking a beetle is that of the condylodera tricondyloides, one of the cricket family from the philippine islands, which is so exactly like a tricondyla (one of the tiger beetles), that such an experienced entomologist as professor westwood placed it among them in his cabinet, and retained it there a long time before he discovered his mistake! both insects run along the trunks of trees, and whereas tricondylas are very plentiful, the insect that mimics it is, as in all other cases, very rare. mr. bates also informs us that he found at santarem on the amazon, a species of locust which mimicked one of the tiger beetles of the genus odontocheila, and was found on the same trees which they frequented. there are a considerable number of diptera, or two-winged flies, that closely resemble wasps and bees, and no doubt derive much benefit from the wholesome dread which those insects excite. the midas dives, and other species of large brazilian flies, have dark wings and metallic blue elongate bodies, resembling the large stinging sphegid㦠of the same country; and a very large fly of the genus asilus has black-banded wings and the abdomen tipped with rich orange, so as exactly to resemble the fine bee euglossa dimidiata, and both are found in the same parts of south america. we have also in our own country species of bombylius which are almost exactly like bees. in these cases the end gained by the mimicry is no doubt freedom from attack, but it has sometimes an altogether different purpose. there are a number of parasitic flies whose larv㦠feed upon the larv㦠of bees, such as the british genus volucella and many of the tropical bombylii, and most of these are exactly like the particular species of bee they prey upon, so that they can enter their nests unsuspected to deposit their eggs. there are also bees that mimic bees. the cuckoo bees of the genus nomada are parasitic on the andrenidã¦, and they resemble either wasps or species of andrena; and the parasitic humble-bees of the genus apathus almost exactly resemble the species of humble-bees in whose nests they are reared. mr. bates informs us that he found numbers of these "cuckoo" bees and flies on the amazon, which all wore the livery of working bees peculiar to the same country. there is a genus of small spiders in the tropics which feed on ants, and they are exactly like ants themselves, which no doubt gives them more opportunity of seizing their prey; and mr. bates found on the amazon a species of mantis which exactly resembled the white ants which it fed upon, as well as several species of crickets (saphura), which resembled in a wonderful manner different sand-wasps of large size, which are constantly on the search for crickets with which to provision their nests. perhaps the most wonderful case of all is the large caterpillar mentioned by mr. bates, which startled him by its close resemblance to a small snake. the first three segments behind the head were dilatable at the will of the insect, and had on each side a large black pupillated spot, which resembled the eye of the reptile. moreover, it resembled a poisonous viper, not a harmless species of snake, as was proved by the imitation of keeled scales on the crown produced by the recumbent feet, as the caterpillar threw itself backward! the attitudes of many of the tropical spiders are most extraordinary and deceptive, but little attention has been paid to them. they often mimic other insects, and some, mr. bates assures us, are exactly like flower buds, and take their station in the axils of leaves, where they remain motionless waiting for their prey. i have now completed a brief, and necessarily very imperfect, survey of the various ways in which the external form and colouring of animals is adapted to be useful to them, either by concealing them from their enemies or from the creatures they prey upon. it has, i hope, been shown that the subject is one of much interest, both as regard a true comprehension of the place each animal fills in the economy of nature, and the means by which it is enabled to maintain that place; and also as teaching us how important a part is played by the minutest details in the structure of animals, and how complicated and delicate is the equilibrium of the organic world. my exposition of the subject having been necessarily somewhat lengthy and full of details, it will be as well to recapitulate its main points. there is a general harmony in nature between the colours of an animal and those of its habitation. arctic animals are white, desert animals are sand-coloured; dwellers among leaves and grass are green; nocturnal animals are dusky. these colours are not universal, but are very general, and are seldom reversed. going on a little further, we find birds, reptiles and insects, so tinted and mottled as exactly to match the rock, or bark, or leaf, or flower they are accustomed to rest upon--and thereby effectually concealed. another step in advance, and we have insects which are formed as well as coloured so as exactly to resemble particular leaves, or sticks, or mossy twigs, or flowers; and in these cases very peculiar habits and instincts come into play to aid in the deception and render the concealment more complete. we now enter upon a new phase of the phenomena, and come to creatures whose colours neither conceal them nor make them like vegetable or mineral substances; on the contrary, they are conspicuous enough, but they completely resemble some other creature of a quite different group, while they differ much in outward appearance from those with which all essential parts of their organization show them to be really closely allied. they appear like actors or masqueraders dressed up and painted for amusement, or like swindlers endeavouring to pass themselves off for well-known and respectable members of society. what is the meaning of this strange travesty? does nature descend to imposture or masquerade? we answer, she does not. her principles are too severe. there is a use in every detail of her handiwork. the resemblance of one animal to another is of exactly the same essential nature as the resemblance to a leaf, or to bark, or to desert sand, and answers exactly the same purpose. in the one case the enemy will not attack the leaf or the bark, and so the disguise is a safeguard; in the other case it is found that for various reasons the creature resembled is passed over, and not attacked by the usual enemies of its order, and thus the creature that resembles it has an equally effectual safeguard. we are plainly shown that the disguise is of the same nature in the two cases, by the occurrence in the same group of one species resembling a vegetable substance, while another resembles a living animal of another group; and we know that the creatures resembled possess an immunity from attack, by their being always very abundant, by their being conspicuous and not concealing themselves, and by their having generally no visible means of escape from their enemies; while, at the same time, the particular quality that makes them disliked is often very clear, such as a nasty taste or an indigestible hardness. further examination reveals the fact that, in several cases of both kinds of disguise, it is the female only that is thus disguised; and as it can be shown that the female needs protection much more than the male, and that her preservation for a much longer period is absolutely necessary for the continuance of the race, we have an additional indication that the resemblance is in all cases subservient to a great purpose--the preservation of the species. in endeavouring to explain these phenomena as having been brought about by variation and natural selection, we start with the fact that white varieties frequently occur, and when protected from enemies show no incapacity for continued existence and increase. we know, further, that varieties of many other tints occasionally occur; and as "the survival of the fittest" must inevitably weed out those whose colours are prejudicial and preserve those whose colours are a safeguard, we require no other mode of accounting for the protective tints of arctic and desert animals. but this being granted, there is such a perfectly continuous and graduated series of examples of every kind of protective imitation, up to the most wonderful cases of what is termed "mimicry," that we can find no place at which to draw the line and say,--so far variation and natural selection will account for the phenomena, but for all the rest we require a more potent cause. the counter theories that have been proposed, that of the "special creation" of each imitative form, that of the action of similar "conditions of existence" for some of the cases, and of the laws of "hereditary descent and the reversion to ancestral forms" for others,--have all been shown to be beset with difficulties, and the two latter to be directly contradicted by some of the most constant and most remarkable of the facts to be accounted for. the important part that protective "resemblance" has played in determining the colours and markings of many groups of animals will enable us to understand the meaning of one of the most striking facts in nature, the uniformity in the colours of the vegetable as compared with the wonderful diversity of the animal world. there appears no good reason why trees and shrubs should not have been adorned with as many varied hues and as strikingly designed patterns as birds and butterflies, since the gay colours of flowers show that there is no incapacity in vegetable tissues to exhibit them. but even flowers themselves present us with none of those wonderful designs, those complicated arrangements of stripes and dots and patches of colour, that harmonious blending of hues in lines and bands and shaded spots, which are so general a feature in insects. it is the opinion of mr. darwin that we owe much of the beauty of flowers to the necessity of attracting insects to aid in their fertilization, and that much of the development of colour in the animal world is due to "sexual selection," colour being universally attractive, and thus leading to its propagation and increase; but while fully admitting this, it will be evident from the facts and arguments here brought forward, that very much of the _variety_ both of colour and markings among animals is due to the supreme importance of concealment, and thus the various tints of minerals and vegetables have been directly reproduced in the animal kingdom, and again and again modified as more special protection became necessary. we shall thus have two causes for the development of colour in the animal world and shall be better enabled to understand how, by their combined and separate action, the immense variety we now behold has been produced. both causes, however, will come under the general law of "utility," the advocacy of which, in its broadest sense, we owe almost entirely to mr. darwin. a more accurate knowledge of the varied phenomena connected with this subject may not improbably give us some information both as to the senses and the mental faculties of the lower animals. for it is evident that if colours which please us also attract them, and if the various disguises which have been here enumerated are equally deceptive to them as to ourselves, then both their powers of vision and their faculties of perception and emotion, must be essentially of the same nature as our own--a fact of high philosophical importance in the study of our own nature and our true relations to the lower animals.[4] footnotes: [4] the author continues this study in chapter ix of "darwinism": new york, macmillan co., 1889.--ed. the evolution of the horse thomas henry huxley [professor huxley as a naturalist, educator, and controversialist was one of the commanding figures of the nineteenth century. to physiology and morphology his researches added much of importance: as an expositor he stood unapproached. as the bold and witty champion of darwinism he gave natural selection an acceptance much more early and wide than it would otherwise have enjoyed. in 1876 he delivered in america three lectures on evolution: the third of the series is here given. all three are copyrighted and published by d. appleton & co., new york, in a volume which also contains a lecture on the study of biology. since 1876 the arguments of professor huxley have been reinforced by the discovery of many fossils connecting not only the horse, but other quadrupeds, with species widely different and now extinct. the most comprehensive collection illustrating the descent of the horse is to be seen at the american museum of natural history, new york, where also the evolution of tapirs, camels, llamas, rhinoceroses, dinosaurs, great ground sloths and other animals are clearly to be traced--in most cases by remains discovered in america. a capital book on the theme broached by professor huxley is "animals of the past," by frederic a. lucas, curator of the division of comparative anatomy, united states national museum, washington, d. c., published by mcclure, phillips & co., new york. "the life and letters of professor huxley," edited by his son, leonard huxley, is a work of rare interest: it is published by d. appleton & co., new york.] the occurrence of historical facts is said to be demonstrated, when the evidence that they happened is of such a character as to render the assumption that they did not happen in the highest degree improbable; and the question i now have to deal with is, whether evidence in favour of the evolution of animals of this degree of cogency is, or is not, obtainable from the record of the succession of living forms which is presented to us by fossil remains. those who have attended to the progress of palã¦ontology are aware that evidence of the character which i have defined has been produced in considerable and continually-increasing quantity during the last few years. indeed, the amount and the satisfactory nature of that evidence are somewhat surprising, when we consider the conditions under which alone we can hope to obtain it. it is obviously useless to seek for such evidence, except in localities in which the physical conditions have been such as to permit of the deposit of an unbroken, or but rarely interrupted, series of strata through a long period of time; in which the group of animals to be investigated has existed in such abundance as to furnish the requisite supply of remains; and in which, finally, the materials composing the strata are such as to insure the preservation of these remains in a tolerably perfect and undisturbed state. it so happens that the case which, at present, most nearly fulfils all these conditions is that of the series of extinct animals which culminates in the horses; by which term i mean to denote not merely the domestic animals with which we are all so well acquainted, but their allies, the ass, zebra, quagga, and the like. in short, i use "horses" as the equivalent of the technical name _equidã¦_, which is applied to the whole group of existing equine animals. the horse is in many ways a remarkable animal; not least so in the fact that it presents us with an example of one of the most perfect pieces of machinery in the living world. in truth, among the works of human ingenuity it cannot be said that there is any locomotive so perfectly adapted to its purposes, doing so much work with so small a quantity of fuel, as this machine of nature's manufacture--the horse. and, as a necessary consequence of any sort of perfection, of mechanical perfection as of others, you find that the horse is a beautiful creature, one of the most beautiful of all land animals. look at the perfect balance of its form, and the rhythm and force of its action. the locomotive machinery is, as you are aware, resident in its slender fore and hind limbs; they are flexible and elastic levers, capable of being moved by very powerful muscles; and, in order to supply the engines which work these levers with the force which they expend, the horse is provided with a very perfect apparatus for grinding its food and extracting therefrom the requisite fuel. without attempting to take you very far into the region of osteological detail, i must nevertheless trouble you with some statements respecting the anatomical structure of the horse; and, more especially, will it be needful to obtain a general conception of the structure of its fore and hind limbs, and of its teeth. but i shall only touch upon these points which are absolutely essential to our inquiry. let us turn in the first place to the fore-limb. in most quadrupeds, as in ourselves, the fore-arms contains distinct bones called the radius and the ulna. the corresponding region in the horse seem at first to possess but one bone. careful observation, however, enables us to distinguish in this bone a part which clearly answers to the upper end of the ulna. this is closely united with the chief mass of the bone which represents the radius, and runs out into a slender shaft which may be traced for some distance downwards upon the back of the radius, and then in most cases thins out and vanishes. it takes still more trouble to make sure of what is nevertheless the fact, that a small part of the lower end of the bone of the horse's fore-arm, which is only distinct in a very young foal, is really the lower extremity of the ulna. what is commonly called the knee of a horse is its wrist. the "cannon bone" answers to the middle bone of the five metacarpal bones, which support the palm of the hand in ourselves. the "pastern," "coronary," and "coffin" bones of veterinarians answer to the joints of our middle fingers, while the hoof is simply a greatly enlarged and thickened nail. but if what lies below the horse's "knee" thus corresponds to the middle finger in ourselves, what has become of the four other fingers or digits? we find in the places of the second and fourth digits only two slender splint-like bones, about two-thirds as long as the cannon bone, which gradually taper to their lower ends and bear no finger joints, or, as they are termed, phalanges. sometimes, small bony or gristly nodules are to be found at the bases of these two metacarpal splints, and it is probable that these represent rudiments of the first and fifth toes. thus, the part of the horse's skeleton, which corresponds with that of the human hand, contains one overgrown middle digit, and at least two imperfect lateral digits; and these answer, respectively, to the third, the second and the fourth fingers in man. corresponding modifications are found in the hind limb. in ourselves, and in most quadrupeds, the leg contains two distinct bones, a large bone, the tibia, and a smaller and more slender bone, the fibula. but, in the horse, the fibula seems, at first, to be reduced to its upper end; a short slender bone united with the tibia and ending in a point below, occupying its place. examination of the lower end of a young foal's shin-bone, however, shows a distinct portion of osseous matter, which is the lower end of the fibula; so that the, apparently single, lower end of the shin-bone is really made up of the coalesced ends of the tibia and fibula, just as the, apparently single, lower end of the fore-arm bone is composed of the coalesced radius and ulna. the heel of the horse is the part commonly known as the hock. the hinder cannon bone answers to the middle metatarsal bone of the human foot, the pastern, coronary, and coffin bones, to the middle toe bones; the hind hoof to the nail; as in the fore-foot. and, as in the fore-foot, there are merely two splints to represent the second and the fourth toes. sometimes a rudiment of a fifth toe appears to be traceable. the teeth of a horse are not less peculiar than its limbs. the living engine, like all others, must be well stoked if it is to do its work; and the horse, if it is to make good its wear and tear, and to exert the enormous amount of force required for its propulsion, must be well and rapidly fed. to this end good cutting instruments and powerful and lasting crushers are needful. accordingly, the twelve cutting teeth of a horse are close-set and concentrated in the fore-part of its mouth, like so many adzes or chisels. the grinders or molars are large, and have an extremely complicated structure, being composed of a number of different substances of unequal hardness. the consequence of this is that they wear away at different rates; and, hence, the surface of each grinder is always as uneven as that of a good millstone. i have said that the structure of the grinding teeth is very complicated, the harder and the softer parts being, as it were, interlaced with one another. the result of this is that, as the tooth wears, the crown presents a peculiar pattern, the nature of which is not very easily deciphered at first, but which it is important we should understand clearly. each grinding tooth of the upper jaw has an _outer wall_ so shaped that, on the worn crown, it exhibits the form of two crescents, one in front and one behind, with their concave sides turned outwards. from the inner side of the front crescent, a crescentic _front ridge_ passes inwards and backwards, and its inner face enlarges into a strong longitudinal fold or _pillar_. from the front part of the hinder crescent, a _back ridge_ takes a like direction, and also has its _pillar_. the deep interspaces or _valleys_ between these ridges and the outer wall are filled by bony substance, which is called _cement_, and coats the whole tooth. the pattern of the worn face of each grinding tooth of the lower jaw is quite different. it appears to be formed of two crescent-shaped ridges, the convexities of which are turned outwards. the free extremity of each crescent has a _pillar_, and there is a large double _pillar_ where the two crescents meet. the whole structure is, as it were, imbedded in cement, which fills up the valleys, as in the upper grinders. if the grinding faces of an upper and of a lower molar of the same side are applied together, it will be seen that the opposed ridges are nowhere parallel, but that they frequently cross; and that thus, in the act of mastication, a hard surface in the one is constantly applied to a soft surface in the other, and _vice versa_. they thus constitute a grinding apparatus of great efficiency, and one which is repaired as fast as it wears, owing to the long-continued growth of the teeth. some other peculiarities of the dentition of the horse must be noticed, as they bear upon what i shall have to say by and by. thus the crowns of the cutting teeth have a peculiar deep pit, which gives rise to the well-known "mark" of the horse. there is a large space between the outer incisors and the front grinders. in this space the adult male horse presents, near the incisors on each side, above and below, a canine or "tush," which is commonly absent in mares. in a young horse, moreover, there is not unfrequently to be seen, in front of the first grinder, a very small tooth, which soon falls out. if this small tooth be counted as one, it will be found that there are seven teeth behind the canine on each side; namely, the small tooth in question, and the six great grinders, among which, by an unusual peculiarity, the foremost tooth is rather larger than those which follow it. i have now enumerated those characteristic structures of the horse which are of most importance for the purpose we have in view. to any one who is acquainted with the morphology [comparative forms] of vertebrated animals, they show that the horse deviates widely from the general structure of mammals; and that the horse type is, in many respects, an extreme modification of the general mammalian plan. the least modified mammals, in fact, have the radius and ulna, the tibia and fibula, distinct and separate. they have five distinct and complete digits on each foot, and no one of these digits is very much larger than the rest. moreover, in the least modified mammals the total number of the teeth is very generally forty-four, while in horses the usual number is forty, and in the absence of the canines it may be reduced to thirty-six; the incisor teeth are devoid of the fold seen in those of the horse: the grinders regularly diminish in size from the middle of the series to its front end; while their crowns are short, early attain their full length, and exhibit simple ridges or tubercles, in place of the complex foldings of the horse's grinders. hence the general principles of the hypothesis of evolution lead to the conclusion that the horse must have been derived from some quadruped which possessed five complete digits on each foot; which had the bones of the fore-arm and of the leg complete and separate; and which possessed forty-four teeth, among which the crowns of the incisors and grinders had a simple structure; while the latter gradually increased in size from before backwards, at any rate in the anterior part of the series, and had short crowns. and if the horse has been thus evolved, and the remains of the different stages of its evolution have been preserved, they ought to present us with a series of forms in which the number of the digits becomes reduced; the bones of the fore-arm and leg gradually take on the equine condition; and the form and arrangement of the teeth successively approximate to those which obtain in existing horses. let us turn to the facts, and see how far they fulfil these requirements of the doctrine of evolution. in europe abundant remains of horses are found in the quaternary and later tertiary strata as far as the pliocene formation. but these horses, which are so common in the cave-deposits and in the gravels of europe, are in all essential respects like existing horses. and that is true of all the horses of the latter part of the pliocene epoch. but in deposits which belong to the earlier pliocene and later miocene epochs, and which occur in britain, in france, in germany, in greece, in india, we find animals which are extremely like horses--which, in fact, are so similar to horses that you may follow descriptions given in works upon the anatomy of the horse upon the skeletons of these animals--but which differ in some important particulars. for example, the structure of their fore and hind limbs is somewhat different. the bones which, in the horse, are represented by two splints, imperfect below, are as long as the middle metacarpal and metatarsal bones; and attached to the extremity of each is a digit with three joints of the same general character as those of the middle digit, only very much smaller. these small digits are so disposed that they could have had but very little functional importance, and they must have been rather of the nature of the dew-claws, such as are to be found in many ruminant animals. the _hipparion_, as the extinct european three-toed horse is called, in fact, presents a foot similar to that of the american _protohippus_ (fig. 9), except that in the _hipparion_ the smaller digits are situated farther back and are of smaller proportional size than in the _protohippus_. the ulna is slightly more distinct than in the horse; and the whole length of it, as a very slender shaft intimately united with the radius, is completely traceable. the fibula appears to be in the same condition as in the horse. the teeth of the _hipparion_ are essentially similar to those of the horse, but the pattern of the grinders is in some respects a little more complex, and there is a depression on the face of the skull in front of the orbit, which is not seen in existing horses. in the earlier miocene, and perhaps the later eocene deposits of some parts of europe, another extinct animal has been discovered, which cuvier, who first described some fragments of it, considered to be a _palã¦otherium_. but as further discoveries threw new light on its structure, it was recognized as a distinct genus under the name of _anchitherium_. in its general characters, the skeleton of _anchitherium_ is very similar to that of the horse. in fact, lartet and de blainville called it _palã¦otherium equinum_ or _hippoides_; and de christol, in 1847, said that it differed from _hipparion_ in little more than the characters of its teeth, and gave it the name of _hipparitherium_. each foot possesses three complete toes; while the lateral toes are much larger in proportion to the middle toe than in _hipparion_, and doubtless rested on the ground in ordinary locomotion. the ulna is complete and quite distinct from that radius, though firmly united with the latter. the fibula seems also to have been complete. its lower end, though intimately united with that of the tibia, is clearly marked off from the latter bone. there are forty-four teeth. the incisors have no strong pit. the canines seem to have been well developed in both sexes. the first of the seven grinders, which, as i have said, is frequently absent, and when it does exist, is small in the horse, is a good-sized and permanent tooth, while the grinder which follows it is but little larger than the hinder ones. the crowns of the grinders are short, and though the fundamental pattern of the horse-tooth is discernible, the front and back ridges are less curved, the accessory pillars, are wanting, and the valleys, much shallower, are not filled up with cement. seven years ago, when i happened to be looking critically into the bearing of palã¦ontological facts upon the doctrine of evolution, it appeared to me that the _anchitherium_, the _hipparion_, and the modern horses, constitute a series in which the modifications of structure coincide with the order of chronological occurrence, in the manner in which they must coincide, if the modern horses really are the result of the gradual metamorphosis, in the course of the tertiary epoch, of a less specialized ancestral form. and i found by correspondence with the late eminent french anatomist and palã¦ontologist, m. lartet, that he had arrived at the same conclusion from the same data. that the _anchitherium_ type had become metamorphosed into the _hipparion_ type, and the latter into the _equine_ type,[5] in the course of that period of time which is represented by the latter half of the tertiary deposits, seemed to me to be the only explanation of the facts for which there was even a shadow of probability. and, hence, i have ever since held that these facts afford evidence of the occurrence of evolution, which, in the sense already defined, may be termed demonstrative. all who have occupied themselves with the structure of _anchitherium_, from cuvier onwards, have acknowledged its many points of likeness to a well-known genus of extinct eocene mammals, _palã¦otherium_. indeed, as we have seen, cuvier regarded his remains of _anchitherium_ as those of a species of _palã¦otherium_. hence, in attempting to trace the pedigree of the horse beyond the miocene epoch and the anchitheroid form, i naturally sought among the various species of palã¦otheroid animals for its nearest ally, and i was led to the conclusion that the _palã¦otherium minus_ (_plagiolophus_) represented the next step more nearly than any form then known. i think that this opinion was fully justifiable; but the progress of investigation has thrown an unexpected light on the question, and has brought us much nearer than could have been anticipated to a knowledge of the true series of the progenitors of the horse. you are all aware that, when your country was first discovered by europeans, there were no traces of the existence of the horse on any part of the american continent. the accounts of the conquest of mexico dwell upon the astonishment of the natives of that country when they first became acquainted with that astounding phenomenon--a man seated upon a horse. nevertheless, the investigations of american geologists have proved that the remains of horses occur in the most superficial deposits of both north and south america, just as they do in europe. therefore, for some reason or other--no feasible suggestion on that subject, so far as i know, has been made--the horse must have died out on this continent at some period preceding the discovery of america. of late years there has been discovered in your western territories that marvellous accumulation of deposits, admirably adapted for the preservation of organic remains, to which i referred the other evening, and which furnishes us with a consecutive series of records of the fauna of the older half of the tertiary epoch, for which we have no parallel in europe. they have yielded fossils in an excellent state of conservation and in unexampled numbers and variety. the researches of leidy and others have shown that forms allied to the _hipparion_ and the _anchitherium_ are to be found among these remains. but it is only recently that the admirably conceived and most thoroughly and patiently worked-out investigations of professor marsh have given us a just idea of the vast fossil wealth, and of the scientific importance, of these deposits. i have had the advantage of glancing over the collections in yale museum; and i can truly say, that so far as my knowledge extends, there is no collection from any one region and series of strata comparable, for extent, or for the care with which the remains have been got together, or for their scientific importance, to the series of fossils which he has deposited there. this vast collection has yielded evidence bearing upon the question of the pedigree of the horse of the most striking character. it tends to show that we must look to america, rather than to europe, for the original seat of the equine series; and that the archaic forms and successive modifications of the horse's ancestry are far better preserved here than in europe. professor marsh's kindness has enabled me to put before you a diagram, every figure of which is an actual representation of some specimen which is to be seen at yale at this present time (fig. 9). the succession of forms which he has brought together carries us from the top to the bottom of the tertiaries. firstly, there is the true horse. next we have the american pliocene form of the horse (_pliohippus_); in the conformation of its limbs it presents some very slight deviations from the ordinary horse, and the crowns of the grinding teeth are shorter. then comes the _protohippus_, which represents the european _hipparion_, having one large digit and two small ones on each foot, and the general characters of the fore-arm and leg to which i have referred. but it is more valuable than the european _hipparion_ for the reason that it is devoid of some of the peculiarities of that form--peculiarities which tend to show that the european _hipparion_ is rather a member of a collateral branch, than a form in the direct line of succession. next, in the backward order in time, is the _miohippus_, which corresponds pretty nearly with the _anchitherium_ of europe. it presents three complete toes--one large median and two smaller lateral ones; and there is a rudiment of that digit, which answers to the little finger of the human hand. the european record of the pedigree of the horse stops here; in the american tertiaries, on the contrary, the series of ancestral equine forms is continued into the eocene formations. an older miocene form, termed _mesohippus_, has three toes in front, with a large splint-like rudiment representing the little finger; and three toes behind. the radius and ulna, the tibia and the fibula, are distinct, and the short crowned molar teeth are anchitheroid in pattern. but the most important discovery of all is the _orohippus_, which comes from the eocene formation, and which is the oldest member of the equine series, as yet known. here we find four complete toes on the front-limb, three toes on the hind-limb, a well-developed ulna, a well-developed fibula, and short-crowned grinders of simple pattern. thus, thanks to these important researches, it has become evident that, so far as our present knowledge extends, the history of the horse-type is exactly and precisely that which could have been predicted from a knowledge of the principles of evolution. and the knowledge we now possess justifies us completely in the anticipation, that when the still lower eocene deposits, and those which belong to the cretaceous epoch, have yielded up their remains of ancestral equine animals, we shall find, first, a form with four complete toes and a rudiment of the innermost or first digit in front, with probably, a rudiment of the fifth digit in the hind foot;[6] while, in still older forms, the series of the digits will be more and more complete, until we come to the five-toed animals, in which, if the doctrine of evolution is well founded, the whole series must have taken its origin. that is what i mean by demonstrative evidence of evolution. an inductive hypothesis is said to be demonstrated when the facts are shown to be in entire accordance with it. if that is not scientific proof, there are no merely inductive conclusions which can be said to be proved. and the doctrine of evolution, at the present time, rests upon exactly as secure a foundation as the copernican theory of the motions of the heavenly bodies did at the time of its promulgation. its logical basis is precisely of the same character--the coincidence of the observed facts with theoretical requirements. the only way of escape, if it be a way of escape, from the conclusions which i have just indicated, is the supposition that all these different equine forms have been created separately at separate epochs of time; and, i repeat, that of such an hypothesis as this there neither is, nor can be, any scientific evidence; and, assuredly, so far as i know, there is none which is supported, or pretends to be supported, by evidence or authority of any other kind. i can but think that the time will come when such suggestions as these, such obvious attempts to escape the force of demonstration, will be put upon the same footing as the supposition made by some writers, who are, i believe, not completely extinct at present, that fossils are mere simulacra [images], are no indications of the former existence of the animals to which they seem to belong; but that they are either sports of nature, or special creations, intended--as i heard suggested the other day--to test our faith. in fact, the whole evidence is in favour of evolution, and there is none against it. and i say this, although perfectly well aware of the seeming difficulties which have been built up upon what appears to the uninformed to be a solid foundation. i meet constantly with the argument that the doctrine of evolution cannot be well founded because it requires the lapse of a very vast period of time; while the duration of life upon the earth, thus implied, is inconsistent with the conclusions arrived at by the astronomer and the physicist. i may venture to say that i am familiar with those conclusions, inasmuch as some years ago, when president of the geological society of london, i took the liberty of criticising them, and of showing in what respects, as it appeared to me, they lacked complete and thorough demonstration. but, putting that point aside, suppose that, as the astronomers, or some of them, and some physical philosophers tell us, it is impossible that life could have endured upon the earth for so long a period as is required by the doctrine of evolution--supposing that to be proved--i desire to be informed, what is the foundation for the statement that evolution does require so great a time? the biologist knows nothing whatever of the amount of time which may be required for the process of evolution. it is a matter of fact that the equine forms, which i have described to you, occur, in the order stated, in the tertiary formations. but i have not the slightest means of guessing whether it took a million of years, or ten millions, or a hundred millions, or a thousand millions of years, to give rise to that series of changes. a biologist has no means of arriving at any conclusions as to the amount of time which may be needed for a certain quantity of organic change. he takes his time from the geologist. the geologist, considering the rate at which deposits are formed and the rate at which denudation goes on upon the surface of the earth, arrives at more or less justifiable conclusions as to the time which is required for the deposit of a certain thickness of rocks; and if he tells me that the tertiary formations required 500,000,000 years for their deposit, i suppose he has good ground for what he says, and i take that as a measure of the duration of the evolution of the horse from the _orohippus_ up to its present condition. and, if he is right, undoubtedly evolution is a very slow process, and requires a great deal of time. but suppose now, that an astronomer or a physicist--for instance, my friend sir william thomson--tells me that my geological authority is quite wrong; and that he has weighty evidence to show that life could not possibly have existed upon the surface of the earth 500,000,000 years ago, because the earth would have then been too hot to allow of life, my reply is: "that is not my affair; settle that with the geologist, and when you have come to an agreement among yourselves i will adopt your conclusions." we take our time from the geologists and physicists, and it is monstrous that, having taken our time from the physical philosopher's clock, the physical philosopher should turn round upon us, and say we are too fast or too slow. what we desire to know is, is it a fact that evolution took place? as to the amount of time which evolution may have occupied, we are in the hands of the physicist and the astronomer, whose business it is to deal with those questions. [illustration: fig. 9] fore foot. hind foot. fore-arm. leg. upper molar. lower molar. recent. equus. pliocene. pliohippus. protohippus (_hipparion_). miocene. miohippus (_anchitherium_). mesohippus. eocene. orohippus. footnotes: [5] i use the word "type" because it is highly probable that many of the forms of _anchitherium_-like and _hipparion_-like animals existed in the miocene and pliocene epochs, just as many species of the horse tribe exist now; and it is highly improbable that the particular species of _anchitherium_ or _hipparion_, which happen to have been discovered, should be precisely those which have formed part of the direct line of the horse's pedigree. [6] since this lecture was delivered, professor marsh has discovered a new genus of equine mammals (_eohippus_) from the lowest eocene deposits of the west, which corresponds very nearly to this description.--_american journal of science_, november, 1876. fighting pests with insect allies leland o. howard [dr. howard is chief of the division of entomology in the united states department of agriculture at washington. he is a lecturer at swarthmore college and at georgetown university. he has written "the insect book," published by doubleday, page & co., new york; and a work on mosquitoes, issued by mcclure, phillips & co., new york. both are books of interest from the hand of a master: they are fully illustrated. the narrative which follows appeared in _everybody's magazine_, june, 1901.] some twenty-five years ago there appeared suddenly upon certain acacia trees at menlo park, california, a very destructive scale bug. it rapidly increased and spread from tree to tree, attacking apples, figs, pomegranates, quinces, and roses, and many other trees and plants, but seeming to prefer to all other food the beautiful orange and lemon trees which grow so luxuriantly on the pacific coast, and from which a large share of the income of so many fruit-growers is gained. this insect, which came to be known as the _white scale_ or _fluted scale_ or the _icerya_ (from its scientific name), was an insignificant creature in itself, resembling a small bit of fluted wax a little more than a quarter of an inch long. but when the scales had once taken possession of a tree, they swarmed over it until the bark was hidden; they sucked its sap through their minute beaks until the plant became so feeble that the leaves and young fruit dropped off, a hideous black smut-fungus crept over the young twigs, and the weakened tree gradually died. in this way orchard after orchard of oranges, worth a thousand dollars or more an acre, was utterly destroyed; the best fruit-growing sections of the state were invaded, and ruin stared many a fruit-grower in the face. this spread of the pest was gradual, extending through a series of years, and not until 1886 did it become so serious a matter as to attract national attention. in this year an investigation was begun by the late professor c. v. riley, the government entomologist then connected with the department of agriculture at washington. he sent two agents to california, both of whom immediately began to study the problem of remedies. in 1887 he visited california himself, and during that year published an elaborate report giving the results of the work up to that point. the complete life-history of the insect had been worked out, and a number of washes had been discovered which could be applied to the trees in the form of a spray, and which would kill a large proportion of the pests at a comparatively small expense. but it was soon found that the average fruit-grower would not take the trouble to spray his trees, largely from the fact that he had experimented for some years with inferior washes and quack nostrums, and from lack of success had become disgusted with the whole idea of using liquid compounds. something easier, something more radical was necessary in his disheartened condition. meantime, after much sifting of evidence and much correspondence with naturalists in many parts of the world, professor riley had decided that the white scale was a native of australia, and had been first brought over to california accidentally upon australian plants. in the same way it was found to have reached south africa and new zealand, in both of which colonies it had greatly increased, and had become just such a pest as it is in california. in australia, however, its native home, it did not seem to be abundant, and was not known as a pest--a somewhat surprising state of affairs, which put the entomologist on the track of the results which proved of such great value to california. he reasoned that, in his native home, with the same food plants upon which it flourished abroad in such great abundance, it would undoubtedly do the same damage that it does in south africa, new zealand, and california, if there were not in australia some natural enemy, probable some insect parasite or predatory beetle, which killed it off. it became therefore important to send a trained man to australia to investigate this promising line. after many difficulties in arranging preliminaries relating to the payment of expenses (in which finally the department of state kindly assisted), one of professor riley's assistants, a young german named albert koebele, who had been with him for a number of years, sailed for australia in august, 1888. koebele was a skilled collector and an admirable man for the purpose. he at once found that professor riley's supposition was correct: there existed in australia small flies which laid their eggs in the white scales, and these eggs hatched into grubs which devoured the pests. he also found a remarkable little ladybird, a small, reddish-brown convex beetle, which breeds with marvellous rapidity and which, with voracious appetite, and at the same time with discriminating taste, devours scale after scale, but eats fluted scales only--does not attack other insects. this beneficial creature, now known as the australian ladybird, or the vedalia, mr. koebele at once began to collect in large numbers, together with several other insects found doing the same work. he packed many hundreds of living specimens of the ladybird, with plenty of food, in tin boxes, and had them placed on ice in the ice-box of the steamer at sydney; they were carried carefully to california, where they were liberated upon orange trees at los angeles. [illustration: vedalia, or australian ladybird] these sendings were repeated for several months, and mr. koebele, on his return in april, 1889, brought with him many more living specimens which he had collected on his way home in new zealand, where the same vedalia had been accidentally introduced a year or so before. [illustration: larv㦠of vedalia eating white scale] the result more than justified the most sanguine expectations. the ladybirds reached los angeles alive, and, with appetites sharpened by their long ocean voyage, immediately fell upon the devoted scales and devoured them one after another almost without rest. their hunger temporarily satisfied, they began to lay eggs. these eggs hatched in a few days into active grub-like creatures--the larv㦠of the beetles--and these grubs proved as voracious as their parents. they devoured the scales right and left, and in less than a month transformed once more to beetles. and so the work of extermination went on. each female beetle laid on an average 300 eggs, and each of these eggs hatched into a hungry larva. supposing that one-half of these larv㦠produced female beetles, a simple calculation will show that in six months a single ladybird became the ancestor of 75,000,000,000 of other ladybirds, each capable of destroying very many scale insects. [illustration: twig of olive infected with black scale] is it any wonder, then, that the fluted scales soon began to disappear? is it any wonder that orchard after orchard was entirely freed from the pest, until now over a large section of the state hardly an icerya is to be found? and could a more striking illustration of the value of the study of insects possibly be instanced? in less than a year from the time when the first of these hungry australians was liberated from his box in los angeles the orange trees were once more in bloom and were resuming their old-time verdure--the icerya had become practically a thing of the past. [illustration: rhizobius, the imported enemy of the black scale of the olive.] this wonderful success encouraged other efforts in the same direction. the state of california some years later sent the same entomologist, koebele, to australia to search for some insect enemy of the black scale, an insect which threatened the destruction of the extensive olive orchards of california. he found and successfully introduced another ladybird beetle, known as _rhizobius ventralis_, a little dark-coloured creature which has thrived in the california climate, especially near the seacoast, and in the damp air of those regions has successfully held the black scale in check. it was found, however, that back from the seacoast this insect did not seem to thrive with the same vigor, and the black scale held its own. then a spirited controversy sprung up among the olive-growers, those near the seacoast contending that the _rhizobius_ was a perfect remedy for the scale, while those inland insisted that it was worthless. a few years later it was discovered that this olive enemy in south europe is killed by a little caterpillar, which burrows through scale after scale eating out their contents, and an effort was made to introduce the caterpillar into california, but these efforts failed. within the past two years it has been found that a small parasitic fly exists in south africa which lays its eggs in the same black scale, and its grub-like larv㦠eat out the bodies of the scales and destroy them. the climate of the region in which this parasite exists is dry through a large part of the year, and therefore this little parasitic fly, known as _scutellista_, was thought to be the needed insect for the dry california regions. with the help of mr. c. p. lounsbury, the government entomologist of cape colony, living specimens of this fly were brought to this country, and were colonized in the santa clara valley, near san josã©, california, where they have perpetuated themselves and destroyed many of the black scales, and promise to be most successful in their warfare against the injurious insect. this same _scutellista_ parasite had, curiously enough, been previously introduced in an accidental manner into italy, probably from india, and probably in scale-insects living on ornamental plants brought from india. but in italy it lives commonly in another scale insect, and with the assistance of the learned italian, professor antonio berlese, the writer made an unsuccessful attempt to introduce and establish it a year earlier in some of our southern states, where it was hoped it would destroy certain injurious insects known as "wax scales." in the meantime the united states, not content with keeping all the good things to herself, has spread the first ladybird imported--the _vedalia_--to other countries. four years ago the white scale was present in enormous numbers in orange groves on the left bank of the river tagus, in portugal, and threatened to wipe out the orange-growing industry in that country. the california people, in pursuance of a far-sighted policy, had with great difficulty, owing to lack of food, kept alive some colonies of the beneficial beetle, and specimens were sent to portugal which reached there alive and flourishing. they were tended for a short time, and then liberated in the orange groves, with precisely the same result as in california. in a few months the scale insects were almost entirely destroyed, and the portuguese orange-growers saved from enormous loss. this good result in portugal was not accomplished without opposition. it was tried experimentally at the advice of the writer, and in the face of great incredulity on the part of certain portuguese newspapers and of some officials. by many prominent persons the account published of the work of the insect in the united states was considered as untrustworthy, and simply another instance of american boasting. but the opposition was overruled, and the triumphant result silenced all opposition. it is safe to say that the general opinion among portuguese orange-growers to-day is very favourable to american enterprise and practical scientific acumen. the _vedalia_ was earlier sent to the people in alexandria and cairo, egypt, where a similar scale was damaging the fig trees and other valuable plants, and the result was again the same, the injurious insects were destroyed. this was achieved only after extensive correspondence and several failures. the active agent in alexandria was rear admiral blomfield, of the british royal navy, a man apparently of wide information, good judgment, and great energy. the same thing occurred when the california people sent this saviour of horticulture to south africa, where the white scale had also made its appearance. it is not only beneficial insects, however, which are being imported, but diseases of injurious insects. in south africa the colonists suffer severely from swarms of migratory grasshoppers, which fly from the north and destroy their crops. they have discovered out there a fungus disease, which under favorable conditions kills off the grasshoppers in enormous numbers. at the bacteriological institute in grahamstown, natal, they have cultivated this fungus in culture tubes, and have carried it successfully throughout the whole year; and they have used it practically by distributing these culture tubes wherever swarms of grasshoppers settle and lay their eggs. the disease, once started in an army of young grasshoppers, soon reduces them to harmless numbers. the united states government last year secured culture tubes of this disease, and experiments carried on in colorado and in mississippi show that the vitality of the fungus had not been destroyed by its long ocean voyage, and many grasshoppers were killed by its spread. during the past winter other cultures were brought over from cape colony, and the fungus is being propagated in the department of agriculture for distribution during the coming summer in parts of the country where grasshoppers may prove to be destructively abundant. [illustration: grasshopper dying from fungus disease] although we practically no longer have those tremendous swarms of migratory grasshoppers which used to come down like devastating armies in certain of our western states and in a night devour everything green, still, almost every year, and especially in the west and south, there is somewhere a multiplication of grasshoppers to a very injurious degree, and it is hoped that the introduced fungus can be used in such cases. persons officially engaged in searching for remedies for injurious insects all over the world have banded themselves together in a society known as the association of economic entomologists. they are constantly interchanging ideas regarding the destruction of insects, and at present active movements are on foot in this direction of interchanging beneficial insects. entomologists in europe will try the coming summer to send to the united states living specimens of a tree-inhabiting beetle which eats the caterpillar of the gipsy moth, and which will undoubtedly also eat the caterpillar so common upon the shade-trees of our principal eastern cities, which is known as the tussock moth caterpillar. an entomologist from the united states, mr. c. l. marlatt, has started for japan, china, and java, for the purpose of trying to find the original home of the famous san josã© scale--an insect which has been doing enormous damage in the apple, pear, peach, and plum orchards of the united states--and if he finds the original home of this scale, it is hoped that some natural enemy or parasite will be discovered which can be introduced into the united states to the advantage of our fruit-growers. professor berlese of italy, and dr. reh, of germany, will attempt the introduction into europe of some of the parasites of injurious insects which occur in the united states, and particularly those of the woolly root-louse of the apple, known in europe as the "american blight"--one of the few injurious insects which probably went to europe from this country, and which in the united states is not so injurious as it is in europe. it is a curious fact, by the way, that while we have had most of our very injurious insects from europe, american insects, when accidentally introduced into europe, do not seem to thrive. the insect just mentioned, and the famous grape-vine _phylloxera_, a creature which caused france a greater economic loss than the enormous indemnity which she had to pay to germany after the franco-prussian war, are practically the only american insects with which we have been able to repay europe for the insects which she has sent us. climatic differences, no doubt, account for this strange fact, and our longer and warmer summers are the principal factor. it is not alone the parasitic and predaceous insects which are beneficial. a new industry has been brought into the united states during the past two years by the introduction and acclimatization of the little insect which fertilizes the smyrna fig in mediterranean countries. the dried-fig industry in this country has never amounted to anything. the smyrna fig has controlled the dried-fig markets of the world, but in california the smyrna fig has never held its fruit, the young figs dropping from the trees without ripening. it was found that in mediterranean regions a little insect, known as the _blastophaga_, fertilizes the flowers of the smyrna fig with pollen from the wild fig which it inhabits. the united states department of agriculture in the spring of 1899 imported successfully some of these insects through one of its travelling agents, mr. w. t. swingle, and the insect was successfully established at fresno in the san joaquin valley. a far-sighted fruit-grower, mr. george c. roeding, of fresno, had planted some years previously an orchard of 5,000 smyrna fig trees and wild fig trees, and his place was the one chosen for the successful experiment. the little insect multiplied with astonishing rapidity, was carried successfully through the winter of 1899-1900, and in the summer of 1900 was present in such great numbers that it fertilized thousands of figs, and fifteen tons of them ripened. when these figs were dried and packed it was discovered that they were superior to the best imported figs. they contained more sugar and were of a finer flavor than those brought from smyrna and algeria. the _blastophaga_ has come to stay, and the prospects for a new and important industry are assured. with all these experiments the criticism is constantly made that unwittingly new and serious enemies to agriculture may be introduced. the unfortunate introduction of the english sparrow into this country is mentioned, and the equally unfortunate introduction of the east indian mongoose into the west indies as well. the fear is expressed that the beneficial parasitic insects, after they have destroyed the injurious insects, will either themselves attack valuable crops or do something else of an equally harmful nature. but there is no reason for such alarm. the english sparrow feeds on all sorts of things, and the east indian mongoose, while it was introduced into jamaica to kill snakes, was found, too late, to be also a very general feeder. as a matter of fact, after the snakes were destroyed, and even before, it attacked young pigs, kids, lambs, calves, puppies, and kittens, and also destroyed bananas, pineapples, corn, sweet potatoes, cocoanuts, peas, sugar corn, meat, and salt provisions and fish. but with the parasitic and predatory insects the food habits are definite and fixed. they can live on nothing but their natural food, and in its absence they die. the australian ladybird originally imported, for example, will feed upon nothing but scale insects of a particular genus, and, as a matter of fact, as soon as the fluted scales became scarce the california officials had the greatest difficulty in keeping the little beetles alive, and were actually obliged to cultivate for food the very insects which they were formerly so anxious to wipe out of existence! with the _scutellista_ parasite the same fact holds. the fly itself does not feed, and its young feed only upon certain scale insects, and so with all the rest. all of these experiments are being carried on by men learned in the ways of insects, and only beneficial results, or at the very least negative ones, can follow. and even where only one such experiment out of a hundred is successful, what a saving it will mean! we do not expect the time to come when the farmer, finding hessian fly in his wheat, will have only to telegraph the nearest experiment station, "send at once two dozen first-class parasites;" but in many cases, and with a number of different kinds of injurious insects, especially those introduced from foreign countries, it is probable that we can gain much relief by the introduction of their natural enemies from their original home. the strange story of the flowers george iles [from "the wild flowers of america," copyright by g. h. buek & co., new york, 1894, by their kind permission. the american edition is out of print: the canadian edition, "wild flowers of canada," is published by graham & co., montreal, canada. the work describes and illustrates in their natural tints nearly three hundred beautiful flowers.] imagine a venetian doge, a french crusader, a courtier of the time of the second charles, an ojibway chief, a justice of the supreme court, in the formal black of evening dress, and how much each of them would lose! where there is beauty, strength or dignity, dress can heighten it; where all these are lacking, their absence is kept out of mind by raiment in itself worthy to be admired. if dress artificial has told for much in the history of human-kind, dress natural has told for yet more in the lesser world of plant and insect life. in some degree the tiny folk that reign in the air, like ourselves, are drawn by grace of form, by charm of colour; of elaborate display of their attractions moths, butterflies and beetles are just as fond as any belles of the ball-room. now let us bear in mind that of all the creatures that share the earth with man, the one that stands next to him in intelligence is neither a biped nor a quadruped, but that king of the insect tribe, the ant, which can be a herdsman and warehouse-keeper, an engineer and builder, an explorer and a general. with all his varied powers the ant lacks a peculiarity in his costume which has denied him enlistment in a task of revolution in which creatures far his inferiors have been able to change the face of the earth. and the marvel of this peculiarity of garb which has meant so much, is that it consists in no detail of graceful outline, or beauty of tint, but solely in the minor matter of texture. the ant, warrior that he is, wears smooth and shining armour; the bee, the moth and the butterfly are clad in downy vesture, and simply because thus enabled to catch dust on their clothes these insects, as weavers of the web of life, have counted for immensely more than the ant with all his brains and character. to understand the mighty train of consequences set in motion by this mere shagginess of coat, let us remember that, like a human babe, every flowering plant has two parents. these two parents, though a county's breadth divide them, are wedded the instant that pollen from the anther of one of them meets the stigma of the other. many flowers find their mates upon their own stem; but, as in the races of animals, too close intermarriage is hurtful, and union with a distant stock promotes both health and vigor. hence the great gain which has come to plants by engaging the wind as their matchmaker--as every summer shows us in its pollen-laden air, the oaks, the pines, the cottonwoods, and a host of other plants commit to the breeze the winged atoms charged with the continuance of their kind. nevertheless, long as the wind has been employed at this work, it has not yet learned to do it well; nearly all the pollen entrusted to it is wasted, and this while its production draws severely upon the strength of a plant. as good fortune will have it, a great many flowers close to their pollen yield an ample supply of nectar: a food esteemed delicious by the whole round of insects, winged and wingless. while ants might sip this nectar of ages without plants being any the better or the worse; a very different result has followed upon the visits of bees, wasps, and other hairy-coated callers. these, as they devour nectar, dust themselves with the pollen near by. yellowed or whitened with this freightage, moth and butterfly, as they sail through the air, know not that they are publishing the banns of marriage between two blossoms acres or, it may be, miles apart. yet so it is. alighting on a new flower the insect rubs a pollen grain on a stigma ready to receive it, and lo! the rites of matrimony are solemnized then and there. unwittingly the little visitor has wrought a task bigger with fate than many an act loudly trumpeted among the mightiest deeds of men! on the threshold of a lady's slipper a bee may often be detected in the act of entrance. in the sage-flower he finds an anther of the stamen which, pivoted on its spring, dusts him even more effectually. [illustration: sage-flower and bee] bountifully to spread a table is much, but not enough, for without invitation how can hospitality be dispensed? to the feast of nectar the blossoms join their bidding; and those most conspicuously borne and massed, gayest of hue, richest in odor, secure most guests, and are therefore most likely to transmit to their kind their own excellences as hosts and entertainers. thus all the glories of the blossoms have arisen in doing useful work; their beauty is not mere ornament, but the sign and token of duty well performed. our opportunity to admire the radiancy and perfume of a jessamine or a pond-lily is due to the previous admiration of uncounted winged attendants. if a winsome maid adorns herself with a wreath from the garden, and carries a posy gathered at the brookside, it is for the second time that their charms are impressed into service; for the flowers' own ends of attraction all their scent and loveliness were called into being long before. let us put flowers of the blue flag beside those of the maple, and we shall have a fair contrast between the brilliancy of blossoms whose marrier has been an insect, and the dinginess of flowers indebted to the services of the wind. can it be that both kinds of flowers are descended from forms resembling each other in want of grace and colour? such, indeed, is the truth. but how, as the generations of the flowers succeeded one another, did differences so striking come about? in our rambles afield let us seek a clue to the mystery. it is late in springtime, and near the border of a bit of swamp we notice a clump of violets: they are pale of hue, and every stalk of them rises to an almost weedy height. [illustration: wild rose, single] twenty paces away, on a knoll of dry ground, we find more violets, but these are in much deeper tints of azure and yellow, while their stalks are scarcely more than half as tall as their brethren near the swamp. six weeks pass by. this time we walk to a wood-lot close to a brimming pond. at its edge are more than a score wild-rose bushes. on the very first of them we see that some of the blossoms are a light pink, others a pink so deep as to seem dashed with vivid red. and while a flower here and there is decidedly larger and more vigorous than its fellows, a few of the blossoms are undersized and puny: the tide of life flows high and merrily in a fortunate rose or two, it seems to ebb and falter by the time it reaches one or two of their unhappy mates. as we search bush after bush we are at last repaid for sundry scratches from their thorns by securing a double rose, a "sport," as the gardener would call it. and in the broad meadow between us and home we well know that for the quest we can have not only four-leaved clovers, but perchance a handful of five and six-leaved prizes. the secret is out. flowers and leaves are not cast like bullets in rigid moulds, but differ from their parents much as children do. usually the difference is slight, at times it is as marked as in our double rose. whenever the change in a flower is for the worse, as in the sickly violets and roses we have observed, that particular change ends there--with death. but when the change makes a healthy flower a little more attractive to its insect ministers, it will naturally be chosen by them for service, and these choosings, kept up year after year, and century upon century, have at last accomplished much the same result as if the moth, the bee, and the rest of them had been given power to create blossoms of the most welcome forms, the most alluring tints, the most bewitching perfumes. in farther jaunts afield we shall discover yet more. it is may, and a heavy rainstorm has caused the petals of a trillium to forget themselves and return to their primitive hue of leafy green. a month later we come upon a buttercup, one of whose sepals has grown out as a small but perfect leaf. later still in summer we find a rose in the same surprising case, while not far off is a columbine bearing pollen on its spurs instead of its anthers. what family tie is betrayed in all this? no other than that sepals, petals, anthers and pistils are but leaves in disguise, and that we have detected nature returning to the form from which ages ago she began to transmute the parts of flowers in all their teeming diversity. the leaf is the parent not only of all these but of delicate tendrils, which save a vine the cost of building a stem stout enough to lift it to open air and sunshine. however thoroughly, or however long, a habit may be impressed upon a part of a plant, it may on occasion relapse into a habit older still, resume a shape all but forgotten, and thus tell a story of its past that otherwise might remain forever unsuspected. thus it is with the somewhat rare "sport" that gives us a morning glory or a harebell in its primitive form of unjoined petals. the bell form of these and similar flowers has established itself by being much more effective than the original shape in dusting insect servitors with pollen. not only the forms of flowers but their massing has been determined by insect preferences; a wide profusion of blossoms grow in spikes, umbels, racemes and other clusters, all economizing the time of winged allies, and attracting their attention from afar as scattered blossoms would fail to do. besides this massing, we have union more intimate still as in the dandelion, the sun-flower and the marigold. these and their fellow composites each seem an individual; a penknife discloses each of them to be an aggregate of blossoms. so gainful has this kind of co-operation proved that composites are now dominant among plants in every quarter of the globe. as to how composites grew before they learned that union is strength, a hint is dropped in the "sport" of the daisy known as "the hen and chickens," where perhaps as many as a dozen florets, each on a stalk of its own, ray out from a mother flower. while for the most part insects have been mere choosers from among various styles of architecture set before them by plants, they have sometimes risen to the dignity of builders on their own account, and without ever knowing it. the buttress of the larkspur has sprung forth in response to the pressure of one bee's weight after another, and many a like structure has had the very same origin,--or shall we say, provocation? in these and in other examples unnumbered, culminating in the marvellous orchids and their ministers, there has come about the closest adaptation of flower-shape to insect-form, the one now clearly the counterpart of the other. we must not forget that the hospitality of a flower is after all the hospitality of an inn-keeper who earns and requires payment. vexed as flowers are apt to be by intruders that consume their stores without requital, no wonder that they present so ample an array of repulsion and defence. best of all is such a resource as that of the red clover, which hides its honey at the bottom of a tube so deep that only a friendly bumblebee can sip it. less effective, but well worth a moment's examination, are the methods by which leaves are opposed as fences for the discouragement of thieves. here, in a bellwort, is a perfoliate leaf that encircles the stem upon which it grows; and there in a honeysuckle is a connate leaf on much the same plan, formed of two leaves, stiff and strong, soldered at their bases. sometimes the pillager meets prickles that sting him, as in the roses and briers; and if he is a little fellow he is sure to regard him with intense disgust, a bristly guard of wiry hair--hence the commonness of that kind of fortification. against enemies of larger growth a tree or shrub will often aim sharp thorns--another piece of masquerade, for thorns are but branches checked in growth, and frowning with a barb in token of disappointment at not being able to smile in a blossom. in every jot and tittle of barb and prickle, of the glossiness which disheartens or the gumminess which ensnares, we may be sure that equally with all the lures of hue, form and scent, nothing, however trifling it may seem, is as we find it, except through usefulness long tested and approved. in flowers, much that at first glance looks like idle decoration, on closer scrutiny reveals itself as service in disguise. in penetrating these disguises and many more of other phases, the student of flowers delights to busy himself. he loves, too, to detect the cousinship of plants through all the change of dress and habit due to their rearing under widely different skies and nurture, to their being surrounded by strangely contrasted foes and friends. often he can link two plants together only by going into partnership with a student of the rocks, by turning back the records of the earth until he comes upon a flower long extinct, a plant which ages ago found the struggle for life too severe for it. he ever takes care to observe his flowers accurately and fully, but chiefly that he may rise from observation to explanation, from bare facts to their causes, from declaring what, to understanding, whence and how. one of the stock resources of novelists, now somewhat out of date, was the inn-keeper who beamed in welcome of his guest, grasped his hand in gladness, and loaded a table for him in tempting array, and all with intent that later in the day (or night) he might the more securely plunge a dagger into his victim's heart--if, indeed, he had not already improved an opportunity to offer to that victim's lips a poisoned cup. this imagined treachery might well have been suggested by the behaviour of certain alluring plants that so far from repelling thieves, or discouraging pillagers, open their arms to all comers--with purpose of the deadliest. of these betrayers the chief is the round-leaved sun-dew, which plies its nefarious vocation all the way from labrador to florida. its favourite site is a peat-bog or a bit of swampy lowland, where in july and august we can see its pretty little white blossoms beckoning to wayfaring flies and moths their token of good cheer! circling the flower-stalk, in rosette fashion, are a dozen or more round leaves, each of them wearing scores of glands, very like little pins, a drop of gum glistening on each and every pin by way of head. this appetizing gum is no other than a fatal stick-fast, the raying pins closing in its aid the more certainly to secure a hapless prisoner. soon his prison-house becomes a stomach for his absorption. its duty of digestion done, the leaf in all seeming guilessness once more expands itself for the enticement of a dupe. to see how much the sun-dew must depend upon its meal of insects we have only to pull it up from the ground. a touch suffices--it has just root enough to drink by; the soil in which it makes, and perhaps has been obliged to make, its home has nothing else but drink to give it. less accomplished in its task of assassination is the common butterwort to be found on wet rocks in scattered districts of canada and the states adjoining canada. surrounding its pretty violet flowers, of funnel shape, are gummy leaves which close upon their all too trusting guests, but with less expertness than the sun-dew's. the butterwort is but a 'prentice hand in the art of murder, and its intended victims often manage to get away from it. built on a very different model is the bladderwort, busy in stagnant ponds near the sea coast from nova scotia to texas. its little white spongy bladders, about a tenth of an inch across, encircle the flowering stem by scores. from each bladder a bunch of twelve or fifteen hairy prongs protrude, giving the structure no slight resemblance to an insect form. these prongs hide a valve which, as many an unhappy little swimmer can attest, opens inward easily enough, but opens outward never. as in the case of its cousinry a-land, the bladderwort at its leisure dines upon its prey. [illustration: venus' fly trap--open with a welcome] in marshy places near the mouth of the cape fear river, in the vicinity of wilmington, north carolina, grows the venus' fly-trap, most wonderful of all the death-dealers of vegetation. like much else in nature's handiwork this plant might well have given inventors a hint worth taking. the hairy fringes of its leaves are as responsive to a touch from moth or fly as the sensitive plant itself. and he must be either a very small or a particularly sturdy little captive that can escape through the sharp opposed teeth of its formidable snare. it is one of the unexplained puzzles of plant life that the venus' fly-trap, so marvellous in its ingenuity, should not only be confined to a single district, but should seem to be losing its hold of even that small kingdom. of still another type is the pitcher plant, or side-saddle flower, which flaunts its deep purple petals in june in many a peat-bog from canada southward to louisiana and florida. its leaves develop themselves into lidded cups, half-filled with sweetish juice, which first lures a fly or ant, then makes him tipsy, and then despatches him. the broth resulting is both meat and drink to the plant, serving as a store and reservoir against times of drought and scarcity. [illustration: shut for slaughter] now the question is, how came about this strange and somewhat horrid means of livelihood? how did plants of so diverse families turn the tables on the insect world, and learn to eat instead of being themselves devoured? a beginner in the builder's art finds it much more gainful to examine the masonry of foundations, the rearing of walls, the placing of girders and joists, the springing of arches and buttresses, than to look at a cathedral, a courthouse, or a bank, finished and in service. in like manner a student of insect-eating plants tries to find their leaves in the making, in all the various stages which bridge their common forms with the shapes they assume when fully armed and busy. availing himself of the relapses into old habits which plants occasionally exhibit under cultivation, mr. dickson has taught us much regarding the way the pitcher plant of australia, the _cephalotus_, has come to be what it is. he has arranged in a connected series all the forms of its leaf from that of a normal leaf with a mere dimple in it, to the deeply pouched and lidded pitcher ready for deceitful hospitalities. and similar transformations have without doubt taken place in the pitcher plants of america. observers in the cape of good hope have noted two plants _roridula dentata_ and _biblys gigantea_, which are evidently following in the footsteps of the sundews, and may be expected in the fulness of years to be their equal partners in crime. but why need we wander so far as south africa to find the germs of this strange rapacity when we can see at home a full dozen species of catch-fly, sedums, primulas, and geraniums pouring out glutinous juices in which insects are entangled? let stress of hunger, long continued, force any of these to turn its attention to the dietary thus proffered, and how soon might not the plant find in felony the sustenance refused to honest toil? but after all the plants that have meat for dinner are only a few. the greater part of the vegetable kingdom draws its supplies from the air and the soil. those plants, and they are many, that derive their chief nourishment from the atmosphere have a decidedly thin diet. which of us would thrive on milk at the rate of a pint to five hogsheads of water? such is the proportion in which air contains carbonic acid gas, the main source of strength for many thousands of trees, shrubs, and other plants. no wonder that they array themselves in so broad an expanse of leafage. an elm with a spread of seventy feet is swaying in the summer breeze at least five acres of foliage as its lungs and stomach. beyond the shade of elms and maples let us stroll past yonder stretch of pasture and we shall notice how the grass in patches here and there deepens into green of the richest--a plain token of moisture in the hollows--a blessing indeed in this dry weather. in the far west and northwest the buffalo grass has often to contend with drought for months together, so that it has learned to strike deep in quest of water to quench its thirst. it is a by-word among the ranchmen that the roots go clear through the earth and are clinched as they sprout from the ground in china. joking apart, they have been found sixty-eight feet below the surface of the prairie, and often in especially dry seasons cattle would perish were not these faithful little well-diggers and pumpers constantly at work for them. in the river valleys of arizona although the air is dry the subsoil water is near the surface of the ground. here flourishes the mesquit tree, _prosopis juliflora_, with a tale to tell well worth knowing. when a mesquit seems stunted, it is because its strength is withdrawn for the task of delving to find water; where a tree grows tall with goodly branches, it betokens success in reaching moisture close at hand. thus in shrewdly reading the landscape a prospector can choose the spot where with least trouble he can sink his well. and plants discover provender in the soil as well as drink. nearer home than arizona we have only to dislodge a beach pea from the ground to see how far in search of food its roots have dug amid barren stones and pebbles. often one finds a plant hardly a foot high with roots extending eight feet from its stem. and beyond the beaches where the beach peas dig so diligently are the seaweeds--with a talent for picking and choosing all their own. dr. julius sachs, a leading german botanist, believes that the parts of plants owe their form, as crystals do, to their peculiarities of substance; that just as salt crystallizes in one shape and sugar in another, so a seaweed or a tulip is moulded by the character of its juices. something certainly of the crystal's faculty for picking out particles akin to itself, and building with them, is shown by the kelp which attracts from the ocean both iodine and bromine--often dissolved though they are in a million times their bulk of sea water. this trait of choosing this or that dish from the feast afforded by sea or soil or air is not peculiar to the seaweeds; every plant displays it. beech trees love to grow on limestone and thus declare to the explorer the limestone ridge he seeks. in the horn silver mine, of utah, the zinc mingled with the silver ore is betrayed by the abundance of the zinc violet, a delicate and beautiful cousin of the pansy. in germany this little flower is admittedly a signal of zinc in the earth, and zinc is found in its juices. the late mr. william dorn, of south carolina, had faith in a bush, of unrecorded name, as betokening gold-bearing veins beneath it. that his faith was not without foundation is proved by the large fortune he won as a gold miner in the blue ridge country--his guide the bush aforesaid. mr. rossiter w. raymond, the eminent mining engineer of new york, has given some attention to this matter of "indicative plants." he is of the opinion that its unwritten lore among practical miners, prospectors, hunters, and indians is well worth sifting. their observations, often faulty, may occasionally be sound and valuable enough richly to repay the trouble of separating truth from error. when we see how important as signs of water many plants can be, why may we not find other plants denoting the minerals which they especially relish as food or condiment? of more account than gold or silver are the harvests of wheat and corn that ripen in our fields. there the special appetites of plants have much more than merely curious interest for the farmer. he knows full well that his land is but a larder which serves him best when not part but all its stores are in demand. hence his crop "rotation," his succession of wheat to clover, of grass to both. were he to grow barley every year he would soon find his soil bared of all the food that barley asks, while fare for peas or clover stood scarcely broached. if he insists on planting barley always, then he must perforce restore to the land the food for barley constantly withdrawn. [illustration: maple seed, with pair of wings] a plant may diligently find food and drink, pour forth delicious nectar, array itself with flowers as gayly as it can, and still behold its work unfinished. its seed may be produced in plenty, and although as far as that goes it is well, it is not enough. of what avail is all this seed if it falls as it ripens upon soil already overcrowded with its kind? hence the vigorous emigration policy to be observed in plants of every name. hence the fluffy sails set to catch the passing breeze by the dandelion, the thistle and by many more, including the southern plant of snowy wealth whose wings are cotton. with the same intent of seeking new fields are the hooks of the burdock, the unicorn plant, and the bur-parsley which impress as carriers the sheep and cattle upon a thousand hills. the touch-me-not and the herb robert adopt a different plan, and convert their seed-cases into pistols for the firing of seeds at as wide range as twenty feet or more. the maple, the ash, the hornbeam, the elm and the birch have yet another method of escape from the home acre. their seeds are winged, and torn off in a gale are frequently borne two hundred yards away. and stronger wings than these are plied in the cherry tree's service. the birds bide the time when a blush upon the fruit betrays its ripeness. then the cherries are greedily devoured, and their seed, preserved from digestion in their stony cases are borne over hill, dale, and river to some islet or brookside where a sprouting cherry plant will be free from the stifling rivalries suffered by its parent. yoked in harness with sheep, ox, and bird as planter is yonder nimble squirrel. we need not begrudge him the store of nuts he hides. he will forget some of them, he will be prevented by fright or frost from nibbling yet more, and so without intending it he will ensure for others and himself a sure succession of acorns and butternuts. very singular are the seeds that have come to resemble beetles; among these may be mentioned the seeds of the castor-oil plant and of the _iatropha_. the pod of the _biserrula_ looks like a worm, and a worm half-coiled might well have served as a model for the mimicry of the _scorpiurus vermiculata_. all these are much more likely to enlist the services of birds than if their resemblances to insects were less striking. nature elsewhere rich in hints to the gardener and the farmer is not silent here. a lesson plainly taught in all this apparatus for the dispersal of seeds is that the more various the planting the fuller the harvest. now that from the wheat fields comes a cry of disappearing gains, it is time to heed the story told in the unbroken prairie that diversity in sowing means wealth in reaping. in a field of growing flax we can find--somewhat oftener than the farmer likes--a curious tribe of plants, the dodders. their stems are thin and wiry, and their small white flowers, globular in shape, make the azure blossoms of the flax all the lovelier by contrast. as their cousins the morning glories are to this day, the dodders in their first estate were true climbers. even now they begin life in an honest kind of way with roots of their own that go forth as roots should, seeking food where it is to be found in the soil. but if we pull up one of these little club-shaped roots we shall see that it has gone to work feebly and doubtfully; it seems to have a skulking expectation of dinner without having to dig and delve for it in the rough dirty ground. nor is this expectation unfounded. watch the stem of a sister dodder as it rises from the earth day by day, and it will be observed to clasp a stalk of flax very tightly; so tightly that its suckers will absorb the juices of its unhappy host. when, so very easily, it can regale itself with food ready to hand why should it take the trouble to drudge for a living? like many another pauper demoralized by being fed in idleness, the plant now abandons honest toil, its roots from lack of exercise wither away, and for good and all it ceases to claim any independence whatever. indeed, so deep is the dodder's degradation that if it cannot find a stem of flax, or hop, or other plant whereon to climb and thrive, it will simply shrivel and die rather than resume habits of industry so long renounced as to be at last forgotten. like the lowly dodder the mistletoe is a climber that has discovered large opportunities of theft in ascending the stem of a supporting plant. on this continent the mistletoe scales a wide variety of trees and shrubs, preferring poplars and apple trees, where these are to be had. its extremely slender stem, its meagre leaves, its small flowers, greenish and leathery, are all eloquent as to the loss of strength and beauty inevitable to a parasite. rising as this singular plant does out of the branches of another with a distinct life all its own, it is no other than a natural graft, and it is very probable that from the hint it so unmistakably gives the first gardeners were not slow to adopt grafts artificial--among the resources which have most enriched and diversified both flowers and fruits. the dodders and mistletoes rob juices from the stem and branches of their unfortunate hosts; more numerous still are the unbidden guests that fasten themselves upon the roots of their prey. the broom-rape, a comparatively recent immigrant from europe, lays hold of the roots of thyme in preference to other place of entertainment; the yellow rattle, the lousewort, and many more attach themselves to the roots of grasses--frequently with a serious curtailment of crop. yet in this very department of hers nature has for ages hidden away what has been disclosed within twenty years as one of her least suspected marvels. it is no other than that certain parasites of field and meadow so far from being hurtful, are well worth cultivating for the good they do. for a long time the men who devoted themselves to the study of peas, beans, clovers, and other plants of the pulse family, were confronted with a riddle they could not solve. these plants all manage to enrich themselves with compounds of nitrogen, which make them particularly valuable as food, and these compounds often exist in a degree far exceeding the rate at which their nitrogen comes out of the soil. and this while they have no direct means of seizing upon the nitrogen contained in its great reservoir--the atmosphere. upon certain roots of beans and peas it was noted that there were little round excrescences about the size of a small pin's head. these excrescences on examination with a microscope proved to be swarming with bacteria of minute dimensions. further investigation abundantly showed that these little guests paid a handsome price for their board and lodging--while they subsisted in part on the juices of their host they passed into the bean or pea certain valuable compounds of nitrogen which they built from common air. at the columbian exposition, of 1893, one of the striking exhibits in the agricultural building set this forth in detail. vials were shown containing these tiny subterranean aids to the farmer, and large photographs showed in natural size the vast increase of crop due to the farmer's taking bacteria into partnership. to-day these little organisms are cultivated of set purpose, and quest is being made for similar bacteria suitable to be harnessed in producing wheat, corn, and other harvests. these are times when men of science are discontented with mere observation. they wish to pass from watching things as nature presents them to putting them into relations wholly new. in 1866 debary, a close observer of lichens, felt confident that a lichen was not the simple growth it seems, but a combination of fungus and algã¦. this opinion, so much opposed to honoured tradition, was scouted, but not for long. before many months had passed stahl took known algã¦, and upon them sowed a known fungus, the result was a known lichen! the fungus turns out to be no other than a slave-driver that captures alg㦠in colonies and makes them work for him. he is, however, a slave-driver of an intelligent sort; his captives thrive under his mastery, and increase more rapidly for the healthy exercise he insists that they shall take. it is an afternoon in august and the sultry air compels us to take shelter in a grove of swaying maples. beneath their shade every square yard of ground bears a score of infant trees, very few of them as much as a foot in stature. how vain their expectation of one day enjoying an ample spread of branch and root, of rising to the free sunshine of upper air! the scene, with its quivering rounds of sunlight, seems peace itself, but the seeming is only a mask for war as unrelenting as that of weaponed armies. for every ray of the sunbeam, for every atom of food, for every inch of standing room, there is deadly rivalry. to begin the fight is vastly easier than to maintain it, and not one in a hundred of these bantlings will ever know maturity. we have only to do what darwin did--count the plants that throng a foot of sod in spring, count them again in summer, and at the summer's end, to find how great the inexorable carnage in this unseen combat, how few its survivors. so hard here is the fight for a foothold, for daily bread, that the playfulness inborn in every healthy plant can peep out but timidly and seldom. but when strife is exchanged for peace, when a plant is once safely sheltered behind a garden fence, then the struggles of the battlefield give place to the diversions of the garrison--diversions not infrequently hilarious enough. now food abounds and superabounds; henceforth neither drought nor deluge can work their evil will; insect foes, as well as may be, are kept at bay; there is room in plenty instead of dismal overcrowding. the grateful plant repays the care bestowed upon it by bursting into a sportiveness unsuspected, and indeed impossible, amidst the alarms and frays incessant in the wilderness. it departs from parental habits in most astonishing fashion, puts forth blossoms of fresh grace of form, of new dyes, of doubled magnitude. the gardener's opportunity has come. he can seize upon such of these "sports" as he chooses and make them the confirmed habits of his wards. take a stroll through his parterres and greenhouses, where side by side he shows you pansies of myriad tints and the modest little wild violets of kindred to the pansies' ancestral stock. let him contrast for you roses, asters, tuberous begonias, hollyhocks, dahlias, pelargoniums, before cultivation and since. were wild flowers clay, were the gardener both painter and sculptor, he could not have wrought marvels more glorious than these. in a few years the brethren of his guild have brought about a revolution for which, if possible at all to her, nature in the open fields would ask long centuries. and the gardener's experiments with these strange children of his have all the charm of surprise. no passive chooser is he of "sports" of promise, but an active matchmaker between flowers often brought together from realms as far apart as france and china. sometimes his experiment is an instant success. mr. william paul, a famous creator of splendid flowers, tells us that at a time when climbing roses were either white or yellow, he thought he would like to produce one of bright dark colour. accordingly he mated the rose athelin, of vivid crimson, with russelliana, a hardy climber, and lo, the flower he had imagined and longed for stood revealed! but this hitting the mark at the first shot is uncommon good fortune with the gardener. no experience with primrose or chrysanthemum is long and varied enough to tell him how the crossing of two different stocks will issue. a rose which season after season opposes only indifference to all his pains may be secretly gathering strength for a bound beyond its ancestral paths which will carry it much farther than his hopes, or, perhaps, his wishes. most flowers are admired for their own sweet sake, but who thinks less of an apple or cherry blossom because it bears in its beauty the promise of delicious fruit? put a red astrachan beside a sorry crab, a bartlett pear next a tough, diminutive wild pear such as it is descended from, an ear of milky corn in contrast with an ear one-fourth its size, each grain of which, small and dry, is wrapped in a sheath by itself; and rejoice that fruits and grains as well as flowers can learn new lessons and remember them. at concord, massachusetts, in an honoured old age, dwells mr. ephraim w. bull. in his garden he delights to show the mother vine of the concord grape which he developed from a native wild grape planted as long ago as 1843. another "sport" of great value was the nectarine, which was seized upon as it made its appearance on a peach bough. throughout america are scattered experiment stations, part of whose business it is to provoke fresh varieties of wheat, or corn, or other useful plant, and make permanent such of them as show special richness of yield; earliness in ripening; stoutness of resistance to jack frost, or blight, or insect pests. suppose that dire disaster swept from off the earth every cereal used as food. professor goodale, professor asa gray's successor at harvard university, has so much confidence in the experiment stations of america that he deems them well able to repair the loss we have imagined; within fifty years, he thinks, from plants now uncultivated the task could be accomplished. among the men who have best served the world by hastening nature's steps in the improvement of flowers and fruits, stands mr. vilmorin, of paris. he it was who in creating the sugar beet laid the foundation for one of the chief industries of our time. one of his rules is to select at first not the plant which varies most in the direction he wishes, but the plant that varies most in any direction whatever. from it, from the instability of its very fibres, its utter forgetfulness of ancestral traditions, he finds it easiest in the long run to obtain and to establish the character he seeks of sweetness, or size, or colour. of flowering plants there are about 110,000, of these the farmer and the gardener between them have scarcely tamed and trained 1,000. what new riches, therefore, may we not expect from the culture of the future? already in certain northern flower-pots the trillium, the bloodroot, the dog's-tooth violet, and the celandine are abloom in may; as june advances, the wild violet, the milkweed, the wild lily-of-the-valley, unfold their petals; later in summer the dog-rose displays its charms and breathes its perfume. all respond kindly to care, and were there more of this hospitality, were the wild roses which the botanist calls _blanda_ and _lucida_, were the cardinal flowers, the may flowers, and many more of the treasures of glen and meadow, made welcome with thoughtful study of their wants and habits, much would be done to extend the wealth of our gardens. let a hepatica be plucked from its home in a rocky crevice where one marvels how it ever contrived to root itself and find subsistence. transplant it to good soil, give it a little care--it asks none--and it will thrive as it never throve before; proving once again that plants do not grow where they like, but where they can. the russian columbine rewards its cultivator with a wealth of blossoms that plainly say how much it rejoices in his nurture of it, in its escape from the frost and tempest that have assailed it for so many generations. but here we must be content to take a leaf out of nature's book, and look for small results unless our experiments are broadly planned. it is in great nurseries and gardens, not in little door-yards that "sports" are likely to arise, and to meet the skill which can confirm them as new varieties. japan has much to teach us with regard to flowers: nowhere else on earth are they so sedulously cultivated, or so faithfully studied in all their changeful beauty. perhaps the most striking revelation of the japanese gardener is his treatment of flowering shrubs and flowering trees disposed in masses. happy the visitors to tokio who sees in springtime the cherry blossoms ready to lend their witchery to the empress's reception! much is done to extend the reign of beauty in a garden when it is fitly bordered with berry-bearers. rows of mountain ash, snow-berry, and hawthorn trees give colour just when colour is most effective, at the time when most flowers are past and gone. in the practical bit of ground where the kitchen garden meets the flowers, japan has long since enlarged its bill of fare with the tuber of a cousin of our common hedge nettle, with the roots of the large burdock, commoner still. in florida, the calla lily has use as well as beauty; it is cultivated for its potato-like tubers. much as the study of flowers heightens our interest in them, their first, their chief enduring charm consists in their simple beauty--their infinitely varied grace of form, their exhaustless wealth of changeful tints. off we go with delight from desk and book to a breezy field, a wimpling brook, a quiet pond in woodland shade. a dozen rambles from may to october will show us all the floral procession, which, beginning with the trilliums and the violets, ends at the approach of frost with the golden-rod and aster. but who ever formed an engaging acquaintance without wishing it might become a close friendship? never yet did the observant culler of bloodroot and columbine rest satisfied with merely knowing their names, and how can more be known unless flowers are set up in a portrait gallery of their own for the leisurely study of their lineaments and lineage? a word then as to the best way to gather wild flowers. a case for them in the form of a round tube, closed at the ends, with a hinged cover, can be made by a tinsmith at small cost. its dimensions should be about thirty inches in length by five inches in diameter, with a strap attached to carry it by. at still less expense a frame can be made, or bought, formed of two boards, one-eighth of an inch thick, twenty-four inches long and eighteen inches broad, with two thin battens fastened across them to prevent warping. a quire of soft brown paper, newspaper will do, and a strap to hold all together, complete the outfit. our gathered treasures at home, we may wish to deck a table or a mantel with a few of them. the lives of impressed blossoms can be, much prolonged by exercising a little care. punch holes in a round of cardboard and put the stalks through these holes before placing the flowers in a vase. this prevents the stalks touching each other, and so decaying before their time. a little charcoal in the water tends to keep it pure; the water should be changed daily. a flower will fade at last be it tended ever so carefully. if we wish to preserve it dried we can best do so as soon as we bring it home, by placing it between sheets of absorbent paper (newspaper will do) well weighted down, the paper to be renewed if the plants are succulent and if there is any risk of mildew. but a dried plant after all is only a mummy. its colours are gone; its form bruised and crumpled, gives only a faint suggestion of it as it lived and breathed. other and more pleasant reminders of our summer rambles can be ours. with a camera of fair size it is easy to take pictures of flowers at their best; these pictures can be coloured in their natural tints with happy effect. in this art mrs. cornelius van brunt, of new york, has attained extraordinary success. or, instead of the camera, why not at first invoke the brush and colour-box? only a little skill in handling them is enough for a beginning. practice soon increases deftness in this art as in every other, and in a few short weeks floral portraits are painted with a truth to nature denied the unaided pencil. for what flower, however meek and lowly, could ever tell its story in plain black and white? the amateur painter of flowers learns a good many things by the way; at the very outset, that drawing accurate and clear must be the groundwork of any painting worthy the name. both in the use of pencil and brush there must be a degree of painstaking observation, wholesome as a discipline and delightful in its harvests. how many of us, unused to the task of careful observation, can tell the number of the musk-mallow's petals, or mark on paper the depth of fringe on a gentian, or match from a series of dyed silks the hues of a common buttercup? drawing and painting sharpen the eye, and make the fingers its trained and ready servants. from the very beginning of one's task in limning bud and blossom, we see them richer in grace and loveliness than ever before. when wild flowers are sketched as they grow it is often easy to give them a new interest by adding the portraits of their insect servitors. amateurs who are so fortunate as to visit the west indies have an opportunity to paint the wonderful blossoms of the marcgravia, whose minister, a humming bird, quivers above it like a bit of rainbow loosened from the sky. early in the history of art the wild flowers lent their aid to decoration. the acanthus which gave its leaves to crest the capital of the corinthian column, the roses conventionalized in the rich fabrics of ancient persia, until they have been thought sheer inventions of the weaver, are among the first items of an indebtedness which has steadily grown in volume until to-day, when the designers who find their inspiration in the flowers are a vast and increasing host. in a modern mansion of the best type the outer walls are enriched with the leonine beauty of the sun-flower; within, the mosaic floors, the silk, and paper hangings, repeat themes suggested by the vine, the wild clematis and the mayflower. the stained glass windows from new york, where their manufacture excels that of any other city in the world, are exquisite with boldly treated lilies, poppies, and columbines. in the drawing-room are embroideries designed by two young women of salem, massachusetts, who have established a thriving industry in transferring the glow of wild flowers to the adornment of noble houses such as this. as one goes from studio to studio, it is cheering to find so many men and women busy at work which is more joyful than play,--which in many cases first taken up as a recreation disclosed a vein of genuine talent and so pointed to a career more delightful than any other,--because it chimes in with the love of beauty and the power of giving it worthy expression. transcriber's note: unable to verify "partnery" nor "tucu-tucu", but they have been left as in the original. the word "sylvain" has been verified as a valid word, and therefore it has been left as in the original. note: project gutenberg also has an html version of this file which includes the original illustrations. see 31316-h.htm or 31316-h.zip: (http://www.gutenberg.org/files/31316/31316-h/31316-h.htm) or (http://www.gutenberg.org/files/31316/31316-h.zip) the cambridge manuals of science and literature the coming of evolution cambridge university press london: fetter lane, e.c. c. f. clay, manager [illustration] edinburgh: 100, princes street london: h. k. lewis, 136, gower street, w.c. berlin: a. asher and co. leipzig: f. a. brockhaus new york: g. p. putnam's sons bombay and calcutta: macmillan and co., ltd. all rights reserved [illustration: charles darwin] the coming of evolution the story of a great revolution in science by john w. judd c.b., ll.d., f.r.s. formerly professor of geology and dean of the royal college of science cambridge: at the university press 1910 cambridge: printed by john clay, m.a. at the university press _with the exception of the coat of arms at the foot, the design on the title page is a reproduction of one used by the earliest known cambridge printer, john siberch, 1521_ contents chap. page i. introductory 1 ii. origin of the idea of evolution 5 iii. the development of the idea of evolution to the inorganic world 14 iv. the triumph of catastrophism over evolution 20 v. the revolt of scrope and lyell against catastrophism 33 vi. _the principles of geology_ 55 vii. the influence of lyell's works 68 viii. early attempts to establish the doctrine of evolution for the organic world 82 ix. darwin and wallace: the theory of natural selection 95 x. _the origin of species_ 115 xi. the influence of darwin's works 136 xii. the place of lyell and darwin in history 149 notes 160 index 165 plates charles darwin _frontispiece_ g. poulett scrope _to face p. 35_ charles lyell " " 41 alfred r. wallace " " 110 chapter i introductory when the history of the nineteenth century--'the wonderful century,' as it has, not inaptly, been called--comes to be written, a foremost place must be assigned to that great movement by which evolution has become the dominant factor in scientific progress, while its influence has been felt in every sphere of human speculation and effort. at the beginning of the century, the few who ventured to entertain evolutionary ideas were regarded by their scientific contemporaries, as wild visionaries or harmless 'cranks'--by the world at large, as ignorant 'quacks' or 'designing atheists.' at the end of the century, evolution had not only become the guiding principle of naturalists, but had profoundly influenced every branch of physical science; at the same time, suggesting new trains of thought and permeating the language of philologists, historians, sociologists, politicians--and even of theologians. how has this revolution in thought--the greatest which has occurred in modern times--been brought about? what manner of men were they who were the leaders in this great movement? what the influences that led them to discard the old views and adopt new ones? and, under what circumstances were they able to produce the works which so profoundly affected the opinions of the day? these are the questions with which i propose to deal in the following pages. it has been my own rare good fortune to have enjoyed the friendship of all the great leaders in this important movement--of huxley, hooker, scrope, wallace, lyell and darwin--and, with some of them, i was long on terms of affectionate intimacy. from their own lips i have learned of incidents, and listened to anecdotes, bearing on the events of a memorable past. would that i could hope to bring before my readers, in all their nobility, a vivid picture of the characteristics of the men to whom science and the world owe so much! for it is not only by their intellectual greatness that we are impressed. every man of science is proud, and justly proud, of the grandeur of character, the unexampled generosity, the modesty and simplicity which distinguished these pioneers in a great cause. it is unfortunately true, that the votaries of science--like the cultivators of art and literature--have sometimes so far forgotten their high vocation, as to have been more careful about the priority of their personal claims than of the purity of their own motives--they have sometimes, it must be sadly admitted, allowed self-interest to obscure the interests of science. but in the story we have to relate there are no 'regrettable incidents' to be deplored; never has there occurred any event that marred the harmony in this band of fellow-workers, striving towards a great ideal. so noble, indeed, was the great central figure--charles darwin--that his senior lyell and all his juniors were bound to him by the strongest ties of admiration, respect and affection; while he, in his graceful modesty, thought more of them than of himself, of the results of their labours rather than of his own great achievement. it is not, as sometimes suggested, the striking out of new ideas which is of the greatest importance in the history of science, but rather the accumulation of observations and experiments, the reasonings based upon these, and the writings in which facts and reasonings are presented to the world--by which a merely suggestive hypothesis becomes a vivifying theory--that really count in making history. talking with matthew arnold in 1871, he laughingly remarked to me 'i cannot understand why you scientific people make such a fuss about darwin. why it's all in lucretius!' on my replying, 'yes! lucretius guessed what darwin proved,' he mischievously rejoined 'ah! that only shows how much greater lucretius really was,--for he divined a truth, which darwin spent a life of labour in groping for.' mr alfred russel wallace has so well and clearly set forth the essential difference between the points of view of the cultivators of literature and science in this matter, that i cannot do better than to quote his words. they are as follows:- 'i have long since come to see that no one deserves either praise or blame for the _ideas_ that come to him, but only for the _actions_ resulting therefrom. ideas and beliefs are certainly not voluntary acts. they come to us--we hardly know _how_ or _whence_, and once they have got possession of us we cannot reject them or change them at will. it is for the common good that the promulgation of ideas should be free--uninfluenced by either praise or blame, reward or punishment.' 'but the _actions_ which result from our ideas may properly be so treated, because it is only by patient thought and work that new ideas, if good and true, become adopted and utilized; while, if untrue or if not adequately presented to the world, they are rejected or forgotten[1].'[a] _ideas_ of evolution, both in the organic and the inorganic world, existed but remained barren for thousands of years. yet by the labours of a band of workers in last century, these ideas, which were but the dreams of poets and the guesses of philosophers, came to be the accepted creed of working naturalists, while they have profoundly affected thought and language in every branch of human enterprise. [a] for references see the end of the volume. chapter ii origin of the idea of evolution in all ages, and in all parts of the world, we find that primitive man has delighted in speculating on the birth of the world in which he lives, on the origin of the living things that surround him, and especially on the beginnings of the race of beings to which he himself belongs. in a recent very interesting essay[2], the author of _the golden bough_ has collected, from the records of tradition, history and travel, a valuable mass of evidence concerning the legends which have grown out of these speculations. myths of this kind would appear to fall into two categories, each of which may not improbably be associated with the different pursuits followed by the uncivilised races of mankind. tillers of the soil, impressed as they must have been by the great annual miracle of the outburst of vegetable life as spring returns, naturally adopted one of these lines of speculation. from the dead, bare ground they witnessed the upspringing of all the wondrous beauty of the plant-world, and, in their ignorance of the chemistry of vegetable life, they imagined that the herbs, shrubs and trees are all alike built up out of the materials contained in the soil from which they grow. the recognition of the fact that animals feed on plants, or on one another, led to the obvious conclusion that the _ultimate_ materials of animal, as well as of vegetable, structures were to be sought for in the soil. and this view was confirmed by the fact that, when life ceases in plants or animals, all alike are reduced to 'dust' and again become a part of the soil--returning 'earth to earth.' in groping therefore for an explanation of the origin of living things, what could be more natural than the supposition that the first plants and animals--like those now surrounding us--were made and fashioned from the soil, dust or earth--all had been 'clay in the hands of a potter.' the widely diffused notion that man himself must have been moulded out of _red_ clay is probably accounted for by the colour of our internal organs. thus originated a large class of legendary stories, many of them of a very grotesque character. even in many mediaeval sculptures, in this country and on the continent, the deity is represented as moulding with his hands the semblance of a human figure out of a shapeless lump of clay. but among the primitive hunters and herdsmen a very different line of speculation appears to have originated, for by their occupations they were continually brought into contact with an entirely different class of phenomena. they could not but notice that the creatures which they hunted or tended, and slew, presented marked resemblances to themselves--in their structures, their functions, their diseases, their dispositions, and their habits. when dogs and horses became the servants and companions of men, and when various beasts and birds came to be kept as pets, the mental and even the moral processes characterising the intelligence of these animals must have been seen by their masters to be identical in kind with those of their own minds. do we not even at the present day compare human characteristics with those of animals, the courage of the lion, the cunning of the fox, the fidelity of the dog, and the parental affection of the bird? and the men, who depended for their very existence on studying the ways of various animals, could not have been less impressed by these qualities than are we. mr frazer has shown how, from such considerations, the legends concerning the relations of certain tribes of men with particular species of animals have arisen, and thus the cults of 'sacred animals' and of 'totemism' have been gradually developed. from comparisons of human courage, sagacity, swiftness, strength or perseverance, with similar qualities displayed by certain animals, it was an easy transition to the idea that such characteristics were derived by inheritance. in the absence of any exact knowledge of anatomy and physiology, the resemblances of animals to themselves would quite outbulk the differences in the eyes of primitive men, and the idea of close relationship in blood does not appear to have been regarded with distaste. in their origin and in their destiny, no distinction was drawn between man and what we now designate as the 'lower' animals. primitive man not only feels no repugnance to such kinship:- 'but thinks, admitted to that equal sky, his faithful dog shall hear him company[3].' it should perhaps be remembered, too, that, in the breeding of domestic animals, the great facts of heredity and variation could not fail to have been noticed, and must have given rise to reflection and speculation. the selection of the best animals for breeding purposes, and the consequent improvement of their stock, may well have suggested the transmutation of one kind of animal into a different kind, just as the crossing of different kinds of animals seems to have suggested the possible existence of centaurs, griffins and other monstrous forms. how early the principles of variation and heredity, and even the possibility of improving breeds by selection, must have been appreciated by early men is illustrated by the old story of the way in which the wily jacob made an attempt--however futile were the means he adopted--to cheat his employer laban[4]. yet, in spite of observed tendencies to variation among animals and plants, early man must have been convinced of the existence of distinct kinds ('species') in both the vegetable and animal worlds; he recognised that plants of definite kinds yielded particular fruits, and that different kinds of animals did not breed promiscuously with one another, but that, pairing each with its own kind, all gave rise to like offspring, and thus arose the idea of distinct 'species' of plants and animals. it must be remembered, however, that for a long time 'the world' was believed to be limited to a few districts surrounding the eastern mediterranean, and the kinds or 'species' of animals and plants were supposed to number a few scores or at most hundreds. this being the case, the sudden stocking of 'the world' with its complement of animals and plants would be thought a comparatively simple operation, and the violent destruction of the whole a scarcely serious result. even the possibility of the preservation of pairs of all the different species, in a ship of moderate dimensions, was one that was easily entertained and was not calculated to awaken either surprise or incredulity. but how different is the problem as it now presents itself to us! in the year 1900 professor s. h. vines of oxford estimated that the number of 'species' of plants that have been described could be little short of 200,000, and that future studies, especially of the lower microscopic forms, would probably bring that number up to 300,000[5]. last year, mr a. e. shipley of cambridge, basing his estimate on the earlier one of dr günther, came to the conclusion that the number of described animals must also exceed 300,000[6]. on the lowest estimate then we must place the number of known species of plants and animals, living on the globe, as 600,000! and if we consider the numbers of new forms of plants and animals that every year are being described by naturalists--about 1500 plants and 1200 animals--if we take into account the inaccessible or as yet unvisited portions of the earth's surface, the very imperfectly known depths of the sea, and, in addition to these, the almost infinite varieties of minute and microscopic forms, i think every competent judge would consider _a million_ as being probably an estimate below, rather than above, the number of 'species' now existing on the earth! while some of these species are very widely distributed over the earth's surface, or in the waters of the oceans, seas, lakes and rivers, there are others which are as strikingly limited in their range. many of the myriad forms of insect-life pass their whole existence, and are dependent for food, on a particular species of plant. not a few animals and plants are parasitical, and can only live in the interior or on the outside of other plants and animals. it will be seen from these considerations that in attempting to decide between the two hypotheses of the _origin_ of species--the only ones ever suggested--namely the fashioning of them out of dead matter, or their descent with modification from pre-existing forms, we are dealing with a problem of much greater complexity than could possibly have been imagined by the early speculators on the subject. the two strongly contrasted hypotheses to which we have referred are often spoken of as 'creation' and 'evolution.' but this is an altogether illegitimate use of these terms. by _whatever method_ species of plants or animals come into existence, they may be rightly said to be 'created.' we speak of the existing plants and animals as having been created, although we well know them to have been 'evolved' from seeds, eggs and other 'germs'--and indeed from those excessively minute and simple structures known as 'cells.' lyell and darwin, as we shall presently see, though they were firmly convinced that species of plants and animals were slowly developed and not suddenly manufactured, wrote constantly and correctly of the 'creation' of new forms of life. the idea of 'descent with modification,' derived from the early speculations of hunters and herdsmen, is really a much nobler and more beautiful conception of 'creation' than that of the 'fashioning out of clay,' which commended itself to the primitive agriculturalists. lyell writing to his friend john herschel, who like himself believed in the derivation of new species from pre-existing ones by the action of secondary causes, wrote in 1836:- when i first came to the notion, ... of a succession of extinction of species, and creation of new ones, going on perpetually now, and through an indefinite period of the past, and to continue for ages to come, all in accommodation to the changes which must continue in the inanimate and habitable earth, the idea struck me as the grandest which i had ever conceived, so far as regards the attributes of the presiding mind[7].' and darwin concludes his presentment of the doctrine of evolution in the _origin of species_ in 1859 with the following sentence:- 'there is a grandeur in this view of life, with its several powers, having been originally breathed by the creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved[8].' compare with these suggestions the ideas embodied in the following lines--ideas of which the crudeness cannot be concealed by all the witchery of milton's immortal verse:- 'the earth obey'd, and straight, op'ning her fertile womb, teem'd at a birth innumerous living creatures, perfect forms, limb'd and full grown. out of the ground up rose as from his lair, the wild beast, where he wons in forest wild, in thicket, brake, or den; among the trees they rose, they walk'd; the cattle in the fields and meadows green: those rare and solitary, these in flocks pasturing at once, and in broad herds upsprung. the grassy clods now calv'd; now half appear'd the tawny lion, pawing to get free his hinder parts, then springs, as broke from bonds, and rampant shakes his brinded mane[9].' can anyone doubt for a moment which is the grander view of 'creation'--that embodied in darwin's prose, or the one so strikingly pictured in milton's poetry? we see then that the two ideas of the method of creation, dimly perceived by early man, have at last found clear and definite expression from these two authors--milton and darwin. it is a singular coincidence that these two great exponents of the rival hypotheses were both students in the same university of cambridge and indeed resided in the same foundation--and that not one of the largest of that university--namely christ's college. chapter iii the development of the idea of evolution to the inorganic world we have seen in the preceding chapter that, with respect to the origin of plants and animals--including man himself--two very distinct lines of speculation have arisen; these two lines of thought may be expressed by the terms 'manufacture'--literally making by hand, and 'development' or 'evolution,'--a gradual unfolding from simpler to more complex forms. now with respect to the _inorganic_ world two parallel hypotheses of 'creation' have arisen, like those relating to _organic_ nature; but in the former case the determining factor in the choice of ideas has been, not the avocations of the primitive peoples, but the nature of their surroundings. the dwellers in the valleys of the euphrates and tigris could not but be impressed by the great and destructive floods to which those regions were subject; and the inhabitants of the shores and islands of the aegean sea, and of the italian peninsula, were equally conversant with the devastations wrought by volcanic outbursts and earthquake shocks. as great districts were seen to be depopulated by these catastrophies, might not some even more violent cataclysm of the same kind actually destroy all mankind, with the animals and plants, in the comparatively small area then known as 'the world'? the great flood, of which all these nations appear to have retained traditions, was regarded as only the last of such destructive cataclysms; and, in this way, there originated the myth of successive destructions of the face of the earth, each followed by the creation of new stocks of plants and animals. this is the doctrine now known as 'catastrophism,' which we find prevalent in the earliest traditions and writings of india, babylonia, syria and greece. but in ancient egypt quite another class of phenomena was conspicuously presented to the early philosophers of the country. instead of sudden floods and terrible displays of volcanic and earthquake violence, they witnessed the annual gentle rise and overflowings of their grand river, with its beneficent heritage of new soil; and they soon learned to recognise that egypt itself--so far as the delta was concerned--was 'the gift of the nile.' from the contemplation of these phenomena, the egyptian sages were gradually led to entertain the idea that all the features of the earth--as they knew it--might have been similarly produced through the slow and constant action of the causes now seen in operation around them. this idea was incorporated in a myth, which was suggested by the slow and gradual transformation of an egg into a perfect, growing organism. the birth of the world was pictured as an act of incubation, and male and female deities were invented to play the part of parents to the infant world. by pythagoras, who resided for more than twenty years in egypt, these ideas were introduced to the greek philosophers, and from that time 'catastrophism' found a rival in the new doctrine which we shall see has been designated under the names of 'continuity,' 'uniformitarianism' or 'evolution.' how, from the first crude notions of evolution, successive thinkers developed more just and noble conceptions on the subject, has been admirably shown by professor osborn in his _from the greeks to darwin_ and by mr clodd in his _pioneers of evolution_. poets, from empedocles and lucretius to goethe and tennyson, have sought in their verses to illustrate the beauty of evolutionary ideas; and philosophers, from aristotle and strabo to kant and herbert spencer, have recognised the principle of evolution as harmonising with, and growing out of, the highest conceptions of science. yet it was not till the nineteenth century that any serious attempts were made to establish the hypothesis of evolution as a definite theory, based on sound reasoning from careful observation. it is true that there were men, in advance of their age, who in some cases anticipated to a certain extent this work of establishing the doctrine of evolution on a firm foundation. thus in italy, the earliest home of so many sciences, a carmelite friar, generelli, reasoning on observations made by his compatriots fracastoro and leonardo da vinci in the sixteenth century, steno and scilla in the seventeenth, and lazzaro moro and marsilli in the eighteenth century, laid the foundations of a rational system of geology in a work published in 1749 which was characterised alike by courage and eloquence. in france, the illustrious nicolas desmarest, from his study of the classical region of the auvergne, was able to show, in 1777, how the river valleys of that district had been carved out by the rivers that flow in them. nor were there wanting geologists with similar previsions in germany and switzerland. but none of these early exponents of geological theory came so near to anticipating the work of the nineteenth century as did the illustrious james hutton, whose 'theory of the earth,' a first sketch of which was published in 1785, was a splendid exposition of evolution as applied to the inorganic world. unfortunately, hutton's theory was linked to the extravagancies of what was known at that day as 'vulcanism' or 'plutonism,' in contradistinction to the 'neptunism' of werner. hutton, while rejecting the wernerian notion of "the aqueous precipitation of basalt," maintained the equally fanciful idea that the consolidation of all strata--clays, sandstones, conglomerates, limestones and even rock-salt--must be ascribed to the action of heat, and that even the formation of chalk-flints and the silicification of fossil wood were due to the injection of molten silica! what was still more unfortunate in hutton's case was that, in his enthusiasm, he used expressions which led to his being charged with heresy and even with being an enemy of religion. his writings were further so obscure in style as often to lead to misconception as to their true meaning, while his great work--so far as the fragment which was published goes--contained few records of original observations on which his theory was based. dr fitton has pointed out very striking coincidences between the writings of generelli and those of hutton, and has suggested that the latter may have derived his views from the eloquent italian friar[10]. but for this suggestion, i think that there is no real foundation. darwin and wallace, as we shall see later, were quite unconscious of their having been forestalled in the theory of natural selection by dr wells and patrick matthew; and hutton, like his successor lyell, in all probability arrived, quite independently, and by different lines of reasoning, at conclusions identical with those of generelli and desmarest. although, as we shall see, hutton failed to greatly influence the scientific thought of his day, yet all will now agree with lyell that 'hutton laboured to give fixed principles to geology, as newton had succeeded in doing to astronomy[11]'; and with zittel that '_hutton's theory of the earth_ is one of the masterpieces in the history of geology[12].' chapter iv the triumph of catastrophism over evolution there is no fact in the history of science which is more certain than that those great pioneers of evolution in the inorganic world--generelli, desmarest and hutton--utterly failed to recommend their doctrines to general acceptance; and that, at the beginning of last century, everything in the nature of evolutionary ideas was almost universally discredited--alike by men of science and the world at large. the causes of the neglect and opprobrium which befel all evolutionary teachings are not difficult to discover. the old greek philosophers saw no more reason to doubt the possibility of creation by evolution, than by direct mechanical means. but, on the revival of learning in europe, evolution was at once confronted by the cosmogonies of jewish and arabian writers, which were incorporated in sacred books; and not only were the ideas of the sudden making and destruction of the world and all things in it regarded as revealed truth, but the periods of time necessary for evolution could not be admitted by those who believed the beginning of the world to have been recent, and its end to be imminent. thus 'catastrophic' ideas came to be regarded as _orthodox_, and evolutionary ones as utterly irreligious and damnable. there are few more curious facts in the history of science than the contrast between the reception of the teaching of the saxon professor werner, and those of hutton, the scotch philosopher, his great rival. while the enthusiastic disciples of the former carried their master's ideas everywhere, acting with missionary zeal and fervour, and teaching his doctrines almost as though they were a divine revelation, the latter, surrounded by a few devoted friends, saw his teachings everywhere received with persistent misrepresentation, theological vituperation or contemptuous neglect. even in edinburgh itself, one of werner's pupils dominated the teaching of the university for half a century, and established a society for the propagation of the views which hutton so strongly opposed. when it is remembered that hutton wrote at a time when 'heresy-hunting' in this country had been excited to such a dangerous extent, through the excesses of the french revolution, that his contemporary, priestley, had been hounded from his home and country for proclaiming views which at that time were regarded as unscriptural, it becomes less difficult to understand the prejudice that was excited against the gentle and modest philosopher of edinburgh. we have employed the term 'catastrophism' to indicate the views which were prevalent at the beginning of last century concerning the origin of the rock-masses of the globe and their fossil contents. these views were that at a number of successive epochs--of which the age of noah was the latest--great revolutions had taken place on the earth's surface; that during each of these cataclysms all living things were destroyed; and that, after an interval, the world was restocked with fresh assemblages of plants and animals, to be destroyed in turn and entombed in the strata at the next revolution. whewell, in 1830, contrasted this teaching with that of hutton and lyell in the following passage:--'these two opinions will probably for some time divide the geological world into two sects, which may perhaps be designated the "uniformitarians" and the "catastrophists." the latter has undoubtedly been of late the prevalent doctrine.' it is interesting to note, as showing the confidence felt in their tenets by the 'catastrophists' of that day, that whewell adds 'we conceive that mr lyell will find it a harder task than he imagines to overturn the established belief[13]!' some authors have suggested that the doctrine taught by generelli, desmarest and hutton, and later by scrope and lyell, for which whewell proposed the somewhat cumbrous term 'uniformitarianism,' but which was perhaps better designated by grove in 1866 as 'continuity[14],' was distinct from, and subsidiary to, evolution--and this view could claim for a time the support of a very great authority. in 1869, huxley delivered an address to the geological society, in which he postulated the existence of 'three more or less contradictory systems of geological thought,' under the names of 'catastrophism,' 'uniformitarianism' and 'evolution.' in this essay, distinguished by all his wonderful lucidity and forceful logic, huxley sought to establish the position that evolution is a doctrine, distinct from and _in advance of_ that of uniformitarianism, and that hutton and playfair--'and to a less extent lyell'--had acted unwisely in deprecating the extension of geology into enquiries concerning 'the beginning of things[15].' but there is no doubt that huxley at a later period was led to qualify, and indeed to largely modify, the views maintained in that address. in a footnote to an essay written in april 1887, he asserts 'what i mean by "evolutionism" is consistent and thoroughgoing uniformitarianism'; and in the same year he wrote in his _reception of the origin of species_[16]: 'consistent uniformitarianism postulates evolution, as much in the organic as in the inorganic world[17].' it is not difficult to trace the causes of this change in the attitude of mind with which huxley regarded the doctrine of 'uniformitarianism.' he assures us 'i owe more than i can tell to the careful study of the _principles of geology_[18],' and again 'lyell was for others as for me the chief agent in smoothing the road for darwin[19].' from the perusal of the letters of lyell, published in 1881, huxley learned that the author of the _principles of geology_ had, at a very early date, been convinced that evolution was true of the organic as well as of the inorganic world--though he had been unable to accept lamarckism, or any other hypothesis on the subject that had, up to that time, been suggested. there can be little doubt, however, that a chief influence in bringing about the change in huxley's views was his intercourse with darwin--who was, from first to last, an uncompromising 'uniformitarian.' we are fully justified, then, in regarding the teaching of hutton and lyell (to which whewell gave the name of 'uniformitarianism') as being identical with evolution. the cockpit in which the great battle between catastrophism and evolution was fought out, as we shall see in the sequel, was the geological society of london, where doughty champions of each of the rival doctrines met in frequent combat and long maintained the struggle for supremacy. fitton has very truly said that 'the views proposed by hutton failed to produce general conviction at the time; and several years elapsed before any one showed himself publicly concerned about them, either as an enemy or a friend[20].' sad is it to relate that, when notice was at last taken of the memoir on the 'theory of the earth,' it was by bitter opponents--such 'philistines' (as huxley calls them) as kirwan, de luc and williams, who declared the author to be an enemy of religion. not only did hutton, unlike the writers of other theories of the earth, omit any statement that his views were based on the scriptures, but, carried away by the beauty of the system of continuity which he advocated, he wrote enthusiastically 'the result of this physical enquiry is that we find no vestige of a beginning--no prospect of an end[21].' this was unjustly asserted to be equivalent to a declaration that the world had neither beginning nor end; and thus it came about that wernerism, neptunism and catastrophism were long regarded as synonymous with orthodoxy, while plutonism and 'uniformitarianism' were looked upon with aversion and horror as subversive of religion and morality. almost simultaneously with the foundation of the wernerian society of edinburgh (in 1807) was the establishment in london of the geological society. originating in a dining club of collectors of minerals, the society consisted at first almost exclusively of mineralogists and chemists, including davy, wollaston, sir james hall, and later, faraday and turner. the bitter but barren conflict between the neptunists and the plutonists was then at its height, and it was, from the first, agreed in the infant society to confine its work almost entirely to the collection of facts, eschewing theory. during the first decade of its existence, it is true, the chief papers published by the society were on mineralogical questions; but gradually geology began to assert itself. the actual founder and first president of the society, greenough, had been a pupil of werner, and used all his great influence to discourage the dissemination of any but wernerian doctrines--foreign geologists, like dr berger, being subsidised to apply the wernerian classification and principles to the study of british rocks. thus, in early days, the geological society became almost as completely devoted to the teaching of wernerian doctrines as was the contemporary society in edinburgh. dr buckland used to say that when he joined the geological society in 1813, 'it had a very _landed_ manner, and only admitted the professors of geology in oxford and cambridge on sufferance.' but, gradually, changes began to be felt in this aristocratic body of exclusive amateurs and wealthy collectors of minerals. william smith, 'the father of english geology'--though he published little and never joined the society--exercised a most important influence on its work. by his maps, and museum of specimens, as well as by his communications, so freely made known, concerning his method of 'identifying strata by their organic remains,' many of the old geologists, who were not aware at the time of the source of their inspiration, were led to adopt entirely new methods of studying the rocks. in this way, the accurate mineralogical and geognostical methods of werner came to be supplemented by the fruitful labours of the stratigraphical palaeontologist. the new school of geologists included men like william phillips, conybeare, sedgwick, buckland, de la beche, fitton, mantell, webster, lonsdale, murchison, john phillips and others, who laid the foundations of british stratigraphical geology. but these great geological pioneers, almost without exception, maintained the wernerian doctrines and were firm adherents of catastrophism. the three great leaders--the enthusiastic buckland, the eloquent sedgwick, and the indefatigable conybeare--were clergymen, as were also whewell and henslow, and they were all honestly, if mistakenly, convinced that the huttonian teaching was opposed to the scriptures and inimical to religion and morality. buckland at oxford, and sedgwick at cambridge, made geology popular by combining it with equestrian exercise; and whewell tells us how the eccentric buckland used to ride forth from the university, with a long cavalcade of mounted students, holding forth with sarcasm and ridicule concerning 'the inadequacy of existing causes[22].' and sedgwick at cambridge was no less firmly opposed to evolutionary doctrine, eloquently declaiming at all times against the unscriptural tenets of the huttonians. i cannot better illustrate the complete neglect at that time by leading geologists in this country of the huttonian teaching than by pointing to the report drawn up in 1833, by conybeare, for the british association, on 'the progress, actual state and ulterior prospects of geological science[23].' this valuable memoir of 47 pages opens with a sketch of the history of the science, in which the chief italian, french and german investigators are referred to, but the name of hutton is not even mentioned! and if positive evidence is required of the contempt which the early geologists felt for hutton and his teachings, it will be found in the same author's introduction to that classical work, the _outlines of geology_ (1822), in which he says of hutton, after praising his views on granite veins and "trap rocks":- 'the wildness of many of his theoretical views, however, went far to counterbalance the utility of the additional facts which he collected from observation. he who could perceive in geology nothing but the _ordinary_ operation of actual causes, carried on in the same manner through infinite ages, without the trace of a beginning or the prospect of an end, must have surveyed them through the medium of a preconceived hypothesis alone[24].' john playfair, the brilliant author of the _illustrations of the huttonian theory_, died in 1819; under happier conditions his able work might have done for inorganic evolution what his great master failed to accomplish; but the dead weight of prejudice and the dread of anything that seemed to savour of infidelity was, at the time of the great european struggle against revolutionary france, too great to be removed even by his lucid statements and eloquent advocacy. james hall and leonard horner, two faithful disciples of hutton, who had joined the infant geological society, forsook it early, the former leaving it on account of the quarrel with the royal society, the latter retaining his fellowship and interest, but going to live at edinburgh. greenough, 'the objector general,' as he was called, was left, fanatically opposing any attempt to stem the current that had set so strongly in favour of wernerism and neptunism, and the catastrophic doctrines which all thought to be necessary conclusions from them. the great heroic workers of that day--while they were laying well and truly the foundations of historical geology--were, one and all, indifferent to, or violently opposed to, the huttonian teaching. neither fitton nor john phillips, who at a later date showed sympathy with evolutionary doctrines, were the men to fight the battle of an unpopular cause. attempts have been made by both playfair and fitton to explain how it was that hutton's teaching failed to arrest the attention it deserved. the former justly asserted that the world was tired of the performances issued under the title of 'theories of the earth'; and that the condensed nature of hutton's writings, with their 'embarrassment of reasoning and obscurity of style[25]' are largely responsible for the neglect into which they fell. fitton, in 1839, wrote in the _edinburgh review_, 'the original work of hutton (in two volumes) is in fact so scarce that no very great number of our readers can have seen it. no copy exists at present in the libraries of the royal society, the linnean, or even the geological society of london[26]!' he also points out that hutton's work, and even the more lucid _illustrations of the huttonian theory_, were almost unknown on the continent, owing to the isolation of great britain during the war; and he even suggests that the popularity of playfair in this country may have not improbably led to the neglect of the original work of hutton[27]. on the continent, indeed, the authority of cuvier was supreme, and in his _essay on the theory of the earth_, prefixed to his _opus magnum_--the _ossemens fossiles_--the great naturalist threw the whole weight of his influence into the scale of catastrophism. he maintained that a series of tremendous cataclysms had affected the globe--the last being the noachian deluge--and that the floods of water that overspread the earth, during each of these events, had buried the various groups of animals, now extinct, that had been successively created. if anything had been wanted in england to support and confirm the views that were then supposed to be the only ones in harmony with the scriptures, it was found in the great authority of cuvier. as zittel justly says, cuvier's theory of 'world-catastrophies'--'which afforded a certain scientific basis for the mosaic account of the "flood," was received with special cordiality in england, for there, more than in any other country, theological doctrines had always affected geological conceptions[28].' britain, which had produced the great philosopher, hutton, had now become the centre of the bitterest opposition to his teachings! but 'the darkest hour of night is that which precedes the dawn,' and while the forces of reaction in this country appeared to be triumphant over hutton's teaching, there was in preparation, to use the words of darwin, a 'grand work' ... 'which the future historian will recognise as having produced a revolution in natural science.' chapter v the revolt of scrope and lyell against catastrophism the year 1797, in which the illustrious hutton died, leaving behind him the noble fragments of a monumental work, was signalised by the birth of two men, who were destined to bring about the overthrow of catastrophism, and to establish, upon the firm foundation of reasoned observation, the despised doctrine of uniformitarianism or evolution--as outlined by generelli, desmarest and hutton. these two men were george poulett thomson (who afterwards took the name of scrope) and charles lyell. both of them were, from their youth upwards, brought under the strongest influences of the prevalent anti-evolutionary teachings; but both emancipated themselves from the effects of these teachings, being led gradually by their geological travels and observations, not only to reject their early faith, but to become the champions of evolution. there was a singular parallel between the early careers of these two men. both were the sons of parents of ample means, and were thus freed from the distractions of a business or profession, while throughout life they alike remained exempt from family cares. each of them received the ordinary education of the english upper classes--scrope at harrow, and lyell at salisbury, in a school conducted by a winchester master on public-school lines. in due course, the two young men proceeded to the university--scrope to cambridge, to come under the influence of the sagacious and eloquent sedgwick, and lyell to oxford, to catch inspiration from the enthusiastic but eccentric buckland. on the opening up of the continent, by the termination of the french wars, each of the young men accompanied his family in a carriage-tour (as was the fashion of the time) through france, switzerland and italy; and both utilised the opportunities thus afforded them, to make long walking excursions for geological study. they both returned again and again to the continent for the purpose of geological research, and in the year 1825, at the age of 28, found themselves associated as joint-secretaries of the geological society. by this time they had arrived at similar convictions concerning the causes of geological phenomena--convictions which were in direct opposition to the views of their early teachers, and equally obnoxious to all the leaders of geological thought in the infant society which they had joined. [illustration: g poulett scrope] it is interesting to note that each of these two young geologists arrived independently, _as the result of their own studies and observations_, at their conclusions concerning the futility of the prevailing catastrophic doctrines. this i am able to affirm, not only from their published and unpublished letters, but from frequent conversations i had with them in their later years. scrope, who was slightly the elder of the two friends, spent a considerable time in that wonderful district of france--the auvergne--in the year 1821, and though he had not seen the map and later memoirs of desmarest, he pourtrayed the structure of the country in a series of very striking panoramic views, and was led, independently of the great french observer, to the same conclusions as his concerning the volcanic origin of the basalts and the formation of the valleys by river-action. scrope was at that time equally ignorant of the views propounded both by generelli and by hutton. by april 6th, 1822, scrope had completed his masterly work _the geology and extinct volcanoes of central france_, and had despatched it to england. it would be idle to speculate now as to what might have been the effect of that work--so full of the results of accurate observation, and so suggestive in its reasoning--had it been published at that time. it is quite possible that much of the credit now justly assigned to lyell, would have belonged to his friend. unfortunately, however, scrope, instead of seeing his work through the press, determined first to make another tour in italy. he arrived at naples just in time to witness and describe the grandest eruption of vesuvius in modern times, that of october 1822. what he witnessed then--the blowing away of the whole upper part of the mountain and the formation of a vast crater 1000 feet deep--made a profound impression on scrope's mind. his interest thus strongly aroused concerning igneous phenomena, scrope continued his travels and observations on the volcanic rocks of the peninsula of italy and its islands, and was thus led to a number of important conclusions in theoretical geology, which he embodied in a work, published in 1825, entitled _considerations on volcanos: the probable causes of their phenomena, the laws which determine their march, the disposition of their products, and their connexion with the present state and past history of the globe; leading to the establishment of a new theory of the earth_. it is only right to point out that, in calling this book a _new_ 'theory of the earth,' scrope had no intention of comparing it with hutton's great work, with which he was at that time altogether unacquainted. nevertheless, his conclusions, though independently arrived at, were almost identical with those of the great scotch philosopher. but scrope made the same mistake as hutton had done before him. he allowed his theoretical conclusions to precede, instead of following upon an account of the observations on which they were based. scrope's book is certainly one of the most original and suggestive contributions ever made to geological science; but the very speculative character of a large portion of the work led to the neglect of the really valuable hypotheses and acute observations which it contained. in the preface, however, the author gives a most striking and complete summary of the doctrine of evolution as opposed to catastrophism, in the inorganic world, as will be shown by the following extracts:- geology has for its business a knowledge of the processes which are in continual or occasional operation within the limits of our planet, and the application of these laws to explain the appearances discovered by our geognostical researches, so as from these materials to deduce conclusions as to the past history of the globe. the surface of the globe exposes to the eye of the geognost abundant evidence of a variety of changes which appear to have succeeded one another during an incalculable lapse of time. these changes are chiefly, i. variations of level between different constituent parts of the solid surface of the globe. ii. the destruction of former rocks, and their reproduction under another form. iii. the production of rocks _de novo_ upon the earth's surface. geologists have usually had recourse for the explanation of these changes to the supposition of sundry violent and extraordinary catastrophes, cataclysms, or general revolutions having occurred in the physical state of the earth's surface. as the idea imparted by the term cataclysm, catastrophe, or revolution, is extremely vague, and may comprehend any thing you choose to imagine, it answers for the time very well as an explanation; that is, it stops further inquiry. but it has also the disadvantage of effectually stopping the advance of science, by involving it in obscurity and confusion. if, however, in lieu of forming guesses as to what may have been the possible causes and nature of these changes, we pursue that, which i conceive the only legitimate path of geological inquiry, and begin by examining the laws of nature which are actually in force, we cannot but perceive that numerous physical phenomena are going on at this moment on the surface of the globe, by which various changes are produced in its constitution and external characters; changes extremely analogous to those of earlier date, whose nature is the main object of geological inquiry. these processes are principally, i. the atmospheric phenomena. ii. the laws of the circulation and residence of water on the exterior of the globe. iii. the action of volcanos and earthquakes. the changes effected before our eyes, by the operation of these causes, in the constitution of the crust of the earth are chiefly- i. the destruction of rocks. ii. the reproduction of others. iii. changes of level. iv. the production of new rocks from the interior of the globe upon its surface. changes which in their general characters bear so strong an analogy to those which are suspected to have occurred in the earlier ages of the world's history, that, until the processes which give rise to them have been maturely studied under every shape, and then applied with strict impartiality to explain the appearances in question; and until, after a long investigation, and with the most liberal allowances for all possible variations, and an unlimited series of ages, they have been found wholly inadequate to the purpose, it would be the height of absurdity to have recourse to any gratuitous and unexampled hypothesis for the solution of these analogous facts[29]. it was not till 1826, four years after the completion of the work, that scrope managed to publish his book on the auvergne, and to tear himself away from the speculative questions by which he had become obsessed. no one could be more candid than he was in acknowledging the causes of his failure to impress his views upon his contemporaries. writing in 1858, he said of his _considerations on volcanos_:- 'in that work unfortunately were included some speculations on theoretic cosmogony, which the public mind was not at that time prepared to entertain. nor was this my first attempt at authorship, sufficiently well composed, arranged or even printed, to secure a fair appreciation for the really sound and, i believe, original views on many points of geological interest which it contained. i ought, no doubt, to have begun with a description of the striking facts which i was prepared to produce from the volcanic regions of central france and italy, in order to pave the way for a favourable reception, or even a fair hearing, of the theoretical views i had been led from these observations to form[30].' he adds that 'this obvious error was pointed out in a very friendly manner' in a notice of the memoir on _the geology of central france_, which was contributed by lyell to the _quarterly review_ in 1827[31]. scrope's geological career however--though one of so much promise--was brought to a somewhat abrupt termination. in 1821 he had married the last representative and heiress of the scropes, the old earls of wiltshire, and soon afterwards he settled down at the family seat of castle combe, eventually devoting his attention almost exclusively to social and political questions. from 1833 to 1868, when he retired from parliament, he was member for stroud; and though he seldom took part in the debates, he became famous as a writer of political tracts, thus acquiring the sobriquet of 'pamphlet scrope.' he himself used to relate an amusing incident at his own expense. his great friend lord palmerston, on being greeted with the question, 'have you read my last pamphlet?' replied mischievously, 'well scrope, i hope i have!' it is sad to relate that, owing to a carriage accident, scrope's wife became a confirmed invalid and he had no child to succeed to the estate. though cut off by other duties from the geological world, scrope maintained his correspondence with his old friend lyell, and, as we shall see in the sequel, was able to render him splendid service by the luminous though discriminating reviews of the _principles of geology_ in the _quarterly review_. throughout his life, however, scrope preserved a love of geology, and occasionally contributed to the literature of the science; and in his closing years, when unable to travel himself, he gave to others the means of carrying on the researches in which he had from the first been so deeply interested. * * * * * fortunately for science, lyell's devotion to geological study was not, like scrope's, interrupted by the claims made upon him by social and political questions. feeling though he did, with his friend, the deepest sympathy in all liberal movements, and being especially interested in the reform of educational methods, his geological work always had the first claim on his time and attention, and nothing was allowed to interfere with his scientific labours. [illustration: cha lyell] charles lyell was the eldest son of a scottish laird, whose forbears, after making a fortune in india, had purchased the estate of kinnordy in strathmore, on the borders of the highlands. lyell's father was a man of culture, a good classical scholar, a translator and commentator on dante, and a cryptogamic botanist of some reputation. lyell's mother, an englishwoman from yorkshire, was a person of great force of character; this she showed when, on coming to kinnordy, she found drunkenness so prevalent among the lairds of this part of scotland, as to cause a fear on her part, that her husband might be drawn into the dangerous society: she therefore induced him, when their son charles was only three months old, to abandon their scottish home, and settle in the new forest of hampshire. thus it came about that the future geologist, though born in scotland, became, by education, habits and association, english. charles lyell's attention was first drawn to geology by seeing the quartz-crystals and chalcedony exposed in the broken chalk-flints, which he, as a boy of ten, used to roll down, in company with his school-fellows, from the walls of old sarum. like charles darwin, too, he became an ardent and enthusiastic collector of insects, and grew to be a tall and active young fellow, a keen sportsman, with only one drawback--a weakness of the eyes which troubled him through all his after life. it was when at the age of seventeen he went to oxford and came under the influence of dr buckland that lyell first became deeply engrossed in geology. lyell used to tell many amusing stories of the oddities of his old teacher and friend buckland. in his lectures, both in the university and on public platforms, buckland would keep his audience in roars of laughter, as he imitated what he thought to be the movements of the iguanodon or megatherium, or, seizing the ends of his long clerical coat-tails, would leap about to show how the pterodactyle flew. lyell became greatly attached to buckland, who used to take him privately on geological expeditions. on one of these occasions, they were dining at an inn, where a gentleman at another table became greatly scandalised by buckland's conversation and manners. the professor, seeing this, became more outrageous than ever, and on parting with lyell for the night took the candle and placed it between his teeth, so as to illuminate the mouth-cavity exclaiming, 'there lyell, practise this long enough and you will be able to do it as well as i do.' when buckland had retired, the stranger revealed himself to lyell as an old friend of his father's, adding 'i hope you will never be seen in the company of that buffoon again.' 'oh! sir,' said the startled undergraduate, 'that is my professor at oxford!' but buckland did not always originate the fun, for lyell told me that, when the professor visited kinnordy in his company, he led him a long tramp under promise of showing him 'diluvium intersected by whin dykes,' and, in the end, pointed to fields in a boulder-clay country separated by gorse ('whin') hedges ('dykes'). buckland, as shown by his _vindiciae geologicae_ (1820) and his _bridgewater treatise_ (1836), was the most uncompromising of the advocates for making all geological teaching subordinate to the literal interpretation of the early chapters of genesis; and in his _reliquiae diluvianae_ (1823) he stoutly maintained the view that all the superficial deposits of the globe were the result of the noachian deluge! he was indeed the great leader of the catastrophists, and it is not surprising to find lyell, while still under his influence, scoffing at 'the huttonians[32].' that buckland greatly influenced lyell in his youth, especially by inoculating him with his splendid enthusiasm for geology, there can be no doubt; and lyell, far as he departed in after life from the views of his teacher, never forgot his indebtedness to the oxford professor. even in 1832, in publishing the second edition of the first volume of his _principles_, he dedicated it to buckland, as one 'who first instructed me in the elements of geology, and by whose energy and talents the cultivation of science in the country has been so eminently promoted[33].' on leaving oxford in 1819, at the age of twenty-two, lyell joined the geological society. what were the dominant opinions at that time on geological theory among the distinguished men, who were there laying the foundations of stratigraphical geology, we have already seen. lyell, in his frequent visits to the continent, became a friend of the illustrious cuvier, whose strong bias for catastrophism was so forcibly shown in his writings and conversation. what then, we may ask, were the causes which led lyell to abandon the views in which he had been instructed, and to become the great champion of evolutionism? it has often been assumed that lyell was led by the study of hutton's works to adopt the uniformitarian' doctrines. but there is ample evidence that such was not the case. as late as the year 1839, lyell wrote of hutton, 'though i tried, i doubt whether i fairly read half his writings, and skimmed the rest[34]'; and he emphatically assured scrope 'von hoff has assisted me most[35].' the fact is certain that lyell, quite independently, arrived at the same conclusions as hutton, _but by totally different lines of reasoning_. as early as 1817, when lyell was only twenty years of age, he visited the norfolk coast and was greatly impressed by the evidence of the waste of the cliffs about cromer, aldborough, and dunwich; and three years later we find him studying the opposite kind of action of the sea in the formation of new land at dungeness and romney marsh. all through his life there may be seen the results of these early studies in a tendency which he showed to _overrate marine action_; the chief defect in his early views consisting in not fully realising the importance of that subaerial denudation--of which hutton was so great an exponent. but it was in his native county of forfarshire that lyell found the most complete antidote to the catastrophic teachings. buckland had taught him that the 'till' of the country had been thrown down, just 4170 years before, by the noachian deluge: while cuvier had asserted that the study of freshwater limestones proved them to differ from any recent deposit by their crystalline character, the absence of shells and the presence of plant-remains, as well as by the occasional occurrence in them of bands of flint. as the result of this, cuvier and brongniart had declared that _the freshwater of the ancient world possessed properties which are not observed in that of modern lakes_[36]. lyell visited kinnordy from time to time between 1817 and 1824, and found on his father's estate and other localities in strathmore a number of small lakes, lying in hollows of the boulder clay. these were being drained and their deposits quarried for the purpose of 'marling' the land; the excavations thus made showed that, under peat containing a boat hollowed out of the trunk of a tree, there were calcareous deposits, sometimes 16 to 20 feet in thickness, which passed into a rock, solid and crystalline in character as the materials of the older geological formations and containing the stems and fruits of the freshwater plant _chara_ (stone wort). with the help of robert brown the botanist, and of analyses made by daubeny, with the advice of his life-long friend, faraday, lyell was able to demonstrate that from the waters of the forfarshire lakes, containing the most minute proportions of calcareous salts, a limestone, identical in all respects with those of the older rocks of the globe, had been deposited, with excessive slowness, by the action of plant-life[37]. he was thus enabled to supply a complete refutation of the views put forward by buckland and cuvier. thus while hutton had been led to his conclusion concerning evolution in the inorganic world, by studying the waste going on in the weathered crags and the flooded rivers of his native land, lyell's conversion to the same views was mainly brought about by the study of changes due to the action of the sea along the english coasts, and by studying the evidence of constant, though slow, deposition of limestone-rocks, by the seemingly most insignificant of agencies. lyell however did not by any means neglect the study of the action of rain and rivers. during his visits to forfarshire, he had his initials and the date cut by a mason on many portions of the rocky river-beds about his home. fifty years afterwards (in 1874) i visited with him the several localities, to ascertain what amount of waste had resulted from the constant flow of water over these hard rocks. it was in most cases singularly small, the inscriptions being still visible, though deprived of their sharpness; even the sandy detritus carried along by the streams, being buoyed up by the water, had not been able in half a century to wear away a thickness of half-an-inch of the hard rock. the most singular result we noticed was, that the leaden small shot fired by sportsmen, in the highland tracts, whence these streams flowed, had collected in great numbers in hollows formed by the young geologist's inscriptions. by his father's request, lyell after leaving oxford studied for the bar, but there is no doubt that his main interest was in geological study. he had made the acquaintance of dr mantell, and carried on a number of researches in the south of england either alone or with that geologist[38]. four years after joining the geological society, in which he was a constant worker, he became one of the secretaries. this was in 1823 when he was only 26 years of age. his frequent visits to paris and to various parts of the continent enabled him to exchange ideas with many foreign naturalists, and it is clear from his correspondence that at this early period he had abandoned the catastrophic doctrines of his teachers and friends. let us now consider the outside influences which were at work on lyell's mind in these early days. in the year 1818, the eminent palaeontologist blumenbach induced the university of göttingen to offer a prize for an essay on '_the investigation of the changes that have taken place in the earth's surface conformation since historic times, and the applications which can be made of such knowledge in investigating earth revolutions beyond the domain of history._' a young german, von hoff, won the prize by a most able book, displaying great erudition, entitled _the history of those natural changes in the earth's surface, which are proved by tradition_. the first volume of this work appeared in 1822, and treated of the results produced on the land by the action of the sea; the second volume, published in 1824, dealt with the effects of volcanoes and earthquakes. von hoff's learned work was confined to the collection of data from classical and other early authors bearing on these subjects, and to reasonings based on these records; for, unfortunately, he did not possess the means necessary for travelling and making observations in the districts described by him. lyell acknowledges the great assistance afforded to him by these two volumes of von hoff's work, but, unlike that author, he was able to visit the various localities referred to, and to draw his own conclusions as to the nature of the changes which must have taken place. it is pleasant to be able to relate that the debt which he owed to von hoff was fully repaid by lyell; for the learned german's third volume appeared after the issue of the _principles of geology_, and as zittel assures us 'its influence on von hoff is quite apparent in the third volume of his work[39].' at this period, too, lyell had the advantage of travelling both on the continent and in various parts of great britain with the eminent french geologist, constant prevost, who had shown his courage by opposing some of the catastrophic teachings of the illustrious cuvier himself. still more important to lyell were the opportunities he enjoyed for comparing his conclusions with those of scrope, who had joined the geological society in 1824, and became a joint secretary with lyell in the following year. from both of them, in their old age, i heard many statements concerning the closeness and warmth of their friendship, and the constant interchange of ideas which took place between them at this time. from scrope, lyell heard of the occurrence of great beds of freshwater limestone in the auvergne, on a far grander scale than in strathmore, with many other facts concerning the geology of central france, which so greatly excited him as in the end to alter all his plans concerning the publication of his own book. as soon as scrope's great work on auvergne was published, lyell undertook the preparation of a review for the _quarterly_--and this review was a very able and discriminating production. although lyell did not derive his views concerning terrestrial evolution directly from hutton, as is sometimes supposed, there were two respects in which he greatly profited when he came to read hutton's work at a later date. in the first place, he was very deeply impressed by the necessity of avoiding the _odium theologicum_, which had been so strongly, if unintentionally, aroused by hutton, of whom he wrote, 'i think he ran unnecessarily counter to the feelings and prejudices of the age. this is not courage or manliness in the cause of truth, nor does it promote progress. it is an unfeeling disregard for the weakness of human nature, for it is our nature (for what reason heaven knows), but as _it is_ constitutional in our minds, to feel a morbid sensibility on matters of religious faith, i conceive that the same right feeling which guards us from outraging too violently the sentiments of our neighbours in the ordinary concerns of the world and its customs, should direct us still more so in this[40].' in the second place, lyell was warned by the fate of hutton's writings that it was hopeless to look for success in combatting the prevailing geological theories, unless he cultivated a literary style very different from that of the _theory of the earth_. lyell's father had to a great extent guided his son's classical studies, and at oxford, where lyell took a good degree in classics, he practised diligently both prose and poetic composition. lyell once told me that his tutor dalby (afterwards a dean) had put gibbon's _decline and fall of the roman empire_ into his hand with certain passages marked as 'not to be read.' when he had studied the whole work (of course including the marked passages) he said he conceived a profound admiration for the author's literary skill--and this feeling he retained throughout his after life. it is not improbable, indeed, that lyell learned from gibbon that a 'frontal attack' on a fortress of error is much less likely to succeed than one of 'sap and mine.' lyell was always most careful in the composition of his works, sparing no pains to make his meaning clear, while he aimed at elegance of expression and logical sequence in the presentation of his ideas. the weakness of his eyes was a great difficulty to him, throughout his life, and, when not employing an amanuensis, he generally wrote stretched out on the floor or on a sofa, with his eyes close to the paper. the relation of lyell's views to those of hutton, may best be described in the words of his contemporary, whewell, whose remarks written immediately after the publication of the first volume of the _principles_, lose nothing in effectiveness from the evident, if gentle, note of sarcasm running through them:- 'hutton for the purpose of getting his continents above water, or manufacturing a chain of alps or andes, did not disdain to call in something more than common volcanic eruptions which we read of in newspapers from time to time. he was content to have a period of paroxysmal action--an extraordinary convulsion in the bowels of the earth--an epoch of general destruction and violence, to usher in one of restoration and life. mr lyell throws away all such crutches, he walks alone in the path of his speculations; he requires no paroxysms, no extraordinary periods; he is content to take burning mountains as he finds them; and, with the assistance of the stock of volcanoes and earthquakes now on hand, he undertakes to transform the earth from any one of its geological conditions to any other. he requires time, no doubt; he must not be hurried in his proceedings. but, if we will allow him a free stage in the wide circuit of eternity, he will ask no other favour; he will fight his undaunted way through formations, transition and flötz--through oceanic and lacustrine deposits; and does not despair of carrying us triumphantly from the dark and venerable schist of skiddaw, to the alternating tertiaries of the isle of wight, or even to the more recent shell-beds of the sicilian coasts, whose antiquity is but, as it were, of yester-myriad of years[41].' never, surely, did words written in a tone of banter constitute such real and effective praise! but though it is certain that lyell did not _derive_ his evolutionary views from hutton, yet when he came to write his historical introduction to the _principles_, he was greatly impressed by the proofs of genius shown by the great scotch philosopher, and equally by the brilliant exposition of those views by playfair in his _illustrations_. to the former he gave unstinted praise for the breadth and originality of his views, and to the latter for the eloquence of his writings--adopting quotations chosen from these last, indeed, as mottoes for his own work. it is only just to add that for the violent prejudices excited by some of his contemporaries against hutton's writings--as being directed against the theological tenets of the day and therefore subversive of religion--there is really no foundation whatever; and every candid reader of the _theory of the earth_ must acquit its author of any such design. the passage quoted on page 51 could only have been written by lyell at a time when he was still unacquainted with hutton's works, and was misled by common report concerning them. it is interesting to note, however, that the passage occurs in a letter written in december 1827, that is after the first draft of the _principles of geology_ had been 'delivered to the publisher,' and before the preparation of the historical introduction, which would appear to have led to the first perusal of hutton's great work, and that of his brilliant illustrator, playfair. chapter vi 'the principles of geology' we have seen that as early as the year 1817, when he visited east anglia, lyell began to experience vague doubts concerning the soundness of the 'catastrophist' doctrines, which had been so strongly impressed upon him by buckland. and these doubts in the mind of the undergraduate of twenty years of age gradually acquired strength and definiteness during his frequent geological excursions, at home and abroad, during the next ten years. at what particular date the design was formed of writing a book and attacking the predominant beliefs of his fellow-geologists, we have no means of ascertaining exactly; but from a letter written to his friend dr mantell, we find that at one time lyell contemplated publishing a book in the form of 'conversations in geology[42],' without putting his name to it. this was probably suggested by the manner in which copernicus and galileo sought to circumvent theological opposition in the case of astronomical theory. but this plan appears to have been soon abandoned; and by the end of the year 1827, when he had reached the age of thirty, lyell had sent to the printer the first manuscript of the _principles of geology_, proposing that it should appear in the course of the following year in two octavo volumes[43]. a great and sudden interruption to this plan occurred however, for just at this time lyell was engaged in writing his review for the _quarterly_ of scrope's work on _the geology of central france_, and while doing this his interest was so strongly aroused by the accounts of the phenomena exhibited in the auvergne, that he was led for a time to abandon the task of seeing his own book through the press; and, having induced murchison and his wife to accompany him, set off on a visit to that wonderful district. he also felt that, before completing the second part of his book, he needed more information concerning the tertiary formations, especially in italy. lyell had been very early convinced of the supreme importance of travel to the geologist. in a letter to his friend murchison he said:--'we must preach up travelling, as demosthenes did "delivery" as the first, second and third requisites for a modern geologist, in the present adolescent state of the science[44].' and professor bonney has estimated that so far did he himself practise what he preached, that no less than one fourth of the period of his active life was spent in travel[45]. the joint excursion of lyell and murchison to the auvergne was destined to have great influence on the minds of these pioneers in geological research; both became satisfied from their studies that, with respect to the excavation of the valleys of the country, scrope's conclusions were irresistible; and in a joint memoir this position was stoutly maintained by them. it is interesting to notice the impression made by these two great geologists on one another during this joint expedition. murchison wrote that he had seen in lyell 'the most scrupulous and minute fidelity of observation combined with close application in the closet and ceaseless exertion in the field[46].' but i recollect that lyell once told me how difficult murchison found it to restrain himself from impatience, when his companion's attention was drawn aside by his entomological ardour. in an early letter, indeed, we find that murchison often expressed a wish that lyell's sisters had been with them to attend to the insect-collecting and thus leave lyell free for geological work[47]. on the other hand, lyell informed me that murchison had rendered him a great service in showing how much a geologist could accomplish by taking advantage of riding on horseback, and he declared in his letters that he 'never had a better man to work with than murchison'; nevertheless he ridiculed his 'keep-moving-go-it-if-it-kills-you' system as--quoting from the elder matthews--he called it[48]. on parting from murchison and his wife, after the auvergne tour, lyell proceeded to italy and for more than a year he was busy studying the tertiary deposits of lombardy, the roman states, naples and sicily, and conferring with the italian geologists and conchologists. thus it came about that he was not free to resume the task of seeing the _principles_ through the press till february 1829. immediately after his return to england lyell was compelled, with the assistance of his companion murchison, to defend their conclusions concerning the excavations of valleys by rivers from a determined attack of conybeare, who was backed up by buckland and greenough; the old geologists endeavoured to prove that the river thames had never had any part in the work of forming its valley[49]. it is interesting to find that, on this occasion, sedgwick, who was in the chair, was so far influenced by the arguments brought forward by the young men, as to lend some aid to those who had come to be called the 'fluvialists,' in contradistinction to the 'diluvialists'; he went so far as to suggest that, with regard to the floods which the catastrophist invoked, it would be wiser at present to 'doubt and not dogmatise[50].' to what extent the ms. of the _principles_, sent to the publisher in 1827, was added to and altered two years later, we have no means of knowing; but that the work was to a great extent rewritten would appear from a letter sent to murchison by lyell, just before his return to england. in it, he says:-'my work is in part written, and all planned. it will not pretend to give even an abstract of all that is known in geology, but it will endeavour to establish _the principle of reasoning_ in the science; and all my geology will come in as illustration of my views of those principles, and as evidence strengthening the system necessarily arising out of the admission of such principles, which, as you know, are neither more nor less than that _no causes whatever_ have from the earliest time to which we can look back to the present, ever acted, but those that are _now acting_, and that they never acted with different degrees of energy from that which they now exert'; but in 1833, in dedicating his third volume to murchison, he refers to the ms., completed in 1827, as a 'first sketch only of my _principles of geology_[51].' at one period, lyell contemplated again delaying publication till he had visited iceland. in the end, however, after declining to act as professor of geology in the new 'university of london' (university college), he set himself down steadily to the task of seeing the book through the press. it was at this time that lyell experienced a singular piece of good fortune, comparable with that which befel darwin thirty years afterwards, by his book falling into the hands of a very sympathetic reviewer. john murray, who had undertaken the publication of the _principles_, was also the publisher of the _quarterly review_, and lockhart, the editor of that publication, undertook that an early notice of the book should appear, if the proof-sheets were sent to the reviewer. buckland and sedgwick were successively approached on the subject of reviewing lyell's book, but both declined on the ground of 'want of time'; though i strongly suspect that their real motive in refusing the task was a disinclination to attack--as they would doubtless have felt themselves compelled to do--a valued personal friend. conybeare was, fortunately, thought to be out of the question, as lockhart said he 'promises and does not perform in the reviewing line.' very fortunately at this juncture, lockhart, who was in the habit of attending the geological society and listening to the debates (for as he used to say to his friends whom he took with him from the athenaeum, 'though i don't care for geology, yet i _do_ like to see the fellows fight') thought of scrope. although he had practically retired from the active work of the geological society at this time, scrope was known as an effective writer, and, happily for the progress of science, he undertook the review of lyell's book. although, of course, lyell had no voice in the choice of a reviewer for the _principles_, yet he could not fail to rejoice in the fact that it had fallen to his friend, who so strongly sympathised with his views, to introduce it to the public. while the book was being printed and the review of it was in preparation, a number of letters passed between lyell and scrope, and the latter, before his death, gave me the carefully treasured epistles of his friend, with the drafts of some of his replies. these letters, some of which have been published, throw much light on the difficulties with which lyell had to contend, and the manner in which he strove to meet them. as we have already seen, many of the leaders in the geological society at that day besides being strongly inclined to wernerian and cataclysmal views, had an honest, however mistaken, dread lest geological research should lead to results, apparently not in harmony with the accounts given in genesis of the creation and the flood. lyell, as this correspondence shows, was most anxious to avoid exciting either scientific or theological prejudice. he wrote, 'i conceived the idea five or six years ago' (that is in 1824 or 5) that 'if ever the mosaic geology could be set down without giving offence, it would be in an historical sketch[52],' and 'i was afraid to point the moral ... about moses. perhaps i should have been tenderer about the koran[53].' he further says 'full _half_ of my history and comments was cut out, and even many facts, because either i, or stokes, or broderip, felt that it was anticipating twenty or thirty years of the march of honest feeling to declare it undisguisedly[54].' under these circumstances the publication by scrope of his two long notices of the _principles_ in the _review_ which was regarded as the champion of orthodoxy, was most opportune. a very clear sketch was given in these reviews of the leading facts and the general line of argument; and at the same time the allowing of prejudice or prepossession to influence the judgment on such questions was very gently deprecated[55]. but scrope's reviews did not by any means consist of an indiscriminate advocacy of lyell's views. in one respect--that of the great importance of subaerial action as contrasted with marine action--scrope's views were at this time in advance of those of lyell, and he called especial attention to the direct effects produced by rain in the earth-pillars of botzen. these lyell had not at the time seen, but took an early opportunity of visiting. scrope, too, was naturally much more speculative in his modes of thought than lyell, and argued for the probably greater intensity in past times of the agencies causing geological change, and for the legitimacy of discussing the mode of origin of the earth. lyell, like hutton, argued that he saw '_no signs_ of a beginning,' but his characteristic candour is shown when he wrote:-'all i ask is, that at any given period of the past, don't stop enquiry, when puzzled, by a reference to a "beginning," which is all one with "another state of nature," as it appears to me. but there is no harm in your attacking me, provided you point out that it is the _proof_ i deny, not the _probability_ of a beginning[56].' lyell clearly foresaw the opposition with which his book would be met and wisely resolved not to be drawn into controversy. he wrote:-'i daresay i shall not keep my resolution, but i will try to do it firmly, that when my book is attacked ... i will not go to the expense of time in pamphleteering. i shall work steadily on vol. ii, and afterwards, if the work succeeds, at edition 2, and i have sworn to myself that i will not go to the expense of giving time to combat in controversy. it is interminable work[57].' in order to maintain this resolve, lyell, the moment the last sheet of the volume was corrected, set off for a four months' tour in france and spain. while absent from england, he heard little of what was going on in the scientific world; but, on his return, lyell was told by murray that in the three months before the _quarterly review_ article appeared, 650 copies of the volume, out of the 1500 printed, had been sold, and he anticipated the disposal of many more, when the review came out. this expectation was realised and led to the issue of a second edition of the first volume, of larger size and in better type. lyell, from the first, had seen that it would be impossible to avoid the conclusion that the principles which he was advancing with respect to the inorganic world must be equally applicable to the organic world. at first he only designed to touch lightly on this subject, in the concluding chapters of his first volume, and to devote the second volume to the application of his principles to the interpretation of the geological record. he, however, found it impossible to include the chapters on changes in the organic world in the first volume and then decided to make them the opening portion of the second volume. it is evident, however, that as the work progressed, the interest of the various questions bearing on the origin of species grew in his mind. while lyell found it impossible to accept the explanation of origin suggested by lamarck, he was greatly influenced by the arguments in favour of evolution advanced by that naturalist; and as he wrote chapter after chapter on the questions of the modification and variability of species, on hybridity, on the modes of distribution of plants and animals, and their consequent geographical relations, and discussed the struggle of existence going on everywhere in the organic world, in its bearings on the question of 'centres of creation,' he found the second volume growing altogether beyond reasonable limits. his intense interest in this part of his work is shown by his remark, 'if i have succeeded so well with inanimate matter, surely i shall make a lively thing when i have chiefly to talk of living beings[58]?' by december 1831, lyell had come to the resolution to publish the chapters of his work which dealt with the changes going on in the organic world as a volume by itself. this second volume of the _principles_ he gracefully dedicated to his friend broderip, who had rendered him such valuable assistance in all questions connected with natural history. this volume appeared in january 1832, at the same time that a second edition of the first volume was also issued. the reception of the second volume by the public appears to have been not less favourable than that of the first. in march 1831, lyell had accepted the professorship of geology in king's college, london. in addition to his desire to aid in the work of scientific education, in which he had always taken so great an interest, lyell seems to have felt that the task of presenting his views in a popular form would be aided by his having to expound them to a miscellaneous audience. for two years, these lectures were delivered, and attracted much attention; the favourable impressions produced by them on a man of the world have been recorded by abraham hayward, and on more scientific thinkers by harriet martineau. the third volume of the _principles_ was not completed till a second edition of the second volume had been issued. this third volume, appearing in may 1833, dealt with the classification of the tertiary strata, to which lyell had devoted so much labour, studying conchology under deshayes, and visiting all the chief tertiary deposits of europe for the collection of materials. the application of the principles enunciated in the two earlier volumes to the unravelling of the past history of the globe, constituted the chief task undertaken in this part of the great work. but not a few controversial questions were dealt with, and the famous 'metamorphic theory' was advanced in opposition to the wernerian hypothesis of 'primitive formations.' the volume was appropriately dedicated to murchison, who had been lyell's companion in the famous auvergne excursion, which had produced such an effect on his mind. within a twelvemonth, a third edition of the whole work in four small volumes was issued, and in the end no less than twelve editions of the _principles of geology_ were issued, in addition to portions separately published under the titles of _manual_, _elements_, and _student's elements of geology_, of all of which a number of editions have appeared. lyell was always the most painstaking and conscientious of authors. he declared 'i must write what will be read[59],' and he spared no labour in securing accuracy of statement combined with elegance of diction. his father, a good classical and italian scholar, had done much towards assisting him to attain literary excellence, and at oxford, where he took a good degree in classics, he was greatly impressed by the style of gibbon's writings, and practised both prose and poetic compositions with great diligence. both darwin and huxley always maintained that the real charm and power of lyell's work are only to be found in the _first edition_[60]. as new discoveries were made or more effective illustrations of his views presented themselves to his mind, passage after passage in the work was modified by the author or replaced by others; and the effects of these constant changes--however necessary and desirable in themselves--could not fail to be detrimental to the book as a work of art. he who would form a just idea of the greatness of lyell's masterpiece, must read the first edition, of course bearing in mind, all the while, the state of science at the time it was written. chapter vii the influence of lyell's works although the _principles of geology_ was received by the public with something like enthusiasm--due to the cogency of its reasoning and the charm of its literary style--there were not wanting critics who attacked the author on the ground of his heterodox views. it had come to be so generally understood, that every expression of geological opinion should, by way of apology, be accompanied by an attempt to 'harmonise' it with the early chapters of genesis, that the absence of any references of this kind was asserted to be a proof of 'infidelity' on the part of the author. but lyell's sincere and earnest efforts to avoid exciting theological prejudice, and the striking illustrations, which he gave in his historical introduction, of the absurdities that had resulted from these prejudices in the past, were not without effect. this was shown in a somewhat remarkable manner in 1831, when, in response to an invitation given to him, he consented to become a candidate for the chair of geology at king's college, london, then recently founded. the election was in the hands of an archbishop, two bishops and two doctors of divinity, and lyell relates their decision, as communicated to him, in the following words:- 'they considered some of my doctrines startling enough, but could not find that they were come by otherwise than in a straightforward manner, and (as _i_ appeared to think) logically deducible from the facts, so that whether the facts were true or not, or my conclusions logical or otherwise, there was no reason to infer that i had made my theory from any hostile feeling towards revelation[61].' the appointment was, in the end, made with only one dissentient, and it is pleasing to find that conybeare, the most determined opponent of lyell's evolutionary views, was extremely active in his efforts in his support. the result was equally honourable to all parties, and affords a pleasing proof of the fact that in the half century which had elapsed since the persecution of priestley and hutton, theological rancour must have greatly declined. but while the reception of the _principles of geology_ by the general public was of such a generally satisfactory character, lyell had to acknowledge that his reasoning had but little effect in modifying the views of his distinguished contemporaries in the geological society. the admiration felt for the author's industry and skill, in the collection and marshalling of facts and of the observations made by him in his repeated travels, were eloquently expressed by the generous sedgwick, as follows:- 'were i to tell "the author" of the instruction i received from every chapter of his work, and of the delight with which i rose from the perusal of the whole, i might seem to flatter rather than to speak the language of sober criticism; but i should only give utterance to my honest sentiments. his work has already taken, and will long maintain a distinguished place in the philosophic literature of this country[62].' nevertheless, in the same address to the geological society, in which these words were spoken, sedgwick goes on to argue forcibly against the doctrine of continuity, and to assert his firm belief in the occurrence of frequent interruptions of the geological record by great convulsions. whewell was equally enthusiastic with sedgwick, concerning the value of the body of facts collected by lyell, declaring that he had established a new branch of science, 'geological dynamics'; but he also believed with sedgwick, that the evolutionary doctrine was as obnoxious to true science as he thought it was to scripture. these were the views of all the great leaders of geological science at that day, and in 1834, after the completion of the _principles_, when a great discussion took place in the geological society on the subject of the effects ascribed by him to existing causes, lyell says that 'buckland, de la beche, sedgwick, whewell, and some others treated them with as much ridicule as was consistent with politeness in my presence[63].' it is interesting to be able to infer from lyell's accounts of these days, that the sagacious de la beche was beginning to weaken in his opposition to evolutionary views, and that fitton and john phillips were inclined to support him, but neither of them was ready to come forward boldly as the champions of unpopular opinions. john herschel, who sympathised with lyell in all his opinions, was absent at the cape, scrope was absorbed in the stormy politics of that day, and it was not till darwin returned from his south american voyage in 1838, that lyell found any staunch supporter in the frequent lively debates at the geological society. it is pleasing, however, to relate that this strong opposition to his theoretical teachings, did not lessen the esteem, or interfere with the friendship, felt for lyell by his contemporaries. during all this time he held the office of foreign secretary to the society, and in 1835 was elected president, retaining the office for two years. the general feeling of the old geologists with respect to lyell's opinions was very exactly expressed by professor henslow, when in parting from young darwin on his setting out on his voyage, he referred to the recently published first volume of the _principles_ in the following terms:-'take lyell's new book with you and read it by all means, for it is very interesting, but do not pay any attention to it, except in regard to facts, for it is altogether wild as far as theory goes.' (i quote the words as repeated to me by darwin, in a conversation i had with him on august 7th, 1880, of which i made a note at the time. darwin has himself referred to this conversation with henslow in his autobiography[64].) except in a few cases, this was the attitude maintained by all the old geologists who were lyell's contemporaries. even as late as 1895 we find the amiable prestwich protesting strongly against 'the _fetish_ of uniformity[65],' and i well remember about the same time being solemnly warned by a geologist of the old school against 'poor old lyell's fads.' it was not, indeed, till a new generation of geologists had arisen, including godwin-austen, edward forbes, ramsay, jukes, darwin, hooker and huxley, that the real value and importance of lyell's teaching came to be recognised and acknowledged. the most important influence of lyell's great work is seen, however, in the undoubted fact that it inspired the men, who became the leaders in the revolution of thought which took place a quarter of a century later in respect to the organic world. were i to assert that if the _principles of geology_ had not been written, we should never have had the _origin of species_, i think i should not be going too far: at all events, i can safely assert, from several conversations i had with darwin, that he would have most unhesitatingly agreed in that opinion. darwin's devotion to his 'dear master' as he used to call lyell, was of the most touching character, and it was prominently manifested in all his geological conversations. in his books and in his letters he never failed to express his deep indebtedness to his 'own true love' as he called the _principles of geology_. in what was darwin's own most favourite work, the _narrative of the voyage of the beagle_, he wrote 'to charles lyell, esq., f.r.s., this second edition is dedicated with grateful pleasure, as an acknowledgment that the chief part of whatever scientific merit this journal and the other works of the author may possess, has been derived from studying the well-known, admirable _principles of geology_.' how lyell's first volume inspired darwin with his passion for geological research, and how his second volume was one of the determining causes in turning his mind in the direction of evolution, we shall see in the sequel. in 1844, darwin wrote to leonard horner how 'forcibly impressed i am with the infinite superiority of the lyellian school of geology over the continental,' he even says, 'i always feel as if my books came half out of lyell's brain'; adding 'i have always thought that the great merit of the _principles_ was that it altered the whole tone of one's mind, and therefore that, when seeing a thing never seen by lyell one yet saw it partially through his eyes[66].' about the same time darwin wrote, 'i am much pleased to hear of the call for a new edition of the _principles_: what glorious good that work has done[67]!' and in the _origin of species_ he gives his deliberate verdict on the book, referring to it as 'lyell's grand work on the _principles of geology_, which the future historian will recognise as having produced a revolution in natural science[68].' darwin seemed always afraid, such was his sensitive and generous nature, that he did not sufficiently acknowledge his indebtedness to lyell. he wrote to his friend in 1845: 'i have long wished not so much for your sake as for my own feelings of honesty, to acknowledge more plainly than by mere reference, how much i geologically owe you. those authors, however, who like you educate people's minds as well as teach them special facts, can never, i should think, have full justice done them except by posterity, for the mind thus insensibly improved can hardly perceive its own upward ascent.' very heartily, as i can bear witness from long intercourse with him, was this deep affection of darwin reciprocated by the man who was addressed by him in his letters as 'your affectionate pupil.' but a stranger who conversed with lyell would have thought that he was the junior and a disciple; so profound was his reverence for the genius of darwin. there can be no doubt that lyell's extreme caution in statement, and his candour in admitting and replying to objections, had much to do with his acquirement of that authority with general, no less than with scientific, readers, which he so long enjoyed. in his candour he resembled his friend darwin; but his caution was carried so far that, even after full conviction had entered his mind on a subject, he would still hesitate to avow that conviction. he was always obsessed by a feeling that there still _might be_ objections, which he had not foreseen and met, and therefore felt it unsafe to declare himself. no doubt the peculiarly trying circumstances under which his work was written--a seemingly hopeless protest against ideas held unswervingly by teachers and fellow-workers--led to the creation in him of this habit of mind. darwin, with all his candour, was of a far more sanguine and optimistic temperament than lyell, and the difference between them, in this respect, often comes out in their correspondence. thus darwin, from the horrors he had witnessed in south america, had come to entertain a most fanatical hatred of slavery--his abhorrence of which he used to express in most unmeasured terms. lyell, in his travels in the southern united states, was equally convinced of the undesirability of the institution; but he thought it just to state the grounds on which it was defended, by those who had been his hosts in the slave-states. even this, however, was too much for darwin, and he felt that he must 'explode' to his friend 'how could you relate so placidly that atrocious sentiment' (it was of course only quoted by lyell) 'about separating children from their parents; and in the next page speak of being distressed at the whites not having prospered: i assure you the contrast made me exclaim out. but i have broken my intention (that is not to write about the matter), so no more of this odious deadly subject[69].' it was just the same in their mode of viewing scientific questions. thus in 1838, while they were in the midst of the fierce battle with the 'old guard' at the geological society, lyell wrote to his brother-in-arms as follows:- 'i really find, when bringing up my preliminary essays in _principles_ to the science of the present day, so far as i know it, that the great outline, and even most of the details, stand so uninjured, and in many cases they are so much strengthened by new discoveries, especially by yours, that we may begin to hope that the great principles there insisted on will stand the test of new discoveries[70].' to which the younger and more ardent darwin warmly replied:- '_begin to hope_: why, the _possibility_ of a doubt has never crossed my mind for many a day. this may be very unphilosophical, but my geological salvation is staked on it ... it makes me quite indignant that you should talk of _hoping_[71].' when talking with lyell at this time about the opposition of the old school of geologists to their joint views, darwin said, 'what a good thing it would be if every scientific man was to die at sixty years old, as afterwards he would be sure to oppose all new doctrines[72].' in conversations that i had with him late in life, darwin several times remarked to me, that 'he had seen so many of his friends make fools of themselves by putting forward new theoretical views in their old age, that he had resolved quite early in life, never to publish any speculative opinions after he was sixty.' but both in conversation and in his writings he always maintained that lyell was an exception to all such rules, seeing that at last he adopted the theory of natural selection in his old age, thus displaying the most 'remarkable candour.' all who had the pleasure of discussing geological questions with lyell will recognise the truth of the portrait drawn of his old friend by darwin, about a year before his own death. he says:- 'his mind was characterised, as it appeared to me, by clearness, caution, sound judgment, and a good deal of originality. when i made a remark to him on geology, he never rested until he saw the whole case clearly, and often made me see it more clearly than i had done before.' and he sums up his admiration of the 'dear old master' in the words 'the science of geology is enormously indebted to lyell--more so, as i believe, than to any other man who ever lived[73].' alfred russel wallace is scarcely less emphatic than charles darwin himself in his expression of affection and admiration for lyell, and his indebtedness to the _principles of geology_. in his autobiography, wallace writes:- 'with sir charles i soon felt at home, owing to his refined and gentle manners, his fund of quiet humour, and his intense love and extensive knowledge of natural science. his great liberality of thought and wide general interests were also attractive to me; and although when he had once arrived at a definite conclusion, he held by it very tenaciously until a considerable body of well-ascertained facts could be adduced against it, yet he was always willing to listen to the arguments of his opponents, and to give them careful and repeated consideration[74].' of the influence of the _principles of geology_ in leading him to evolution, he wrote: 'along with malthus i had read, and been even more deeply impressed by, sir charles lyell's immortal _principles of geology_; which had taught me that the inorganic world--the whole surface of the earth, its seas and lands, its mountains and valleys, its rivers and lakes, and every detail of its climatic conditions--were and always had been in a continual state of slow modification. hence it became obvious that the forms of life must have become continually adjusted to these changed conditions in order to survive. the succession of fossil remains throughout the whole geological series of rocks is the record of the change; and it became easy to see that the extreme slowness of these changes was such as to allow ample opportunity for the continuous automatic adjustment of the organic to the inorganic world, as well as of each organism to every other organism in the same area, by the simple processes of "variation and survival of the fittest." thus was the fundamental idea of the "origin of species" logically formulated from the consideration of a series of well ascertained facts[75].' nor were the two men (who, like aaron and hur so steadily sustained the hands of darwin in his long vigil), behind the two authors of natural selection themselves in their devotion to lyell. how touching is hooker's tribute of affection on the death of his friend, 'my loved, my best friend, for well nigh forty years of my life. to me the blank is fearful, for it never will, never can be filled up. the most generous sharer of my own and my family's hopes, joys, and sorrows, whose affection for me was truly that of a father and brother combined[76].' and huxley speaking of lyell, the day after his death said, 'sir charles lyell would be known in history as the greatest geologist of his time. some days ago i went to my venerable friend, and put before him the results of the _challenger_ expedition. nothing could then have been more touching than the conflict between the mind and the material body, the brain clear and comprehending all; while the lips could hardly express the views which the busy mind formed[77].' how well do i recollect my last visit to lyell a day or two after this farewell interview with huxley, the glow of gratitude which lighted up the noble features as with trembling lips he told me how 'huxley had repeated his whole royal institution lecture at his bedside.' huxley was a most devoted student of lyell. speaking to his fellow geologists in 1869 he said, 'which of us has not thumbed every page of the _principles of geology_[78]?' and writing in 1887 on the reception of the _origin of species_, he said:- 'i have recently read afresh the first edition of the _principles of geology_; and when i consider that this remarkable book had been nearly thirty years in everybody's hands, and that it brings home to any reader of ordinary intelligence a great principle and a great fact--the principle, that the past must be explained by the present, unless good cause be shown to the contrary; and the fact, that, so far as our knowledge of the past history of life on our globe goes, no such cause can be shown--i cannot but believe that lyell, for others, as for myself, was the chief agent in smoothing the road for darwin. for consistent uniformitarianism postulates evolution as much in the organic as in the inorganic world. the origin of a new species by other than ordinary agencies would be a vastly greater 'catastrophe' than any of those which lyell successfully eliminated from sober geological speculation[79].' how strongly lyell had become convinced, as early as 1832, of the truth and importance of the doctrine of evolution--in the _organic_ as well as in the inorganic world--in spite of his emphatic rejection of the theory of lamarck, we shall show in the next chapter. it was this conviction, as we shall see, which led to his friendly encouragement of darwin in his persevering investigations and to his constant solicitude that the results of his friend's labours should not be lost through delay in their publication. chapter viii early attempts to establish the doctrine of evolution for the organic world in studying the history of evolutionary ideas, it is necessary to keep in mind that there are two perfectly distinct lines of thought, the origin and development of which have to be considered. _first._ the conviction that species are not immutable, but that, by some means or other, new forms of life are derived from pre-existing ones. _secondly._ the conception of some process or processes, by which this change of old forms into new ones may be explained. buffon, kant, goethe, and many other philosophic thinkers, have been more or less firmly persuaded of the truth of the first of these propositions; and even linnaeus himself was ready to make admissions in this direction. it was impossible for anyone who was convinced of the truth of the doctrine of continuity or evolution in the _inorganic_ world, to avoid the speculation that the same arguments by which the truth of that doctrine was maintained must apply also to the _organic_ world. hence we find that directly the _principles of geology_ was published, thinkers, like sedgwick and whewell, at once taxed lyell with holding that 'the creation of new species is going on at the present day,' and lyell replied to the latter:- 'it was impossible, i think, for anyone to read my work and not to perceive that my notion of uniformity in the existing causes of change always implied that they must for ever produce an endless variety of effects, _both in the animate and inanimate world_[80].' and to sedgwick, lyell wrote:- 'now touching my opinion,' concerning the creation of new species at the present day, 'i have no right to object, _as i really entertain it_, to your controverting it; at the same time you will see, on reading my chapter on the subject, that i have studiously avoided laying down the doctrine dogmatically as capable of proof. i have admitted that we have only data for _extinction_, and i have left it to be inferred, instead of enunciating it even as my opinion, that the place of lost species is filled up (as it was of old) from time to time by new species. i have only ventured to say that had new mammalia come in, we could hardly have hoped to verify the fact[81].' that lyell was convinced of the truth of the doctrine of the evolution of species is shown by his correspondence with friends and sympathisers like scrope and john herschel. but he wrote: 'if i had stated ... the possibility of the introduction or origination of fresh species being a natural, in contradistinction to a miraculous process, i should have raised a host of prejudices against me, which are unfortunately opposed at every step to any philosopher who attempts to address the public on these mysterious subjects[82].' that lyell was justified in not increasing the difficulties which would retard the reception of his views, by introducing matter, which he still regarded as of a more or less speculative character, i think everyone will be prepared to admit. darwin had to contend with the same difficulty in writing the _origin of species_. to have included the question of the origin of mankind _prominently_ in that work would have raised an almost insurmountable barrier to its reception. he says in his autobiography, 'i thought it best, in order that no honourable man should accuse me of concealing my views, to add that by the work "light would be thrown on the origin of man and his history." it would have been useless and injurious to the success of the book to have paraded, without giving evidence, my conviction with respect to his origin[83].' huxley and haeckel have both borne testimony to the fact that lyell, at the time he wrote the _principles_, was firmly convinced that new species had originated by evolution from old ones. indeed in a letter to john herschel in 1836 he goes very far in the direction of anticipating the lines in which enquiries on the _method_ of evolution must proceed, having even a prevision of the doctrine of _mimicry_, long afterwards established by bates and others. lyell wrote:- 'in regard to the origination of new species, i am very glad to find that you think it probable that it may be carried on through the intervention of intermediate causes. i left this rather to be inferred, not thinking it worth while to offend a certain class of persons by embodying in words what would only be a speculation.... one can in imagination summon before us a small part at least of the circumstances that must be contemplated and foreknown, before it can be decided what powers and qualities a new species must have in order to enable it to endure for a given time, and to play its part in due relation to all other beings destined to coexist with it, before it dies out.... it may be seen that unless some slight additional precaution be taken, the species about to be born would at a certain era be reduced to too low a number. there may be a thousand modes of ensuring its duration beyond that time; one, for example, may be the rendering it more prolific, but this would perhaps make it press too hard upon other species at other times. now if it be an insect it may be made in one of its transformations to resemble a dead stick, or a leaf, or a lichen, or a stone, so as to be somewhat less easily found by its enemies; or if this would make it too strong, an occasional variety of the species may have this advantage conferred on it; or if this would be still too much, one sex of a certain variety. probably there is scarcely a dash of colour on the wing or body of which the choice would be quite arbitrary, or which might not affect its duration for thousands of years. i have been told that the leaf-like expansions of the abdomen and thighs of a certain brazilian mantis turn from green to yellow as autumn advances, together with the leaves of plants among which it seeks its prey. now if species come in succession, such contrivances must sometimes be made, and such relations predetermined between species, as the mantis, for example, and plants not then existing, but which it was foreseen would exist together with some particular climate at a given time. but i cannot do justice to this train of speculation in a letter, and will only say that it seems to me to offer a more beautiful subject for reasoning and reflecting on, than the notion of great batches of new species all coming in and afterwards going out at once[84].' we have cited this very remarkable passage, as it affords striking evidence of how deeply lyell had thought on this great question at a very early period. nevertheless it is certain that when he wrote the second volume of the _principles_, he had not been able to satisfy himself that any hypothesis of the _mode_ of evolution, that had up to that time been suggested, could be regarded as satisfactory. the only serious attempt to _explain_ the derivation of new species from old ones that came before lyell was that of the illustrious lamarck. very noteworthy was the work of that old wounded french soldier, afflicted in his later years as he was by blindness. by his early labours, lamarck had attained a considerable reputation as a botanist, and later in life he turned his attention to zoology, and then to palaeontology and geology. in zoology, he did for the study of invertebrate animals what his great contemporary cuvier was accomplishing for the vertebrates; but, with regard to the origin of species, he arrived at conclusions directly at variance with those of his distinguished rival. we are indebted to professor osborn[85] for calling attention to that remarkable, but little known work of lamarck's--_hydrogéologie_--published in 1802, seven years before his _philosophie zoologique_ appeared. this work is especially interesting as showing to how great an extent--as in the case of darwin, wallace and others--it was geological phenomena which played an important part in leading lamarck to evolutionary convictions. "in geology," professor osborn writes, 'lamarck was an ardent advocate of uniformity, as against the cataclysmal school. the main principles are laid down in his _hydrogéologie_, that all the revolutions of the earth are extremely slow. "for nature," he says, "time is nothing. it is never a difficulty, she always has it at her disposal; and it is for her the means by which she has accomplished the greatest as well as the least results[86]."' on the subject of subaerial denudation (the action of rain and rivers in wearing down the earth's surface), lamarck's views were as clear and definite as those of hutton himself; though it is almost certain that he could never have seen, or even heard of, the writings of the great scottish philosopher. on some other questions of geological dynamics, however, it must be confessed that lamarck's views and speculations were rather crude and unsatisfactory. in his _philosophie zoologique_, published in the same year that charles darwin was born (1809), lamarck brought forward a great body of evidence in favour of evolution, derived from his extensive knowledge of botany, zoology and geology. he showed how complete was the gradation between many forms ranked as species, and how difficult it was to say what forms should be classed as 'varieties' and what as 'species.' but when he came to indicate a possible method by which one species might be derived from another, he was less happy in his suggestions. he recognised the value of the evidence derived from the study of the races which have arisen among domestic animals, and from the crossing of different forms. but his main argument was derived from the acknowledged fact that use or disuse may cause the development or the partial atrophy of organs--the case of the 'blacksmith's arm.' unfortunately some of the suggestions made by lamarck, in this connexion--like that of the elongation of the giraffe's neck to enable it to browse on high trees--were of a kind that made them very susceptible to ridicule. his theory was of course dependent on the admission that acquired characters were transmitted from parents to children, and in the absence of any suggestion of 'selection,' it did not appeal strongly to thinkers on this question. lyell first became acquainted with the writings of lamarck in 1827. as he was returning from the oxford circuit for the last time--having now resolved to give up law and devote himself to geological work exclusively--he wrote to his friend mantell as follows:- 'i devoured lamarck _en voyage_.... his theories delighted me more than any novel i ever read, and much in the same way, for they address themselves to the imagination, at least of geologists who know the mighty inferences which would be deducible were they established by observations. but though i admire even his flights, and feel none of the _odium theologicum_ which some modern writers in this country have visited him with, i confess i read him rather as i hear an advocate on the wrong side, to know what can be made of the case in good hands. i am glad he has been courageous enough and logical enough to admit that his argument, if pushed as far as it must go, if worth anything, would prove that men may have come from the ourang-outang. but after all, what changes species may really undergo! how impossible will it be to distinguish and lay down a line, beyond which some of the so-called extinct species have never passed into recent ones. that the earth is quite as old as he supposes, has long been my creed, and i will try before six months are over to convert the readers of the _quarterly_ to that heterodox opinion[87].' lyell was at that time at work on his review for the _quarterly_ of scrope's _central france_, and was also completing the 'first sketch' of the _principles_. but it is evident that as the result of continued study of lamarck's book, lyell found it, in spite of its fascination, to embody a theory which he could not but regard as unsound and not calculated to prove a solution of the great mystery of evolution. accordingly when the second volume of the _principles_ was issued in 1832, it was found to contain in its opening chapters a very trenchant criticism of lamarck's theory. it is only fair to remember, however, that in 1863, after lyell had accepted the theory of natural selection he wrote to darwin: 'when i came to the conclusion that after all lamarck was going to be shown to be right, and that we must "go the whole orang" i re-read his book, and remembering when it was written, i felt i had done him injustice[88].' it is interesting also to notice that darwin, like lyell, gradually came to entertain a higher opinion of the merit of lamarck's works, than he did on his first perusal of them. in 1844, darwin wrote to hooker, 'heaven forfend me from lamarck nonsense!' and in the same year he speaks of lamarck's book as 'veritable rubbish,' an 'absurd though clever work[89].' when, after the publication of the _origin of species_, lyell referred to the _conclusions_ arrived at in that work as similar to those of lamarck, darwin expressed something like indignation, and he wrote to their 'mutual friend' hooker, 'i have grumbled a bit in my answer to him' (lyell) 'at his _always_ classing my book as a modification of lamarck's, which it is no more than any author who did not believe in the immutability of species[90].' in this case, as is so frequently seen in the writings of darwin, it is evident that he attaches infinitely less importance to the establishment of the _fact_ of the evolution of species, than to the demonstration of a possible _mode of origin_ of that evolution. but that later in life darwin came to take a more indulgent view of the result of lamarck's labours is shown by a passage in his 'historical sketch' prefixed to the _origin_, in 1866. lamarck, he says, 'first did the eminent service of arousing attention to the probability of all change in the organic world, as well as in the inorganic world, being the result of law and not of miraculous interposition[91].' in the opinion of dr schwalbe and others there are indications in darwin's later writings that he had come into much closer relation with the views of lamarck, than was the case when he wrote the _origin_[92]. it is interesting, however, to note that erasmus darwin, the grandfather of charles, published independently and contemporaneously, views on the nature and causes of evolution in striking agreement with those of lamarck; but perhaps the poetical form, in which he chose to embody his ideas, led to their receiving less attention than they deserved. as is now well known a number of writers during the earlier years of the nineteenth century published statements in favour of evolutionary views, and in several cases the theory of natural selection was more or less distinctly outlined. in addition to geoffroy and isidore saint hilaire and d'omalius d'halloy on the continent, a number of writers in this country, such as dr wells, mr patrick matthew, dr pritchard, professor grant, dean herbert, all expressed views in favour of evolution, even, in some cases, foreshadowing natural selection as the method. but these authors attached so little importance to their suggestions, that they did not even take the trouble to place them on permanent record, and it is certain that neither lyell nor darwin was acquainted with their writings at the time they were themselves working at the subject. there was indeed one work which, during the time that the _origin of species_ was in preparation, attracted much popular attention. in 1844, robert chambers, who was favourably known as the author of some geological papers, wrote a book which excited a great amount of attention--the well-known _vestiges of creation_. this work was a very bold pronouncement of evolutionary views. beginning with a statement of the nebular hypothesis of kant and laplace, it discussed the question of the origin of life--when life became possible on a cooling globe--and, arguing strongly in favour of the view that all plants and animals, as the conditions under which they existed change, had given rise to new forms, better adapted to their environment, insisted that the whole living creation had been gradually developed from the simplest types. chambers published his book anonymously, being naturally afraid of the prejudices that would be excited against him--especially in his own country--by a work so outspoken, and it was not till after his death that its authorship was definitely known. the _vestiges of creation_ met with very different receptions at the hands of the general public and from the scientific world, at the time it was published. the former were startled but captivated by its fearless statements and suggestive lines of thought; while the latter were repelled and incensed by the want of judgment, too frequently shown, in accepting as indisputable, facts and experiments which really rested on a very slender basis or none at all. so popular was the book, however, that it passed through twelve editions, the last being published after the appearance of the _origin of species_. it is interesting to read darwin's judgment in later life on this once famous book; he says:- 'the work from its powerful and brilliant style, though displaying in the earlier editions little accurate knowledge and a great want of scientific caution, immediately had a very wide circulation. in my opinion it has done excellent service in this country in calling attention to the subject, in removing prejudice, and in thus preparing the ground for the reception of analogous views[93].' if we enquire what was the attitude of scientific naturalists towards the doctrine of evolution, immediately before the occurrence of the events to be recorded in the next chapter, we shall find some diversity of opinion to exist. the late professor newton, an eminent ornithologist, has asserted that, at this period, many systematic zoologists and botanists had begun to feel great 'searchings of heart' as to the possibility of maintaining what were the generally prevalent views concerning the reality and immutability of species. huxley, however, declared that he and many contemporary biologists were ready to say 'to mosaists and evolutionists a plague to both your houses!' and were disposed to turn aside from an interminable and fruitless discussion, to labour in the fields of ascertainable fact[94]. chapter ix darwin and wallace: the theory of natural selection charles darwin was the grandson of erasmus darwin, who, as we have seen, arrived independently at conclusions concerning the origin of species very similar to those of lamarck, and embodied his views in poems, which, at the time of their publication, achieved a considerable popularity. in the younger philosopher, however, imagination was always kept in subjection by a determination to '_prove_ all things' and 'to hold fast that which is good'; though, in other respects, there were not wanting indications of the existence of hereditary characteristics in the grandson. born at shrewsbury and educated in the public school of that town, charles darwin from the first exhibited signs of individuality in his ideas and his tastes. the rigid classical teaching of his school did not touch him, but, with the aid of his elder brother, he surreptitiously started a chemical laboratory in a garden tool-house. from his earliest infancy he was a collector, first of trifles, like seals and franks, but later of stones, minerals and beetles. at the outset, only the desire to possess new things animated him, then a wish to put names to them, but, at a very early period, a passion arose for learning all he could about them. thus when only 9 or 10 years of age, he had 'a desire of being able to know something about every pebble in front of the hall-door,' and at 13 or 14, when he heard the remark of a local naturalist, 'that the world would come to an end before anyone would be able to explain how' a boulder (the 'bell-stone' of local-fame) came to be brought from distant hills--the lad had such a deep impression made on his mind, that he says in after life, 'i _meditated_ over this wonderful stone[95].' at the age of 16, he was sent to edinburgh university to prepare himself for the work of a doctor--the profession of his father and grandfather. but here his independence of character again asserted itself. he found most of the lectures 'intolerably dull,' so he occupied himself with other pursuits, making many friendships among the younger naturalists and doing a little in the way of biological research himself. that he was not altogether destitute of ambition in the eyes of his companions, however, is, i think, indicated by an amusing circumstance. in the library of charles darwin, which is carefully preserved at cambridge, there is a copy of jameson's _manual of mineralogy_, published in 1821, which was evidently used by the young student in his classwork at edinburgh. in this a quizzical fellow-student has written 'charles darwin esq., m.d., f.r.s.'--mischievously adding 'a.s.s.'! even for geology, the science to which in all his after life he became so deeply devoted, young darwin conceived the most violent aversion; and as he listened to jameson's wernerian outpourings at salisbury crags, he 'determined never to attend to geology,' registering the terrible vow 'never as long as i lived to read a book on geology, or in any way to study the science[96].' as it became evident that charles darwin would never make a doctor, his father, after two years' trial, sent him to cambridge with the object of his qualifying for a clergyman. but at christ's college, in that university, he again took his own line--which was not that of divinity--riding, shooting and beetle-hunting being his chief delights. nevertheless, at cambridge as at edinburgh, he seems to have shown an appreciation for good and instructive society, and in henslow, the judicious and amiable professor of botany, the young fellow found such sympathy and kindly help that he came to be distinguished as 'the man who walks with henslow[97].' after achieving a 'pass degree,' darwin went back to the university for an extra term, and by the advice of henslow began to 'think about' the despised science of geology. he was introduced to that inspiring teacher, sedgwick, with whom he made a geological excursion into wales; but though he said he 'worked like a tiger' at geology, yet he, when he got the chance of shooting on his uncle's estate, had to make the confession, 'i should have thought myself mad to give up the first days of partridge-shooting for geology or any other science[98].' there is a sentence in one of the letters written at this time which suggests that, even at this early period in his geological career, darwin had begun to experience some misgivings concerning the catastrophic doctrines of his teachers and contemporaries. he says:- 'as yet i have only indulged in hypotheses, but they are such powerful ones that i suppose, if they were put into action but for one day, the world would come to an end[99].' was he not poking fun at other hypotheses besides his own? darwin's real scientific education began when, after some hesitation on his father's part, he was allowed to accept the invitation, made to him through his friend henslow, to accompany, at his own expense, the surveying ship _beagle_ in a cruise to south america and afterwards round the world. in the narrow quarters of the little 'ten-gun brig,' he learned methodical habits and how best to economise space and time; during his long expeditions on shore, rendered possible by the work of a surveying vessel, he had ample opportunities for observing and collecting; and, above all, the absence of the distractions from quiet meditation, afforded by a long sea-voyage, proved in his case invaluable. very diligently did he work, accumulating a vast mass of notes, with catalogues of the specimens he sent home from time to time to henslow. he had received no careful biological training, and huxley considered that the voluminous notes he made on zoological subjects were almost useless[100]. very different was the case, however, with his geological notes. he had learned to use the blowpipe, and simple microscope, as well as his hammer and clinometer; and the notes which he made concerning his specimens, before packing them up for cambridge, were at the same time full, accurate and suggestive. darwin has recorded in his autobiography the wonderful effect produced on his mind by the reading of the first volume of lyell's _principles_--an effect very different from that anticipated by henslow[101]. from that moment he became the most enthusiastic of geologists, and never fails in his letters to insist on his preference for geology over all other branches of science. again and again we find him recording observations that he thinks will 'interest mr lyell' and he says in another letter:- 'i am become a zealous disciple of mr lyell's views, as known in his admirable book. geologising in south america, i am tempted to carry parts to a greater extent even than he does[102].' before reaching home after his voyage, the duration of which was fortunately extended from two to five years, he had sent home letters asking to be elected a fellow of the geological society; and, immediately on his arrival, he gave up his zoological specimens to others and devoted his main energies for ten years to the working up of his geological notes and specimens. it may seem strange that the grandson of erasmus darwin should in early life have felt little or no interest in the question of the 'origin of species,' but such was certainly the case. he tells us in his autobiography that he had read his grandfather's _zoonomia_ in his youth, without its producing any effect on him, and when at edinburgh he says he heard his friend robert grant (afterwards professor of zoology in university college, london) as they were walking together 'burst forth in high admiration of lamarck and his views on evolution'--yet darwin adds 'i listened in silent astonishment, and as far as i can judge without any effect on my mind[103].' the reason of this indifference towards his grandfather's works is obvious. all through his life, darwin, like lyell, showed a positive distaste for all speculation or theorising that was not based on a good foundation of facts or observations. in this respect, the attitude of darwin's mind was the very opposite of that of herbert spencer--who, huxley jokingly said, would regard as a 'tragedy'--'the killing of a beautiful theory by an ugly fact.' darwin tells us himself that, while on his first reading of _zoonomia_ he 'greatly admired' it--evidently on literary grounds--yet 'on reading it a second time after an interval of ten or fifteen years, i was much disappointed; _the proportion of speculation being so large to the facts given_.' huxley who knew charles darwin so well in later years said of him that:- 'he abhors mere speculation as nature abhors a vacuum. he is as greedy of cases and precedents as any constitutional lawyer, and all the principles he lays down are capable of being brought to the test of observation and experiment[104].' what then, we may ask, were the facts and observations which turned darwin's mind towards the great problem that came to be the work of his after life? i think it is possible from the study of his letters and other published writings to give an answer to this very interesting question. in november 1832, darwin returned to monte video, from a long journey in the interior of the south american continent, bringing with him many zoological specimens and a great quantity of fossil bones, teeth and scales, dug out by him with infinite toil from the red mud of the pampas--these fossils evidently belonging to the geological period that immediately preceded that of the existing creation. the living animals represented in his collection were all obviously very distinct from those of europe--consisting of curious sloths, anteaters, and armadilloes--the so-called 'edentata' of naturalists. and when young darwin came to examine and compare his _fossil_ bones, teeth and scales he found that they too must have belonged to animals (megatherium, mylodon, glyptodon, etc.) quite distinct from but of strikingly similar structure to those now living in south america. what could be the meaning of this wonderful analogy? if cuvier and his fellow catastrophists were correct in their view that, at each 'revolution' taking place on the earth's surface, the whole batch of plants and animals was swept out of existence, and the world was restocked with a 'new creation,' why should the brand-new forms, at any particular locality, have such a 'ghost-like' resemblance to those that had gone before? it is interesting to note that, just at the same time, a similar discovery was made with respect to australia. in caves in that country, a number of bones were found which, though evidently belonging to 'extinct' animals, yet must have belonged to forms resembling the kangaroos and other 'pouched animals' (marsupials) now so distinctive of that continent. but of this fact darwin was not aware until after his return to england in 1836. among the objects sent from home, which awaited darwin on his return to monte video, was the second volume of lyell's _principles_, then newly published; this book, while rejecting lamarckism, was crowded with facts and observations concerning variation, hybridism, the struggle for existence, and many other questions bearing on the great problem of the origin of species. i think there can be no doubt that from this time darwin came to regard the question of species with an interest he had never felt before. it is of course not suggested that, at this early date, darwin had formed any definite ideas as to the _mode_ in which new species might possibly arise from pre-existing ones or even that he had been converted to a belief in evolution. indeed in 1877 he wrote 'when i was on board the _beagle_ i believed in the permanence of species' yet he adds 'but as far as i can remember _vague doubts_ occasionally flitted across my mind.' such 'vague doubts' could scarcely have failed to have arisen when, as happened during all his journeys from north to south of the south american continent, he found the same curious correspondence between existing and late fossil forms of life again and again illustrated. but towards the end of the voyage, an even stronger element of doubt as to the immutability of species was awakened in his mind. when he came to study the forms of life existing in the galapagos islands, off the west coast of south america, he was startled by the discovery of the following facts. each small island had its own 'fauna' or assemblage of animals--this being very strikingly shown in the case of the reptiles and birds. and yet, though the _species_ were different, there was obviously a very wonderful 'family likeness' to one another between the forms in the several islands and between them all and the animals living in the adjoining portion of the continent. surely this could not be accidental, but must indicate relationships due to descent from common ancestors! charles darwin returned to england in 1836, and at once made the acquaintance of lyell. he says in one place, 'i saw a great deal of lyell' and in another that 'i saw more of lyell than of any other man, both before and after my marriage.' in one of his letters he writes, 'you cannot conceive anything more thoroughly good natured than the heart-and-soul manner in which he put himself in my place and thought what would be best to do[105].' for two years darwin was comparatively free from the distressing malady which clouded so much of his after life. and, during that time, he engaged very heartily with lyell in those combats at the geological society (of which he had become one of the secretaries) in which their joint views concerning the truth of continuity or evolution in the inorganic world were defended against the attacks of the militant catastrophists. darwin, however, did not act on the defensive alone, but brought forward a number of papers strongly supporting his new friend's views. there can be little doubt that, while thus engaged, and in constant friendly intercourse with lyell, darwin must have felt--like other earnest thinkers on geology at that day--that the principles they were advocating of 'continuity' in the inorganic world must be equally applicable to the organic world--and thus that the question of evolution would acquire a new interest for him. but it was undoubtedly the revision of the notes made on board the _beagle_, and the study of the specimens which had been sent home by him from time to time, that produced the great determining influence on darwin's career. all through the voyage he had endeavoured, with as much literary skill as he could command, to record with accuracy the observations he made, and the conclusions to which, on careful reflection, they seemed to point. and on his return to england, these patiently written journals were revised and prepared for publication forming that charming work _a naturalist's voyage. journal of researches into the natural history and geology of the countries visited during the voyage of h.m.s. 'beagle' round the world._ as darwin, with the specimens before him, revised his notes, and reconsidered the impressions made on his mind, the 'vague doubts' he had entertained, from time to time, concerning the immutability of species, would come back to him with new force and cumulative effect. 'i then saw,' he says, 'how many facts indicated the common descent of species,' and further, 'it occurred to me in 1837, that something might perhaps be made out on this question by patiently accumulating and reflecting on all sorts of facts which could possibly have any bearing on it.' in july of that year, he opened his first note-book on the subject[106]--the note-books being soon replaced by a series of portfolios, in which extracts from the various works he read, facts obtained by correspondence, the records of experiments and observation, and ideas suggested by constant meditation were slowly accumulated for twenty years. mr francis darwin has published a series of extracts from the note-book of 1837, which amply prove that by this time charles darwin had become 'a convinced evolutionist[107].' fifteen months after this 'systematic enquiry' began, darwin happened to read the celebrated work of malthus _on population_, for amusement, and this served as a spark falling on a long prepared train of thought. the idea that as animals and plants multiply in geometrical progression, while the supplies of food and space to be occupied remain nearly constant, and that this must lead to a 'struggle for existence' of the most desperate kind, was by no means new to darwin, for the elder de candolle, lyell and others had enlarged upon it; yet the facts with regard to the human race, so strikingly presented by malthus, brought the whole question with such vividness before him that the idea of 'natural selection' flashed upon darwin's mind. this hypothesis cannot be better or more succinctly stated than in huxley's words. 'all _species_ have been produced by the development of _varieties_ from common stocks: by the conversion of these, first into _permanent races_ and then into _new species_, by the process of _natural selection_, which process is essentially identical with that artificial selection by which man has originated the races of domestic animals--the _struggle for existence_ taking the place of man, and exerting, in the case of natural selection, that selective action which he performs in artificial selection[108].' with characteristic caution, darwin determined not to write down 'even the briefest sketch' of this hypothesis, that had so suddenly presented itself to his mind. his habit of thought was always to give the fullest consideration and weight to any possible objection that presented itself to his own mind or could be suggested to him by others. though he was satisfied as to the truth and importance of the principle of natural selection, there is evidence that for some years he was oppressed by difficulties, which i think would have seemed greater to him than to anyone else. in my conversations with darwin, in after years, it always struck me that he attached an exaggerated importance to the merest suggestion of a view opposed to that he was himself inclined to adopt; indeed i sometimes almost feared to indicate a _possible_ different point of view to his own, for fear of receiving such an answer as 'what a very striking objection, how stupid of me not to see it before, i must really reconsider the whole subject.' while a divinity student at cambridge, darwin had been much struck with the logical form of the works both of euclid and of paley. the rooms of the latter he seems to have actually occupied at christ's college and the works of the great divine were so diligently studied that their deep influence remained with him in after life[109]. i think it must have been the remembrance of the arguments of paley on the 'proofs of design' in nature, that seem in after life to have haunted darwin so that for long he failed to recognise fully that the principle of natural selection accounted not only for the _adaptation_ of an organism to its environment, but at the same time explains that _divergence_, which must have taken place in species in order to give rise to their wonderfully varied characters. it was not till long after he came to down in 1842, he tells us in his autobiography, that his mind freed itself from this objection. he says:- 'i can remember the very spot in the road, whilst in my carriage, when to my joy the solution occurred to me,' and he compares the relief to his mind as resembling the effect produced by 'columbus and his egg[110].' some may think the 'solution' of columbus was itself not a very satisfactory one; and i am inclined to regard the difficulties of which darwin records so sudden and dramatic a removal as more imaginary than real! there can be no doubt that, as pointed out by the late professor alfred newton[111], there was among naturalists during the second quarter of the nineteenth century a feeling of dissatisfaction with respect to current ideas concerning the origin of species, accompanied in many cases with one of expectation that a solution might soon be found. others, however, despairingly regarded it as 'the mystery of mysteries' for which it was hopeless to attempt to find a key. there was, however, one man, who simultaneously with darwin was meditating earnestly on the problem and who eventually reached the same goal. alfred russel wallace was born thirteen years after darwin, and a quarter of a century after lyell. he did not possess the moderate income that permits of entire devotion to scientific research--an advantage, the importance of which in their own cases, both lyell and darwin were always so ready to acknowledge. wallace, after working for a time as a land-surveyor and then as a teacher, at the age of 26 set off with another naturalist, h. w. bates, on a collecting tour in south america--hoping by the sale of specimens to cover the expenses of travel. like lyell and darwin, he was an enthusiastic entomologist, and had conceived the same passion for travel. he had, as we have already seen, been deeply impressed by reading the _principles of geology_, and after spending four years in south america undertook a second collecting tour, which lasted twice that time, in the malay archipelago. [illustration: alfred r. wallace] before leaving england in 1848, wallace had read and been impressed by reading the _vestiges of creation_, and there can be no doubt that from that period the question of evolution was always more or less distinctly present in his mind. while in sarawak in the wet season, he tells us, 'i was quite alone with one malay boy as cook, and during the evenings and wet days i had nothing to do but to look over my books and ponder over the problem which was rarely absent from my thoughts.' he goes on to say that by 'combining the ideas he had derived from his books that treated of the distribution of plants and animals with those he obtained from the great work of lyell' he thought 'some valuable conclusions might be reached[112].' thus originated the very remarkable paper, _on the law which has regulated the introduction of new species_, the main conclusion of which was as follows: 'every species has come into existence coincident both in space and time with a pre-existing closely allied species.' as wallace has himself said, 'this clearly pointed to some kind of evolution ... but the _how_ was still a secret.' this essay was published in the _annals and magazine of natural history_ in september 1855. it attracted much attention from lyell and darwin and later from huxley. one important result of it was that darwin and wallace entered into friendly correspondence. but although darwin in his letters to wallace informed him that he had been engaged for a long time in collecting facts which bore on the question of the origin of species, he gave no hint of the theory of natural selection he had conceived seventeen years before--indeed his friends lyell and hooker appear at that time to have been the only persons, outside his family circle, whom he had taken into his confidence. in the spring of 1858, wallace was at ternate in the island of celebes, where he lay sick with fever, and as his thoughts wandered to the ever-present problem of species, there suddenly recurred to his memory the writings of malthus, which he had read twelve years before. then and there, 'in a sudden flash of insight' the idea of natural selection presented itself to his mind, and after a few hours' thought the chief points were written down, and within a week the matter was 'copied on thin letter-paper' and sent to darwin by the next post, with a letter to the following effect[113]. wallace stated that the idea seemed new to himself and he asked darwin, if he also thought it new, to show it to lyell, who had taken so much interest in his former paper. little did wallace think, in the absence of all knowledge on his part of darwin's own conclusions, what stir would be made by his paper when it arrived in england! wallace's essay was entitled _on the tendency of varieties to depart indefinitely from the original type_, and it is a singularly lucid and striking presentment, in small compass, of the theory of natural selection. had these two men been of less noble and generous nature, the history of science might have been dishonoured by a painful discussion on a question of priority. fortunately we are not called upon for anything like a judicial investigation of rival claims; for darwin as soon as he read the essay saw that--as lyell had often warned him might be the case--he was completely forestalled in the publication of his theory. the letter and paper arrived at a sad time for darwin--he was at the moment very ill, there was 'scarlet fever raging in his family, to which an infant son had succumbed on the previous day, and a daughter was ill with diphtheria[114].' darwin at once wrote hurriedly to lyell enclosing the essay and saying: 'i never saw a more striking coincidence; if wallace had my ms. sketch written out in 1842, he could not have made a better short abstract! even his terms now stand as heads of my chapters. please return me the ms., which he does not say he wishes me to publish, but i shall, of course, at once write and offer to send to any journal. so all my originality, whatever it may amount to, will be smashed, though my book, if it ever have any value, will not be deteriorated, as all the labour consists in the application of the theory. i hope you will approve of wallace's sketch, that i may tell him what to say[115].' and wallace--what was the line taken by him in the unfortunate complication that had thus arisen? from the very first his action was all that is generous and noble. not only did he, from the first, entirely acquiesce in the course taken by lyell and hooker, but, writing in 1870, when the fame of darwin's work had reached its full height, he said:- 'i have felt all my life and i still feel, the most sincere satisfaction that mr darwin had been at work long before me, and that it was not left for me to attempt to write _the origin of species_. i have long since measured my own strength and know well that it would be quite unequal to that task. for abler men than myself may confess, that they have not that untiring patience in accumulating, and that wonderful skill in using, large masses of facts of the most varied kind,--that wide and accurate physiological knowledge,--that acuteness in devising and skill in carrying out experiments,--and that admirable style of composition, at once clear, persuasive and judicial,--qualities which in their harmonious combination mark out mr darwin as the man, perhaps of all men now living, best fitted for the great work he has undertaken and accomplished[116].' and fifty years after the joint publication of the theory of natural selection to the linnean society he said: '_i_ was then (as often since) the "young man in a hurry," _he_' (darwin) 'the painstaking and patient student, seeking ever the full demonstration of the truth he had discovered, rather than to achieve immediate personal fame[117].' and when he referred to the respective shares of darwin and himself to the credit of having brought forward the theory of natural selection, he actually suggests as a fair proportion '_twenty years to one week_'--those being the periods each had devoted to the subject[118]! never surely was such a noble example of personal abnegation! we admire the generosity, though we cannot accept the estimate, for do we not know that, for at least half the period of darwin's patient quest, wallace had spent in deeply pondering upon the same great question? chapter x the origin of species in the preceding chapter i have endeavoured to show how the hypothesis of natural selection originated in the minds of its authors, and must now invite attention to the way in which it was introduced to the world. what has been said earlier with respect to the labours and writings of hutton, scrope and lyell may serve to indicate the great importance of the _manner_ of presentment of new ideas--the logical force and literary skill with which they are brought to the notice of scientific contemporaries and the world at large. there are some striking passages in darwin's naive 'autobiography and letters' which indicate the beginnings of his ambition for literary distinction. it must always be borne in mind in reading this autobiography, however, that it was not intended by darwin for publication, but only for the amusement of the members of his own family. but the charming and unsophisticated self-revelations in it will always be a source of delight to the world. when making his first original observations among the volcanic cones and craters of st jago in the cape-de-verde islands, he says 'it then first dawned on me that i might perhaps write a book on the geology of the different countries visited, and this made me thrill with delight[119].' he tells us concerning his regular occupations on board the _beagle_, that 'during some part of the day, i wrote my journal and took much pains in describing carefully and vividly all that i had seen: and this was good practice[120].' 'later in the voyage' he says 'fitzroy' (the captain of the _beagle_) 'asked me to read some of my journal and declared it would be worth publishing, so here was a second book in prospect[121]!' darwin's first published writings were the extracts from his letters which henslow read to the philosophical society of cambridge, and those which sedgwick submitted to the geological society. at ascension, on the voyage home, a letter from darwin's sisters had informed him of the commendation with which sedgwick had spoken to his father of these papers, and he wrote fifty years afterwards: 'after reading this letter, i clambered over the mountains of ascension with a bounding step, and made the volcanic rocks ring under my geological hammer.' when in 1839 his charming _journal of researches_ was published he records that 'the success of this my first literary child always tickles my vanity more than that of any of my other books[122].' as a matter of fact, no one could possibly be more diffident and modest about his actual literary performances than was charles darwin. i have heard him again and again express a wish that he possessed 'dear old lyell's literary skill'; and he often spoke with the greatest enthusiasm of the 'clearness and force of huxley's style.' on one occasion he mentioned to me, with something like sadness in his voice, that it had been asserted 'there was a want of connection and continuity in the written arguments,' and he told me that, while engaged on the _origin_, he had seldom been able to write, without interruption from pain, for more than twenty minutes at a time! charles darwin never spoke definitely to me about the nature of the sufferings that he so patiently endured. on the occasion of my first visit to him at down he wrote me a letter (dated august 25th, 1880) in which, after giving the most minute and kindly directions concerning the journey, he arranged that his dog-cart should bring me to the house in time for a 1 o'clock lunch, telling me that to catch a certain train for return, it would be necessary to leave his house a little before 4 o'clock. but he added significantly:- 'but i am bound to tell you that i shall not be able to talk with you or anyone else for this length of time, however much i should like to do so--but you can read newspaper or take a stroll during part of the time.' his constant practice, whenever i visited him, either at down or at his brother's or daughter's house in london, was to retire with me, after lunch, to a room where we could 'talk geology' for about three quarters of an hour. at the end of that time, mrs darwin would come in smilingly, and though no word was spoken by her, darwin would at once rise and beg me to read the newspaper for a time, or, if i preferred it, to take a stroll in the garden; and after urging me to stay 'if i could possibly spare the time,' would go away, as i understood to lie down. on his return, about half an hour later, the discussion would be resumed where it had been left off, without further remark. mr francis darwin has told us that the nature and extent of his father's sufferings--so patiently and uncomplainingly borne--were never fully known, even to his own children, but only to the faithful wife who devoted her whole life to the care of his health. as is well known, darwin seldom visited at other houses, besides those of immediate relatives, or the hydropathic establishment at which he sought relief from his illness. but he was in the habit of sometimes, when in london, calling upon david forbes the mineralogist (a younger brother of edward forbes) then living in york street, portman square. the bonds of union between charles darwin and david forbes were, first, that they had both travelled extensively in south america, and secondly, that both were greatly interested in methods of preserving and making available for future reference all notes and memoranda collected from various sources. david forbes devoted to the purpose a large room with the most elaborate system of pigeon-holes, about which he told me that darwin was greatly excited. he also mentioned to me that, on one or more occasions, while darwin was in his house, pains of such a violent character had seized him that he had been compelled to lie down for a time and had occasioned his host the greatest alarm. it must always therefore be remembered, in reading darwin's works, what were the sad conditions under which they were produced. it seems to be doubtful to what extent his ill-health may be regarded as the result of an almost fatal malady, from which he suffered in south america, or as the effect of the constant and prolonged sea-sickness of which he was the victim during the five years' voyage. but certain it is that his work was carried on under no ordinary difficulties, and that it was only by the exercise of the sternest resolution, in devoting every moment of time that he was free from pain to his tasks, that he was able to accomplish his great undertakings. i do not think, however, that any unprejudiced reader will regard darwin's literary work as standing in need of anything like an apology. he always aims--and i think succeeds--at conveying his meaning in simple and direct language; and in all his works there is manifest that undercurrent of quiet enthusiasm, which was so strikingly displayed in his conversation. it was delightful to witness the keen enjoyment with which he heard of any new fact or observation bearing on the pursuits in which he was engaged, and his generous nature always led him to attach an exaggerated value to any discovery or suggestion which might be brought to his knowledge--and to appraise the work of others above his own. the most striking proof of the excellence and value of darwin's literary work is the fact that his numerous books have attained a circulation, in their original form, probably surpassing that of any other scientific writings ever produced--and that, in translations, they have appealed to a wider circle of readers than any previous naturalist has ever addressed! we have seen that the idea of natural selection 'flashed on' darwin's mind in october 1838, and although he was himself inclined to think that his _complete_ satisfaction with it, as a solution of the problem of the origin of species, was delayed to a considerably later date, yet i believe that this was only the result of his over-cautious temperament, and we must accept the date named as being that of the real birth of the hypothesis. at this early date, too, it is evident that darwin conceived the idea that he might accomplish for the principle of evolution in the organic world, what lyell had done, in the _principles_, for the inorganic world. to cite his own words, 'after my return to england it appeared to me that by following the example of lyell in geology, and by collecting all facts which bore in any way on the variation of animals and plants under domestication and nature, some light might perhaps be thrown on the whole subject[123].' 'in june 1842,' he says, 'i first _allowed_ myself' (how significant is the phrase!) 'the satisfaction of writing a brief abstract of my theory in pencil in 35 pages[124].' for many years it was thought that this first sketch of darwin's great work had been lost. but after the death of mrs darwin in 1896, when the house at down was vacated, the interesting ms. was found 'hidden in a cupboard under the stairs which was not used for papers of any value but rather as an overflow of matters he did not wish to destroy[125].' by the pious care of his son, this interesting ms.--hurriedly written and sometimes almost illegible--has been given to the world, and it proves how completely darwin had, at that early date, thought out the main lines of his future _opus magnum_. darwin, however, had no idea of publishing his theory to the world until he was able to support it by a great mass of facts and observations. lyell, again and again, warned him of the danger which he incurred of being forestalled by other workers; while his brother erasmus constantly said to him, 'you will find that some one will have been before you[126]!' the utmost that darwin could be persuaded to do, however, was to enlarge his sketch of 1842 into one of 230 pages. this he did in the summer of 1844. his manner of procedure seems to have been that, keeping to the same general arrangement of the matter as he had adopted in his original sketch, he elaborated the arguments and added illustrations. each of the 35 pages of the pencilled sketch, as it was dealt with, had a vertical line drawn across it and was thrown aside. while the 'pencilled sketch' of 1842 was little better than a collection of memoranda, which, though intelligible to the writer at the time, are sometimes difficult either to decipher or to understand the meaning of, the expanded work of 1844 was a much more connected and readable document, which darwin caused to be carefully copied out. the work was done in the summer months, while he was absent from home, and unable therefore to refer to his abundant notes--darwin speaks of it, therefore, as 'done from memory.' the two sketches, as mr francis darwin points out, were each divided into two distinct parts, though this arrangement is not adopted in the _origin of species_, as finally published. charles darwin on many occasions spoke of having adopted the _principles of geology_ as his model. that work as we have seen consisted of a first portion (eventually expanded from one to two volumes), in which the general principles were enunciated and illustrated, and a second portion (forming the third volume), in which those principles were applied to deciphering the history of the globe in the past. i think that darwin's original intention was to follow a similar plan; the first part of his work dealing with the evidences derived from the study of variation, crossing, the struggle for existence, etc., and the second to the proofs that natural selection had really operated as illustrated by the geological record, by the facts of geographical distribution, and by many curious phenomena exhibited by plants and animals. although this plan was eventually abandoned--no doubt wisely--when the _origin_ came to be written, we cannot but recognise in it another illustration of the great influence exercised by lyell and his works on darwin--an influence the latter was always so ready to acknowledge. on the 5th july 1844, darwin wrote a letter to his wife in which he said, 'i have just finished my sketch of my species theory. if, as i believe, my theory in time be accepted, even by one competent judge, it will be a considerable step in science.' he goes on to request his wife, 'in case of my sudden death' to devote £400 (or if found necessary £500) to securing an editor and publishing the work. as editor he says 'lyell would be the best, if he would undertake it,' and later, 'lyell, especially with the aid of hooker (and if any good zoological aid), would be best of all.' he then suggests other names from which a choice might be made, but adds 'the editor must be a geologist as well as naturalist.' fortunately for the world mrs darwin was never called upon to take action in accordance with the terms of this affecting document[127]. it must be remembered that, at this time, darwin was hard at work on the three volumes of the _geology of the beagle_, and on the second and revised edition of his _journal of researches_. this which he considered his 'proper work' he stuck to closely, whenever his health permitted. he had hoped to complete these books in three or four years, but they actually occupied him for _ten_, owing to constant interruptions from illness. his occasional neglect of this task, and indulgence in his 'species work,' as he called it, was always spoken of at this time by darwin as 'idleness.' and when the geological and narrative books were finished, darwin took up the systematic study of the barnacles (_cirripedia_), both recent and fossil, and wrote two monumental works on the subject. these occupied eight years, two out of which he estimated were lost by interruptions from illness. so absorbed was he in this work, that his children regarded it as the _necessary occupation_ of a man,--and when a visitor in the house was seen not to be so employed one of them enquired of their mother, 'when does mr ---do _his_ barnacles?' huxley has left on record his view that in devoting so long a time to the study of the barnacles darwin 'never did a wiser thing,' for it brought him into direct contact with the principles on which naturalists found 'species[128].' and hooker has expressed the same opinion. daring these years of labour in geology and zoology--interrupted only by the 'hours of idleness'--devoted to 'the species question,' darwin, though leading at down almost the life of a hermit, was nevertheless in frequent communication with two or three faithful friends who followed his labours with the deepest interest. cautious as was darwin himself, he found in his life-long friend lyell, a still more doubting and critical spirit, and it is clear from what darwin says that he derived much help by laying new ideas and suggestions before him. the year before darwin's death he wrote of lyell, 'when i made a remark to him on geology, he never rested till he saw the whole case clearly, and often made me see it more clearly than i had done before.' lyell's father was a botanist of considerable repute, the friend of sir william hooker and his distinguished son dr (now sir joseph) hooker. while darwin was writing his _journal of researches_, he handed the proof-sheets to lyell with permission to show them to his father, who was a man of great literary judgment. the elder lyell, in turn, showed them to young mr hooker, who was then preparing to join sir james ross, in his celebrated antarctic voyage with h.m. ships _erebus_ and _terror_. hooker was then working hard to take his doctor's degree before joining the expedition as surgeon, but he kept darwin's proof-sheets under his pillow, so as to get opportunities of reading them 'between waking and rising.' before leaving england, however, hooker in 1839 casually met and was introduced to darwin, and thus commenced a friendship which resulted in such inestimable benefits to science. before sailing with the antarctic expedition the young surgeon received from charles lyell, as a parting gift, 'a copy of darwin's _journal_ complete'; and he tells us that the perusal stimulated in him 'an enthusiasm in the desire to travel and observe[129].' on hooker's return from the voyage in 1843, a friendly letter from darwin commenced that remarkable correspondence, which will always afford the best means of judging of the development of ideas in darwin's mind. hooker's wide knowledge of plants--especially of all questions concerning their distribution--was of invaluable assistance to darwin, at a time when his attention was more particularly absorbed by geology and zoology, while botany had not as yet received much attention from him. hooker's experience, gained in travel, his sound judgment and balanced mind made him a judicious adviser, while his caution and candour fitted him to become a trenchant critic of new suggestions, scarcely inferior in that respect to lyell. darwin does not appear to have made the acquaintance of huxley till a considerably later date; but we find the great comparative anatomist had in 1851 already become so deeply impressed by darwin, that he said in writing to a friend he 'might be anything if he had good health[130].' huxley used to visit darwin at down occasionally, and i have often heard the latter speak of the instruction and pleasure he enjoyed from their intercourse. for many years of his life, darwin used to come to london and stay with his brother or daughter for about a week at a time, and on these occasions--which usually occurred about twice in the year i believe--he would meet lyell to 'talk geology,' hooker for discussions on botany, and huxley for zoology. for twenty years darwin had 'collected facts on a wholesale scale, more especially with respect to domesticated productions, by printed enquiries, by conversations with skilful breeders and gardeners, and by extensive reading.' 'when,' he added, 'i see the list of books of all kinds which i read and abstracted, including whole series of journals and transactions, i am surprised at my industry[131].' in september 1854 the barnacle work was finished and 10,000 specimens sent out of the house and distributed, and then he devoted himself to arranging his 'huge pile of notes, to observing and experimenting in relation to the transmutation of species.' it was early in 1856 when this work had been completed, that, again urged by lyell, he actually commenced writing his book. it was planned as a work on a considerable scale and, if finished, would have reached dimensions three or four times as great as did eventually the _origin of species_. working steadily and continuously he had got as far as chapter x, completing more than one half the book, when as he says wallace's letter and essay came 'like a bolt from the blue.' oppressed by illness, anxiety and perplexity, as we have seen that darwin was at the time, he fortunately consented to leave matters--though with great reluctance--in the hands of his friends lyell and hooker. they took the wise course of reading wallace's paper at the linnean society on july 1st, 1858, at the same time giving extracts from darwin's memoir written in 1844, and the abstract of a letter written by darwin in 1857 to the distinguished american botanist, asa gray. this solution of the difficulty happily met with the complete approval of wallace; and, as the result of the episode, darwin came to the conclusion that it would not be wise to defer full publication of his views, until the extensive work on which he was engaged could be finished, but an 'abstract' of them must be prepared and issued with as little delay as possible. for a time there was hesitation, as darwin's correspondence with lyell and hooker shows, between the two plans of sending this 'abstract' to the linnean society in a series of papers or of making it an independent book. but darwin entertained an invincible dislike to submitting his various conclusions to the judgment of the council of a society, and, in the end, the preparation of the 'abstract' in the form of a book of moderate size, was decided on. this was the origin of darwin's great work. the sickness at down had led to the abandonment of the house for a time, and, three weeks after the reading of the joint paper at the linnean society, we find darwin temporarily established at sandown, in the isle of wight, where the writing of the _origin of species_ was commenced. the work was resumed in september when the family returned to down, and from that time was pressed forward with the greatest diligence. for the first half of the book, the task before darwin was to condense, into less than one half their dimensions, the chapters he had already written for the large work as originally projected. but for the second half of the book, he had to expand directly from the essay of 1844. so closely did darwin apply himself to the work, that, by the end of march 28th, 1859, he was able to write to lyell telling him that he hoped to be ready to go to press early in may, and asking advice about publication: he says, 'my abstract will be about five hundred pages of the size of your first edition of the _elements of geology_.' lyell introduced darwin to john murray, who had issued all his own works, and the present representative of that publishing firm has placed on record a very interesting account of the ever thoughtful and considerate relations between darwin and his publishers, which were maintained to the end[132]. the ms. of the book seems to have been practically finished early in may, and darwin's health then broke down for a time, so completely that he had to retire to a hydropathic establishment. by june 21st he was able to write to lyell 'i am working very hard, but get on slowly, for i find that my corrections are terrifically heavy, and the work most difficult to me. i have corrected 130 pages, and the volume will be about 500. i have tried my best to make it clear and striking, but very much fear that i have failed; so many discussions are and must be very perplexing. _i have done my best._ if you had all my materials, i am sure you would have made a splendid book. i long to finish, for i am certainly worn out[133].' on september 10th the last proof was corrected and the preparation of the index commenced. at the meeting of the british association in aberdeen, lyell made the important announcement of the approaching publication of the great work. on november 24th the book was issued, 1250 copies having been printed, and darwin wrote to murray, 'i am infinitely pleased and proud at the appearance of my child.' the edition was sold out in a day, and was followed early in the next year by the issue of 3000 copies; and untold thousands have since appeared. the writing of such a work as the _origin of species_, in so short a time--especially taking into consideration the condition of its author's health--was a most remarkable feat. it would, of course, not have been possible but for the fact that darwin's mind was completely saturated with the subject, and that he had command of such an enormous body of methodically arranged notes. he showed the greatest anxiety to convince his scientific contemporaries, and at the same time to make his meaning clear to the general reader. with the former object, both ms. and printed proofs were submitted to the criticism of lyell and hooker; and the latter end was obtained by sending the ms. to a lady friend, miss g. tollet--she, as darwin says 'being an excellent judge of style, is going to look out errors for me.' finally the proofs of the book were carefully read by mrs darwin herself. the splendid success achieved by the work is a matter of history. its clearness of statement and candour in reasoning pleased the general public; critics without any profound knowledge of natural history were beguiled into the opinion that they _understood_ the whole matter! and, according to their varying tastes, indulged in shallow objection or slightly offensive patronage. the fully-anticipated, theological vituperation was of course not lacking, but most of the 'replies' to darwin's arguments were 'lifted' from the book itself, in which objections to his views were honestly stated and candidly considered by the author. the best testimony to the profound and far-reaching character of the scientific discussions of the _origin of species_ is found in the fact that both hooker and huxley, in spite of their wide knowledge and long intercourse with darwin, found the work, so condensed were its reasonings, a 'very hard book' to read, one on which it was difficult to pronounce a judgment till after several perusals! it would be idle to speculate at the present day whether the cause of evolution would have been better served by the publication, as darwin at one time proposed, of a 'preliminary essay,' like that of 1844, or by the great work, which had been commenced and half completed in 1858, rather than by the 'abstract,' in which the theory of natural selection was in the end presented to the world. probably the more moderate dimensions of the _origin of species_ made it far better suited for the general reader; while the condensation which was necessitated did not in the end militate against its influence with men of science. it will i think be now generally conceded that the great success of this grand work was fully deserved. a subject of such complexity as that which it dealt with could only be adequately discussed in a manner that would demand careful attention and thought on the part of the reader; and darwin's well-weighed words, carefully balanced sentences, and guarded reservations are admirably adapted to the accomplishment of the difficult task he had undertaken. the _origin of species_ has been read by the millions with pleasure, and, at the same time, by the deepest thinkers of the age with conviction. it is scarcely possible to refer to the literary style of darwin's work without a reference to a misconception arising from that very candid analysis of his characteristics which he wrote for the satisfaction of his family, but which has happily been given to the world by his son. in his early life darwin was exceedingly fond of music, and took such delight in good literature, especially poetry, that when on his journeys in south america he found himself able to carry only one book with him, the work chosen was the poems of milton--the former student of his own christ's college, cambridge. but towards the end of his life, darwin had sadly to confess that he found that he had quite lost the capacity of enjoying either music or the noblest works of literature. some have argued that darwin's scientific labours must have actually proved destructive to his artistic and literary tastes, and have even gone so far as to assert--in spite of numerous examples to the contrary--that there is a natural antithesis between the mental conditions that respectively favour scientific and artistic excellence. but i think there is a very simple explanation of the loss by darwin of his powers of enjoyment of music and poetry, a loss which he evidently greatly deplored. his scientific undertaking was so gigantic, and, at the same time, his health was so broken and precarious, that he felt his only chance of success lay in utilizing, for the tasks before him, every moment that he was free from acute suffering and retained any power of working. consequently, when the self-imposed task of each day was completed, he found himself in a state of mental collapse. now to appreciate the beauties of fine music or the work of a great writer certainly demands that the mind should be fresh and unjaded, whereas, at the only times darwin had for relaxation, he was quite unfitted for these higher delights. we are not surprised then to learn that he sought and found relief in listening to his wife's reading of some pleasant novel or in the nightly game of backgammon, as the only means of resting his wearied brain. no one who had the privilege of conversing with darwin in his later years can doubt of his having retained to the end the full possession of his refined tastes as well as his great mental powers. his love for and sympathy with every movement tending to progress--especially in the scientific and educational world--his devotion to his friends, with no little indulgence of indignation for what he thought false or mean in others, these were his conspicuous characteristics, and they were combined with a gentle playfulness and sense of humour, which made him the most delightful and loveable of companions. chapter xi the influence of darwin's works in two essays 'on the coming of age of the origin of species[134],' and 'on the reception of the origin of species[135],' published in 1880 and 1887 respectively, huxley has discussed the course of events following the publication of darwin's great work, he having the advantage of being one of the chief actors in those events. there is a striking parallelism between the manner that the _principles of geology_ had been received thirty years earlier, and the way that the _origin of species_ was met, both by darwin's scientific contemporaries and the reading public. at the outset, as we have already intimated, lyell and darwin were equally fortunate, in that each found a critic, in one of the chief organs of public opinion, who was at the same time both competent and sympathetic. the story of the lucky accident by which this came about in darwin's case has been told by huxley himself[136]. 'the _origin_ was sent to mr lucas, one of the staff of the _times_ writers at that time, in what was i suppose the ordinary course of business. mr lucas, though an excellent journalist, ... was as innocent of any knowledge of science as a babe, and bewailed himself to an acquaintance on having to deal with such a book. whereupon, he was recommended to ask me to get him out of the difficulty, and he applied to me accordingly, explaining, however, that it would be necessary for him formally to adopt anything i might be disposed to write, by prefacing it with two or three paragraphs of his own.' 'i was too anxious to seize upon the opportunity thus offered of giving the book a fair chance with the multitudinous readers of the _times_, to make any difficulty about conditions; and being then very full of the subject, i wrote the article faster, i think, than i ever wrote anything in my life, and sent it to mr lucas who duly prefixed his opening sentences[137].' many journalists, however, were less conscientious than mr lucas, and most of the other early notices of the book were pretty equally divided between undiscriminating praise of it as a novelty and foolish reprobations of its 'wickedness.' it was fortunate that darwin followed the strong advice given to him by lyell, and did not attempt to reply to the adverse criticisms; for the only effect of these was to arouse curiosity and thus to increase the circulation of the book. although darwin had wisely avoided the danger of exciting prejudice against his work by definitely applying the theory of natural selection to the case of man--simply remarking, in order to avoid the charge of concealing his views, that 'light would be thrown on the origin of man and his history'--yet friends and foes alike at once drew what was the necessary corollary from the theory. it is as amusing, as it is surprising at the present day, to recall the storm of prejudice which was excited. at the british association meeting at oxford in 1860, after an american professor had indignantly asked the question, 'are we a fortuitous concourse of atoms?' as a comment on darwin's views, dr samuel wilberforce, the bishop of oxford, ended a clever but flippant attack on the _origin_ by enquiring of huxley, who was present as darwin's champion, if it 'was through his grandfather or his grandmother that he claimed his descent from a monkey?' huxley made the famous and well-deserved retort:- 'i asserted--and i repeat--that a man has no reason to be ashamed of having an ape for his grandfather. if there were an ancestor whom i should feel ashamed in recalling, it would rather be a _man_--a man of restless and versatile intellect--who not content with success in his own sphere of activity, plunges into scientific questions with which he has no real acquaintance, only to obscure them by an aimless rhetoric, and distract the attention of his hearers from the real point at issue by eloquent digressions and skilled appeals to religious prejudice[138].' the violent attack on darwin's views by the once-famous bishop of oxford was outdone, a few years later, by an even more absurd outburst on the part of benjamin disraeli, who--after stigmatising darwinism as the question 'is man an ape or an angel?'--declared magniloquently to the episcopal chairman, 'my lord, i am on the side of the angels!' but in spite of attacks like these and numerous bitter pasquinades and comic cartoons--perhaps to some extent in consequence of them--darwin's views became widely known and eagerly discussed, so that the circulation of the _origin of species_ went up by leaps and bounds. nevertheless, as huxley said, 'years had to pass away before misrepresentation, ridicule and denunciation, ceased to be the most notable constituents of the multitudinous criticisms of his work which poured from the press.' among his contemporary men of science darwin could at first count few converts. hooker, whose candid and valuable criticisms of his friend's work had been continued up to the very end during its composition, did an eminent service to the cause of evolution by publishing, almost simultaneously with the _origin of species_, his splendid memoir on _the flora of australia, its origin, affinities, and distribution_, in which similar views were, not obscurely, indicated. of lyell, darwin's other friend and counsellor, huxley justly says: 'lyell, up to that time a pillar of the antitransmutationists (who regarded him, ever afterwards, as pallas athene may have looked at dian, after the endymion affair), declared himself a darwinian, though not without putting in a serious _caveat_. nevertheless, he was a tower of strength and his courageous stand for truth as against consistency, did him infinite honour[139].' huxley himself accepted the theory of natural selection--but not without some important reservations--these, however, did not prevent him from becoming its most ardent and successful champion. darwin used to acknowledge huxley's great service to him in undertaking the defence of the theory--a defence which his own hatred of controversy and the state of his health made him unwilling to undertake--by laughingly calling him 'my general agent!' while huxley himself in replying to the critics, declared that he was 'darwin's bulldog.' although, at first, darwin was able to enumerate less than a dozen naturalists who were prepared to accept his views, while influential leaders of thought in science--like richard owen in this country and louis agassiz in america--were bitterly opposed to them, the theory gradually obtained supporters especially among the younger cultivators of botany, zoology and geology. it is evident that darwin for some time regarded his 'abstract,' as he called the _origin of species_, as only a temporary expedient--one to be superseded by the publication of the much more extended work, designed and commenced long before. although the _origin_ was only published late in november 1859, and he was called upon immediately to prepare a second edition, we find that on january 1st, 1860, darwin began to arrange his materials for dealing with the first great division of his subject, 'the variation of animals and plants under domestication.' so numerous and important were his notes and records of experiments, however, that he soon found that to expand the whole of the 'abstract,' on the same scale, would be an impossible task for any one man, however able and diligent. unwilling that the results of some of his special researches should be lost, he wisely determined to issue them as separate books. the first of these to appear was that on the _fertilisation of orchids_, a beautiful illustration of the relation of insects to flowers in producing crossing. he had been more than twenty years working and experimenting on this subject, his interest in it having been quickened by having read an almost forgotten book of the botanist sprengel. almost at the same time, and in following years, he wrote papers for the linnean society on dimorphic and trimorphic forms of flowers, and their bearing on the question of cross-fertilisation. these papers were the foundation of his well-known work, _the different forms of flowers on plants of the same species_. in the same way, a paper read in 1864 to the linnean society was subsequently expanded into _the movements and habits of climbing plants_. owing to delays caused by the preparation and publication of these books and frequent interruptions from sickness, the work on variation did not appear till 1868. it was a very extensive piece of work in two volumes, and, at its end, darwin tentatively propounded a hypothesis to account for the facts of heredity and variation to which he gave the name of 'pangenesis.' charles darwin had reached the age of fifty, when he wrote the _origin of species_. at a very early period in his career, he had resolved that he would never start a new theory or revise an old one after he was sixty; as he used laughingly to say, 'i have seen too many of my friends make fools of themselves by doing that.' but as he approached this 'fatal age,' one more subject of a theoretical and highly controversial nature remained to be dealt with, namely, the question of the application of the theory of natural selection to man, both as regards his physical structure and his intellectual and moral characteristics. darwin tells us that in 1837 or '38, as soon as he had become 'convinced that species were mutable productions,' he 'could not avoid the belief that man must come under the same law[140].' from that time, he began collecting facts bearing on the question. as each of his children was born, he examined closely the signs of dawning intelligence, and made notes of the manner in which new sensations and passions were exhibited by them. his dog and other animals, for whom he always showed the greatest fondness, were closely watched with the object of noting correspondences between their mental and moral processes and their modes of exhibiting them and our own; while visits were made by him to the zoological gardens with the same object. by reading and correspondence also, an enormous mass of notes was collected, and on february 4th, 1868, having seen his great work on variation under domestication published, darwin was able to make the entry in his diary, 'began work on man.' as was usual with most of his works, darwin underestimated the time required to complete it. through all the years 1867--'68, '69 and '70 we find the entries in his diary 'working at _descent of man_,' and only early in the year 1871 was the book finished. his original plan of compressing his notes on the expression of the emotions into a chapter at the end of the book proved to be impracticable, and the material was reserved for a new work. this work, _the expression of the emotions in man and animals_, was commenced directly the _descent of man_ was out of hand, a rough copy was finished by april 27th, 1871, but the last proofs were not corrected till august 23rd, 1873. in dealing with the question of the origin of the human race, darwin was led to propound his views concerning sexual selection, the results of the preferences shown by males and females, respectively, not only among mankind, but in various other animals. it was with respect to some of the conclusions contained in this work that wallace found himself unable to follow darwin. wallace maintained that while man's body could have been developed by natural selection, his intellectual and moral nature must have had a different origin. he also declined to adopt the theory of sexual selection, so far as it depends on preferences exhibited by females for beauty in the males. wallace, however, in some respects has always been disposed to attach more importance to natural selection, as the greatest, if not the only factor in evolution, than darwin himself. it will be seen that although darwin had in all probability thought out all his important theoretical conclusions before 1869, when he reached the 'fatal age,' yet, owing to various delays, the books, in which he embodied his views, had not all appeared till more than four years later. lyell, who was a convinced evolutionist before the publication of the _principles of geology_, as is shown by his letters,--and the fact is strongly insisted on both by huxley and haeckel[141],--was slow in coming into _complete_ agreement with darwin concerning the theory of natural selection. while he followed his friend's investigations with the deepest interest, his less sanguine nature led him often to despair of the possibility of solving 'the mystery of mysteries.' as darwin wrote only a year before his own death, lyell 'would advance all _possible_ objections to my suggestions, and _even after these were exhausted_ would long _remain dubious_[142].' it is evident from the correspondence that darwin was at times tempted to become impatient with the friend, for whose advocacy of his views he so deeply longed. fourteen years after the publication of the _origin of species_, however, lyell, in his _antiquity of man_, gave in his adhesion to darwin's theory but, even then, not in the unqualified manner that the latter desired. yet i have reason to know that some years before his death, lyell was able to assure his friend of his _complete_ agreement, and darwin, six years after the loss of his friend, wrote, 'his candour was highly remarkable. he exhibited this by becoming a convert to the descent theory, though he had gained much fame by opposing lamarck's views, _and this after he had grown old_.' darwin adds that lyell, referring to the '_fatal_ age' of sixty, said 'he hoped that now he might be allowed to live[143]!' when i first came into personal relations with darwin, after the death of lyell in 1875, he was in the habit of deprecating any idea of his writing on theoretical questions. he used to talk of 'playing with plants and such things,' and undoubtedly derived the greatest pleasure from his ingenious experimental researches. the result of this 'play' in which darwin took such delight is seen in his books on the _power of movement in plants_ and _insectivorous plants_; full of the records of ingenious experiments and patient observation. it was a great relief to darwin that his friend wallace was able in 1871 to undertake the preparation of a work on _the geographical distribution of animals_, for, on many points, the views held by wallace on this subject were more in accordance with darwin's own, than were those of lyell and hooker. nevertheless, on all questions connected with the geographical distribution of plants, and the causes by which they were brought about, darwin always expressed the fullest confidence in hooker's judgment, and the greatest satisfaction with his results. with regard to another great division of his work, that dealing with the imperfection, but yet great value, of the geological record, darwin was always anxious, when i met him, to learn of any new discoveries. but he felt that he had done all that was possible in his outline of the subject in the _origin_, and that he must leave to palaeontologists all over the world the filling in of these outlines. so great was the delight with which he used to hear of new discoveries in palaeontology, that i often recall our conversations in these later days, when so many interesting forms of extinct animal and vegetable life--veritable 'missing links'--are being discovered in all parts of the globe, and wish that he could have known of them. they are indeed 'facts for darwin.' very happy indeed was charles darwin in the last years of his useful life, in returning to his oldest 'love'--geology. in studying the action of earthworms he found a geological study in which his rare powers of ingenious experimentation could be employed with profit. his earliest published memoir had dealt with the question, and for more than forty years with dogged perseverance, he had laboured at it from time to time. it was delightful to watch his pleasure as he examined what was going on in the flower-pots full of mould in his study, and when his book was published and favourably received, he rejoiced in it as 'the child of his old age[144].' charles darwin's death took place rather more than twenty-two years after the publication of the _origin of species_. before he passed away, he had the satisfaction of knowing that the doctrine of evolution had come to be--mainly through his own great efforts--the accepted creed of all naturalists and that even for the world at large it had lost its imaginary terrors. as huxley wrote a few days after our sad loss, 'none have fought better, and none have been more fortunate, than charles darwin. he found a great truth trodden underfoot, reviled by bigots, and ridiculed by all the world; he lived long enough to see it, chiefly by his own efforts, irrefragably established in science, inseparably incorporated with the common thoughts of men, and only hated and feared by those who would revile, but dare not. what shall a man desire more than this[145]?' more than a quarter of a century has passed since these words were written. how during that period the influence of darwin's writings on human thought has grown, in an accelerated ratio, will be seen by anyone who will turn the pages of the memorial volume--_darwin and modern science_--published fifty years after the _origin of species_. therein, not only zoologists, botanists and geologists, but physicists, chemists, anthropologists, psychologists, sociologists, philologists, historians--and even politicians and theologians--are found testifying to the important part which darwin's great work has played, in revolutionising ideas and moulding thought in connexion with all branches of knowledge and speculation. chapter xii the place of lyell and darwin in history from the account given in the foregoing pages, it will be seen that--without detracting from the merits of their predecessors or the value of the labours of their contemporaries--we must ascribe the work of establishing on a firm foundation of observation and reasoning the doctrine of evolution--both in the inorganic and the organic world--to the investigations and writings of lyell and darwin. lyell had to oppose the geologists of his day, who led by buckland in this country and by cuvier on the continent, were almost, without exception, hopelessly wedded to the doctrines of 'catastrophism,' and bitterly antagonistic to all ideas savouring of continuity or evolution. and, in the same way, darwin, at the outset, found himself face to face with a similarly hostile attitude, on the part of biologists, with respect to the mode of appearance of new species of plants and animals. while darwin doubtless derived his inspiration, and much valuable aid, from the _principles of geology_, and its gifted author, yet lyell, with all his clearness of vision, logical faculty and literary skill, did not possess the strong faith and resolute courage--to say nothing of that wonderful tenacity of purpose and power of research which were such striking characteristics of darwin--which would have enabled him to do for the organic what he did for the inorganic world. if it be true, as darwin used to suggest, that the _origin of species_ might never have been written had not lyell first produced the _principles of geology_, i believe it is no less certain that the crowning of lyell's great edifice, by the full application of his principles to the world of living beings, could only have been accomplished by a man possessing, in unique combination, the powers of observation, experiment, reasoning and criticism, joined to unswerving determination, which distinguished darwin. starting from lyell's most advanced post, darwin boldly advanced into regions in which his friend was unable to lead, and indeed long hesitated to follow. together, for nearly forty years, the two men--influencing one another 'as iron sharpeneth iron'--thought and communed and worked, aided at all times by the wide knowledge and judicious criticism of the sagacious hooker; and together the fame of these men will go down to posterity. there is a tendency, when a great man has passed from our midst, to estimate his merits and labours with undiscriminating, and often perhaps exaggerated, admiration; and this excessive praise is too often followed by a reaction, as the result of which the idol of one generation becomes almost commonplace to the next. a still further period is required before the proper position of mental perspective is reached by us, and a just judgment can be formed of the man's real place in history. the reputations of both lyell and darwin have, i think, passed through both these two earlier phases of thought, and we may have arrived at the third stage. there was one respect in which both lyell and darwin failed to satisfy many both of their contemporaries and successors. lyell, like hutton, always deprecated attempts to go back to a 'beginning,' while darwin, who strongly supported lyell in his geological views, was equally averse to speculations concerning the 'origin of life on the globe.' scrope[146], and also huxley[147] in his earlier days, held the opinion that it was legitimate to assume or imagine a beginning, from which, with ever diminishing energy, the existing 'comparatively quiet conditions,' thought to characterise the present order of the world, would be reached. both lyell and darwin insisted that geology is a historical science, and must be treated as such quite distinct from cosmogony. and in the end, huxley accepted the same view[148]. 'geology,' he asserted, 'is as much a historical science as archaeology.' the sober historian has always had to contend against the traditional belief that 'there were giants on the earth in those days!' the love of the marvellous has always led to the ascription of past events to the work of demigods who were not of like powers and passions with ourselves. hence the invention of those 'catastrophies'--in which the reputations of deities as well as of men and women have often suffered. it is the same tendency in the human mind which makes it so difficult to conceive of all the changes in the earth's surface-features and its inhabitants being due to similar operations to those still going on around us. lyell's views have constantly been misrepresented by the belief being ascribed to him that 'the forces operating on the globe have never acted with greater intensity than at the present day.' but his real position in this matter was a frankly 'agnostic' one. 'bring me evidence,' he would have said, 'that changes have taken place on the globe, which cannot be accounted for by agencies still at work _when operating through sufficiently long periods of time_, and i will abandon my position.' but such evidence was not forthcoming in his day, and i do not think has ever been discovered since. professor sollas has very justly said, 'geology has no need to return to the catastrophism of its youth; in becoming evolutional it does not cease to remain essentially uniformitarian[149].' alfred russel wallace, who has always been as stout a defender of the views of lyell as he has of those of darwin, has given me his permission to quote from a letter he wrote me in 1888. after referring to what he regards as the weak and mistaken attacks on lyell's teachings, 'which have of late years been so general among geologists,' he says:- 'i have always been surprised when men have advanced the view that volcanic action _must_ have been greater when the earth was hotter, and entirely ignore the numerous indications that both subterranean and meteorological forces, even in palaeozoic times, were of the same order of magnitude as they are now--and this i have always believed is what lyell's teaching implies.' i believe that mr wallace's expression, adopted from the mathematicians, 'the same order of magnitude,' would have met with lyell's complete acquiescence. he was not so unwise as to suppose that, in the limited periods of human history, we must necessarily have had experience--even at krakatoa or 'skaptar jokull'--of nature's greatest possible convulsions, but he fought tenaciously against any admission of 'cataclysms' that would belong to a totally different category to those of the present day. apart from theological objections, the most formidable obstacle to the reception of evolutionary ideas had always been the prejudice against the admission of vast duration of past geological time. it was unfortunate that, even when rational historical criticism had to a great extent neutralised the effect of archbishop usher's chronology, the mathematicians and physicists, assuming certain sources of heat in the earth and sun could have been the only possible ones, tried to set a limit to the time at the disposal of the geologist and biologist. happily the discovery of radio-activity and the new sources of heat opened up by that discovery, have removed those objections, which were like a nightmare to both geology and biology. lyell used to relate the story of a man, who, from a condition of dire poverty, suddenly became the possessor of vast wealth, and when remonstrated with by friends on the inadequacy of a subscription he had offered, the poor fellow exclaimed sadly, 'ah! you don't know how hard it is to get the chill of poverty out of one's bones.' geologists and biologists alike have long been the victims of this 'chill of poverty,' with respect to past time. so long as physicists insisted that one hundred millions, or forty millions, or even ten millions of years, must be the limit of geological time, it was not possible to avoid the conclusion stated by lord salisbury in 1894, 'of course, if the mathematicians are right the biologists cannot have what they demand[150].' but now geologists and biologists may alike feel that the liberty with respect to _space_, which is granted ungrudgingly to the astronomer, is no longer withheld from them in regard to _time_. we can say with old lamarck:- 'for nature, time is nothing. it is never a difficulty, she always has it at her disposal; and it is for her the means by which she has accomplished the greatest as well as the least results. for all the evolution of the earth and of living beings, nature needs but three elements--space, time and matter[151].' darwin, equally with lyell, has suffered from a reaction following on extravagant and uninformed praise of his work. the fields in which he laboured single-handed, have yielded to hundreds of workers in many lands an abundant harvest. new doctrines and improved methods of enquiry have arisen--mutationism, mendelism, weismannism, neo-lamarckism, biometrics, eugenics and what not--are being diligently exploited. but all of these vigorous growths have their real roots in darwinism. if we study darwin's correspondence, and the successive essays in which he embodied his views at different periods, we shall find, variation by mutation (or _per saltum_), the influence of environment, the question of the inheritance of acquired characters and similar problems were constantly present to darwin's ever open mind, his views upon them changing from time to time, as fresh facts were gathered. no one could sympathise more fully than would darwin, were he still with us, in these various departures. he was compelled, from want of evidence, to regard variations as spontaneous, but would have heartily welcomed every attempt to discover the laws which govern them; and equally would he have delighted in researches directed to the investigation of the determining factors, controlling conditions and limits of inheritance. the man who so carefully counted and weighed his seeds in botanical experiments, could not but rejoice in the refined mathematical methods now being applied to biological problems. let us not 'in looking at the trees, lose sight of the wood.' underlying all the problems, some of them very hotly discussed at the present day, there is the great central principle of natural selection--which if not the sole factor in evolution, is undoubtedly a very important and potent one. it is only necessary to compare the present position of the natural history sciences with that which existed immediately before the publication of the _origin of species_, to realise the greatness of darwin's achievement. the fame of both lyell and darwin will endure, and their names will remain as closely linked as were the two men in their lives, the two devoted friends, whose remains found a meet resting-place, almost side by side, in the abbey of westminster. very touching indeed was it to witness the marks of affection between these two great men; an affection which remained undiminished to the end. lyell was twelve years senior to darwin, and died seven years before his friend. during the last year of lyell's life, i spent the summer with him at his home in forfarshire. how well do i recollect the keenness with which--in spite of a near-sightedness that had increased with age almost to blindness--he still devoted himself to geological work. the 264 note-books, all carefully indexed, were in constant use, and visits were made to all the haunts of his youth, with the frequent pathetic appeal to me, 'you must lend me your eyes.' in spite of age and weakness, he would insist on clambering up the steepest hills to show me where he had found glacial markings, and would eagerly listen to my report on them. but the _great_ delight of those days was the arrival of a letter from darwin! lyell was the recipient of many honours, and he declined many more, when he feared that they might interfere with the work to which he had devoted his life, but the distinction he prized most of all was that conferred on him by his life-long friend, who used to address him as 'my dear old master,' and subscribe himself 'your affectionate pupil.' during the seven years that elapsed after the death of lyell, i saw darwin from time to time, for he loved to hear 'what was doing' in his 'favourite science.' on board the _beagle_, before he had met the man whose life and work were to be so closely linked with his own, he was in the habit of specially treasuring up any 'facts that would interest mr lyell'; in middle life he declared that 'when seeing a thing never seen by lyell, one yet saw it partially through his eyes[152]'; and never, i think, did we meet after the friend was gone, without the oft repeated query, 'what would lyell have said to that?' these reminiscences of the past, in which i have ventured to indulge, may not inappropriately conclude with a reference to the last interview i was privileged to have with him, who was 'the noblest roman of them all!' on the occasion of his last visit to london, in december, 1881, charles darwin wrote asking me to take lunch with him at his daughter's house, and to have 'a little talk' on geology. greatly was i surprised at the vigour which he showed on that afternoon, for, contrary to his usual practice, he did not interrupt the conversation to retire and rest for a time, though i suggested the desirability of his doing so, and offered to stay. his brightness and animation, which were perhaps a little forced, struck me as so unusual that i laughingly suggested that he was 'renewing his youth.' then a slight shade passed over his countenance--but only for a moment--as he told me that he had 'received his warning.' the attack, to which his son has alluded, as being the prelude to the end[153], had occurred during this visit to town; and he intimated to me that he knew his heart was seriously affected. never shall i forget how, seeing my concern, he insisted on accompanying me to the door, and how, with the ever kindly smile on his countenance, he held my hand in a prolonged grasp, that i sadly felt might perhaps be the last. and so it proved. and now all the world is united in the conviction which darwin so modestly expressed concerning his own career, 'i believe that i have acted rightly in steadily following and devoting myself to science!' for has not that _devotion_ resulted in a complete reform of the natural-history sciences! the doctrine of the 'immutability of species'--like that of 'catastrophism' in the inorganic world--has been eliminated from the biological sciences by darwin, through his _steadily following_ the clues found by him during his south american travels; and continuity is now as much the accepted creed of botanists and zoologists as it is of geologists. as a result of the labours of darwin, new lines of thought have been opened out, fresh fields of investigation discovered, and the infinite variety among living things has acquired a grander aspect and a special significance. very justly, then, has darwin been universally acclaimed as 'the newton of natural history.' notes in the following references, l.l.l. indicates the "life and letters of sir charles lyell" by mrs k. lyell (1881), d.l.l. the "life and letters of charles darwin" by f. darwin (1887), m.l.d. "more letters of charles darwin" edited by f. darwin and a. c. seward (1903), and h.c.e. huxley's "collected essays." [1] the darwin-wallace celebration, linn. soc. (1908), p. 10. [2] darwin and modern science (1909), pp. 152-170. [3] pope, essay on man, ep. i. lines 111-2. [4] genesis, chap. xxx. verses 31-43. [5] brit. assoc. rep. 1900 (bradford), pp. 916-920. [6] _ibid._ 1909 (winnipeg), pp. 491-493. [7] l.l.l. vol. i. p. 468. [8] origin of species, chap. xv. end. [9] milton, paradise lost, bk. vii. lines 454-466. [10] edinb. rev. lxix. (july 1839), pp. 446-465. [11] principles of geology, vol. i. (1830), p. 61. [12] zittel, hist. of geol. &c. eng. transl. p. 72. [13] quart. rev. vol. xlviii. (march 1832), p. 126. [14] brit. assoc. rep. 1866 (nottingham). [15] h.c.e. vol. viii. p. 315. [16] _ibid._ p. 190. [17] d.l.l. vol. ii. pp. 179-204. [18] h.c.e. vol. v. p. 101. [19] d.l.l. vol. ii. p. 190. [20] edinb. rev. vol. lxix. (july 1839), p. 455 _note_. [21] 'theory of the earth,' vol. ii. p. 67. [22] l.l.l. vol. i. p. 272. [23] brit. assoc. rep. 1833 (cambridge), pp. 365-414. [24] outlines of the geology of england and wales, p. xliv. [25] illustrations of the huttonian theory, p. iii. [26] edinb. rev. lxix. (july 1839), p. 455 _note_. [27] _ibid._ [28] zittel, hist. of geol. &c. eng. transl. p. 141. [29] considerations on volcanoes, &c. (1825), pp. iv-vi. [30] volcanoes of central france, 2nd ed. (1858), p. vii. [31] see quart. rev. vol. xxxvi. (oct. 1827), pp. 437-485. [32] l.l.l. vol. i. p. 46. [33] principles of geology, vol. ii. 2nd ed. [34] l.l.l. vol. ii. pp. 47-8. [35] _ibid._ vol. i. p. 268. [36] environs de paris (1811), p. 56. [37] trans. geol. soc. 2nd ser. vol. ii. pp. 73-96. [38] see mantell's geology of the isle of wight and l.l.l. vol. i. pp. 114-122. [39] hist. of geol. &c. eng. transl. p. 188. [40] l.l.l. vol. i. p. 173. [41] british critic and theological review (1830), p. 7 of the review. [42] l.l.l. vol. i. p. 177. [43] preface to vol. iii. of the 'principles' (1833), p. vii. [44] l.l.l. vol. i. pp. 233-4. [45] charles lyell and modern geology (1898), p. 214. [46] proc. geol. soc. vol. i. p. 374. [47] l.l.l. vol. i. p. 196. [48] _ibid._ vol. i. p. 197. [49] proc. geol. soc. vol. i. pp. 145-9. [50] l.l.l. vol. i. p. 253. [51] _ibid._ vol. i. p. 234. [52] _ibid._ vol. i. p. 271. [53] _ibid._ vol. i. p. 270. [54] _ibid._ vol. i. p. 271. [55] quart. rev. vol. xliii. (oct. 1830), pp. 411-469 and vol. liii. (sept. 1835), pp. 406-448. both these reviews are by scrope. the review of the 2nd vol. of the 'principles,' q.r. vol. xlvii. (march 1832), pp. 103-132 is by whewell. [56] l.l.l. vol. i. p. 270. [57] _ibid._ vol. i. pp. 260-1. [58] _ibid._ vol. i. p. 314. [59] _ibid._ vol. i. p. 165. [60] m.l.d. vol. ii. p. 232 and d.l.l. vol. ii. p. 190. [61] l.l.l. vol. i. pp. 316-7. [62] proc. geol. soc. vol. i. pp. 302-3. [63] l.l.l. vol. ii. p. 41. [64] see also d.l.l. vol. i. pp. 72-3. [65] nineteenth century, oct. 1895, and controverted questions in geology (1895), pp. 1-18. [66] m.l.d. vol. ii. p. 117. [67] d.l.l. vol. i. pp. 337-8 and p. 342. [68] origin of species, chap. x. see also darwin and modern science, pp. 337-385. [69] d.l.l. vol. i. pp. 341-2. [70] l.l.l. vol. ii. p. 44. [71] d.l.l. vol. i. p. 296. [72] _ibid._ p. 72. [73] _ibid._ p. 71. [74] a. r. wallace, 'my life, &c.' (1905), vol. i. p. 433. [75] the darwin-wallace celebration, linn. soc. (1908), p. 118. [76] l.l.l. vol. ii. p. 459. [77] report of lecture at forrester's hall. [78] h.c.e. vol. viii. p. 312. [79] d.l.l. vol. ii. p. 190. [80] l.l.l. vol. ii. pp. 2, 3. [81] _ibid._ vol. ii. p. 36. [82] _ibid._ vol. ii. p. 5. [83] d.l.l. vol. i. p. 94. [84] l.l.l. vol. i. pp. 417-8. [85] h. f. osborn, 'from the greeks to darwin' (1894), p. 165. [86] _loc. cit._ pp. 467-469. [87] l.l.l. vol. i. p. 168. [88] _ibid._ vol. ii. p. 365. [89] d.l.l. vol. ii. pp. 23, 29, 39. [90] _ibid._ vol. iii. p. 15 (see also pp. 11-14). [91] 'origin of species,' 6th ed. (1875), p. xiv. [92] 'darwin and modern science,' p. 125. [93] 'origin of species,' 6th ed. (1875), pp. xvi, xvii. [94] m.l.d. vol. i. p. 3. [95] d.l.l. vol. i. p. 41. [96] _ibid._ vol. i. p. 41. [97] _ibid._ vol. i. p. 52. [98] _ibid._ vol. i. p. 58. [99] _ibid._ vol. i. p. 58. [100] h.c.e. vol. ii. p. 271. [101] d.l.l. vol. i. p. 73. [102] _ibid._ vol. i. p. 263. [103] _ibid._ vol. i. p. 38. [104] h.c.e. vol. ii. p. 20. [105] d.l.l. vol. i. p. 275. [106] _ibid._ vol. i. p. 83. [107] _ibid._ vol. ii. pp. 5-10. [108] h.c.e. vol. ii. p. 71. [109] d.l.l. vol. i. p. 47. [110] _ibid._ vol. i. p. 84. [111] macmillan's magazine, feb. 1888, p. 241. [112] my life, &c. vol. i. p. 355. [113] darwin-wallace celebration, linn. soc. (1908), pp. 6-7. [114] _ibid._ pp. 14-16. [115] d.l.l. vol. ii. pp. 116-7. [116] 'contributions to the theory of natural selection' (1871), preface, pp. iv, v. [117] darwin-wallace celebration, linn. soc. (1908), p. 7. [118] _ibid._ p. 7. [119] d.l.l. vol. i. p. 66. [120] _ibid._ vol. i. pp. 62-3. [121] _ibid._ vol. i. p. 66. [122] _ibid._ vol. i. p. 66. [123] d.l.l. vol. i. p. 83. [124] _ibid._ vol. i. p. 84. [125] 'the foundations of the origin of species' (1909), p. xv. [126] letter to a. r. wallace, christ's coll. mag. vol. xxiii. (1909), p. 229. [127] d.l.l. vol. ii. pp. 16-18. [128] _ibid._ vol. i. p. 347. [129] d.l.l. vol. ii. pp. 19-21. [130] huxley's life and letters (1900), vol. i. p. 94. [131] d.l.l. vol. i. p. 83. [132] science progress, vol. iii. (1908), pp. 537-542. [133] d.l.l. vol. ii. p. 160. [134] h.c.e. vol. ii. pp. 227-243. [135] d.l.l. vol. ii. pp. 179-204. [136] _ibid._ vol. ii. p. 255. [137] the review is republished in h.c.e. vol. ii. pp. 1-21. [138] huxley's life and letters, vol. i. pp. 179-189. [139] d.l.l. vol. ii. p. 185. [140] _ibid._ vol. i. p. 93. [141] see haeckel's 'history of creation.' [142] d.l.l. vol. i. p. 71. [143] _ibid._ vol. i. p. 72. [144] d.l.l. vol. i. p. 98; vol. iii. pp. 217-218. [145] h.c.e. vol. ii. p. 247. [146] quart. rev. xliii. pp. 464-467 and vol. liii. pp. 446-448. [147] h.c.e. vol. viii. p. 315. [148] h.c.e. vol. v. p. 99. [149] the age of the earth and other geological studies, p. 322. [150] brit. assoc. rep. 1894 (oxford), p. 13. [151] 'hydrogéologie,' p. 67. [152] m.l.d. vol. ii. p. 117. [153] d.l.l. vol. iii. p. 356. index adaptation, in relation to divergence of species, darwin's recognition of, 108, 109 agriculturalists, ideas of creation, 5, 6 arnold, matthew, on lucretius and darwin, 3, 4 auvergne, n. desmarest on, 17; scrope on, 35; visited by lyell and murchison, 56, 57; their memoir on, 58 'beagle,' h.m.s., darwin's voyage in, 98, 99; narrative of, 106 bonney, t. g., estimate of amount of lyell's travels by, 56, 57 botanical works of darwin, 141 _british critic_, whewell's review of lyell in, 53 broderip, w. j., aid given to lyell by, 65; vol. ii. of _principles_ dedicated to, 65 brown, robert, assistance to lyell by, 47 buckland, dr, on infant geological society, 26; champion of 'catastrophism' in england, 27; his eccentricity, 42-44; 'equestrian geology' of, 28; influence on lyell, 34, 44; 2nd edition of vol. i. of _principles_ dedicated to, 44; his opposition to lyell, 71 cambridge, darwin at, 97, 98 candolle, a. p. de, on struggle for existence, 107 catastrophism, origin of idea of, 14, 15; defined, 22; origin of term, 22; connexion with orthodoxy, 21; championed by buckland, sedgwick &c., 27; by cuvier, 31, 50, 102; opposition by lyell and darwin to, 105 centres of creation, lyell's views on, 65 chambers, robert, publishes _vestiges of creation_, 92; his reasons for anonymity, 93 chemists, part played in early days of geological society by, 26 christ's college, cambridge, the home of milton and darwin, 13; of paley, 108 clodd, e., his _pioneers of evolution_, 16 continuity, term for evolution suggested by grove, 23 conybeare, w. d., advocacy of catastrophism, 27; criticism of hutton, 28; misconception of hutton, 29; on formation of thames valley, 58; friendship with lyell, 69 creation, legends of, 5-7; use of term by lyell and darwin, 11; contrast of their views with those of milton, 12, 13 criticisms of the _principles of geology_, 68, 69, 70, 71; of the _origin of species_, 132-139 cuvier, his strong support of catastrophism, 31, 46, 50, 102 darwin, charles, nobility of character, 3; his use of term 'creation,' 11; on grandeur of idea of evolution, 12; his devotion to lyell and the _principles of geology_, 63, 73-75, 78; his horror of slavery, 76; opposition to catastrophism, 77; opinion of lamarck's works, 90, 91: on the _vestiges of creation_, 94; his dislike for speculation, 101; his optimism and courage, 77; his birth and education, 95, 96; life at edinburgh, 97; at cambridge, 97, 98; voyage in the 'beagle,' 99, 100; first awakening to the idea of evolution, 102, 104; work with lyell at geological society, 105; begins 'species work,' 106; influence of malthus's work on, 107; intercourse with wallace, 113; action in respect to theory, 128, 129; his first literary ambitions, 116; difficulties of work caused by ill-health, 117, 118, 119; his loss of appreciation for music and literature, and its cause, 134, 135; later writings on evolution, 141, 144; his declining years, 147, 158, 159; his death, 147; present position of his theory of natural selection, 155, 156, 159 darwin, erasmus, his independent conception of lamarckism, 91, 92; absence of influence on his grandson, 95, 101 darwin, erasmus (the younger), advice given to charles on publication, 122 darwin, francis, edited _life and letters_ &c., 121; extracts from c.d.'s note-books &c., and _foundations of the origin of species_, 123; on his father's health, 118 darwin, mrs, her care of her husband's health, 118; read proofs of _origin of species_, 132 daubeny, c. g. b., assists lyell in his researches, 47 de la beche, h., his attitude with respect to evolution, 71 deshayes, g. b., assists lyell in conchological work, 66 desmarest, n., work in auvergne, 17; evolutionary views of, 17, 20 earthworms, darwin's work on, 147 edinburgh, darwin's life at, 97; wernerian society at, founded by jameson, 21, 25 egypt, idea of inorganic evolution originated in, 15 entomology, influence of, on lyell, 42, 57; on darwin, 96; on wallace, 110 'equestrian geology,' popularity of, at oxford, 27; at cambridge, 28 evolution, in _organic_ and _inorganic_ world, 14; how ideas originated, 15-16, 82, 83; revolution effected by, 1, 32, 159; causes of opposition to, 20, 21, 155; opposition of sedgwick and whewell, 83; support of herschel, 83 euclid, influence on darwin, 108 faraday, m., assistance given to lyell by, 47 fitton, dr, on supposed indebtedness of hutton to generelli, 18; and of lyell to hutton, 18; on causes of hutton's failure to reform geology, 23, 25; his attitude towards lyell's views, 30, 71 fluvialists, 58 forbes, david, intercourse with darwin, 119 fossil bones, discovery of, in south america first suggests to darwin mutability of species, 102 _foundations of the origin of species_, 123 frazer, j. g., on legends of creation, 5, 7 galapagos islands, influence of study of fauna on darwin, 104 generelli, advocacy of evolution, 17, 20 geographical distribution, lyell on, 65; wallace on, 146 geological society, foundation of, 25; early history, 26; connexion of lyell with, 44, 71: of darwin, 100, 105: of scrope, 50; discussions on rival doctrines at, 24, 25, 29, 30, 60, 76, 77, 105 geology, darwin's interest in, 96, 99, 124, 147, 158 gibbon, his influence on lyell, 52, 67 greenough, g. b., founds geological society and first president, 26; his strong support of wernerism, 26, 29 grove, r., suggests term 'continuity,' 23 günther, dr, his estimate of number of species of animals, 10 haeckel, e., credits lyell with early conviction of evolution, 84 henslow, j. s., friendship for and help of darwin, 97, 98, 99; opposition to evolution, 27, 72 heredity, early recognition of importance, 9 herschel, j., belief in evolution, 12, 71; correspondence with lyell, 12, 83, 85 hoff, c. von, influence of his works on lyell, 49 hooker, j. d., friendship with lyell's father, 126; voyage to antarctic with ross, 126; introduction to darwin, 126; correspondence with, 127; assistance to darwin, 126; advice to, 129; on origin of australian flora, 139; friendship with lyell, 79, 126 hutton, his _theory of the earth_, 17, 18, 19, 20; rarity of the book, 30; small influence of, 21; supposed infidelity and persecution of, 21, 22, 25, 69; lyell's mistaken views on, 54; difference of his theory from lyell's, 53 huxley, t. h., early views on distinction of uniformitarianism and evolution, 23; later view of identity, 23, 24; influence of darwin on, 24, 127, 144; on 1st edition of principles, 67, 80, 81; argues for lyell's belief in evolution, 84; reviews _origin of species_, 136, 137; reply to bishop of oxford, 138; defence of darwinism, 140; on darwin's death, 147, 148; on lyell's death, 80 hybridity, lyell's discussion on, 65, 103 hypotheses of creation, twofold character of, 5-8 ideas _v._ actions, wallace on, 4 independent discovery of natural selection by wallace, 113; darwin's letter on, 113 italian geologists, their anticipation of evolutionary ideas, 17 jacob, his frauds based on ideas of heredity and variation, 9 jameson, r., founds wernerian society 1807, 25; influence on darwin, 97 _journal of researches_, by darwin, 106; dedicated to lyell, 72 king's college, london, lyell professor at, 65, 66 kinnordy, lyell at, 42, 43, 46 kirwan, de luc, and williams, opposition to hutton, 25 lamarck, his _hydrogéologie_, 87; _philosophie zoologique_, 88; lyell's admiration of, 64, 89; criticism of theory, 64, 90; views of darwin on, 90, 91; on geological time, 155 lectures by lyell, 65, 66 linnean society, papers of darwin and wallace at, 112, 129, 130 literature, lyell and, 52, 67; darwin and, 116, 117, 120; his loss of interest in, 134, 135 lockhart and _quarterly review_, 60 lucretius, belief in evolution, 3, 4 lyell, charles, use of term 'creation,' 11; on grandeur of idea of evolution, 12; birth and ancestry, 41; education, 34, 42; influence of buckland on, 34, 42-44; on cuvier, 46; change of views not due to hutton's works, 45; but to travel and observation, 45; in east anglia, 45; in strathmore, 46, 47; abandons career as barrister for geology, 48; work with dr mantell, 48; visits to continent, 48; influence of von hoff's works, 49; of scrope, 50; his remarks on hutton's supposed heresies, 51, 54; influence of gibbon on his literary style, 52; praise of hutton and playfair at later date, 53; review of scrope's book on auvergne, 56; visit to auvergne with murchison, 56; advocacy of travel for geologists, 56; journeys in italy, 58; lyell on murchison, 57; murchison on lyell, 58; lyell's avoidance of controversy, 63; differences of opinion with scrope, 62, 63; attention to literary style, 65; professorship at king's college, london, 65, 69; lectures, 66; controversies at geological society, 71; aid of darwin in discussions, 71; his friendship with darwin, 73, 104, 105; his extreme caution, 75-77; candour in finally accepting natural selection, 77; opposition to his views, 83, 84; his belief in evolution at an early date, 81, 84-86; his anticipation of 'mimicry,' 85, 86; his action in darwin-wallace episode, 113, 129; induces darwin to commence writing his work, 128; his attitude towards theory of natural selection, 139, 140, 145; great influence of lyell's works on darwin and evolution, 150; misrepresentation of his views, 152-154; his declining years, 157; last hours, 80; hooker's tribute to his memory, 79, 80 lyell, charles (the elder), botanist and student of dante, 41; intercourse with the hookers, 126 malthus, _on population_, influence of work on darwin, 107; on wallace, 112 man, descent of, darwin's work on, 142, 144; wallace's views on, 144 mantell, lyell's researches with, 48; correspondence with, 55, 89 matthew, p., anticipation of theory of natural selection, 92 milton, description of creation, 13; darwin's early love of his poetry, 134; at christ's college, cambridge, 13 mimicry, doctrine of, lyell's early recognition of importance, 85, 86 _modern science, darwin and_, 148 murchison, accompanies lyell to auvergne, 56; opinion of lyell, 57; lyell's opinion of, 57, 58; 3rd vol. of _principles_ dedicated to, 66; correspondence with, 59 murray, john, and _quarterly review_, 60; publishes lyell's works, 60; publishes darwin's works, 130; his reminiscences of darwin, 132 music, darwin's loss of power to appreciate, and its cause, 134, 135 natural selection, theory of, defined by huxley, 106; forestalled by wells, matthew &c., 18, 19; first conception of by darwin, 107; by wallace, 112 'neptunism' or 'wernerism' and catastrophism, 18 newton, professor a., on vague hopes of solution of 'species question' before darwin, 94, 109 _origin of species_, first idea of, 121; plan proposed to follow _principles_, 123; first sketch of 1842, enlarged draft of 1844, commencement of great treatise on evolution in 1856, interruption by arrival of wallace's papers, 128, 129; the 'abstract' or _origin of species_ commenced, 130; finished, 131; reception of, 132-139; influence of, 1, 159 osborn, h. f., his _from the greeks to darwin_, 16; on lamarck, 87 paley, his influence on darwin, 108 phillips, john, his attitude towards lyell's views, 30, 71 philosophers, on evolution, 16, 82 playfair, john, his _illustrations of the huttonian theory_, 29; explains the causes of hutton's failure, 30 'plutonism,' 'vulcanism,' or 'huttonism,' 18 poets and evolution, 16 prestwich, sir j., opposition to lyell's views, 72 prevost, constant, aid to lyell, 50; opposition to cuvier, 50 priestley, persecution of, 21, 69 _principles of geology_, first idea of, 55; early draft sent to publisher in 1827, 56; withdrawn and rewritten in 1830, 56; issue of first volume, 63; success, 64; review by scrope, 60-62; decision to confine vol. ii. to organic evolution, 65; 3rd volume, classification of tertiaries and metamorphic theory, 66; later editions, 66; _elements, manual and student's elements_, 67; success of work, 67; darwin's opinion on, 67; of huxley, 67, 80, 81; wallace on, 79; criticisms of, 68, 69, 70, 71 pythagoras, his evolutionary ideas, 16 _quarterly review_, articles by lyell, 56, 89; by scrope, 60, 62 reviews, of the _principles_ by scrope, 56, 89; by whewell, 22, 53; of the _origin_ by huxley, 136, 137 scrope, g. poulett, education, 34; travels, 34; work in auvergne, 35; in italy, 35; delay in publishing, 35; work on volcanoes, 36; his just views on evolution, 37-39; cause of want of recognition of his work, 39, 40; devotion to politics, 40; reviews of _principles_, 41, 61; correspondence with and influence on lyell, 50, 61; his differences of opinion from lyell, 62, 63, 151; effects of his review, 64 sedgwick, a., advocates catastrophism, 27, 28; opposition to hutton, influence on scrope, 34; on darwin, 98; opposition to lyell, 83; weakening of opposition to, 58; on _principles_, 70, 71; dislike to evolution, 83 shipley, a. e., estimate of number of species of animals, 10 slavery, views of lyell and darwin, 76 smith, w., influence of his teaching on geological society, 27 sollas, w. j., on evolution and uniformitarianism, 152, 153 species, origin of idea of, 9; number of species of animals, 10; of plants, 11 struggle for existence, lyell on, 103, 107; de candolle on, 107 _theory of the earth_, hutton's, 17; scrope's, 36 thompson, g. p., _see_ scrope, 33 time geological, lyell on, 154; lamarck on, 155 tollet, miss g., aids darwin in revising _origin of species_, 132 uniformitarianism, origin of the term, 14, 15, 22 uniformity (or continuity), lyell's real views on, 62, 63; misconceptions of his views on, 151, 152, 155 university of london, lyell's connexion with, 59, 65 variation, early recognition of its importance, 9; lyell's discussion of, 64, 103; darwin's work on, 141 _vestiges of creation_, influence of, 93; darwin on, 94; wallace on, 110 vines, s. h., estimate of number of species of plants, 10 volcanoes, scrope on, 36 vulcanism, _see_ plutonism &c., 18 wallace, alfred russel, on ideas and actions, 4; his early life, 110; in south america, 110; in malay archipelago, 110; influence of _principles_ on, 79, 110; speculations at sarawak, 111; influence of malthus on, 112; conception of idea of natural selection, 111, 112; ignorance of darwin's views, 112; statement on his relation to darwin, 113, 114; his magnanimity, 114; on geographical distribution of animals, 146; his defence of lyell's principle of uniformity, 153 wells, dr, his anticipation of theory of natural selection, 92 werner, success of his teachings, 21, 26, 27; his influence on early geologists, 26 wernerian society, founded, 1807, by jameson, 21, 25 wernerism, 18 whewell, dr, contrast of doctrines of hutton and lyell, 22, 53; originates terms 'catastrophism,' 'uniformitarianism,' 22; and 'geological dynamics,' 70; reviews _principles_, 53; opposition to evolution, 83 world, small part known to ancients, 9 worms, darwin's work on, 147 zittel, k. von, on hutton's work, 19; on von hoff and lyell, 50 _zoonomia_ of erasmus darwin, 101 cambridge: printed by john clay, m.a. at the university press * * * * * transcribers' note: general: inconsistent capitalisation of von in von hoff as in original general: no period (full stop) after mr, mrs, dr as in original page 24: ) added after 'uniformitarianism' to create matching pair pages 33, 171: inconsistent spelling of thomson/thompson as in original. page 59: missing anchor [50] added after dogmatise as this seemed the most likely place page 80: " changed to ' after [76] to create matching pair page 89: his changed to his in his theories delighted me page 94: eniment corrected to eminent page 102: re-stocked standardised to restocked page 111: . added after september 1855 page 149: . added after plants and animals page 157: lifelong standardised to life-long page 167: wernerianism standardised to wernerism; index entry for herschel, j., correspondence with lyell corrected from non-existent page 183 to page 12 omphalos: an attempt to untie the geological knot. by philip henry gosse, f.r.s. with fifty-six illustrations on wood. [greek: auxanetai de ta zôa panta, osa echei omphalon, dia tou omphalou.] arist.; _hist. anim._ vii. 8. london: john van voorst; paternoster row. 1857. london: r. clay, printer, bread street hill. preface. "you have not allowed for the wind, hubert," said locksley, in "ivanhoe;" "or that had been a better shot." i remember, when i was in newfoundland, some five-and-twenty years ago, the disastrous wreck of the brig _elizabeth_, which belonged to the firm in which i was a clerk. the master had made a good observation the day before, which had determined his latitude some miles north of cape st. francis. a thick fog coming on, he sailed boldly by compass, knowing that, according to his latitude, he could well weather that promontory. but lo! about midnight the ship plunged right against the cliffs of ferryland, thirty miles to the south, crushing in her bows to the windlass; and presently went down, the crew barely saving their lives. the captain _had not allowed for the polar current_, which was setting, like a sluice, to the southward, between the grand bank and the land. when it was satisfactorily ascertained that the heavenly body, now known as uranus, was a planet, its normal path was soon laid down according to the recognised law of gravitation. but it would not take this path. there were deviations and anomalies in its observed course, which could in nowise be referred to the operation of any known principle. astronomers were sorely puzzled to explain the irregularities, and to reconcile facts with laws. various hypotheses were proposed: some denied the facts; that is, the observed places of the planet, boldly assuming that the observers had been in error: others suggested that perhaps the physical laws, which had been supposed to govern the whole celestial machinery, did not reach so far as uranus's orbit. the secret is now known: _they had not allowed for the disturbances produced by neptune_. in each of these cases the conclusions were legitimately deduced from the recognised premises. hubert's skilled eye had calculated the distance; his experience had taught him the requisite angle at which to shoot, the exact amount of force necessary, and every other element proper to insure the desired result, _except one_. there was an element which he had overlooked; and it spoiled his calculations. _he had forgotten the wind._ the master of the ill-fated brig had calculated his latitude correctly; he knew the rate of his vessel's speed; the compass had showed him the parallel on which to steer. these premises ought to have secured a safe conclusion; and so they would, but for an unrecognised power that vitiated all; he was not aware of the silent and secret current, that was every hour setting him to the south of his supposed latitude. the path of uranus had been calculated by the astronomers with scrupulous care, and every known element of disturbance had been considered; not by one, but by many. but for the fact that the planet had been previously seen in positions quite inconsistent with such a path, it would have been set down as beyond controversy correct. stubborn fact, however, would not give way; and hence the dilemma, till le verrier suggested the unseen antagonist. i venture to suggest in the following pages an element, hitherto overlooked, which disturbs the conclusions of geologists respecting the antiquity of the earth. their calculations are sound on the recognised premises; _but they have not allowed for the law of prochronism in creation_. the enunciation of this principle will lie in a nut-shell; the reader will find it at p.124; or p.347. all the rest of the book is illustration. i do not claim originality for the thought which i have here endeavoured to work out. it was suggested to me by a tract, which i met with some dozen years ago, or more; the title of which i have forgotten: i am pretty sure it was anonymous, but it was published by campbell, of 1, warwick square. whether it is still in print i do not know; i never saw another copy. if the author is alive, and if he should happen to cast his eye on this volume, he will doubtless recognise his own bantling, and accept this my acknowledgment. the germ of the argument, however, i have found, since these pages were written, in "the mineral and mosaical geologies," of granville penn (1822). the state of physical science when he wrote did not enable him to press the argument to a demonstration, as i have endeavoured to do; for he could not refer to structural peculiarities as sensible records of past processes, _inseparable from newly created organisms_. i would not be considered as an opponent of geologists; but rather as a co-searcher with them after that which they value as highly as i do, truth. the path which i have pursued has led me to a conclusion at variance with theirs. i have a right to expect that it be weighed; let it not be imputed to vanity if i hope that it may be accepted. but what i much more ardently desire is, that the thousands of thinking persons, who are scarcely satisfied with the extant reconciliations of scriptural statements and geological deductions,--who are silenced but not convinced,--may find, in the principle set forth in this volume, a stable resting-place. i have written it in the constant prayer that the god of truth will deign so to use it; and if he do, to him be all the glory! p. h. g. marychurch, torquay, _october, 1857_. contents. i the cause. evidence of the senses often delusive--deductions of reason fallible--essentials sometimes overlooked--discrepancy between scripture and geological conclusions--painful dilemma--efforts to escape from it--supremacy of truth--various attempts at reconciliation--denouncers--opinions of brown--blackwood--macbrair--ure--penn--young--cockburn- miller--sedgwick--turner--sumner--chalmers--harris--gray- conybeare--hitchcock--pye smith--"protoplast"--babbage- powell--"vestiges"--amplitude of choice _page_ 1-29 ii. the witness for the macro-chronology. a court of inquiry--the witnesses--testimony of one--strata of thames tunnel--of hertfordshire--of yorkshire--of the globe--granite--granitic strata--organic remains--silurian system--corals--trilobites--mollusks--devonian system--old red sandstone--its formation--fishes--carboniferous system--coral limestone--millstone grit--coal--predominance of carbonic acid--extent and thickness of coal-fields--formation of coal--conjecture as to its age--antediluvian theory untenable--sauroid fishes--earliest reptiles--footprints of frogs 30-53 iii. the same--(_continued_.) disturbances of strata--internal heat--changes of land and sea--new red sandstone--footprints--labyrinthodon--lias formation--crinoids--ammonites--belemnites--fishes--marine reptiles--ichthyosaur--plesiosaur--european archipelago--oolitic formation--cycads--megalosaur- bat-lizards--iguanodon--hylæosaur--earliest mammal--chalk formation--infusoria--diatomaceæ--their minuteness and numbers--chambered cephalopods--mosasaur--end of secondary formations--convulsions--basalt--uprearing of mountain chains--london clay--plants and animals--fishes--reptiles--birds--mammals--anoplotherium--condition of europe--dinotherium--mastodon--mammoth--trees--crag formation--tertiary fauna--bone caves--kirkdale--erratic blocks--glaciers--sloths--marsupials--birds--raised beaches--human period--moho--present cosmical operations--river deltas--coral beefs--volcanoes--changes of level--earthy deposits--stalagmite--shells--recapitulation. 54-101 iv. the cross-examination. grandeur of the evidence--proposed line of objection--it is but circumstantial--example of confusion of thought--analysis of the reasoning---dependent on the exhaustive power of observation--relation of precedence and sequence--of cause and effect--force of my position. 102-109 v. postulates. the creation of matter--the persistence of species. 110-112 vi. laws. the course of nature a circle--illustrations--scarlet runner--lady-fern--hawkmoth--plumularia--cow--universality of the law--creation an irruption into a circle--false witness to past processes--prochronism and diachronism--phenomena illusory--recapitulation 113-126 vii. parallels and precedents. (_plants._) ideal tour on creation-day--chronological investigations--queried age of a tree-fern--data for the inquiry--development of the leaves--leaf-scars--report--its manifest error--selaginella--bamboo- couch-grass--screw-pine--pashiuba--sugar palm--areca--rattan--agave--traveller's tree--butterfly flower--orchis--gladiolus--grass-tree--white lily--testudinaria--caffer-bread--fig--banyan--euphorbia- tulip-tree--bignonia--loranthus--prickly pear--mangrove--silk-cotton-tree--locust-tree--restriction of the inquiry--uniform testimony to untruth 127-181 viii. parallels and precedents. (_invertebrate animals._) resumption of the examination--seapen--millepore- madrepore--organ-pipe--medusa--sea-urchin--feather-star- tapeworm--serpula--terebella--white-ant--goliath-beetle- gnat--case-fly--melicerta--julus--buprestis--shore-crab- barnacle--lepralia--botryllus--clavagella--prickly venus--scorpion stromb--tiger cowry--thorny murex--pearly nautilus--cuttlefish 182-239 ix. parallels and precedents. (_vertebrate animals._) examination of the vertebrata--sword-fish--gilt-head- laminæ of scales--shark--arrangement of teeth--their structure--tree-frog--metamorphosis--rattlesnake- crocodile--tortoise--laminæ of plates--skull of cassowary--peacock--humming-bird--trogon--structure and growth of feathers--whalebone of whale--horn of ibex--horn of stag--teeth of horse--of babiroussa--of hippopotamus--tusk of elephant--molars of elephant 240-273 x. parallels and precedents. (_man._) examination of primal man--blood--its formation--its oxygenation--nails--hair--bones--teeth--all formed by successive processes--stature--thyroid cartilage--beard--development of teeth--proportion of bloods--condition of skeleton--navel--false conclusion 274-291 xi. parallels and precedents. (_germs._) assumption of adult development at creation--its reasonableness--the position waived--assumption of the germ-hypothesis--double cocoa-nut--coral tree--tulip--earth-pea--mangrove--medusa--connexion of germs with parent--in echinoderms--in annelids--in insects--egg of butterfly--of nut weevil--of bots--of ichneumon--of pill chafer--of gall-fly--of lace-fly--of spider--of gipsy moth--of coccus--of saw-fly--of cockroach--of dirt-dauber--metamorphosis of star-fish--eggs attached to brachionus--viviparous progeny of rotifer--of asplanchna--of daphnia--egg-purse of shark--economy of surinam toad--egg of fowl--foetus of kangaroo--umbilicus 292-334 xii. the conclusion. uniformity of results--prochronism of organic nature--phenomena inadequate to settle chronology--historic testimony alone oracular--familiar illustration--objections met--analogy between an organism and a world--illustration from a tree--analogy between the life of a species and that of an individual--history divinely projected--grand plan of nature--diachronic existence not necessary--deceptive phenomena inseparable from created organisms--illustrations abundant--hypothesis of the life-history of the globe--supposition of 1857 being the era of creation--what its state?--minuteness and verity of proofs of life present no difficulty--coprolites--fæcal residua in newly-created animals--_cyclical_ not _organic_ condition the test of prochronism--illustrations from the inorganic world--rivers--ocean currents--celestial bodies--velocity of light--records of entities actually passed--"no tree has leaves"--plates of testudinaria--leaf-scars of palm--column of nerita--spines of murex--madreporic plate of cribella--hilum of seed--navel of mammal--argument of "great and small"--old hypothesis of _lusus naturæ_--demonstration of a law--effect of this principle on the study of geology--summing up 335-372 list of illustrations. page geological section of yorkshire 35 calymene blumenbachii 41 cephalaspis 44 labyrinthodon 57 snake-necked marine lizards 59 megalosaurus bucklandi 61 bat-lizards 62 hylæosaurus armatus 63 mammoth 74 moho 84 germination of scarlet-runner 114 diagram of bean 116 " fern 117 " hawkmoth 119 " polype 120 " cow 121 leaf-scars of tree-fern 132 roots of iriartea 139 traveller's tree 148 corm of gladiolus 153 section of lily-bulb 157 testudinaria 159 encephalartos 162 twig of tulip-tree 167 young plant of loranthus 171 silk-cotton tree 175 section of exogenous tree 179 muricated madrepore 185 organ-pipe 187 comatula and young 194 serpula 200 goliath beetle and pupa case 206 larva of case-fly 209 melicerta 210 lepas 218 botryllus 224 clavagella 226 dione veneris 228 murex tenuispina 233 scale of gilt-head 242 plates of tortoise 251 growth of a feather 254 horns of stag 258 skull of babiroussa 262 skull of hippopotamus 265 skull of elephant 267 growth of hair 278 section of human tooth 282 garden tulip 298 germination of earth-pea 300 seed of mangrove 303 lace-fly and eggs 312 brachionus with eggs 322 pregnant asplanchna 323 hen's egg 329 gyroceras 371 [greek: ho omphalos.] i. the cause. "is there not a cause?"--1 sam. xvii. 29. an eminent philosopher has observed that "nothing can be more common or frequent than to appeal to the evidence of the senses as the most unerring test of physical effects. it is by the organs of sense, and by these alone, that we can acquire any knowledge of the qualities of external objects, and of their mutual effects when brought to act one upon another, whether mechanically, physically, or chemically; and it might, therefore, not unreasonably be supposed, that what is called the evidence of the senses must be admitted to be conclusive, as to all the phenomena developed by such reciprocal action. "nevertheless, the fallacies are numberless into which those are led who take what they consider the immediate results of sensible impressions, without submitting them to the severe control and disciplined analysis of the understanding."[1] if this verdict is confessedly true with regard to many observations which we make on things immediately present to our senses, much more likely is it to be true with respect to conclusions which are not "the immediate results of sensible impressions," but are merely deduced by a process of reasoning from such impressions. and if the direct evidence of our senses is to be received with a prudent reserve, because of this possibility of error, even when we have no evidence of an opposing character, still more necessary is the exercise of caution in judging of facts assumed to have occurred at a period far removed from our own experience, and which stand in contradiction (at least apparent, _primâ facie_, contradiction) to credible historic testimony. nay, the caveat acquires a greatly intensified force, when the testimony with which the assumed facts are, or seem to be, at variance, is no less a testimony than his who ordained the "facts," who made the objects of investigation; the testimony of the creator of all things; the testimony of him who is, from eternity to eternity, "[greek: ho apseudês theos]"! i hope i shall not be deemed censorious in stating my fear that those who cultivate the physical sciences are not always sufficiently mindful of the "_humanum est errare_." what we have investigated with no little labour and patience, what we have seen with our eyes many many times, in many aspects, and under many circumstances, we naturally believe firmly; and we are very prone to attach the same assurance of certainty to the inferences we have, _bonâ fide_, and with scrupulous care to eliminate error, deduced from our observations, as to the observations themselves; and we are apt to forget that some element of error may have crept into our actual investigations, and still more probably into our deductions. even if our observations be so simple, so patent, so numerous, as _almost_ to preclude the possibility of mistake in them, and our process of reasoning from them be without a flaw, still we may have overlooked a principle, which, though perhaps not very obvious, ought to enter into the investigation, and which, if recognised, would greatly modify our conclusions. in this volume i venture to suggest such a principle to the consideration of geologists. it will not be denied that geology is a science that stands peculiarly in need of being cultivated with that salutary self-distrust that i have above alluded to. though a strong and healthy child, it is as yet but an infant. the objects on which its senses have been exercised, its [greek: ta blepomena], are indeed plain enough and numerous enough, when once discovered; but the inferences drawn from them, its [greek: bebaia], find their sphere in the most venerably remote antiquity,--an antiquity mensurable not by years or centuries, but by _secula seculorum_. and the dicta, which its votaries rest on as certitudes, are at variance with the simple literal sense of the words of god. i am not assuming here that the inspired word has been rightly read; i merely say that the plain straightforward meaning, the meaning that lies manifestly on the face of the passages in question, is in opposition with the conclusions which geologists have formed, as to the antiquity and the genesis of the globe on which we live. perhaps the simple, superficial sense of the word is not the correct one; but it is at least that which its readers, learned and unlearned, had been generally content with before; and which would, i suppose, scarcely have been questioned, but for what appeared the exigencies of geological facts. now while there are, unhappily, not a few infidels, professed or concealed, who eagerly seize on any apparent discrepancy between the works and the word of god, in order that they may invalidate the truth of the latter, there are, especially in this country, many names of the highest rank in physical (and, among other branches, in geological) science, to whom the veracity of god is as dear as life. they cannot bear to see it impugned; they know that it cannot be overthrown; they are assured that he who gave the word, and he who made the worlds, is one jehovah, who cannot be inconsistent with himself. but they cannot shut their eyes to the startling fact, that the records which _seem_ legibly written on his created works do flatly contradict the statements which _seem_ to be plainly expressed in his word. here is a dilemma. a most painful one to the reverent mind! and many reverent minds have laboured hard and long to escape from it. it is unfair and dishonest to class our men of science with the infidel and atheist. they did not rejoice in the dilemma; they saw it at first dimly, and hoped to avoid it.[2] at first they believed that the mighty processes which are recorded on the "everlasting mountains" might not only be harmonized with, but might afford beautiful and convincing demonstrations of holy scripture. they thought that the deluge of noah would explain the stratification, and the antediluvian era account for the organic fossils. as the "stone book" was further read, this mode of explanation appeared to many untenable; and they retracted their adherence to it. to a mind rightly constituted, truth is above every thing: there is no such thing as a pious fraud; the very idea is an impious lie: god is light, and in him is no darkness at all; and that religion which can be maintained only by dissembling or denying truth, cannot proceed from "him that is holy, him that is true," but from him who "is a liar, and the father of it." many upright and ardent cultivators of the young science felt that truth would be compromised by a persistence in those explanations which had hitherto passed current. the discrepancy between the readings in science and the hitherto unchallenged readings in scripture, became manifest. partisans began to array themselves on either side; some, jealous for the honour of god, knew little of science, and rushed into the field ill-prepared for the conflict; some, jealous for science, but little conversant with scripture, and caring less for it, were willing to throw overboard its authority altogether: others, who knew that the writings were from the same hand, knew therefore that there must be some way of reconciling them, and set themselves to find it out. have they succeeded? if i thought so, i would not publish this book. many, i doubt not, have been convinced by each of the schemes by which the discrepant statements have been sought to be harmonized. each of them has had sufficient plausibility to convince its propounder; and, probably, others too. and some of them have attained a large measure of public confidence. yet if any one of them is true, it certainly has not commanded universal assent. let us examine how far they agree among themselves, who propose to reconcile scripture and science, "the mosaic and the mineral geologies." and first, it is, perhaps, right to represent the opinions of those who stand by the literal acceptation of the divine word. there have been some, indeed, who refuse to entertain the question of reconciliation, taking the high ground that, as the word of god is and must be true, it is impious to set any evidence in competition with it. i cannot but say, my sympathies are far more with these than with those who, at the opposite pole of the argument, would make scientific deduction paramount, and make the word go to the wall. but, then, we ought to be quite sure that we have got the very word of god; and, so far from being impious, it seems highly proper and right, when conflicting evidence appears to flow out of what is indubitably god's _work_, to examine afresh the witnesses on both sides, that we may not make either testify what it does not. those good men who merely _denounce_ geology and geologists, i do not quote. there are the facts, "written and engraven in stones," and that by the finger of god. how can they be accounted for? some have recourse to the assumption that the natural processes by which changes in the earth's surface are now going on, may have operated in antediluvian times with a rapidity and power of which we can form little conception from what we are cognisant of. the rev. j. mellor brown takes this ground, adducing the analogies of steam-power and electricity, as effecting in a few moments or hours, what formerly would have required several days or weeks to accomplish. "god's most tremendous agencies may have been employed in the beginning of his works. if, for instance, it should be conceded that the granitic or basaltic strata were once in a state of fusion, there is no reason why we should not call in the aid of supposition to produce a _rapid_ refrigeration. we may surround the globe with an atmosphere (not as yet warmed by the rays of the newly kindled sun) more intensely cold than that of saturn. the degree of cold may have been such as to cool down the liquid granite and basalt in a few hours, and render it congenial to animal and vegetable life; while the gelid air around the globe may have been mollified by the abstracted caloric."[3] a writer in blackwood (xli. 181; xlii. 690), in like manner, adheres to the literal sense of genesis and the decalogue, and alludes to "the great agencies--the magnetic, electrical, and ethereal influences--probably instrumental in all the phenomena of nature," as being far more powerful than is generally suspected. mr. macbrair--who does not, however, appear, from the amount of his acquaintance with science, competent to judge of the physical evidence--supposes stratification to have proceeded with immense rapidity, because limestone is now deposited in some waters at the rate of six inches per annum. because a mass of timber, ten miles in length, was collected in the mississippi, in thirty-eight years, he considers that a "capital coal field" might be formed in a single century. alluvial strata are mud lavas ejected from volcanoes. the whole difficulty of fossil remains is got rid of by ignoring the distinctions of species, and assuming that the ancient animals and the recent ones are identical. the pterodactyle and the plesiosaurus he does not allude to.[4] according to dr. ure,--"the demiurgic week ... is manifestly composed of six working days like our own, and a day of rest, each of equal length, and, therefore, containing an evening and a morning, measured by the rotation of the earth round its axis.... neither reason nor revelation will justify us in extending the origin of the material system beyond six thousand years from our own days. the world then received its substance, form, and motions from the volition of the omnipotent." his theory of the stratification extends over the whole antediluvian era. he supposes that successive irruptions of the central heat broke up the primitive strata and deposited the secondary and tertiary. "the basaltic or trap phenomena lead to the conclusion that such upheavings and subversions were not confined to one epoch of the antediluvian world, but that, coeval with its birth, they pervaded the whole period of its duration.... the deluge--that universal transflux of the ocean--was the last and greatest of these terraqueous convulsions."[5] another class of this school of interpreters refers the stratification of the earth, either to the deluge alone, or to that convulsion conjoined with the one which is considered to have taken place on the third day of the mosaic narrative. perhaps the most eminent writer of this class is mr. granville penn, whose opinions may be thus condensed. he supposes that this globe has undergone only two revolutions. the first was the violent rupture and depression of the surface to become the bed of the sea, and the simultaneous elevation of the other portion to become dry land,--the theatre of terrestrial existence. this first revolution took place before the creation of any organized beings. the second revolution was at the noachic flood, when the former bed of the sea was elevated to become the dry land, with all its organic accumulations of sixteen centuries, while the former land was correspondingly depressed and overflowed. "the earth must, therefore, necessarily exhibit manifest and universal evidences of the vast apparent ruin occasioned by its first violent disruption and depression; of the presence and operation of the marine fluid, during the long interval which succeeded; and of the action and effects of that fluid in its ultimate retreat."[6] mr. fairholme[7] so nearly agrees with the above, that i need not quote his opinions in detail. another class, represented by dr. young and the rev. sir w. cockburn, dean of york, have maintained with considerable power, backed by no mean geological knowledge, that the deluge is a sufficient _vera causa_ for the stratification of the globe, and for the fossilization of the organic remains. dr. young supposes that an equable climate prevailed all over the globe in the antediluvian period. "were the highest mountains transferred to the equatorial regions, the most extensive oceans removed towards the poles, and fringed with a border of archipelago,--while lands of moderate height occupied most of the intermediate spaces, between these archipelagos and the equatorial mountains; then a temperature, almost uniform, would prevail throughout the world." this "perpetual summer" would account for the prodigious quantities of animal and vegetable remains:--every region teemed with life. at the flood, "the bed of the ocean must have been elevated, and the dry land at the same time depressed," an expansive force acting from below to heave up the ocean's bed. to this agency are attributed the vast masses of granite, gneiss, basalt, and other rocks of igneous origin, which seem to have been forced upwards in a state of fusion, into their present lofty stations. the ancient bed of the ocean may have consisted of numerous layers of sand, clay, lime, and other substances, including corals and marine shells,--to a certain degree consolidated into rocks. by the progressive rising of the waters and the currents so made, fresh materials would be conveyed to the depths of the ocean, so that the magnesian limestone, the saliferous beds, the lias, &c., would be deposited.[8] the dean of york, in like manner, considers that the convulsions produced by the deluge, are sufficient to account for all the stratification and fossil remains. that the gradual rise of the waters, and their penetration into the recesses of the rocks, would cause successive volcanic eruptions; the earlier of which would inclose marine fishes and reptiles; then others in turn, the pachyderms and great reptiles of the plains; and, finally, the creatures more exclusively terrestrial. that these repeated heavings of mighty volcanoes raised great part of what had been the bottom of the sea, above its level, and that hence the present land had been for sixteen centuries under water. that the animals which entered the ark, were not selected till after many species had already perished in the earlier convulsions, and hence the number of extinct species now exhumed.[9] my reader will kindly bear in mind that i am not examining these opinions; i adduce them as examples of the diversity of judgment that still prevails on a question which some affect to consider as settled beyond the approach of doubt. a totally different solution of the difficulty has been sought in the hypothesis, that the six "days" of the inspired record signify six successive periods of immense though of undefined duration. this opinion is as old as the fathers at least,[10] and not a few able maintainers of it belong to our own times. it has been put forth, however, with most power, by a late lamented geologist, whose wonderful vigour of description and felicity of illustration, have done, perhaps, more than the efforts of any other living man, to render his favourite science popular. perhaps i can scarcely set his views in a more striking light than he himself has done in his own peculiarly graphic report of a conversation, which he sustained with some humble inquirers in the paleontological gallery of the british museum. "i last passed," says mr. hugh miller, "through this wonderful gallery at the time when the attraction of the great exhibition had filled london with curious visitors from all parts of the empire; and a group of intelligent mechanics, fresh from some manufacturing town in the midland counties, were sauntering on through its chambers immediately before me. they stood amazed beneath the dragons of the oolite and lias; and, with more than the admiration and wonder of the disciples of old, when contemplating the huge stones of the temple, they turned to say, in almost the old words, 'lo! master, what manner of great beasts are these?' 'these are,' i replied, 'the sea-monsters and creeping things of the second great period of organic existence.' the reply seemed satisfactory, and we passed on together to the terminal apartments of the range appropriated to the tertiary organisms. and there, before the enormous mammals, the mechanics again stood in wonder, and turned to inquire. anticipating the query, i said, 'and these are the huge beasts of the earth, and the cattle of the third great period of organic existence; and yonder in the same apartment, you see, but at its farther end, is the famous fossil man of guadaloupe, locked up by the petrifactive agencies in a slab of limestone.' the mechanics again seemed satisfied; and, of course, had i encountered them in the first chamber of the suite, and had they questioned me respecting the organisms with which _it_ is occupied, i would have told them that they were the remains of the herbs and trees of the _first_ great period of organic existence. but in the chamber of the mammals we parted, and i saw them no more."[11] a large and influential section of the students of geology regard this hypothesis as untenable. generally they may be described as holding that the history which is recorded in the igneous and fossiliferous strata does not come into the sacred narrative in any shape. as, however, that narrative commences with "the beginning," and comes down to historic times, the facts so recorded must find their chronology within its bounds. their place is accordingly fixed by this school of interpretation between the actual primordial creation (gen. i. 1), and the chaotic state (ver. 2). let us hear an able and eloquent geologist, professor sedgwick, on the hypothesis just mentioned of the elongation of the six days:-"they [certain excellent christian writers on the subject of geology] have not denied the facts established by this science, nor have they confounded the nature of physical and moral evidence; but they have prematurely (and, therefore, without an adequate knowledge of all the facts essential to the argument) endeavoured to bring the natural history of the earth into a literal accordance with the book of genesis; first, by greatly extending the periods of time implied by the six days of creation; and secondly, by endeavouring to show that under this new interpretation of its words, the narrative of moses may be supposed to comprehend, and to describe in order, the successive epochs of geology. it is to be feared that truth may, in this way, receive a double injury; and i am certain that the argument just alluded to has been unsuccessful."--"we must consider the old strata of the earth as monuments of a date long anterior to the existence of man, and to the times contemplated in the moral records of his creation."[12] many able theologians, who, though well acquainted with natural science, can scarcely be considered as geologists, have been satisfied with this solution of the problem. thus sharon turner:-"what interval occurred between the first creation of the material substance of our globe, and the mandate for light to descend upon it, whether months, years, or ages, is not in the slightest degree noticed [in the sacred record]. geology may shorten or extend its duration, as it may find proper."[13] thus the present archbishop of canterbury:-"we are not called upon to deny the possible existence of previous worlds, from the wreck of which our globe was organized, and the ruins of which are now furnishing matter for our curiosity."[14] thus dr. chalmers:-"the present economy of terrestrial things was raised about six thousand years ago on the basis of an earth then without form and void; while, for aught of information we have in the bible, the earth itself may before this time have been the theatre of many lengthened processes, the dwelling-place of older economies that have now gone by, but whereof the vestiges subsist even to the present day, both to the needless alarm of those who befriend christianity, and the unwarrantable triumph of those who have assailed it."[15] thus dr. harris:-"the first verse of genesis was designed to announce the absolute origination of the material universe by the almighty creator; and, passing by an indefinite interval, the second verse describes the state of our planet immediately prior to the adamic creation; and the third verse begins the account of the six days' work."[16] thus mr. gray:-"that an antecedent state of the earth existed before the recorded mosaical epoch, will clearly come out to view by the consideration of the terms used in the second verse. there was at that period, according to the express mosaic record, anterior to the six days' reduction into order, _existing earth_ and _existing water_."[17] probably the majority of our ablest geologists, men who have devoted their lives to the study and elucidation of geological phenomena, are to be found among those who advocate this scheme of reconciling those phenomena with the statements of the holy scriptures. thus one of the earliest cultivators of the science, the rev. dr. conybeare:-"i regard gen. i. 1 as an universal proposition, intended to contradict all the heathen systems which supposed the eternity of matter or polytheism; and ver. 2 i regard as proceeding to take up our planet in a state of ruin from a former condition, and describing a succession of phenomena effected in part by the laws of nature (which are no more than our expression of god's observed method of working), and in part by the immediate exercise of divine power in directing and creating."[18] dr. hitchcock, president of amherst college, u.s., gives in his adhesion to this principle. after summing up the evidence in favour of the earth's high antiquity, he inquires, "who will hesitate to say that it ought to settle the interpretation of the first verse of genesis, in favour of that meaning which allows an intervening period between the creation of matter and the creation of light? this interpretation of genesis is entirely sufficient to remove all apparent collision between geology and revelation. it gives the geologist full scope for his largest speculations concerning the age of the world. it permits him to maintain that its first condition was as unlike to the present as possible, and allows him time enough for all the changes of mineral constitution and organic life which its strata reveal. it supposes that all these are passed over in silence by the sacred writers, because irrelevant to the object of revelation; but full of interest and instruction to the men of science who should afterwards take pleasure in exploring the works of god. "it supposes the six days' work of creation to have been confined entirely to the fitting up the world in its present condition, and furnishing it with its present inhabitants. thus, while it gives the widest scope to the geologist, it does not encroach upon the literalities of the bible; and hence it is not strange that it should be almost universally adopted by geologists, as well as by many eminent divines."[19] dr. pye smith, accepting the immense undefined interval between the event of the first verse, and the condition chronicled in the second, held the somewhat remarkable opinion that the term "earth" in that verse, and throughout the whole description of the six days, is "designed to express the part of our world which god was adapting for the dwelling of man and the animals connected with him." and that portion he conceived to have been "a part of asia, lying between the caucasian ridge, the caspian sea, and tartary on the north, the persian and indian seas on the south, and the high mountain ridges which run at considerable distances on the eastern and western flank." the whole of the six days' creation was confined, on this hypothesis, to the re-stocking, with plants and animals, of this limited region after an inundation caused by its subsidence. the flood of noah was nothing more than a second overflowing of the same region, by "an elevation of the bed of the persian and indian seas, or a subsidence of the inhabited land towards the south."[20] the author of "the protoplast" has made the very original suggestion, that the geological periods may have occurred during the paradisaical condition of man, which he thinks was of an indefinitely protracted duration, human chronology commencing at the fall. "we have no data in scripture from which to gather certain information, and adam may have lived unfallen _one day_, or _millions of years_." the years of the first man's mortal life began to be reckoned when his immortality ceased. he was nine hundred and thirty years _old_:[21] he had been nine hundred and thirty years gradually decaying, slowly dying. "it may, indeed, be said that no man could have survived those convulsions of nature, of which traces have been discovered in the earth's crust. i would reply to this;--first, that we have no reason to suppose that these changes affected the whole globe _at once_; they may have been _partial and successive_; and the world's eden may have been a spot peculiarly exempted from their influence. secondly, that adam's body before the fall was not constituted as ours now are; it was incorruptible and immortal: physical phenomena could have had no deleterious effect upon him." "why should we find any difficulty in supposing that the geological changes which appear to have passed upon the globe, _after_ its creation, and _before_ its curse, were to the first man sources of ever-renewing admiration, delight, and advantage? "inclining to the belief that both the animal fell and the animal curse were considerably antecedent to the sin of adam, i see no difficulty in the admission, that animal death may also have prevailed prior to that event."[22] while all those writers whose opinions i have cited, feel it more or less incumbent on them to seek a reconciliation between the words of inspiration and the phenomena of geology, there are not a few who decline the task altogether. some eminent in science seem, by their entire avoidance of the question, to allow judgment to go by default. others more boldly deny that the two can be accommodated. mr. babbage appears to think the archaic hebrew so insuperably obscure a language, that no confidence can be put in our constructions of its statements; an opinion which, if true, would make the revelation of god to us, with all its glorious types, and promises, and prophecies, more dubious than the readings of egyptian papyri, or the decipherment of assyrian cuneiforms. on this notion, however, dr. pye smith observes:--"all competent scholars, of whatever opinions and parties they may be in other respects, will agree to reject any imputation of uncertainty with respect to the means of ascertaining the sense of the language." others find no difficulty in understanding the hebrew, but in believing it. professor baden powell sees in the plain, unvarnished narrative of the holy spirit, only myth and poetry: it "was not intended for an historical narrative" at all; and he thinks (i hope incorrectly), that there is a pretty general agreement with his views. "most rational persons," he says, "now acknowledge the failure of the various attempts to reconcile the difficulty [between geology and scripture] by any kind of verbal interpretation; they have learnt to see that the 'six days of thousands of years' have, after all, no more correspondence with anything in geology than with any sane interpretation of the text. and that the 'immense period at the beginning,' followed by a recent literal great catastrophe, and final reconstruction in a week, is, if possible, more strangely at variance with science, scripture, and common sense. yet while they [viz. the 'rational persons,'] thus view the labours of the bible-geologists as fruitless attempts, they often do not see--," &c. &c.[23] of course this gives up the authority of scripture altogether; and, consistently enough, the author is severe upon the prevalent "indiscriminate and unthinking bibliolatry." "if in any instance the letter of the narrative or form of expression may be found _irreconcilably at variance with physical truth_,[24] we may allow, to those who prefer it, the alternative of understanding them either as religious truths, represented under sensible images, or as descriptions of events according to the preconceptions of the writers, or the traditions of the age." the author of "vestiges of the natural history of creation" propounds a theory of organic origin much more worthy of god, than that "mean view," which supposes him "to come in on frequent occasions with new fiats or special interferences." coolly bowing aside his authority, this writer has hatched a scheme, by which the immediate ancestor of adam was a chimpanzee, and his remote ancestor a maggot! * * * * * in reviewing this array of opinions, is there not sufficient ground for regarding with caution the claim to certainty which has been boldly put forth for the conclusions of geology? it cannot be denied that there is here room for a very considerable amplitude of choice among discordant hypotheses. all cannot be true, unless on the principle which was claimed for the church by the council of trent--"_cum enim ecclesia duarum expositionum ubertate gaudeat, non esse eam ad unius penuriam restrigendam!_" i do not for a moment intend to put all these hypotheses and assumptions on the same level. they vary widely as to their tenableness, and as to their prevalence. but if we leave out of view the fears of those who, from insufficient acquaintance with science, are not competent to adjudicate on its positions, and those who despise or decline biblical authority altogether on this subject, we have still a somewhat wide range to choose from. shall we accept the _antediluvian_, or the _diluvian_ stratification? the six _ages_ or the six _days_ of creation? the irruptions of internal fire that occurred chiliads _before man was made_--those during his protracted _paradisaic state_, or those at the time _of the flood_?--the extension of the mosaic record _to universal nature_, or its limitation to a region of _south-western asia_? i am not blaming, far less despising, the efforts that have been made for harmonizing the teachings of scripture and science. i heartily sympathise with them. what else could good men do? they could not shut their eyes to the facts which geology reveals: to have said they were not facts would have been simply absurd. granting that the whole truth was before them--the whole evidence--they could not arrive at other conclusions than those just recorded; and, therefore, i do not blame their discrepancy _inter se_. _the true key has not as yet been applied to the wards._ until it be, you may force the lock, but you cannot open it. whether the key offered in the following pages will open the lock, remains to be seen. ii. the witness for the macro-chronology. "you shall well and truly try, and a true deliverance make,... and a true verdict give, according to the evidence."--(_jury oath._) a high court of inquiry has been sitting now for a good many years, whose object is to determine a chronological question of much interest. it is no less than the age of the globe on which we live. counsel have been heard on both sides, and witnesses have been called, and most of the judges have considered that an overwhelming preponderance of testimony is in favour of an immeasurably vast antiquity. a single witness on the other side, however, has deposed in a contrary sense: and, though he has said but little, some of those who have heard the cause attach such weight to his testimony, that they do not feel satisfied to let it be overborne. counsel on the former side have, indeed, cross-examined the witness, and dissected his testimony with much skill, and they contend that what he said has been misunderstood by the minority; and that, as his words may at least bear a sense which would not contradict those of the opposing witness, the clear, copious, and unvarying deposition previously made, ought to command the verdict of the court. the minority are silenced, but not satisfied; they know not how to give up the witness on whose veracity they have been wont to rely; but they are unable to answer the arguments brought against him. counsel for the brachy-chronology speaks. "we respectfully ask the court for another hearing. will our learned brother permit his witness briefly to recapitulate his testimony, and we will endeavour to examine it once more; for we think we shall be able to detect some flaw in it?" rule granted. witness for the macro-chronology. the following, then, is the substance of what the witness deposes. he is not a living witness; his testimony, therefore, is not oral, but written--lithographed, in fact. it consists of a number of documents, which are couched in a language and character not to be understood without some previous study, but yet very capable of translation--very clear and unmistakeable. the following, i say, is a condensed summary of the leading points. if a curious person had watched the process of making the excavations that were preliminary to the boring of the thames tunnel, he would have observed that the labourers exposed successive layers of earth, differing much in colour, consistency, and general character. first, an accumulation of soil, consisting of decayed vegetable and animal matter, mingled with broken pottery, and other rubbish of man's production, was removed; then a layer of sand, gravel, and river mud; then a bed of reddish clay; then a layer of clay, mixed with silt or fine sandy mud; then a thin layer of silt, much filled with shells; then a stratum of stiff blue clay; then a layer of clay of more mottled character, containing a portion of silt, and some shells; then a stratum of very firm clay, so solid that it required to be broken with wedges; then a bed of gravel and sand of a green colour; and finally, a similar layer, but of a coarser texture. in the course of the hundred feet or so of perpendicular depth thus exposed, he would have seen a succession of layers, apparently deposited upon one another. but as yet he would have formed a very inadequate notion of the stratification of the earth's crust. with the knowledge thus gained, however, let him now make a little excursion into hertfordshire; we will suppose at the time when the cuttings for the great northern railway were being made. when he came near cheshunt, he would see that the london clay, which he found underlying the thames, crops out, or disappears by the stratum coming obliquely to the surface. he would see, however, another bed of clay--the plastic clay--beneath this, which now forms the superficial stratum, and continues to do so, till he gets beyond hertford. there this stratum crops out; and the chalk, which for some time he has seen to underlie the plastic clay, now comes to the surface. business or pleasure calls him to bridlington on the yorkshire coast; and he determines to make a pedestrian tour across the diameter of england to whitehaven. he soon recognises the chalk, which constitutes the wolds, and rises to about 800 feet above the sea level. below its escarpment he traces the kimmeridge clay, the uppermost of a series of strata more than 2,000 feet in thickness, that constitute the oolitic system--including, among others, the coralline oolite, the calcareous grit, the cornbrash, thin, but rich in fossils; the lower sandstone and coal of the cleveland hills, the alum shale, the marlstone, and the lower lias shale. then comes a stratum of the saliferous system or the new red sandstone, with the red marls, perhaps not much short of a thousand feet deep. below them the observer finds the strata of the magnesian limestone formation, for nearly 400 feet, resting on the great coal formations of vast depth. of these the coal field of the west riding is not less than 4,000 feet in depth, and beneath it lie the millstone grit, and the mountain limestone, 2,500 feet more, the latter displayed in noble grandeur on the faces of those wall-like precipices that inclose the romantic dales of the swale and the ure, and that subsequently tower in magnificent altitude on the sides of pennygant and ingleborough. [illustration: geological section of yorkshire.] on the western escarpment of the pennine ridge, just as the traveller is entering westmoreland, he would detect the bottom of the limestone; and here he would have an opportunity of seeing, what is rare in these parts, a stratum of the old red sandstone, lying between the former and the slaty rocks of the cumbrian formations. and here at length, in the wild and magnificent scenery of these mountains, he sees the primitive and transition series, the greenstone, the sienite, and the granite, each of which is discernible in succession on the face of one or other of the lofty fells of cumberland. our traveller now comes home, and, musing on what he has seen, counts up some thirty or more distinct strata lying in regular succession one on another. but he has not seen all the world, nor even all england; but he reads the results of many independent observations, and finds that while, for the most part, the strata which he has seen are common to the whole surface of the globe, and while the order of their superposition is invariable everywhere, others are in some parts added, while perhaps some of those which he has observed are locally absent. thus he is able to form a more distinct idea of the stratification of the earth's crust as a whole. it is composed of about forty distinct formations, generally increasing in thickness as we go downwards, so that the whole cannot be much less than ten miles in depth, supposing them in any locality to be all present, and to be lying in the horizontal plane. mathematicians have satisfactorily determined that the mean density of the globe is about five-and-a-half times that of water, or about twice that of granite, a fact inconsistent with any other supposition than that the interior is occupied by substances maintained in a fluid state by intense heat. the lowest point that has yet been patent to human observation is occupied by the granite, a compound rock, which bears evident marks of having been once in a state of fusion, and of having cooled slowly, and that under immense pressure, contracting and crystallizing as it parted with its heat. there is every reason to believe that the granite is not defined at its inferior surface, but that it merges into the molten mass, probably still solidifying. after the outer portion of the granite had cooled sufficiently to become solid, there is evidence that it was covered by water, agitated by powerful currents, and probably in a heated state. the action of these currents disintegrated the rock, and deposited the constituent substances at the bottom of the sea--on the surface, and in the hollows, of the granite. for there is reason to think that the contraction of the primitive rock in the process of cooling, produced irregular undulations or crumplings of the surface, and frequent fractures and dislocations, elevating some parts and depressing others. the gneiss, the mica-schist, and the clay-slate, which are found immediately overlying the granitic rock in strata of vast thickness, are but the components of granite, separated and rearranged. "if we imagine common granite coarsely pounded, and thrown into a vessel of water, it will arrange itself at the bottom of the vessel in a condition very much like that of gneiss, which is indeed nothing else than stratified granite. if the water in which the pounded rock is thrown is moving along at a slow rate, and the clayey portion of the granite, called _felspar_, happens to be somewhat decomposed, as it often is, then the felspar (which is so truly _clay_ that it makes the best possible material for the use of the potteries) and the thin shining plates of mica, will be carried further by the water than the lumps of white quartz or flint sand, which, with the other two ingredients, made up the granite; and the two former will be deposited in layers, which, by passing a galvanic current through them, would in time become mica-schist. if the mica were absent, or if the clay were deposited without it, owing to any cause, then a similar galvanic current would turn the deposit into something like clay-slate."[25] the deposition of these strata, being formed out of granite, supposes the pre-existence of that rock; and as they occur in vast thicknesses, even of many thousand feet, then separation, deposition, and reconsolidation must have occupied, however rapidly we may suppose the processes to have been accomplished, considerable periods of time. in these lower rocks, no trace of organic remains has been found. the shoreless ocean that covered the cooling surface of the earth's crust, harboured no polype or sponge, no rhizopod or infusorium, and the angles and clefts of the granite were fringed by no fucus, or conferva: all was waste and void. and if certain parts were elevated above the waters, the bleak and barren points were not clothed with grass, or moss, or even a lichen, and no animal wandered over their ridges. or, if such did exist, either in land or water, all vestiges of their presence have been destroyed by the agency of the intense heat that subsequently prevailed. but, in the numerous strata that overlie the rocks of granitic origin, there are found, in varying abundance, proofs that, when they were deposited, the surface of our earth had become the abode of organic life. zoophytes lived in the ocean, some of which were engaged in secreting lime from the water, and depositing it in coral-reefs; stalked and jointed star-fishes waved like lilies of stone from the submerged rocks; sea-worms twined over the mud; mailed crustaceans swam to and fro; and mollusks, both bivalve and univalve, crawled over the ledges or reposed in the crevices. the remains of these occur in the silurian rocks that lie immediately on the primitive granitic formations of cumberland and north wales. the construction of the coral-reefs of that deposit, in particular, must have occupied a lengthened period, continuing to go on, "month after month, year after year, century after century, until at length the depth changed, in which they could most conveniently live, or, owing to some other cause, their labours were brought to a close, and they disappeared from amongst existing species."[26] [illustration: a trilobite. (_calymene blumenbachii._) _a._ extended; back view. _b._ rolled up; side view. _c._ rolled up; front view.] not a single species, or even a single genus of those early strata, is identical with any that exists now. the coral-polypes, for instance, while allied to ours, are quite distinct from them, though endowed with similar powers and habits, so that we may reason from analogy on the laws of their deposits. the trilobites were allied to the tiny water-fleas (_entomostraca_) of the present day: like the _oniscidæ_ (wood-lice, buttons, &c.) of our gardens, they had the habit of rolling their plated bodies into a ball. these are found in great numbers, their remains often heaped on one another. the mollusca of those seas were chiefly of the class _cephalopoda_--one of the least populous now-a-days, but then existing in vast number and variety; the brachiopoda, conchifera, and gastropoda, were, however, well represented also. such were the inhabitants of the sea during the silurian period, in which a series of solid deposits were made, the aggregate, probably, exceeding 50,000 feet in thickness. each deposit, though not more than a few inches in depth, "is provided with its own written story, its sacred memoranda, assuring us of the regularity and order that prevailed, and of the perfect uniformity of plan." over all these, however, we see laid the strata of the devonian system, especially the old red sandstone, which in some places attains a thickness of 10,000 feet. it is composed of a coarse agglomeration of broken fragments of the old granitic rocks, rolled and tossed about, apparently by the ever-breaking waves of shingle-beaches, until the hardest stones are worn into rounded pebbles by long and constant attrition. an examination of the old red sandstone, as is seen in herefordshire, will aid us in forming a notion of the time required for its production. it is composed of fragments obtained by the disintegration of more ancient rocks, which, by a long process of rolling together in a breaking sea, or in the bed of a rapid current, have lost all their angles. the pebbles, thus worn, have at length settled,--the heaviest lowest,--and the whole has been consolidated into firm rock. "in many places," says dr. pye smith, "the upper part of this vast formation is of a closer grain, showing that it was produced by the last and finest deposits of clayey and sandy mud, tinged, as the whole is, with oxides and carbonates of iron, usually red, but often of other hues. but, frequently, the lower portions, sometimes dispersed heaps, and, sometimes, the entire formation, consist of vast masses of conglomerate, the pebbles being composed of quartz, granite, or some other of the earliest kinds; and thus showing the previous rocks, from whose destruction they have been composed. let any person first acquire a conception of the extent of this formation, and of its depth, often many hundreds, and, sometimes, two or three thousand feet; (but such a conception can scarcely be formed without actual inspection;) then let him attempt to follow out the processes which the clearest evidence of our senses shows to have taken place; and let him be reluctant and sceptical to the utmost that he can, he cannot avoid the impression that ages innumerable must have rolled over the world, in the making of this single formation."[27] here, fishes are added to the invertebrate animals. a sort of shark with the mouth terminal, instead of beneath the head, was the earliest representative of this class. but closely following on this, were some curious species, enveloped in plate mail, and remarkable for the singularity of their forms, as the _cephalaspis_ and the _pterichthys_. [illustration: cephalaspis.] this great period passed away, and was succeeded by that of the carboniferous deposits, indicative of a vast change in the physical character of the earth's surface and atmosphere. this change of character may be briefly summed up as consisting of an immense abundance of lime in the ocean, and of an equally vast charge of carbonic acid in the atmosphere. strata of limestone, 2,500 feet in thickness, were accumulated in the ocean by the labours of coral-polypes, allied to, but totally distinct from, those which had previously existed in the primary system. on the floor of a shallow sea, which then occupied the middle of what is now england, the coral reefs rose perpetually towards the day, atom by atom, the strata on which they were founded slowly and steadily sinking ever to a lower level, while successive generations of the industrious zoophytes wrought upwards, to maintain their position within reach of the light and warmth. what period of time was requisite for the aggregation of coral structure to the perpendicular thickness of 2,500 feet? while this was going on, other invertebrata were living in the shallow seas, mostly differing from the older species, which had become by this time extinct. encrinites and sea-urchins existed; some _foraminifera_ were astonishingly abundant; the _cephalopoda_ and the _brachiopoda_ presented a vast variety of species; and about seventy sorts of fishes, mostly sharks, characterised the age. on the coral limestone lies a sort of conglomerate, known as the millstone grit; and on this is laid that source of britain's eminence, the _coal_. the coal measures of south wales are estimated at 12,000 feet in thickness. the profusion of vegetable life that must have combined to make the coal in these, has no parallel in this age; no, not in the teeming forests of south america, or the great isles of the oriental archipelago. the circumstances which favoured this enormous development of plants, seem never to have been repeated in subsequent ages, since the coal measures which are found in the later strata are thin and inconsiderable, compared with those we are considering. m. adolphe brogniart suggests that in this period, from some source or other, carbonic acid was generated in vast abundance; or, at least, that it existed in the air, in a far greater proportion than it does now; and it is singularly confirmatory of his view, that terrestrial animals, to which this gas is fatal, have left almost no traces of their existence, during the age of these vast forests--a circumstance otherwise strange and unaccountable. "those parts," says mr. ansted, "of the great carboniferous series which generally include the beds of coral, consist of muddy and sandy beds, alternating with one another, and with the coal itself. some of them would appear to be of fresh-water, and some of marine origin; and they abound, for the most part, with remains of the leaves of ferns and fern-like trees, together with the crushed trunks of these and other trees, whose substance may have contributed to form the great accumulations of bituminised and other vegetable carbon obtained from these strata. "it is not easy to communicate such an idea of beds of coal as shall enable the reader to understand clearly the nature of the circumstances under which they may have been deposited, and the time required for this purpose. the actual total thickness of the different beds in england varies considerably in different districts, but appears to amount, in the lancashire coal-field, to as much as 150 feet. in north america there is a coal-field of vast extent, in which there appears at least as great a thickness of workable coal as in any part of england; while in belgium and france the thickness is often much less considerable, although the beds thicken again still further to the east. "but this account of the thickness of the beds gives a very imperfect notion of the quantity of vegetable matter required to form them; and, on the other hand, the rate of increase of vegetables, and the quantity annually brought down by some great rivers, both of the eastern and western continents, is beyond all measure greater than is the case in our drier and colder climate. certain kinds of trees which contributed largely to the formation of the coal, seem to have been almost entirely succulent, and capable of being squeezed into a small compass during partial decomposition. this squeezing process must have been conducted on a grand scale, both during and after the formation of separate beds; and each bed in succession was probably soon covered up by muddy and sandy accumulations, now alternating with the coal in the form of shale and grit-stone. sometimes, trunks of trees caught in the mud would be retained in a slanting or nearly vertical position, while the sands were accumulating round them; sometimes the whole would be quietly buried, and soon cease to exhibit any external marks of vegetable origin.[28] "to relate the various steps in the formation of a bed of coal, and the gradual superposition of one bed upon another, by which at length the whole group of the coal-measures was completed, would involve an amount of detail little adapted to these pages; and when it is remembered that the woody fibres, after being deposited, had to be completely changed, and the whole character of the vegetable modified, before it could be reduced to the bituminous, brittle, almost crystalline mineral now dug out of the earth for fuel, it will rather seem questionable whether the origin of coal was certainly and necessarily vegetable, than reasonable to doubt the importance of the change that has taken place, and the existence of extraordinary means to produce that change. nothing, however, is more certain than that all coal was once vegetable; for in most cases woody structure may be detected under the microscope; and this, if not in the coal in its ordinary state, at least in the burnt ashes which remain after it has been exposed to the action of heat, and has lost its bituminous and semi-crystalline character. this has been too well and too frequently proved by actual experiment, to require more than the mere statement of the fact."[29] an eminent practical geologist thus essays to guess the age of the coal-fields, and of the sandstone that underlies it. "the great tract of peat near stirling has demanded [for its formation] two thousand years; for its registry is preserved by the roman works below it. it is but a single bed of coal. shall we multiply it by 100? we shall not exceed,--far from it,--did we allow 200,000 years for the production of the coal-series of newcastle, with all its rocky strata. a scottish lake does not shoal at the rate of half a foot in a century; and that country presents a vertical depth of far more than 3,000 feet in the single series of the oldest sandstone. no sound geologist will accuse a computer of exceeding, if he allow 600,000 years for the production of _this series alone_. and yet what are the coal deposits, and what the oldest sandstone, compared to the entire mass of the strata?"[30] the conjecture, that the whole of the vegetable material now constituting the coal, was the growth of the antediluvian centuries, and that it was floated away and deposited by the flood, is untenable. in not a few instances trunks are found broken, and worn by water-action; but the great mass warrants the conclusion that trees of vast dimensions and of close array--dense, majestic forests, such as now occur only in the most humid regions of the tropics--were submerged in their native abodes, lying where they fell, and where they have left the impressions, side by side, on the upper and under surfaces of the shale, of their delicate peculiarities of structure, which would have been totally obliterated, if the trees had been sea-borne and shore-rolled, as pretended. the result of a careful and minute examination of the phenomena of coal, by mr. binney, is, that the vegetable matter now forming coal had grown in vast _marine_ swamps, subjected to a series of _subsidences_ with long intervals of repose; that the trees, and perhaps smaller plants, were submerged under _tranquil_ water, in the places of their growth; and that very inconsiderable portions, if any, of the beds, are owing to drifting.[31] while the coal was in process of deposition, the sea was occupied with invertebrata, not widely differing from those which had marked the previous eras. fishes, however, were advancing in development; and several new and strange forms, some of them of gigantic dimensions and formidable armature, were introduced. these were chiefly remarkable for their affinities with reptiles (whence they are often called _sauroid_ fishes); and one of them--_megalichthys_--was famished with jaws of serried teeth, surpassing those of the crocodile. with these were associated other and more ordinary fishes; and swarms of sharks of many species, and varying much in size, roved through the sea, maintaining the same pirate character as their representatives of our modern seas--fierce, subtle, voracious, and powerful. at this time, too, appeared the earliest reptiles, chiefly of the amphibia sub-class. some of these are known only by their foot-prints; and the late hugh miller has graphically described the appearance of some of these, which, he met with marking the roof of a coal-mine, four hundred feet below the surface. these must have been _batrachia_ of large size, as the fore feet were thirteen inches apart across the breast.[32] they will be alluded to again. with these exceptions, remains of terrestrial animals are, as has already been observed, rare in this formation. iii. the witness for the macro-chronology. (continued.) "always distrust very plain cases: beware lest a snake suddenly start out upon you, in the shape of some concealed and utterly unexpected difficulty."--warren: _law studies_. we have hitherto been considering the strata as if they had remained permanent when once deposited, subject to no change, save the successive superposition of other strata upon them. but this is very far from being true. enormous displacements, upheavings, contortions, and fractures, are observed in the strata, which tell of mighty forces having been at work upon them after their formation. the explanation of these phenomena is due to the internal heat, which ever and anon seems to concentrate its action on some special point, seeking and finding vent for itself by some alteration in the already consolidated crust. sometimes, the mode of action has been the transmission of undulations through the crust, producing earthquakes, cracking and forcing apart strata already petrified, and bending and variously contorting those that have but partially become solid. sometimes, the fiery impulse is sufficiently concentrated to break through the superincumbent materials, forcing a passage for the molten and incandescent rock, which then flows forth from the surface, penetrates into the cracks and fissures of the fractured strata, and frequently spreads into the hollows and over the summits of the latest formations. it is owing to such causes as these, that we find the rocky layers so often inclined at various angles to the horizon, instead of being parallel to it, as they would be of course deposited; occasionally standing quite perpendicularly, and even to a small extent reversed. the outcropping of formations, the long lines of cliff running across a country in parallel series, ("crag and tail,") the dipping of strata from some central point or ridge, and the non-correspondence between the bottom of one stratum and the top of the underlying one,--are all phenomena of this sort of powerful action, which has been more or less energetic at all periods. after the deposit of the old red sandstone, the internal fire appears to have enjoyed a lull of its energy, if not a complete cessation, until the coal measures were complete. then the long tranquility was again broken, and concussions so extensive and violent ensued, that hardly a single square mile of country can anywhere be found which is not full of fractured and contorted strata, the record of subterranean movements, which mostly occurred between the carboniferous and the premian deposits. the effects of these convulsions were manifest in the changed relations of land and sea, existing continents and islands being dislocated, severed, and swallowed up, while others were elevated from the depths of the previous ocean. it was from the wave-worn materials thus obtained from pre-existing strata, that the new red sandstone was consolidated. it consists chiefly of sand and mud, with few organic remains; and the hiatus thus found, in animals and vegetables, seems to be almost a complete one between the organisms of the preceding and the succeeding periods. the most interesting traces of the earth's tenants during the new red formation, consist of foot-tracks impressed by the progress of animals along the yielding mud between the ranges of high and low tide. they afford a remarkable example (not, i think, sufficiently dwelt on) of the extreme rapidity with which deposits were consolidated; since the tracks must have been made, and the material consolidated, during the few hours, _at most_, that intervened between the recess and the reflux of the tide; since, if the mud had not so soon become solid, the flow of the sea would have instantly obliterated such marks, as it does now on our shores. [illustration: labyrinthodon pachygnathus.] the principal animal, whose foot-prints have been identified, was an enormous frog (_labyrinthodon_), as big as a hippopotamus, but apparently allied, in its serried teeth, and in the bony plates with which it was covered, to the crocodiles, which were its associates. it is curious that marks in the same material have chronicled the serpentine trail of a sea-worm, the scratchings of a crab, the ripple of the wavelets, and even the drops of a passing shower; the last revealing, by their margins, the direction of the wind by which the slanting rain was driven. if the triassic formations display but little evidence of organic existence, the lack is supplied by the abundance of such records, which is contained in the oolitic system, and specially in its lowest component,--the lias. animals now existed in profusion, but of species which were for the most part peculiar. the coral-making polypes existed not (or very rarely) in the seas of that age, but lime was secreted by an unusual number of crinoid echinoderms, which seem to have fringed the rocks and floating pieces of timber, much as barnacles do now. among the mollusca now began to appear the inhabitants of those very elegant shells, the _ammonites_, allied to the nautilus of our southern seas, which may be considered as the lingering representative of those swarms of shelled cephalopoda. they were accompanied by their near relations, the _belemnites_, more resembling a cuttle, with a long internal, pointed shell. fishes, chiefly belonging to a curiously armed tribe of sharks, together with some enclosed in bony-mail like pavement, were present in the shallows, where the lias was probably deposited. [illustration: snake-necked marine lizards. _plesiosaurus dolichodeirus_ and _p. macrocephalus_.] but the most characteristic animals were great marine reptiles, of strange and uncouth forms, to which the present world presents us no known analogy. one of these was the _ichthyosaurus_, which closely resembled a porpoise in form, but thirty or forty feet in length, with a vertical fish-like tail, and two pairs of paddles; a mouth set with stout crocodilian teeth, and enormous eyes. another form was that of the _plesiosaurus_, scarcely less in size than its fellow, which in the outline of its body it resembled: it was distinguished, however, by an extraordinary length of neck, slender and swan-like, consisting of thirty or forty vertebræ. it adds to the interest of these great marine reptiles, that around their fossil skeletons are preserved pellets of excrement (known as coprolites) containing fragments of bone, teeth, and scales of fishes, which clearly reveal the nature of their food. in some instances, the stomach and intestines of these great carnivorous creatures, filled with half-digested food, have left indubitable traces of their presence _in situ_. again, the geography of the globe changed. new lands arose from the sea, and old lands partially or wholly sank. the german ocean, and part of western europe, of our maps, were a great group of islands. the oolitic formation was deposited. the general character of the organization of this period differed little from that of the lias. new forms of plants, such as _cycadeæ_, were abundant, with, considerable numbers of corals, encrinites, sea-urchins and mollusks. macrurous crustacea, much like those of our times (but essentially different in species), inhabited the sea, and some beetles and flies represented the insects of the land. the fishes and marine reptiles were pretty much the same with those of the lias, though they received some important additions. [illustration: megalosaurus bucklandi.] it is, however, among the terrestrial vertebrata that we must look for the characteristic organisms of this age. and these are, still, reptiles. the huge _megalosaurus_, with a body as big as an elephant's, stood high on his legs, and stretched open a pair of gaping jaws, set with jagged teeth. the _pterodactyles_ flew about,--carnivorous lizards, with the body and wings of bats,[33] except that the membrane was stretched upon the enormously developed little finger;--creatures, perhaps, the most unlike to anything familiar to us, of all fossil forms. and, in the marshy margins of the great river valley which formed the wealden of our south-eastern districts, the giant _iguanodon_, and his fellow, the _hylæosaurus_, waged their peaceful warfare on the succulent plants that became their unresisting prey. [illustration: bat-lizards. _pterodactylus crassirostris_, and _p. brevirostris_.] [illustration: hylæosaurus armatus.] the circle of animal life was completed in this epoch, thus far, that every class was represented by some one or more of its constituent species. no fossil skeletons of birds have, indeed, been found so low as the oolite, but numerous foot-prints of some of the grallatores are found in a sandstone of this period; and in the stonesfield slate, which is contemporary with it, a genus of mammalia has been discovered,--a small marsupial, allied to the opossums of america. the duration of the oolitic period must have been considerable. "the lias sea-bottom was succeeded first by a sandy, and then by a calcareous deposit, and the animals were modified accordingly." the deposit of carbonate of lime, which took place under circumstances that caused it to attract around its nodules the organic particles, whence the name _oolite_ (egg-stone) is derived, was not continuous, but repeated at intervals. the shells of mollusks were developed in great abundance, and accumulations of these formed thick bands, which consolidated into layers of shell-limestone. three hundred feet of strata, largely composed of organic remains, were formed before the clay was deposited which made the stonesfield and contemporaneous slates. once more the dry land sank, probably by slow successive subsidences, and the sea flowed many fathoms deep above the great european archipelago. and upon its quiet bottom settled down, first a few sandy and clayey beds, and then the great layer of the chalk. creatures of very minute size and low grades of organization were now playing a very important part. a large portion of the lime that was deposited, in the form of a pure carbonate, was doubtless supplied by the coral structures, which, were exceedingly numerous; the polypidoms being gnawed down by strong-jawed fishes that fed upon the zoophytes. _foraminifera_ also were abundant, and contributed to the supply. nodules of flint exist in the chalk, sometimes scattered, sometimes arranged in bands. two sources are indicated for this substance. one is sponge, the most common kinds of which are composed of skeletons of siliceous spicula; and these can be discerned with the microscope in the interior of the chalk-flints. but millions upon millions of infusoria swam through the waters, and many of these were encased in siliceous loricæ, while the rocks and sea-weeds were fringed with as incalculably numerous examples of siliceous _diatomaceæ_, whose elegant forms are recognisable without difficulty throughout the chalk. the inconceivable abundance of these forms may be illustrated by the often-cited fact, that whole strata of solid rock appear to be so exclusively composed of their solid remains, that a cube of one-tenth of an inch is computed by ehrenberg to contain five hundred millions of individuals. the increase of these organisms is very rapid, and their duration proportionately short; but allowing for this, what period would elapse before the successive generations of entities, of which forty-one thousand millions are required to make a cubic inch, would have accumulated into solid strata fourteen feet in thickness? without pausing to examine the whole cretaceous fauna, we may observe that the mollusca with chambered shells--the ammonites and their allies--were developed in singular variety and profusion during this period, after which they suddenly disappeared from the ocean. the fishes present little that is remarkable; of birds, few, and of mammals, no remains exist; and the reptiles, while not absolutely extinct, are few and rare. one great marine form, however, the _mosasaurus_, was added to their number. at length the sea ceased to deposit chalk, and its bed appears to have been slowly elevated, until all the animals that had inhabited the waters of that formation were destroyed; so that their race and generation perished.[34] the grand epoch of secondary formations was closed. it was followed by an extensive disruption of the then existing strata, and by changes and modifications so great as to alter the whole face of nature. "it would appear that a long period of time elapsed before newer beds were thrown down, since the chalky mud not only had time to harden into chalk, but the surface of the chalk itself was much rubbed and worn." during this protracted period, eruptions of molten rock occurred of enormous extent, producing the basaltic formation which covers the chalk in the north of ireland, and in some of the hebrides. in the south of europe the pyrenees were elevated, and the apennines and carpathians were pushed to a greater altitude than before, if they were not then formed. the alps and the caucasus also experienced a series of upward movements, continuing through a considerable range of the tertiary epoch. the rich collections of vegetable remains--chiefly fruits and seeds--that have been made from the london clay, show that the earliest land of this period was clothed with a great abundance and variety of plants; and these are of such alliances as would now require a tropical climate. many species of palms, screw-pines, gourds, _piperaceæ_, _mimoseæ_, and other _leguminosæ_, _malvaceæ_, and _coniferæ_, dropped their woody pods and fruits where now these pages are written; and the animals manifest no less interesting an approximation to existing forms than the plants. the zoophytes, the echinoderms, the foraminifera, the worms, the crustacea, the mollusca, the fishes and the reptiles of the eocene beds, exhibit a great preponderance of agreement with those that now exist, _so far as genus is concerned_, though the _species_ are still almost wholly distinct. the approximation is particularly marked in the molluscous sub-kingdom, by the almost entire disappearance of the hitherto swarming brachiopod and cephalopod forms, and the progressive substitution for them of the _conchifera_ and _gastropoda_, which had, however, throughout the secondary epoch, been gradually coming forward to their present predominance in nature. among the fishes, the placoid type was diminished in number; and those that were produced were mostly sharks and rays, of modern genera; but the chief difference was the paucity of those mailed forms (ganoids), which were so abundant during the oolitic period. on the other hand, the ctenoid and cycloid forms, which had begun to make their appearance in small numbers in the chalk, are well represented. in both this deficiency and this plenitude, there is a very decided approach to existing conditions; for the ganoids are almost unknown with us, while the last-named two orders are abundant. representatives of our perches, maigres, mackerels, blennies, herrings, and cods, were numerous; _distinct, however, from the present species_. but not a single member of the great salmon family was yet introduced. the great saurian reptiles had entirely disappeared, and were quite unrepresented in the tertiary beds, except by a crocodile or two, and a small lizard. turtles were, however, numerous, both of the marine and lacustrine kinds; and there is an interesting stranger, in the form of a large serpent, allied to our pythons, some twenty feet in length. birds and mammals began now to assume their place on the land. the london clay presents us with a little vulture; and the paris basin contains remnants of species representing the raptores, the rasores, the grallatores, and the natatores. the quadrupeds came in in some force; not developed from the lowest to the highest scale of organization; for the monkey and the bat occur in sands, certainly not later, if not earlier, than the london clay, contemporaneously with the racoon, and before the existence of any rodent or cetacean. some carnivora, as the wolf and the fox, roamed the woods, but the character of the epoch was given by the pachyderms. these, however, were not the massive colossi that browse in the african or indian jungles of our days; no elephant, no rhinoceros, no hippopotamus was as yet formed. but several kinds of tapir wallowed in the morasses; and a goodly number of largish beasts, whose affinities were with the pachydermata, while their analogies were with the ruminantia, served as substitutes for the latter order, which was wholly wanting. these interesting quadrupeds, forming the genus _anoplotherium_, were remarkable for two peculiarities,--their feet were two-toed, and their teeth were ranged in a continuous series, without any interval between the incisors and the molars. they varied in size from that of an ass to that of a hare. the physical conditions of our earth, when it was tenanted by these creatures, is thus described:--"all the great plains of europe, and the districts through which the principal rivers now run, were then submerged; in all probability, the land chiefly extended in a westerly direction, far out into the atlantic, possibly trending to the south, and connecting the western shores of england with the volcanic islands off the west coast of africa. the great mountain chains of europe, the pyrenees, the alps, the apennines, the mountains of greece, the mountains of bohemia, and the carpathians, existed then only as chains of islands in an open sea. elevatory movements, having an east and west direction, had, however, already commenced, and were producing important results, laying bare the wealden district in the south-east of england. the southern and central european district, and parts of western asia, were the recipients of calcareous deposits (chiefly the skeletons of _foraminifera_), forming the apennine limestone; while numerous islands were gradually lifted above the sea, and fragments of disturbed and fractured rock were washed upon the neighbouring shallows or coast-lines, forming beds of gravel covering the chalk. the beds of nummulites and miliolites, contemporaneous with those containing the sheppey plants and the paris quadrupeds, seem to indicate a deep sea at no great distance from shore, and render it probable that there were frequent alternations of elevation and depression, perhaps the result of disturbances acting in the direction already alluded to. "the shores of the islands and main land were, however, occasionally low and swampy, rivers bringing down mud in what is now the south-east of england, and the neighbourhood of brussels, but depositing extensive calcareous beds near paris. deep inlets of the sea, estuaries, and the shifting mouths of a river, were also affected by numerous alterations of level not sufficient to destroy, but powerful enough to modify, the animal and vegetable species then existing; and these movements were continued for a long time."[35] after the elevation of the mountain summits of europe above the sea, and while the same causes were still in operation, deposits were being made in the narrow intervening seas of the archipelago, such as the present south of france, the valleys of the rhine and danube, the eastern districts of england and portugal. these deposits were partly marine and partly lacustrine; the former consisting largely of loose sands, mingled with shells and gravel. in switzerland is a thick mass of conglomerate; and in the district around mayence, there is a series of fresh-water limestones, and sandstones charged with organic remains. the changes which took place during this comparatively recent epoch were not sudden, but gradual; the results of operations which were probably going on without intermission, and perhaps have not yet ceased. the land was more and more upheaved, till at length, what had been an archipelago of islands became a continent, and europe assumed the form which it bears on our maps. the most interesting addition to the natural history of the miocene, or middle tertiary period, was the _dinotherium_--a huge pachyderm, twice as large as an elephant, with a tapir-like proboscis, and two great tusks curving downward from the lower jaw. it was, doubtless, aquatic in its habits, and possibly (for its hinder parts are not known), it may have been allied to the dugong and manatee, those whale-like pachyderms, with a broad horizontal tail, instead of posterior limbs. other great herbivorous beasts roamed over the new-made land. the mastodons, closely allied to the elephant, had their head-quarters in north america, but extended also to europe. and the elephants themselves, of several species, were spread over the northern hemisphere, even to the polar regions. the hippopotamus, the rhinoceros, and other creatures, now exclusively tropical, were also inhabitants of the same northern latitudes. [illustration: mammoth.] from some specimens of elephants and rhinoceroses of this period, which seem to have been buried in avalanches, and thus to have been preserved from decomposition, even of the more transitory parts, as muscle and skin, we learn something of the climate that prevailed. the very fact of their preservation, by the antiseptic power of frost, shows that it was not a tropical climate in which they lived; and the clothing of thick wool, fur, and hair, which protected the skin of the mammoth, or siberian elephant, tends to the same conclusion. at the same time, those regions were not so intensely cold as they are now. for the district in which the remains of elephants and their associates are found, in almost incredible abundance, is that inhospitable coast of northern asia which bounds the polar sea. the trees of a temperate climate--the oak, the beech, the maple, the poplar, and the birch--which now attain their highest limit somewhere about 70° of north latitude, and there are dwarfed to minute shrubs, appear then to have grown at the very verge of the polar basin; and that in the condition of vast and luxuriant forests, perhaps occupying sheltered valleys between mountains whose steep sides were covered with snow, already become perennial, and ever and anon rolling down in overwhelming avalanches, such as those which now occasionally descend into the valleys of the swiss alps. the coast of suffolk displays a formation known as the crag--a local name for gravel--which rests partly on the chalk; but, as it lies in other parts over the london clay, it is assigned to the later tertiary, or what is called the pleiocene period. it is divided into the _coralline_ and the _red_ crag, the latter being uppermost where they exist together, and therefore being the more recent. the coralline crag is nearly composed of corals and shells, the former almost wholly extinct now; but the latter containing upwards of seventy species still existing in the adjacent seas. the red crag contains few zoophytes, but is remarkable for the remains of at least five species of whales. other mammalia occur in this formation, among which are the red deer and the wild boar of modern europe. the gradual but rapid approximation of the tertiary fauna to that of the present surface is well indicated by mr. lyell's table (1841) of recent and fossil species in the english formations:- per-centage no. of periods. localities. of fossils recent. compared. eocene {london and hampshire } 1 or 2 400 miocene {red and coralline } 20 to 30 450 { crag, suffolk } older pleiocene {mamaliferous or norwich } 60 to 70 111 { crag } newer pleiocene {marine strata near } 85 to 90 160 { glasgow } post pleiocene {fresh-water of the valley} 99 to 100 40 { of the thames } it is to this period that are assigned the animals whose bones are found in astonishing numbers in limestone caverns, as, for example, that notable one at kirkdale, in yorkshire, which was examined by professor buckland. this is a cave in the oolitic limestone, with a nearly level floor, which was covered with a deposit of mud, on which an irregular layer of sparry stalagmite had formed by the dripping of water from the low roof, carrying lime in solution. beneath this crust the remains were found. of the animals to which the bones belonged, six were _carnivora_, viz. _hyæna_, _felis_, bear, wolf, fox, weasel; four _pachydermata_, viz. elephant, rhinoceros, hippopotamus, horse; four _ruminantia_, viz. ox, and three species of deer; four _rodentia_, viz. hare, rabbit, water-rat, mouse; five birds, viz. raven, pigeon, lark, duck, snipe. the bones were almost universally broken; the fragments exhibited no marks of rolling in the water, but a few were corroded; some were worn and polished on the convex surface; many indented, as by the canine teeth of carnivorous animals. in the cave the peculiar excrement of hyænas (_album græcum_) was common; the remains of these predacious beasts were the most abundant of all the bones; their teeth were found in every condition, from the milk-tooth to the old worn stump; and from the whole evidence dr. buckland adopted the conclusion, in which almost every subsequent writer has acquiesced, that kirkdale cave was a den of hyænas during the period when elephants and hippopotami (not of existing species) lived in the northern regions of the globe, and that they dragged into it for food the bodies of animals which frequented the vicinity.[36] thus in these spots we find, observes professor ansted, "written in no obscure language, a portion of the early history of our island after it had acquired its present form, while it was clothed with vegetation, and when its plains and forests were peopled by many of the species which still exist there; but when there also dwelt upon it large carnivorous animals, prowling about the forests by night, and retiring by day to these natural dens." in our own country, and in many other parts of the world, we find fragments of stone distributed over the surface, sometimes in the form of enormous blocks, bearing in their fresh angles evidence that they have been little disturbed since their disruption, but sometimes much rubbed and worn, and broken into smaller pieces, till they form what is known as gravel. in many cases the original rock from which these masses have been separated does not exist in the vicinity of their locality; and it is not till we reach a distance, often of hundreds of miles, that we find the formation of which they are a component part. various causes have been suggested for the transport of these erratic blocks, of which the most satisfactory is the agency of ice, either as slow-moving glaciers, or as oceanic icebergs. "the common form of a glacier," says professor j. forbes, "is a river of ice filling a valley, and pouring down its mass into other valleys yet lower. it is not a frozen ocean, but a frozen torrent. its origin or fountain is in the ramifications of the higher valleys and gorges, which descend amongst the mountains perpetually snow-clad. but what gives to a glacier its most peculiar and characteristic feature is, that it does not belong exclusively or necessarily to the snowy region already mentioned. the snow disappears from its surface in summer as regularly as from that of the rocks which sustain its mass. it is the prolongation or outlet of the winter-world above; its gelid mass is protruded into the midst of warm and pine-clad slopes and green-sward, and sometimes reaches even to the borders of cultivation."[37] the glacier moves onward with a slow but steady march towards the mouth of its valley. its lowest stratum carries with it numerous fragments of rock, which, pressed by the weight of the mighty mass, scratch and indent the surfaces over which they move, and sometimes polish them. these marks are seen on many rock-surfaces now exposed, and they are difficult to explain on any other hypothesis than that of glacial action. but the alternate influence of summer and winter--the percolation of rain into the mountain fissures, and the expansion of freezing--dislodge great angular fragments of rock, which fall on the glacier beneath. slowly but surely these then ride away towards the mouth of the valley, till they reach a point where the warmth of the climate does not permit the ice to proceed; the blocks then are deposited as the mass melts. but if the climate itself were elevated, or if the surface were lowered so as to immerse the glacier in the sea, it would melt throughout its course, and then the blocks would be found arranged in long lines or _moraines_, such as we see now in many places. if the glacier-valley debouch on the sea, the ice gradually projects more and more, until the motions of the waves break off a great mass, which floats away, carrying on its surface the accumulation of boulders, gravel, and other _débris_ which it had acquired during its formation. it is now an iceberg, which, carried by the southern currents, approaches a warmer climate, melts, and deposits its cargo, perhaps hundreds of leagues from the valley where it was shipped, and as fresh as when its component _frusta_ were detached from the primitive rock. if the abundance of such erratic blocks and foreign gravel seem to require a greater amount of glacial action than is now extant, it has been suggested that the volcanic energy which elevated europe may have been succeeded by a measure of subsidence before the land attained its present permanent condition. hence there may have been, during the tertiary epoch, mountain chains of great elevation, sufficient to supply the glaciers, which, on their subsidence, melted on the spot where they were submerged, or floated away as icebergs on the pelagic currents, till they grounded on the bays and inlets of other shores, which were subsequently elevated again. thus a large portion of the animals which then inhabited these islands (up to that time, perhaps, united to the continent) would be drowned, and many species quite obliterated, a few alone remaining to connect our present fauna with that of the submerged area, when the land rose again to its existent state. it would not materially augment the force of the evidence already adduced on the question of chronology, to examine in detail the fossil remains of south america, australia, and new zealand. the gigantic sloths[38] of the first, the gigantic marsupials of the second, and the gigantic birds of the third, however interesting individually, and especially as showing that a prevailing type governed the fauna in each locality then as now--are all formations of the tertiary period, and some of them, at least, seem to have run on even into the present epoch. indeed, it is not quite certain that the enormous birds of new zealand and madagascar are even yet extinct. the phenomenon of raised sea-beaches is one of great interest, and seems to be connected with the alternate elevations and depressions of the tertiary epoch, perhaps marking the successive steps of the upheaval of the land. in several parts of england the coast-line exhibits one or more shelves parallel with the existing sea-beach, and covered with similar shingle, sand, and sea-shells. and the same phenomenon is exhibited on a still more gigantic scale in south america. mr. darwin[39] found that for a distance of at least 1,200 miles from the rio de la plata to the straits of magellan on the eastern side, and for a still longer distance on the west, the coast-line and the interior have been raised to a height of not less than 100 feet in the northern part, but as much as 400 feet in patagonia. all this change has taken place within a comparatively short period; for in valparaiso, where the effect is most considerable, modern marine deposits, with human remains, are seen at the height of 1,300 feet above the sea. at what exact point, geologically, the period of human history begins, it is impossible to say. no evidence of man's presence has occurred older than the latest tertiary deposits, which insensibly merge into the alluvial. it seems certain that human remains have been found in chronological association with those of animals long extinct, and there appears no reason to doubt that some species of animals, as the irish deer, the moa of new zealand, and the dodo of the mauritius, have disappeared from creation within a period of a few centuries.[40] it is not improbable that the last of the moho race may have lived only long enough to grace the pages of the "birds of australia." [illustration: the moho.] it is as important as it is interesting, to observe that the same kinds of physical operations have been, within the present epoch, and are still, going on, as those whose results are chronicled in the rocks. strata of alluvium are constantly being formed on a scale which, though it does not _suddenly_ affect the outline of coasts, and therefore appears small, yet is great in reality. the ganges is estimated to pour into the indian ocean nearly 6,400 millions of tons of mud every year; and its delta is a triangle whose sides are two hundred miles long. the delta of the mississippi is of about the same size, and it advances steadily into the gulf of mexico at the rate of a mile in a century. the accumulation of river-mud is gradually filling up the adriatic sea. from the northernmost point of the gulf of trieste to the south of ravenna, there is an uninterrupted series of recent accessions of land, more than a hundred miles in length, which, within the last twenty centuries, have increased from two to twenty miles in breadth. the coral-polypes are working still with great energy. mr. darwin mentions two or three examples of the rate of increase, one of which only i shall cite. in the lagoon of keeling atoll, a channel was dug for the passage of a schooner built upon the island, through the reef into the sea; in ten years afterward, when it was examined, it was found almost choked up with living coral. volcanic action is busy in many parts of the earth, pouring forth clouds of ashes and torrents of molten rock; and instances are not wanting in which new islands have been raised from the bed of the ocean by this means, within the sphere of history. slow and permanent changes of level are still being produced on the earth's crust. the bottom of the baltic has been, for several centuries at least, in process of continuous elevation, the effects of which are palpable. many rocks formerly covered are now permanently exposed; channels between islets, formerly used, are now closed up, and beds of marine shells have become bare. on the other hand, the whole area of the pacific polynesia seems subsiding. deposits are being made by waters which hold earthy substances in solution. the principal of these is _lime_. several remarkable examples of this kind are quoted by sir charles lyell, in one of which there is a thickness of 200 or 300 feet of travertine of recent deposit, while in another a solid mass thirty feet thick was deposited in about twenty years. he also states that there are other countless places in italy where the constant formation of limestone may be seen, while the same may be said of auvergne and other volcanic districts. in the azores, iceland, and elsewhere, _silica_ is deposited often to a considerable extent. deposits of _asphalt_ and other bituminous products occur in other places.[41] the floors of limestone caverns are frequently strewn with fossil bones, which are imbedded in stalagmite, and this incrustation is still in progress of formation. it is remarkable that in this deposit alone we obtain the bones of man in a fossil condition. the two creations,--the extinct and the extant,--or rather the prochronic and the diachronic--here unite. but there is no line of demarcation between them; they merge insensibly into each other. the bones of man, and even his implements and fragments of pottery, are found mingled with the skeletons of extinct animals in the caves of devonshire, in those of brazil,[42] and in those of franconia. in peru, some scores of human skeletons have been found in a bed of travertine, associated with marine shells; the stratum itself being covered by a deep layer of vegetable soil, forming the face of a hill crowned with large trees. from a very interesting paper by m. marcel de serres, it appears indubitable that the existing shells of the mediterranean are even now passing in numbers into the fossil state, and that not in quiet spots only, but where the sea is subject to violent agitations. specimens of common species, "completely petrified, have been converted into carbonate of lime at the same time that they have lost the animal matter which they originally contained. their hardness and solidity are greater than those of some petrified species from tertiary formations." "in the collection of m. doumet, mayor of cette, there exists an anchor which exhibits the same circumstances, and which is also covered with a layer of solid calcareous matter. this contains specimens of _pecten_, _cardium_, and _ostrea_, completely petrified, and the hardness of which is equal to that of fossil species from secondary formations. on the surface of the deposit in which the anchor is imbedded, there are _anomiæ_ and _serpulæ_, which were living when the anchor was got out of the sea; these present no trace of alteration."[43] thus we have brought down the record to an era embraced by human history, and even to individual experience; and we confidently ask, is it possible, is it imaginable, that the whole of the phenomena which occur below the diluvial deposits can have been produced within six days, or seventeen centuries? let us recapitulate the principal facts. 1. the crust of the earth is composed of many layers, placed one on another in regular order. all of these are solid, and most are of great density and hardness. most of them are of vast thickness, the aggregate not being less than from seven to ten miles. 2. the earlier of these were made and consolidated before the newer were formed; for in several cases, it is demonstrable that the latter were made out of the _débris_ of the former. thus the compact and hard granite was disintegrated grain by grain; the component granules were rolled awhile in the sea till their angles were rubbed down; they were slowly deposited, and then consolidated in layers. 3. a similar process goes on again and again to form other strata, all occupying long time, and all presupposing the earlier ones.[44] 4. after some strata have been formed and solidified, convulsions force them upward, contort them, break them, split them asunder. melted matter is driven through the outlets, fills the veins, spreads over the surface, settles into the hollows, cools and solidifies. 5. after the outflowing and consolidation of these volcanic streams, the action of running water cuts them down, cleaving beds of immense depth through their substance. mr. poulett scrope, speaking of the solidified streams of basalt, in the volcanic district of southern france, observes:- "these ancient currents have since been corroded by rivers, which have worn through a mass of 150 feet in height, and formed a channel even in the granite rocks beneath, since the lava first flowed into the valley. in another spot, a bed of basalt, 160 feet high, has been cut through by a mountain stream. the vast excavations effected by the erosive power of currents along the valleys which feed the ardèche, since their invasion by lava-currents, prove that even the most recent of these volcanic eruptions belong to an era incalculably remote."[45] 6. a series of organic beings appears, lives, generates, dies; lives, generates, dies; for thousands and thousands of successive generations. tiny polypes gradually build up gigantic masses of coral,--mountains and reefs--microscopic foraminifera accumulate strata of calcareous sand; still more minute infusoria--forty millions to the inch--make slates, many yards thick, of their shells alone. 7. the species at length die out--a process which we have no data to measure,[46] though we may reasonably conclude it very long. sometimes the whole existing fauna seems to have come to a sudden violent end; at others, the species die out one by one. in the former case suddenly, in the latter progressively, new creatures supply the place of the old. not only do species change; the very genera change, and change again. forms of beings, strange beings, beings of uncouth shape, of mighty ferocity and power, of gigantic dimensions, come in, run their specific race, propagate their kinds generation after generation,--and at length die out and disappear; to be replaced by other species, each approaching nearer and nearer to familiar forms. 8. though these early creatures were unparalleled by anything existing now, yet they were animals of like structure and economy essentially. we can determine their analogies and affinities; appoint them their proper places in the orderly plan of nature, and show how beautifully they fill hiatuses therein. they had shells, crusts, plates, bones, horns, teeth, exactly corresponding in structure and function to those of recent animals. in some cases we find the young with its milk-teeth by the side of its dam with well-worn grinders. the fossil excrement is seen not only dropped, but even in the alimentary canal. bones bear the marks of gnawing teeth that dragged them and cracked them, and fed upon them. the foot-prints of birds and frogs, of crabs and worms, are imprinted in the soil, like the faithful impression of a seal.[47] 9. millions of forest-trees sprang up, towered to heaven, and fell, to be crushed into the coal strata which make our winter fires. hundreds of feet measure the thickness of what were once succulent plants, but pressed together like paper-pulp, and consolidated under a weight absolutely immensurable. yet there remain the scales of their stems, the elegant reticulated patterns of their bark, the delicate tracery of their leaf-nerves, indelibly depicted by an unpatented process of "nature-printing." and when we examine the record,--the forms of the leaves, the structure of the tissues, we get the same result as before, that the plants belonged to a flora which had no species in common with that which adorns the modern earth. very gradually, and only after many successions, not of individual generations, but of the cycles of species, genera, and even families, did the vegetable creation conform itself to ours.[48] 10. at length the species both of plants and animals grew,--not by alteration of their specific characters, but by replacement of species by species--more and more like what we have now on the earth, and finally merged into our present flora and fauna, about the time when we find the first geological traces of man. 11. during the course of these successive cycles of organic life, the map of the world has changed many times. up to a late period the ocean washed over mont blanc and mount ararat; the continent of europe was a wide sea; then it was a polynesia, then an archipelago of great islands, then a continent much larger than it is now, with england united to it, and the solid land stretching far away into the atlantic;--then it sank again, and was again raised, not all at once, but by several stages, each of which has left its coast line, and its shingle beach. all these changes must have been the work of vast periods of time. "excepting possibly, but not certainly, the higher parts of some mountains, which at widely different epochs have been upheaved, and made to elevate and pierce the stratified masses which once lay over them, there is scarcely a spot on the earth's surface which has not been many times in succession the bottom of the sea, and a portion of dry land. in the majority of cases, it is shown, by physical evidences of the most decisive kind, that each of those successive conditions was of extremely long duration; a duration which it would be presumptuous to put into any estimate of years or centuries; for any alteration, of which vestiges occur in the zoological state and the mineral constitution of the earth's present surface, furnishes no analogy (with regard to the nature and continuance of causes), that approaches in greatness of character to those changes whose evidences are discernible in almost any two continuous strata. it is an inevitable inference, unless we are disposed to abandon the principles of fair reasoning, that each one of such changes in organic life did not take place till after the next preceding condition of the earth had continued through a duration, compared with which six thousand years appear an inconsiderable fraction of time."[49] 12. the climate of our atmosphere has undergone corresponding mutations. at one time the palms, the treeferns, the cycads of the tropical jungles found their congenial home here: the elephant, the rhinoceros, and the tiger roamed over england; nay, dwelt in countless hosts on the northern shores of siberia: then the climate gradually cooled to a temperate condition: then it became cold, and glaciers and icebergs were its characteristic features: finally it became temperate again. 13. the icebergs and the glaciers were the ships and railways of past epochs; they were freighted with their heavy but worthless cargoes of rock-boulders and gravel, and set out on their long voyages and travels, over sea and land, sometimes writing their log-books in ineffaceable scratches on the rocky tables over which they passed, and at length discharging their freights in harbours and bays, on inland plains, on mountain sides and summits, where they remain unclaimed, free for any trader in such commodities, without the ceremony of producing the original bill of lading. let the remainder be told in the words of one of our most eloquent and able geologists, professor sedgwick. "the fossils demonstrate the time to have been _long_, though we cannot say _how_ long. thus we have generation after generation of shell-fish, that have lived and died on the spots where we find them; very often _demonstrating_ the lapse of _many years_ for a few perpendicular inches of deposit. in some beds we have large, cold-blooded reptiles, creatures of long life. in others, we have traces of ancient forests, and enormous fossil trees, with concentric rings of structure, marking the years of growth. phenomena of this kind are repeated again and again; so that we have three or four distinct systems of deposit, each formed at a distinct period of time, and each, characterised by its peculiar fossils. coeval with the tertiary masses, we have enormous lacustrine deposits; sometimes made up of very fine thin laminæ, marking slow tranquil deposits. among these laminæ, we can find sometimes the leaf-sheddings and the insects of successive seasons. among them also we find almost mountain-masses of the _indusioe tubulatoe_ [the cases of _phryganeoe_], and other sheddings of insects, year after year. again, streams of ancient lava alternate with some of these lacustrine tertiary deposits. "in central france, a great stream of lava caps the lacustrine limestone. at a _subsequent period_ the waters have excavated deep valleys, cutting down into the lacustrine rock-marble many hundred feet; and, at a newer epoch, anterior to the authentic history of europe, new craters have opened, and fresh streams of lava have run down the existing valleys. even in the tertiary period we have thus a series of demonstrative proofs of a long succession of physical events, each of which required a long lapse of ages for its elaboration. "again, as we pass downwards from the bottom tertiary beds to the chalk, we instantly find new types of organic life. the old species, which exist in millions of individuals in the upper beds, disappear, and new species are found in the chalk immediately below. this fact indicates a long lapse of time. had the chalk and upper beds been formed simultaneously at the same period [as the supporters of the diluvial theory represent], their organic remains must have been more or less mixed; but _they are not_. again, at the base of the tertiary deposits resting on the chalk, we often find great masses of conglomerate or shingle, made up of chalk-flints rolled by water. these separate the chalk from the overlying beds, and many of the rolled flints contain certain petrified _chalk_-fossils. now, every such fossil proves the following points:- "1. there was a time when the organic body was alive at the bottom of the sea. "2. it was afterwards imbedded in the cretaceous deposit. "3. it became petrified; a very slow process. "4. the chalk was, by some change of marine currents, washed away, or degraded, [_i. e._ worn away under the atmosphere by the weather and casualties, a process slow almost beyond description,] and the solid flints and fossils [thus detached from their imbeddings], were rolled into shingles. "5. afterwards, these shingles were covered up, and buried under tertiary deposits. "in this way of interpretation, a section of _a few perpendicular feet_ indicates a long lapse of time, and the co-ordinate fact of the entire change of organic types, between the beds above and those below, falls in with the preceding inference, and shows the lapse of time to have been very long."[50] iv. the cross-examination. "when the fact itself cannot be proved, that which comes nearest to the proof of the fact is the proof of the circumstances that necessarily and usually attend such facts; and _these are called presumptions, and not proofs_, for they stand instead of the proofs of the fact, till the contrary be proved."--gilbert; law of evidence. such, then, is the evidence for the macro-chronology. i hope i have summed it up fairly; of course, many details i have been forbidden to adduce by want of space, but they would have been of the same kind as those brought forward. i am not conscious of having in any degree cushioned, or concealed, or understated a single proof which would have helped the conclusion. a mighty array of evidence it certainly is, and such as appears at first sight to compel our assent to the sequent claimed for it. i must confess that i have no sympathy with the _reasonings_ of those, however i honour their design, who can find a sufficient cause for these phenomena in the natural operations of the antediluvian centuries, or in the convulsion that closed them. but is there no other alternative? am i compelled to accept the conclusions drawn from the phenomena thus witnessed unto, as undeniable facts, since they refuse to be normally circumscribed within the limits of the historic period? i verily believe there is another, and a perfectly legitimate solution. my first business is to examine, and, if i can, to disprove this testimony. if i can show the witness to be liable to error; if i can adduce a principle which invalidates all his proofs; if i can make it undeniably manifest that, in a case precisely parallel, similar conclusions, deduced from exactly analogous phenomena, would be notoriously false; if i can do this, i think i have a right to demand that the witness be bowed out of court, as perfectly nugatory and worthless _in this cause_. in the first place, there is nothing here but _circumstantial_ evidence; there is no _direct_ testimony to the facts sought to be established. let it not seem unfair to make this distinction; it is one of great importance. no witness has deposed to actual observation of the processes above enumerated; no one has appeared in court who declares he actually saw the living _pterodactyle_ flying about, or heard the winds sighing in the tops of the _lepidodendra_. you will say, "it is the same thing; we have seen the skeleton of the one, and the crushed trunk of the other, and therefore we are as sure of their past existence as if we had been there at the time." no, it is not the same thing; it is not _quite_ the same thing; not quite. strong as is the evidence, it is not _quite_ so strong as if you had actually seen the living things, and had been conscious of the passing of time while you saw them live. it is only by a process of reasoning that you infer they lived at all.[51] the process is something like this. here is an object in a mass of stone, which has a definite form,--the form of the bone of a beast. the more minutely you examine it, the more points of resemblance you find; you say, if this is a bone, it ought to have so and so--condyles, scars for the attachment of muscles in particular spots, a cavity for the reception of marrow, a mark for the insertion of the ligament; you look for each of these, and find all in the very conditions you have prescribed; it is not only a bone, but a particular bone, the thigh-bone, for instance. here in the same block of stone is another object: you work it out; it is another bone; its joint accurately fits the preceding; it answers precisely to the tibia of a mammal. other bones at length appear, and you have got a perfect skeleton, no part redundant, none wanting; the most minute, the most elaborate, the most delicate portions of the osseous frame of a mammal are present, and every one exactly correspondent to the rest in size, in maturity, _in fit._ each bone, out of the scores, displays exactly those characters, and no other, which an anatomist would have said beforehand it ought to have. allowing for the difference of species, the skeleton, when worked out of its matrix, and set up, is precisely like that of the little beast at whose death you were actually present, whose bones you cleaned with your own hands, and mounted for your own museum. it would be as reasonable to deny that the one is the skeleton of a real animal as the other. thus far there is matter of fact--observed, witnessed fact; you have found in a stone a real skeleton. you immediately infer that this skeleton once belonged to a living animal, that breathed, and fed, and walked about, exactly as animals do now. this conclusion seems so obvious and unavoidable, that we naturally conclude it to rest on the same foundation as the fact that the object _is_ a skeleton, or that _it was_ in the stone. but really it rests on a totally different foundation; it is a conclusion deduced by a process of reasoning from certain assumed premises. myriads, perhaps millions of skeletons of animals like this one have come at different times under human observation, which have been obviously referrible to creatures that, within the same sphere of observation, had been alive. no similar skeleton has ever come within the range of recorded observation that could be referred to any other source than that of a quondam living animal. on these premises you build the conclusion that a skeleton must, at some time or other, have belonged to a living animal. and it may seem an impregnable position; but yet its validity altogether depends on the exhaustive power of human observation. if i could show, to your satisfaction, that a skeleton might have existed; still more, if i could show you that a skeleton _must_ have existed; still more, if i could prove that myriads of skeletons, precisely like this, must have existed, without ever having formed parts of antecedent living bodies; you would yourself acknowledge that your conclusions were untenable. the utmost you could affirm, would be, that possibly, perhaps probably, the skeleton you had found in the stone had at some time belonged to a living animal, but that, so far as any recognised premises exist, there was no certainty about it. but the premises have not been fairly stated. there is more than the relation of precedence and sequence in what we know of the connexion between skeletons and living animals; there is the relation of cause and effect. it is not only that universal experience has declared the _fact_ that every skeleton was once part of a living body; it has shown that the very structure and nature of the skeleton _implied_ living body. the skeleton, in every part, displays a regard for the advantages of the living animal; it is built expressly for it; by itself it is nothing--a machine without any object; its joints, its cavities, its apophyses, its processes, all have special reference to tissues and organs which are not here now, but which belong to the living body. and then experience has shown that the skeleton is made in a particular manner. the bone is deposited, atom by atom, in living organic cells, which are formed by living blood, which implies a living animal. the microscopic texture of your stone-girt skeleton does not differ from that of the skeleton which you cleaned from the muscles with your own hands; and therefore you infer that it was constructed in the same way, namely, by the blood of a living body. well, i come back, notwithstanding, to my position,--that your right to _affirm_ this must altogether depend on the exhaustive power of that experience on which you build. and it will be overthrown, if i can show that skeletons have been made in some other way than by the agency of living blood. can i do this? i think i can. at least i think i can show enough greatly to diminish, if not altogether to destroy, the confidence with which you inferred the existence of vast periods of past time from geological phenomena. i can adduce a principle, having the universality (within its proper sphere) of law, hitherto unrecognised, whose tendency is to invalidate the testimony of your witness. v. postulates. "a little philosophy inclineth a man's mind to atheism; but depth in philosophy bringeth men's minds about to religion; for while the mind of man looketh upon second causes scattered, it may sometimes rest in them, and go no farther; but when it beholdeth the chain of them confederate and linked together, it must needs fly to providence and deity."--bacon. "'what was the opinion of pythagoras concerning wildfowl?' 'that the soul of our grand-dam might haply inhabit a bird.' 'what thinkest thou of his opinion?' 'i think nobly of the soul, and in nowise receive his opinion.'" shakspeare. as without some common ground it is impossible to reason, i shall take for granted the two following principles:- i. the creation of matter. ii. the persistence of species. i. if any geologist take the position of the necessary eternity of matter, dispensing with a creator, on the old ground, _ex nihilo nihil fit_,--i do not argue with him. i assume that at some period or other in past eternity there existed nothing but the eternal god, and that he called the universe into being out of nothing. ii. i demand also, in opposition to the development hypothesis, the perpetuity of specific characters, from the moment when the respective creatures were called into being, till they cease to be. i assume that each organism which the creator educed was stamped with an indelible specific character, which made it what it was, and distinguished it from everything else, however near or like. i assume that such character has been, and is, indelible and immutable; that the characters which distinguish species from species _now_, were as definite at the first instant of their creation as now, and are as distinct now as they were then. if any choose to maintain, as many do, that species were gradually brought to their present maturity from humbler forms,--whether by the force of appetency in individuals, or by progressive development in generations--he is welcome to his hypothesis, but i have nothing to do with it. these pages will not touch him. i believe, however, there is a large preponderance of the men of science,[52] at least in this country, who will be at one with me here. they acknowledge the almighty _fiat_ of god, as the energy which produced being; and they maintain that the specific character which he then stamped on his organic creation remains unchangeable. vi. laws. "----[greek: ton trochon tês geneseôs]."--james iii. 6. the course of nature is a circle. i do not mean the _plan_ of nature; i am not speaking of a circular arrangement of species, genera, families, and classes, as maintained by macleay, swainson, and others. their theories may be true, or they may be false; i decide nothing concerning them; i am not alluding to any _plan_ of nature, but to its _course_, _cursus_,--the way in which it _runs on_. this is a circle. here is in my garden a scarlet runner. it is a slender twining stem some three feet long, beset with leaves, with a growing bud at one end, and with the other inserted in the earth. what was it a month ago? a tiny shoot protruding from between two thick fleshy leaves scarcely raised above the ground. a month before that? the thick fleshy leaves were two oval cotyledons, closely appressed face to face, with the minute plumule between them, the whole enclosed in an unbroken, tightly-fitting, spotted, leathery coat. it was a bean, a seed. [illustration: germination of a scarlet runner. _a._ the ripe bean, showing the hilum at *; _b._ the same bean, with one cotyledon removed, to show the plumule. _c._ a similar bean, twenty-four hours after planting. _d._ the same, on the sixth day after planting. _e._ the same, on the twelfth day. _f._ the same, on the fourteenth day. n.b. from _b_, _c_, _d_, _e_, the front cotyledon has been cut away, to show the progress of the plumule.] was this the commencement of its existence? o no! six months earlier still it was snugly lying, with several others like itself, in a green fleshy pod, to the interior of which it was organically attached. a month before that, this same pod with its contents was the centre of a scarlet butterfly-like flower, the bottom of its pistil, within which, if you had split it open, you would have discerned the tiny beans, whose history we are tracing backwards, each imbedded in the soft green tissue, but no bigger than the eye of a cambric needle. but where was this flower? it was one of many that glowed on my garden wall all through last summer; each cluster springing as a bud from a slender twining stem, which was the exact counterpart of that with which we commenced this little life-history. and this earlier stem,--what of it? it too had been a shoot, a pair of cotyledons with a plumule, a seed, an integral part of a carpel, which was a part of an earlier flower, that expanded from an earlier bud, that grew out of an earlier stem, that had been a still earlier seed, that had been--and backward, _ad infinitum_, for aught that i can perceive. the course, then, of a scarlet runner is a circle, without beginning or end:--that is, i mean, without a natural, a normal beginning or end. for at what point of its history can you put your finger, and say, "here is the commencement of this organism, before which there is a blank; here it began to exist?" there is no such point; no stage which does not look back to a previous stage, on which _this_ stage is inevitably and absolutely dependent. to some of my readers this may be rendered more clear by the accompanying diagram:---[illustration: legume--reed--cotyledons--shoot--stem--bud--flower--carpel] [illustration: theca--spore--prothallus--sporal frond--tuft--caudex--fertile frond--sorus] see that magnificent tuft of lady-fern on yonder bank, arching its exquisitely cut fronds so elegantly on every side. a few years ago this ample crown was but a single small frond, which you would probably not have recognised as that of a lady-fern. somewhat earlier than this, the plant was a minute flat green expansion (_prothallus_), of no definite outline, very much like a liverwort. this had been previously a three-sided spore lying on the damp earth, whither it had been jerked by the rupture of a capsule (_theca_). for this spore, though so small as to be visible only by microscopic aid, had a previous history, which may be traced without difficulty. it was generated with hundreds more, in one of many capsules, which, were crowded together, beneath the oval bit of membrane, that covered one of the brown spots (_sori_), which were developed in the under surface of the fronds of an earlier lady-fern. that earlier individual had in turn passed through the same stages of sporal frond, prothallus, spore, theca, sorus, frond, prothallus, spore, theca, sorus, frond, prothallus, &c.--_ad infinitum_. this sounding-winged hawkmoth, which like a gigantic bee is buzzing around the jasmine in the deepening twilight, hovering ever and anon to probe the starry flowers that make the evening air almost palpable with fragrance,--this moth, what "story of a life" can he tell? nearly a year of existence he has spent as a helpless, almost motionless pupa, buried in the soft earth, from whence he has emerged but this evening. about a twelvemonth ago he was a great fat green caterpillar with an arching horn over his rump, working ever harder and harder at devouring poplar leaves, and growing ever fatter and fatter. but before that he had one day burst forth a little wriggling worm, from a globular egg glued to a leaf. whence came the egg? it was developed within the ovary of a parent hawkmoth, whose history is but an endless rotation of the same stages,--pupa, larva, egg, moth, pupa, larva, &c. &c. [illustration: larva--pupa--moth--egg] behold this specimen of _plumularia_, a shrub-like zoophyte, comprising within its populous branches some twenty thousand polypes. every individual cell, now inhabited by its tentacled hydra, has in its turn budded out from a branch, which was itself but a lateral process from the central axis. and this was but the prolongation of what was at first a single cell, shooting up from a creeping root-thread. a little earlier than this, there was neither cell nor root-thread, but the organism existed in the form of a _planule_, a minute soft-bodied, pear-shaped worm, covered with cilia, that crawled slowly over the stones and sea-weeds. whence came it? a few hours before, it had emerged from the mouth of a vase-like cell, one of the ovarian capsules, which studded the stem of an old well-peopled plumularia-shrub, and which had been gradually developed from its substance by a process analogous to budding. and then if we follow the history of this earlier shrub backward, it will only lead us through exactly correspondent stages, primal cell, planule, ovarian capsule, stem, and so on interminably. [illustration: primal cell--axis--branch--polype--capsule--planule] once more. the cow that peacefully ruminates under the grateful shadow of yonder spreading beech, was, a year or two ago, a gamesome heifer with budding horns. the year before, she was a bleating calf, which again had been a breathless foetus wrapped up in the womb of its mother. earlier still it had been an unformed embryo; and yet earlier, an embryonic vesicle, a microscopically minute cell, formed out of one of the component cells of a still earlier structure,--the germinal vesicle of a fecundated ovum. but this ovum, which is the remotest point to which we can trace the history of our cow as an individual, was, before it assumed a distinct individuality, an undistinguishable constituent of a viscus,--the ovary,--of another cow, an essential part of _her_ structure, a portion of the tissues of _her_ body, to be traced back, therefore, through all the stages which i have enumerated above, to the tissues of another parent cow, thence to those of a former, and so on, through a vista of receding cows, as long as you choose to follow it. [illustration: embryo--foetus--calf--heifer--cow--ovum--germ. vesicle--embr. vesicle] this, then, is the order of all organic nature. when once we are in any portion of the course, we find ourselves running in a circular groove, as endless as the course of a blind horse in a mill. it is evident that there is no one point in the history of any single creature, which is a legitimate beginning of existence. and this is not the law of some particular species, but of all: it pervades all classes of animals, all classes of plants, from the queenly palm down to the protococcus, from the monad up to man: the life of every organic being is whirling in a ceaseless circle, to which one knows not how to assign any commencement,--i will not say any certain or even probable, but any _possible_, commencement. the cow is as inevitable a sequence of the embryo, as the embryo is of the cow. looking only at nature, or looking at it only with the lights of experience and reason, i see not how it is possible to avoid one of these two theories, the development of all organic existence out of gaseous elements, or the eternity of matter in its present forms. creation, however, solves the dilemma. i have, in my postulates, begged the fact of creation, and i shall not, therefore, attempt to prove it. creation, the sovereign fiat of almighty power, gives us the commencing point, which we in vain seek in nature. but what is creation? it is _the sudden bursting into a circle_. since there is no one stage in the course of existence, which, more than any other affords a natural commencing point, whatever stage is selected by the arbitrary will of god, must be an unnatural, or rather a preter-natural, commencing point. the life-history of every organism commenced at some point or other of its circular course. it was created, called into being, in some definite stage. possibly, various creatures differed in this respect; perhaps some began existence in one stage of development, some in another; but every separate organism had a distinct point at which it began to live. before that point there was nothing; this particular organism had till then no existence; its history presents an absolute blank; _it was not_. but the whole organisation of the creature thus newly called into existence, looks back to the course of an endless circle in the past. its whole structure displays a series of developments, which as distinctly witness to former conditions as do those which are presented in the cow, the butterfly, and the fern, of the present day. but what former conditions? the conditions thus witnessed unto, as being necessarily implied in the present organisation, were non-existent; the history was a perfect blank till the moment of creation. the past conditions or stages of existence in question, can indeed be as triumphantly inferred by legitimate deduction from the present, as can those of our cow or butterfly; they rest on the very same evidences; they are identically the same in every respect, except in this one, that they were _unreal_. they exist only in their results; they are effects which never had causes. perhaps it may help to clear my argument if i divide the past developments of organic life, which are necessarily, or at least legitimately, inferrible from present phenomena, into two categories, separated by the violent act of creation. those unreal developments whose apparent results are seen in the organism at the moment of its creation, i will call _prochronic_, because time was not an element in them; while those which have subsisted since creation, and which have had actual existence, i will distinguish as _diachronic_, as occurring during time. now, again i repeat, there is no imaginable difference to sense between the prochronic and the diachronic development. every argument by which the physiologist can prove to demonstration that yonder cow was once a foetus in the uterus of its dam, will apply with exactly the same power to show that the newly created cow was an embryo, some years before its creation. look again at the diagram by which i have represented the life-history of this animal. the only mode in which it can begin is by a sudden sovereign act of power, an irruption into the circle. you may choose _where_ the irruption shall occur; there must be a bursting-in at some point. suppose it is at "calf;" or suppose it is at "embr. vesicle." put a wafer at the point you choose, say the latter. this then is the real, actual commencement of a circle, to be henceforth ceaseless. but the embryonic vesicle necessarily implies a germinal vesicle, and this necessitates an ovum, and the ovum necessitates an ovary, and the ovary necessitates an entire animal,--and thus we have got a quarter round the circle in back development; we are irresistibly carried along the prochronic stages,--the stages of existence which were before existence commenced,--as if they had been diachronic, actually occurring within our personal experience. if i know, as a _historic fact_, that the circle was commenced where i have put my wafer, i may begin it there; but there is, and can be, nothing in the _phenomena_ to indicate a commencement there, any more than anywhere else, or, indeed, anywhere at all. the commencement, as a fact, i must learn from testimony; i have no means whatever of inferring it from phenomena. * * * * * permit me, therefore, to repeat, as having been proved, these two propositions:-all organic nature moves in a circle. creation is a violent irruption into the circle of nature. vii. parallels and precedents. (_plants._) "where wast thou when i laid the foundations of the earth? declare, if thou hast understanding."--job xxxviii. 4. since every organism, considering it, throughout its generations, as an unit, has been created, or made to commence existence, it is manifest that it was created or made to commence existence at some moment of time. i will ask some kind geological reader to imagine that moment, and to accompany me in an ideal tour of inspection among the creatures, taking up each for examination at the instant that it has been called into existence. do not be alarmed! i am not about to assume that the moment in question was six thousand years ago, and no more; i will not rule the actual date at all; you, my geological friend, shall settle the chronology just as you please, or, if you like it better, we will leave the chronological date out of the inquiry, as an element not relevant to it. it may have been six hundred years ago, or six thousand, or sixty times six millions; let it for the present remain an indeterminate quantity. only please to remember that the date _was_ a reality, whether we can fix it or not; it _was_ as precise a moment as the moment in which i write this word. well then, like two of those "morning stars" who, when "the foundations were fastened," "shouted for joy," we will, in imagination, take our stand on this round world at exactly ---minutes past ---o'clock, on the morning of the ----th of ----, in the year b.c. ----. the noble tree-fern before us (_alsophila aculeata_) has this instant been called into being by the creating voice of god. here it stands, lifting up its columnar stem, and spreading its minutely fretted fronds all around, in a vaulted canopy above our heads, through the filagree work of whose expanse the sunbeams play in a soft green radiance. it has this instant been created. but i will suppose, further, that we have the power to call into our council some experienced botanist; who is not acquainted, as we are, with the fact of this just recent creation, and whom we will ask to give us his opinion on the age of this beautiful plant. _the botanist._--"you wish to ascertain the age of this _alsophila_. i know of no data by which this can be determined with precision, but i can indicate it approximately. let us take it in order. the most recent development is the growing point in the centre of the arching crown of leaves. around this you would see, if your eyes were above the plane, close ring-like bodies, or, perhaps, more like snail-shells, protruding from the growing bud; then young leaves, partially opened in various degrees, but coiled up scroll-wise at their tips, and around these the elegant fretted fronds, which expand broadly outwards in a radiating manner, and arch downwards. "now every one of these broad fronds was at first a compactly coiled ring; but it has, in the course of development, uncoiled itself, growing at the same time from its extremity, and from the extremity of each of its formerly wrapped-up pinnæ and pinnules, until at length it has attained the expanse you behold. this process has certainly occupied several days. "but let us look farther. the outermost fronds that compose this exquisite cupola, you see, are nearly naked; indeed, the extreme outermost are quite naked, being stripped of their verdant honours, their pinnæ and pinnules, and left mere dry and sapless sticks,--the long and taper midribs of what were once green fronds, as graceful as those that now surmount them. some of them, you see, are hanging downward, almost detached from the stem, and ready to drop at the first breath of wind. now remember, each of these brown unsightly sticks was once a frond, that had passed through all the steps of uncoiling from its circinate condition. this whole process has certainly occupied several months. "look, now, below these withered midribs, lifting up the most drooping of them. the stem is marked with great oval scars; and see, this old frond-rib has come off in my hand, leaving just such a scar, and adding one more to the number that were there before. and look down the stem; it is studded all over with these oval scars. there are a hundred and fifty at least; but i cannot count them nearly all, for towards the lower part they become more undefined, and the growth of the stem has thrown them further apart; and besides, there is, as you observe, a matted mass of tangled rootlets, like tarred twine, which, springing from between the lower scars, increases downwards, till the whole inferior extremity of the stem is encased in the dank and reeking mass. "you can have no doubt that every one of these scars indicates where a leaf has grown, where it has waved its time, and whence, after death and decay, it at length sloughed away. the form of the uppermost, which are not distorted by age, agrees exactly with the outline of the bulging base of the candelabrum-like frond; the arrangement of the scars is that of the fronds; and you may notice in every scar marks where the horseshoe-shaped plates of woody fibre have been broken off, which once passed into the interior of the stem from the midrib of the frond. "these scars, then, are ocular demonstrations of former fronds; we may no more doubt that fronds were once growing from these spots, than we may that the green and leafy arches were once coiled up in a circinate vernation. they are the record of the past history of this organism, and they evidently reach far back into time. the periodic ratio of development of new fronds may be, perhaps, roughly estimated at six in the course of a year. now there are about a dozen unfolded or unfolding, as many withering midribs, and about a hundred and fifty leaf-scars that we can count with ease, not reckoning such as are indistinct, nor such as are concealed beneath the tangled drapery of roots. [illustration: leaf-scars of tree-fern.] "i have no hesitation, then, in pronouncing this plant to be thirty years old; it is probably much older, but it is, at least, as old as this." such is the report of our botanical adviser; such is his argument; and we cannot but admit that it is invulnerable; his conclusion is inevitable, but for one fact, which he is not aware of. there is one objection, however, to which it is open--a fatal one; you and i know that the tree-fern is not five minutes old, _for it was created but this moment_. here is another act of creation. it may be the same day as that of the tree-fern, or one as remote as you please from it, before or after. a few moments ago this was a great mass of rough, naked limestone, but by creative energy it has been suddenly clothed with a luxuriant mantle of _selaginella_. how exquisitely beautiful the aggregation of flattened branching stems, studded with their tiny imbricated leaflets of tender green, bloomed with blue! and how thick and soft the carpet that thus conceals the angles and points and crevices of the unsightly stone! broad as is this expanse of verdure, covering many square yards without a flaw, and rooted as it is at ten thousand points of its creeping stem, we shall yet find that it is one unbroken structure. our friend the botanist would infer unhesitatingly that every part of this widespread ramification has originally proceeded from one central shoot, and that several years' growth must have concurred to form this compact mass. yet _we_ know that such an inference would be false. the plant has been this instant called into being. on the summit of this rounded hill is a very different plant from the last. beautiful it also is, but grandeur and majesty are its leading attributes. it is a dense and massive clump of the tulda bamboo. how noble these straight-jointed stems, cylinders of polished green, shooting their points right upwards, and towering to a height of eighty feet! the numerous panicles of tufty blossom are gracefully bending from the summits, and from the tip of every branch, nodding in the breeze. there are scores of the tall stems, as straight as an arrow, beset at every joint with diverging horizontal branches, crossing and recrossing in inextricable confusion. and see, amidst the crowd, there are others as thick and tall, but without a single side-shoot, clothed, however, to atone for the deficiency, in swaddling-clothes peculiarly their own. these swathed stems are infant shoots,--vigorous and promising children, indeed; these brown triangular sheaths, covered with down, are the clothing of infancy; they increase in number, and are closer together towards the summit of the shoot, where the growing point is rapidly extending. when the stems have attained their full height, these sheaths will fall off, the polished shafts will stand revealed in their glossy beauty, and the lateral pointed branches will at once start forth from every joint, and pierce horizontally through the dense tangled bush. now these young shoots do not bear testimony to so great an age as you would suppose. the whole seventy feet of their altitude have been attained within thirty days! but then their massive size and vigour indicate a mature age in the clump. for all the hundred stems that are crowded together in this dense bamboo-clump are organically united; they are parts of one and the same plant, the root-stock of which has been creeping to and fro year after year, sending up in constant succession its arrowy stems, until it has attained the present magnificence. many years must have elapsed between the present condition of the grove, and that of the slender blade that shot up from the tiny seed in this spot. yes, so you may think. but it is not so, for the great bamboo-clump has been created in its pride and glory this very hour! yonder is a considerable area of land covered with the green blades of young wheat, and very healthy and strong it looks. no, it is couch-grass! the whole green sward which we see is a single plant; the creeping stem of which has spread its ramifications in all directions beneath the surface of the soil; and still the long succulent shoots are extending in every direction, as shewn by the green leaf-blades. this is a rapidly growing plant, it is true; yet still there must be an accumulated growth of many months here, if not years! no, it was created this morning. contrasting with this humble grass, observe that luxuriant screw-pine. see its singular crown of foliage at the summit of its equally singular stem. its great prickle-edged stiff leaves grow in long diagonal rows, each sheathing its successor, and alternating with those of the next row. how rich and fragrant an odour is diffused from its crowded blossoms! every one of those sword-like leaves is, of course, the record of a period of time. a tree of this size makes a "screw," or imperfect spire, of leaves in about three years; and there are about sixteen pairs of leaves in each screw, which will give us nearly eleven leaves for the development of each season. now, on the trunk, there are numerous waved lines quite covering its surface, which are the traces of old leaves that have in succession been produced and decayed away;--the trunk is, in fact, composed of these leaf-bases. by counting these, we may obtain then an approximate notion of the age of this plant;--an _approximate_ notion only, because in its young stages the development of leaves probably took place more rapidly than it does now. there are then on this trunk about one hundred and fifty horizontal rows of scars, and each row numbers four leaf-bases, so that the trunk is inscribed with an autographic record of six hundred leaves. if then we reckon eleven leaves as the produce of a single season, and add the four screws which are still flourishing, we shall obtain a result of about fifty-five years as the age of this _pandanus_. this, for the reason just assigned, would probably be considerably too much; perhaps, forty years would be nearer the truth. there are, however, other marks of age here, though they are less definite. the great hardness of the surface-wood, which we perceive on trying to indent it, is an indication of age, as it is produced by the successive bundles of woody fibre, which, year after year, have passed down from each leaf, curving, in their descent, towards the circumference of the stem, and, therefore, constantly augmenting the density of the outer portions. another very curious proof of age is seen in the number of aerial roots which descend from various points of the trunk towards the soil. you would at first be inclined to think them posts, which a carpenter had set to "shore up" the tree, as props to prevent its being blown down. and truly this is their purpose; but they are natural adjuncts, not artificial. these thick rods, some of which have not yet reached the ground, have been shot forth in turn from the stem, in order to afford it additional support in the loose sandy soil. and mark, by the way, a beautiful contrivance here. because the growing tender extremity of the root has to pass through the sun-parched air in its progress towards the earth, there is a curious exfoliation of its extremity, forming a sort of cup, which, collecting the scanty dews, retains sufficient moisture for the refreshment of the spongy rootlet. now, i say, these supporting roots, since they must have originated from the trunk, after the latter had attained a considerable height, are so many evidences--and cumulative evidences--of age, though their testimony cannot be so well made to bear on a known period as that of the leaf-bases. should we not then be amply warranted in asserting this screw-pine to be many years old, if we were not assured that, as a fact, it has been this instant created? [illustration: roots of iriartea.] a phenomenon analogous to that which we have just observed is presented by yonder pashiuba palm (_iriartea exorhiza_). its straight arrowy stem has shot up to the height of fifty feet, like a slender iron column. on the summit there is the usual divergent crown of leaves that distinguishes this most graceful and queenly tribe; and at the foot, a tall open cone of roots, strangely supporting the column on its apex. "but what most strikes attention in this tree, and renders it so peculiar, is, that the roots are almost entirely above ground. they spring out from the stem, _each one at a higher point than the last_, and extend diagonally downwards till they approach the ground, when they often divide into many rootlets, each of which secures itself in the soil. as fresh ones spring out from the stem, _those below become rotten and die off_; and it is not an uncommon thing to see a lofty tree supported entirely by three or four roots, so that a person may walk erect beneath them, or stand with a tree seventy feet high growing immediately over his head." "in the forests where these trees grow, numbers of young plants of every age may be seen, all miniature copies of their parents, except that they seldom possess more than three legs, which gives them a strange and almost ludicrous appearance."[53] this tall pashiuba before us, however, is supported on several scores of roots, in various stages of development, some descending through the air, some already fixed in the soil. as the presence of these, moreover, implies the decay and disappearance of earlier ones, their number and height may be accepted as a fair testimony to the age of the tree; independent of what we might have deduced from the trunk and other sources. (my reader will bear in mind, that, throughout this chapter, i am supposing that we have the opportunity of seeing each organism at the moment following that of its creation.) the _iriartea_ before us, then, notwithstanding its marks of maturity, is but--a new-born infant, i was about to say, rather--a new-made adult. another and more massive palm appears, where a moment ago there was nothing but smooth ground and empty air. it is the sugar palm (_saguerus saccharifer_), remarkable in its appearance for the swathes of what looks to be _sackcloth of hair_, in which its stem is enveloped. each of its great pinnate leaves forms with the dilated base of its midrib a broad sheath, which springs out of a loose fold of this coarse cloth that is wrapped around it. and not only the bases of the still flourishing leaves are swathed in this natural textile fabric, but the dead and dry leaf-bases of the former leaves, which may be traced all down the stem. but let us look at this strange cloth: what is it? it is composed of the exterior fibres of the leaf-bases themselves, which in process of growth have partially separated themselves, and from which the parenchyma and the lamina have decayed away. the appearance of a woven fabric is deceptive; there is no interlacing; but its semblance is produced by the fibres lying in layers one over the other, and by some of them having a direction at right angles to the others. originally all the fibres were parallel and longitudinal, but as they have been, in the growth of the leaf, pulled out laterally, the main fibres, which are indefinitely divisible, have adhered to each other at various parts, and the result has been that innumerable constituent fibrillæ have been stretched across from fibre to fibre. every square inch, then, of this sackcloth tells of the lapse of time; these horse-hair-like fibres were once green and vascular, enclosing a soft pulp; in short, they were a part of a verdant leaf; the reduction of each congeries of veins to this condition was a work of time, and this has been effected by many leaf-bases in succession. an examination of this _gomuti_, as it is called, does not indeed help us to identify the actual interval lapsed in the history of the plant; but we may arrive at this from other considerations. the great sheathing bases themselves remain in numbers attached to the upper portion of the stem, though the greater portion of the midrib with the pinnæ has decayed and fallen; and in the lower part, where even the bases have disappeared, still broad lateral scars are left, marking off the stipe into horizontal rings, which are not less conclusively certain evidences of the former existence of similar bases, and therefore, still earlier, of leaves. the sugar palm developes and matures on an average six leaves every year.[54] on counting the dry leaf-bases, and the scars, i find on this trunk, a hundred and twenty: besides which there are about a dozen expanded leaves, and two visible, which are not unfolded. a hundred and thirty-four leaves then have left proofs of their existence here; which divided by six, gives about twenty-two years as the age of this palm. this is the age of this tree, however, since it began to form a stem; but several years of infancy must be added to the sum, during which its fronds sprang in succession from the surface of the soil. look at this _areca_. by-and-by it will grow to the loftiest stature attained by any of its tribe, and its noble crown of leaves will wave on the summit of a slender pillar a hundred and fifty feet in height. but at present it has no stem at all; the widely arching leaves diverge from a central point which is below the surface of the soil. here, then, are no dead leaf-bases; here are no old historical scars:--have we any evidence of past time here? yes, surely. see this fully developed leaf. it is composed of a stout midrib, along the two opposite edges of which grow, like the beards of a feather, narrow sword-like leaflets, separated from each other by intervals of about two inches. but this pinnate condition,--which is so inseparable from the developed leaf of a great division of the palm tribe, that our idea of a palm-leaf almost always is that of an enormous feather,--is by no means the original state. observe this young leaf which is not yet thoroughly expanded; the leaflets are, indeed, separated everywhere, except that the tips of all are connected by a very narrow ribbon of the common green lamina, which runs from one to another. in the fully opened leaves, this has been torn apart and is not distinguishable. but, let us carefully open this still younger leaf, which is protruding like a thin green rod, or rather like a closed fan, from the centre of the crown. we must handle it delicately, for it is very tender. now you see it is not pinnate at all; the leaf is as entire as a _musa_ leaf, which, indeed, it much resembles, except that each half is folded transversely, and then these transverse folds are packed one on another longitudinally, fan-fashion. each of the transverse folds answers to a future leaflet. it is the development of the midrib in length that tears asunder the divisions of the lamina, and converts them into separate, and by-and-by remote, pinnæ. it is manifest then that every leaflet on the midrib of a pinnate-leaved palm is a record of past time, as real as the leaf-bases on the trunk, inasmuch as, in each case, there is ocular proof that the conditions of existence are different from what they have been. and yet in this case, the evidences are fallacious, since the _areca_ before us has even now been created. here is an extraordinary plant. though no thicker than your little finger, it will be found almost a quarter of a mile in length.[55] this is a kind of cane (_calamus_); its slender jointed and polished stem is encased in the closely-sheathing and tubular bases of the leaves, which are spiny on their midribs, spiny on their pinnæ, and horridly spiny on the long and tough whip-lash in which the point of each leaf terminates. this lengthened cord is studded, at intervals of a few inches, with whorls of stout and acute prickles which are hooked backwards, and performs an important part in the economy of the plant. we see how it sprawls along the ground a few yards, then climbs up a tall tree, runs over the summit, descends on the opposite side to the ground, mounts over another tree, and thus pursues its wormlike course. now as the pinnate leaves are put forth at every joint, the formidably armed flagellum affords a secure holdfast to the climbing stem, which otherwise would be liable to be blown prostrate by the first gust of wind; the recurved hooks, however, catch in the leaves and twigs of the trees, and effectually maintain the domination of the prickly intruder. it is obvious that every inch sprawled over by this trailing stem supposes all the previous inches of its lengthening course; that every successive joint implies the existence of all the earlier joints; that every whorl of spines involves the development of every former whorl. yet our reasoning is at fault; there has been as yet no succession; the development has been simultaneous, for it is the development, not of growth, but of creation. enough of palms. look at this _agave_. its thick, fleshy, glaucous leaves, with spinous margins and pointed ends, are arranged in many whorls on the summit of a stem, which is scarcely visible, as it barely rises above the soil. from the centre of the crown springs the stately flower-stalk, itself a tree of forty feet in stature, having a cluster of yellow blossoms at the extremities of its candelabra-like branches. have we here any clue to the past history of the plant? the tall flower-stalk, it is true, is of rapid growth, its whole stature having been attained within three or four weeks. but those massive leaves! each of these lasts many years, and their development is as slow as that of the flower-stalk is rapid. certainly we cannot assign to this individual, in the very vigour of its inflorescence, an antiquity less than half a century, and perhaps it may be considerably more. you are altogether wrong; for it is but just called into existence. [illustration: traveller's tree.] we pass on, and pause before a noble example of one of the stateliest of plants,--the traveller's tree (_urania speciosa_). it is a great musaceous plant, resembling one of those fans which in the southern states of america are made by ladies out of the broad tail-feathers of a turkey. its leaves, of vast size, consist of a broad oblong lamina of the most brilliant green hue, divided equally by a midrib which descends in a smooth cylindrical petiole, much longer than the lamina (which is itself eight feet or more in length). each leaf-stalk terminates below in a great demi-sheath, out of which springs another, in a zigzag or distichous fashion, the whole diverging, as they rise, in the same plane. below the alternately-sheathing leaves, of which there are but eight at present existing, there are the bases of others, now dead, which, when alive, evidently followed the same arrangement; and these give place yet lower to rings, each partly surrounding a massive conical stem. i fear we have no criterion for determining the exact age of such a plant as this from actual observations on its rate of growth. from the fewness of its existing leaves they probably endure a considerable time; but at all events here are indubitable evidences of successive generations of leaves which are now past and gone; some of which are represented by withered rib-bases, while older ones have left but the scars which indicate the positions on the trunk where once they stood. here are distinct testimonies to the lapse of a considerable period of time since the magnificent _urania_, began its existence. yet we should err egregiously by giving credence to them, since these developments are all _prochronic_. "what a lovely butterfly!" nay, it is a flower: though it dances in the air with an insect's fluttering flight, and seems to present in its broad wings of yellow and orange, and in its long and slender members, an insect's form and hues, it is but a flower fixed at the end of a lengthened stalk, which hangs from, a mass of leaves and bulbs, seated in the fork of this huge mahogany-tree. we will neglect the flower, curious and beautiful as it is, and examine this crowded mass of roots and fleshy leaves and oval bulbs. tracing the slender lengthened footstalk to its origin, we see that it springs from the lower part of a flat, ovate, or nearly round, ridged, pseudo-bulb, of a purplish-green hue, of which there are many, much crowded together. the point of issue of the flower-stalk is concealed by an enveloping husky scale, which is the withered condition of a former leaf. from the base of another bulb a thick obtuse cone is pushing forth, which is the commencement of a new leaf-shoot; and here is one considerably advanced. in this latter there is nothing very remarkable; it is a thick, growing shoot, formed by fleshy leaves nearly doubled together, each sheathed by its predecessor. but soon this will cease to grow, and the point will dilate into an oval bulb, which will be a reservoir of nutriment for the future flower. in fact it will add another to the matted mass of bulbs which are already accumulated, crowned with two great thick, leathery, ovate, brown-spotted leaves, and marked with the scars of the leaves which are now growing, but which will then have sloughed away. in this _oncidium_, then, we have evidently a record of many bygone processes. before the flower could open, the flower-stalk must have been developed; before this, the pseudo-bulb must have been formed; before this, there must have been a well-formed leaf-shoot, which must have been first a conical bud pushing forth from some anterior bulb;--or, if that shoot had been the first of the mass, then it must have looked back to a seed, which of course looked back to the capsule of a pre-existent flower, and so on. yet this is all fallacious; for the butterfly-flower is but just created. as beautiful, if less curious, is the crowded spike of purple blossom that adorns the tall stalk of this terrestrial orchis. the flower-stalk springs from the midst of a few large spotted leaves, which terminate below in an irregular fleshy tuber of glutinous consistence. this tuber is shrivelled, and is in process of exhaustion and decay; but a horizontal stem has pushed out underground, which has at its extremity a second tuber, as yet immature, but plump and swelling. this growing tuber contains the elements of the leaves and flower-spike of next season: the shrivelling one was, last year at this period, in exactly the same condition as the swelling one is now; it too was pushed out horizontally from a preceding one which was then shrivelling, and so backward. these pre-existing stages can with certainty be announced by the vegetable physiologist; who yet would be deceived in this instance, because the plant has been but just created. this elegant _gladiolus_ that displays its tall spike of crimson blossoms from the midst of its flattened folded leaves, affords us a similar example of retrospective energy. if i dig away the light soil from around its base, i discover two globose corms, fleshy swellings of the stem, accumulations of nutriment obtained during the vegetative activity of the plant, and destined to support it during the season of inaction, and therefore stored up for that purpose. [illustration: corm of gladiolus in june.] the uppermost of these globose corms is that of the present season; it is as yet small and immature, being in process of formation by the assimilation, consolidation, and deposition of new matter by the action of the leaves. this is sheathed in the tubular bases of the leaves, which expand above; and it is seated on a larger, riper, and more spherical corm, which is wrapped in a brown fibrous skin. this is the matter which was deposited in the course of last spring and summer, and the brown skin is the remains of the leaves of last year. this corm has remained inactive, since the decay of last year's leaves, until this winter, when the root fibres, which we see descending from the lower surface, began to form, and an upward prolongation of the stem followed, which, as it grew, swelled into the upper corm. in the centre of the under surface of the corm of last season, in a depression surrounded by the white root-fibres, there are some almost decayed remains of a deep brown hue. these are the last vestiges of the preceding year's corm, and they exhibit the condition in which the large corm will be next spring, when the small half-formed one will be in the state and position of this larger one, and will in like manner be surmounted by its rising successor. thus there are in this plant ocular proofs of two years' history before the present; yet these proofs are invalidated by the fact of its creation this day. behold now that singular plant, the grass-tree (_kingia australis_), displaying what seems an immense tuft of wiry grass elevated on the summit of a trunk which is formed of the united bases of myriads of decayed leaves, the representatives of many generations of these organs. the silvery leaves which constitute the existing crown, and the numerous spikes of blossom which stand up in a circle diverging from the midst of them, give to this plant a most striking effect. that, however, is not our present concern, but the evidences which we may be able to gather from it of a previous history. for some distance below the living leaves, the trunk is connected by the withered, hanging, but still persistent leaves of several successive developments, a ragged drapery, of which we might certainly say- "----when unadorn'd, adorn'd the most." the lower portion of the stem is, however, destitute of the decayed leaves themselves, the lozenge-formed bases of them alone remaining, still separable, indeed, but sufficiently compact to make in the aggregate a sub-cylindrical column of loose texture, which may in familiar parlance be termed a _trunk_. this portion is marked by alternate enlargements and constrictions of the outline, which appear to indicate seasonal growths. the specimen before us is about twenty feet in height, exclusive of the crown; supposing these swellings to mark a year's growth, and to be continued in the same proportion on that part of the trunk which is masked by the decayed leaves as on the exposed part, we should conclude this tree to be about thirty-five years old; for there are about thirty-four such swellings, each of which contains about four hundred of the lozenge-shaped bases of the fallen leaves.[56] remember, however, that we are looking at the grass-tree, not as it now appears on the sandy plains of western australia, in the nineteenth century, but as it came out of the hands of its almighty creator at some precise but unknown period of past time. this white lily, crowned with its cluster of nodding flowers, magnificently beautiful, each a fair emblem of the spotless purity of a noble virgin--if we remove the soil from its base, we shall find that the stem springs out of a fleshy bulb. this is covered with thick yellow scales, by taking away each of which in turn, we see that the bulb is made up of such, surrounding the central mass which has pushed upward, in the form of the stalk, with its leaves and flowers. [illustration: section of lily-bulb in july.] now the whole of this beautiful array which we see was formed last summer, when, if we had divided the bulb longitudinally, we should have seen every leaf, every tiny blossom, folded together, and most snugly packed within the encircling scales, which are, indeed, undeveloped leaves; while from the base of the bulb so formed we should have seen pushed up on the outside of it, but yet within the common envelope of the exterior scales, the flower-stem of last season. there could not possibly have been this raceme of virgin blossom, if it had not been formed during the preceding season within the bulb; so that its existence is a record of a year's growth at least. yet this is the first hour of the lovely lily's life; an hour ago it was not. the face of the rugged cliff that rises perpendicularly above us was, a few moments ago, quite naked and bare, or diversified only by a few stunted prickly shrubs that sprang from its crevices. now, by the mighty fiat of god, it is in an instant festooned from top to bottom with a most graceful drapery of round pale-green leaves, and slender stems no thicker than whipcord, and multitudes of spiral tendrils that climb, and hook, and catch, and entwine among the thorny bushes, and around the angles and prominences of the rock. we trace this curtain of verdure downwards, and find that it resolves itself into some half a dozen of wiry-stems, that issue from different points of the surface of what seems a boulder of brown stone, or a block of rough-hewn timber, at the foot of the cliff. [illustration: testudinaria.] this angular block is, however, worthy of closer examination. it is of no definite form, huge and uncouth, lying as if cast accidentally on the ground. its whole surface is divided into a multitude of polyhedral pieces, that look as if they had been cut into these forms by human art. each division has a small angular face, and its sides display close parallel lines, all following the directions and angles of the outer face, but each line enclosing a slightly wider area than the one above it. these woody plates closely resemble in their angular forms and their concentric lines the plates of a tortoise's shell, and hence our botanical friend, to whom we will appeal for an opinion as to the age of the block, will call the generic name _testudinaria_. "well, i cannot give you any very precise judgment on the matter. the block itself is the tuber of a sort of yam, which grows above ground instead of below. it is a woody mass of great age. the angular plates are the bark, and they are so divided in consequence of the gradual growth of the tuber, tearing open its periphery to obtain more room. the concentric lines on the edges of the plates will not give us any adequate idea of the age of the mass, for though they indicate seasonal growths, the earlier layers have been worn away in the lapse of ages, and there are many layers of bark that have not yet been burst by the expansive force of the growing wood. it is known that these blocks are of very slow growth; in tropical regions they last, with scarcely perceptible increase, from generation to generation. from such vague data as we possess, i might loosely conjecture this tuber to be a thousand years old." we thank our scientific friend, and think it a very satisfactory report on an organism, which we saw called into existence five minutes ago, before our eyes. come away; for i wish you to look at this _encephalalartos_. a horrid plant it is, a sort of caricature of the elegant palms, somewhat as if a founder had essayed a cocoa-nut tree in cast iron. out of the thick, rough, stiff stem spring a dozen of arching fronds, beset with sharp, sword-shaped leaflets, but having the rigidity of horn, of a greyish hue, all harsh and repulsive to excess. in the midst of this rigid coronal sits the fruit, like an immense pine-cone. the swelling column that constitutes the stem is but a mass of pith, surrounded by a thin case of wood, and enclosed by the remains of former leaves. the whole surface is covered with the lozenge-shaped scars of these, in vast number. thousands of these there must be in this trunk of eight feet high, and a foot thick. the leaves of the existing crown are few and very durable, so that it would be no unreasonable conjecture to suppose that this great cycadaceous plant is seven or eight centuries old. [illustration: encephalartos.] nay, for this also has been created even now! what shall we say to _this_ singular phenomenon? observe yonder gigantic fig (_ficus australis_) growing out of the face of that vast rocky precipice. it is not so much to the massive grandeur of the trunk, nor to the widespread head of dense foliage, that i call your attention, as to the broad expanse of roots, from the thickness of your body to that of your little finger, which have crossed and interlaced and separated and re-united, in all imaginable ways, until the whole forms a great flat network of wood, investing the surface of the rock, and following all its projections and angles with singular faithfulness, for a space of many square yards. would you not say, admitting that the figs are rapid growers, that many years must have elapsed since the minute seed was dropped in yonder crevice, by some vagrant parrot that wiped his beak after breakfast on the point of rock? would you not say that many years must have passed from the time when the tiny shoot peeped from the rocky chink, to the present moment, when the leafy honours of the crown above and the woody wall of the roots below combine to repay the protection which the plant in infancy received from its stony foster mother? of course you would; and most truly too, did you not know that the fig-tree is now rejoicing in the first hour of its new-created being. so with its noble congener here, the many-trunked banyan (_ficus indica_). although not an old tree, its canopy of broad downy leaves is already supported by so many secondary trunks, that it is not easy to say which of the larger stems is the mother trunk, and which the hopeful daughters. every one of these stems, some just protruding from the horizontal limbs, others hanging midway between the leafy roof and the earth, some just inserting their slender spongy tips into the soil, others thick and pillar-like--is an evidence of progressive development, and therefore of lapsed time; only for the qualifying fact, that the development in this case is _prochronic_. here is the great _euphorbia grandidens_ of africa. its stout trunk is marked with a number of holes, some four or five inches apart, arranged in perpendicular rows. in some cases they are rather depressions or pittings than holes, and look like what would result from borings made with an auger in pitch in warm weather, the margins of which had nearly closed, subsequently. what is the explanation of these marks? they are all records of time. from each of these spots once grew one of those angular prickly branches, that look like our commonest sorts of _cactus_, and which are now confined to the summit of the trunk, arching out from it, somewhat like the branches of a candlestick. it is the habit of this plant, when the stem has acquired a certain thickness, that the branches should, after a time, decay and drop off at the point of their union with the trunk, or rather a little below the surface, so as to leave the shallow holes or pits which we see. after their decadence, the growing bark gradually swells around the scars, and has a tendency to obliterate them. this may account for the non-appearance of them on the lower parts of the stem. here, then, are demonstrations of several successive stages of development. first, the stem must have been in existence before any lateral branches could have sprung from it. secondly, the branch shot out. thirdly, it put forth its spines and leaves. fourthly, it died and sloughed away. fifthly, the growing bark encroached on, and finally obliterated the cicatrice. in this individual, all these stages are illusory, or rather they are prochronic. see this noble tulip-tree (_liriodendron tulipiferum_), a giant of this primeval forest; its towering trunk is crowned with a head of large massy foliage, of a rich deep verdure, among which shine numbers of great golden tulip-like blossoms, as fragrant as beautiful. it is, however, the leaves that grow on the terminal twigs that i wish you specially to notice. these, which, as you see, are large, and of a remarkably elegant form, are fixed at the end of long petioles, which are set alternately on the twig. notice, now, the manner of their development; the young unexpanded leaves grow within two large leaf-like bracts, forming an oval sac, which, as the young leaf increases, swell, and at length burst, and are left on each side of the base of the leaf-stalk. there is a succession of these. on this growing twig, for instance, i find three leaves already expanded (_a a a_ in the accompanying figure), and as many pairs of these bracts (_b b b_) at their bases; the twig is terminated by a pair (_c_) convex outwardly, and whose edges are in contact with each other; if, now, i cut off one of these (as represented at _d_), i expose the next leaf (_e_) folded together, and bent downward, in its pretty manner of _vernation_; beside it is another pair of bracts (_f_), whose edges are not only in contact, but mutually adherent, and that with considerable force. on tearing these apart, i discover another smaller leaf, and another smaller pair of adhering bracts, which again contain a similar set, only yet more minute, and so on in succession, till i can no longer trace them. [illustration: twig of tulip-tree.] now it is manifest that the uppermost of the three leaves, together with the developing terminal bud, was at one time enclosed in the pair of bracts immediately below its base; that, before that, the middle leaf, with all above it, was similarly incarcerated in its own proper tracts; and, at a period anterior to that, the lowest leaf also. each pair of bracts is therefore a record of a past period; and together they testify to a succession of past periods. and yet their combined testimony is utterly worthless, because the noble tree was created in its magnificence this very day. the beautiful twiner (_bignonia_), which has cast its ample festoons over the topmost branches of yonder towering mora-tree, almost concealing the natural foliage with its own elegantly pinnate leaves, and adorning it with its gorgeous trumpet-shaped flowers, is distinguished by a curious property, indicative of the years that have passed over it. in its adult maturity, as we now see it--the glory of this tropical forest--we should find, if we cut across the main stem, that its wood is divided into lobes arranged in a radiate or star-like fashion, like the divisions seen on dividing an orange transversely; and these lobes are thirty-two in number. but this condition has not existed through the life of the plant. the wood has always been lobed, but the number of the divisions has varied, and that in geometrical ratio. before the present stage, the constituent lobes were sixteen, which became thirty-two by the subdivision of each. in an earlier stage there were eight lobes, and, earlier still, four, which was the commencing number; the duplication having proceeded in each case by the fission of each of the existing lobes into two.[57] now though this phenomenon will afford us, on the data we at present possess, no insight into the age of the plant, considered as an actual chronological period, an examination of a transverse section would always determine which stage is then present, and, by consequence, how many previous stages have been passed through. and thus we obtain a distinct clue to the former history of the organism, though we cannot mark it off into months and years. yet the fact of creation stultifies all the conclusions that we might form from such premises; since it does, _ipso facto_, contradict every such thing as a previous history. on this _anona_ there is an intruder more strictly parasitical; it is a _loranthus_, with long, club-shaped, richly-coloured blossoms. the branches of the supporting tree--a nurse who feeds her foster-child on her own vital juices--are over-spread for a large space with the shoots; which, springing each from its own disk, appear like so many distinct individuals, but are really all parts of a single plant, springing from a single seed. (for this curious fact we are indebted to the observations of mr. griffith, who has investigated the singular history of these parasites.) the ripe seeds firmly adhere to the substance on which they are applied, by means of their viscid envelope, which soon hardens into a transparent glue. in the course of two or three days, the radicle curves towards its support, and, as soon as it reaches it, becomes dilated and flattened. an union is gradually formed between the woody system of the parasite and that of the stock, after which the former lives exclusively on the latter, the fibres of the sucker-like root of the parasite expanding on the wood of the support in the form of a _paté d'oie_. up to that time the parasite had been nourished by its own albumen, which is now exhausted. as soon as the young parasite has acquired the height of one or two inches, when an additional supply of nourishment is required, a lateral shoot is sent out, which is, especially towards the point, of a green colour. this at one, or two, and subsequently at various points, adheres to the support by means of sucker-like productions, which are precisely similar in structure and mode of attachment to the original seminal one. the fibres of the parasite never penetrate beyond their original attachment; in the adult the sucker-bearing shoots frequently run to a considerable distance, many plants being literally covered with parasites, all of which have originated from one and the same seed.[58] [illustration: young plant of loranthus.] in this case, again, how delusive would be any inference of actual lapse of time deduced from the condition of a plant, which had been created as an adult capable of reproducing its race! here is a great impenetrable thicket of prickly pear. the delicate sulphur-hued flowers expand their broad bosoms to the sun, and the swelling fruit beneath is already putting on its lovely blush of crimson. how curious are the leafless but leaf-like dilatations of the stem--these flat oval plates of parenchyma, studded with clusters of woody and most acute spines!--every one of these expansions is an expression of time, as they are of course successive, though several may be formed in a single season; and not only so, but the tufts of spines, which grow at the points of intersection of crossing lines, in a network pattern, are all successive, appearing in turn as the expanded joint of the stem grows out. the jointed dilatations themselves are, however, transitory; in the slow lapse of years the common woody axis enlarges, and the interspaces between the oval plates become gradually filled up with cellular tissue, and thus are obliterated; the stem, as may be seen in the central part of this spreading thicket, becoming round, almost smooth, and of dense woody texture. "this condition is the result of many years," you say. it is so, in the ordinary course of nature; but in the case before us, it has been educed in a totally different manner, and by a totally different energy, viz. prochronically, by the omnipotent fiat of the creator. we have emerged from the forest glooms, and are come within the light and the music of the sparkling sea. and here at its margin, washed by its wavelets, there has been suddenly created a mangrove tree (_rhizophora_), destined to be, doubtless, the fruitful parent of a grove, which by and by will fringe this flat and muddy shore for miles, shutting out the light and air which now freely play over the beach, and keeping in, beneath a long canopy of dense and leathery foliage, the murky vapours which will rise from the decomposition of its successive exuviations. as yet it is a single tree, but in its perfection of maturity. and see how characteristically we find here that singular structure, or rather habit, which in mangroves of normal development would be the effect of age. the trunk springs from the union of a number of slender arches, each forming the quadrant of a circle, whose extremities penetrate into the muddy soil. these are the roots of the tree--there are no others--that shoot out in this arched form from the base, or "crown" of the stem, taking a very regular curve of six feet or more in length before they dip into the mud. the larger arches send out secondary shoots from their sides, which take the same curved form, but in a direction at right angles to the former; and thus a complex array of vaulted lines is formed, which, to the crabs that run beneath--if they were only able to institute the comparison, must be like the roof-groins of some gothic church, supposing the interspaces to be open to the sky. now, normally, it would require a lapse of several years from the first dip of the radicle of the seed into the soft soil, to form these arches, and to lift the axis of the tree a foot or eighteen inches above the surface. but here the same result is achieved in a moment, by the exercise of creative power. look at this _eriodendron_. what a magnificent accumulation of vegetable cells is here! its colossal trunk rises in naked majesty, a massive column, to the height of a hundred feet, without a branch. and then what branches! those limbs themselves are of the bulk of ordinary forest trees; they break out, three or four on the same plane, and radiate horizontally to a vast distance, supporting a noble flat "roof of inwoven shade." [illustration: silk-cotton tree.] perhaps the most remarkable feature of this majestic tree is found at the foot of the trunk, which sends out vast spurs, radiating in all directions, and extending to a circle of seventy or eighty feet in diameter. these spurs take the form of perpendicular walls of timber, commonly not more than six or eight inches thick, pretty equal in their thickness throughout, and varying in height from fifteen or twenty feet, where they spring from the trunk, to the point where they enter the soil. now the silk-cotton tree has not had this form through its life. when young, say up to twenty or thirty years old, there was no appearance of spurs; the trunk was covered with a green bark, and was studded with great triangular low spines, an inch in diameter. and, what had a curious effect, the middle of the stem swelled into an ovate form, quite symmetrical on all sides. but, as years passed, the ventricose form of the trunk was gradually lost; the bark became of a hoary grey hue or even almost white; the three-sided prickles disappeared from the bole, and were retained only on the upper surfaces of the limbs; and the great lateral buttresses began to fill up the angles which had hitherto existed between the trunk and the main horizontal and superficial roots. i called the noble tree before us an accumulation of vegetable cells. and viewed in that aspect, what an irresistible evidence of the lapse of time does this vast organism present to us! since the whole of this immense structure originated in a single cell, which, by repeated acts of self-division[59] (or, possibly, other modes of reproduction), has gradually built up the mass. yet such a retrospect would be most fallacious in the case before us, since the plant, as a perfect compound organism, with its parts--root, trunk, limbs and leaves, and its tissues--cellular, fibrous, and vascular, has been produced by the instantaneous putting forth of the divine volition. once again. more gigantic even than the towering ceiba, this immense locust-tree (_hymenæa_) appears to penetrate the very sky with its crowd of foliage, which is so remote from the earth, that our eyes cannot avail to discern the forms of the leaves. the straight columnar trunk, like some triumphal monument in the midst of a great metropolis, is of so vast a bulk that a dozen of such men as you and i could scarcely embrace it with stretched arms and joined hands.[60] can our friend, the vegetable physiologist, help us here to form a notion of the time which would be required for the production of this tree in the ordinary way? it is the last favour we will ask of him to-day. come, sir, give us your thoughts on the matter. _the botanist._--"there is a principle which, in trees of this character, namely, such as are of exogenous structure, will determine the age with very close accuracy. each generation of leaves sends down woody fibres, which unite into a cylinder on the outside of the wood previously formed, and beneath the bark." "now, as these cylinders are in general sufficiently distinct, in those trees which renew their leaves but once in a year, it will be enough to count the concentric circles which appear on a transverse section of the trunk, and we shall obtain the number of years during which the tree has existed. in the case of this great locust, the rule, to be sure, is rather difficult of application in that way; a transverse section of this trunk would cost a little labour. but with this circular saw, which i always carry about with me for investigations of this sort, i can take out a horizontal cylinder on each of two or three sides of the tree, by counting the layers in which i can form a tolerably accurate estimate of the number in the whole diameter. [illustration: section of exogenous tree.] "see; in these cylinders, which do not materially differ, there are seventy-two layers in a foot, that is, each layer is one-sixth of an inch wide. the trunk is, at the part i have tested, about fifty feet in diameter, or twenty-five feet in radius; which would therefore contain just eighteen hundred such layers. as the deposition of new wood, however, is generally more abundant in youth and middle life than in age, the layers are probably a little wider, that is, fewer in a given space, as we approach the centre. for this we must make allowance, and may conjecture that this tree is probably not less than one thousand five hundred years old." now whether the premises of the botanist will bear out this conclusion or not, is not a vital question. for the question at issue is, not, _how long_ it has lived, but, _whether it has lived at all_, before the present moment. it is enough for our point that the tree does, in its concentric zones, afford ocular evidence of successive epochs of growth. and the proof of this would be equally good, if ten layers were deposited in a year, or if one deposit were made every ten years; equally good, if there were fifteen hundred zones, or if there were but five. it would be easy to confirm the testimony of the zones by that of other parts of the structure. the dimensions of the tree itself bear a fixed and, to a certain extent, recognisable ratio to its age; every leaf on a given twig has been successively developed from a leaf-bud, the opening of which and its elongation into a twig occupied, normally, a definite period; each bough, each of those mighty limbs, was once a twig, was once an undeveloped leaf-bud, whose expansion to its present condition was a process, of which time was an inseparable and, within certain limits, a mensurable element. if, then, we were precluded from examining any other organism, as it proceeded from the formative hand of its creator, than this single tree, we should be amply warranted in inferring a past existence (be it longer or shorter, which is no matter) from the phenomena of its structure, which inference the fact of its creation would flatly contradict. viii. parallels and precedents. (_invertebrate animals._) "there is a kind of character in thy life that to th' observer doth thy history fully unfold.----" (_shakspeare._) leaving the vegetable kingdom, those organisms which, though beautiful indeed and instructive, are yet inanimate, let us seek others which are endowed with a higher style of life, a life which is distinguished by a measure of consciousness of the exterior world, and a perception of relations to it. let us look for animals. we retrace our steps to the verge of the rippling sea, where the belt of umbrageous mangroves fringes its margin. beneath the arching roots of these are now reposing in the warm sunlit shallows many creatures which number this as the first day of their existence. it is their natal, or rather (to make a word) their _creatal_ day. here is a specimen of the sea-pen (_pennatula_), closely resembling a rather thick and fleshy feather, with its quill-end inserted in the tenacious marl which constitutes the floor of the sea along this shore, and with the greater part of its body, including all the pinnated portion, erect, and waving lightly in the gentle swell of the bay. its central stem is beset on each side with about twenty-five horizontal purple pinnæ, and each pinna bears from five to fifteen polypes with eight tentacles each. let us wade out to yonder reef. see this great mass of millepore, growing in thin irregular perpendicular plates, which join each other at various angles, so as to form a large open honeycomb-like structure, much resembling the second stomach of an ox. it is covered with what appears a thin stratum of fawn-coloured jelly, but this consists of innumerable disks, which protrude from myriads of orifices not larger than those produced by the punctures of a fine needle; as we may discern by touching the soft slimy surface, when the whole retires, and leaves apparent only the white stony surface dotted with numberless holes, within which the disks have disappeared, and whence they will again presently re-appear. here too is a massive shrub of stone, a noble example of the muricated madrepore. it consists of a great multitude of short tranches, which are themselves branched and branched again, every part covered with little mammillary warts, and pierced with innumerable holes in which stand radiating plates of the common stone. out of these plated orifices, especially those towards the tips of the branches, for the older ones are empty and dead, we see perpetually peeping forth, expanding for an instant, and then coyly withdrawing, lovely little green disks, surrounded with thread-like tentacles; and from the extreme end of each branch there protrudes one exactly similar to the rest in all respects, except that it is nearly twice as large. here then are the living architects; these have secreted within their gelatinous membranes the calcareous atoms, whose aggregate forms the stony shrub before us. shall we try to estimate the number of polypes that have been occupied in building this tree? there are about a hundred branches, which, taken one with another, and followed along the sinuous course of their many branchlets, we may estimate to average a continuous length of eight feet each; that is, 800 feet of branch in all. now we may consider these branches as averaging a thickness of two inches and a half in circumference, which gives us a surface of 24,000 square inches. finally, there are about ten polype-cells in each square inch; and thus there are or have been in this coral-mass, nearly a quarter of a million of polype inhabitants. [illustration: muricated madrepore.] but look at this dark crimson edifice of many stories, tier above tier, each horizontal floor of red stone sustained by a multitude of slender cylindrical pillars. when we look closely at them, we see that the pillars are tubes, perforating one or more of the floors, from the lowest tier to the uppermost. have we any clue to the age of these corals, or to that of either of them, supposing we did not know that they have been created to-day? not definitely, perhaps; but indefinitely we have, certainly. in the case of the sea-pen, the polypes have all been formed in succession; as also in that of the stony millepore and madrepore, with this addition, that every newly formed polype deposited an increase to the stony substance, which thus went on increasing till the great foliated or ramified mass that we see was formed.[61] and so, with this series of floors and pillars, which is the solid portion of another coral-polype, the organ-pipe (_tubipora musica_). [illustration: organ-pipe.] every one of these stories has been formed in succession. from the tips of some of the tubes we see protruding an elegant polype of an emerald-green hue, having eight starry tentacles, and giving off from its base an enveloping membrane, which spreads over the rim of the tube and descends on the outside to the floor. by means of this vascular membrane, both tube and floor have been formed. calcareous particles, deposited, one by one, in its substance, gradually built up the tube of the primary polype, or probably the tubes of the first series, the basement or ground-floor. when these tubes had arrived at a certain height, all simultaneously began to develope the fleshy membrane horizontally, which expanded until that from each touched that from its neighbour, with which it united. meanwhile the calcareous deposition went on in this horizontal layer, and thus the first floor was made. now from the living vascular upper surface of this layer sprang up at certain spots buds,[62] offshoots of the common flesh, which soon rose into columns, and, by a process of calcareous deposition, became tubes with terminal polypes, which in turn spread out a horizontal layer, and thus the second floor was built. hence a new race of polypes budded, which by and by formed the third floor; and so on in succession, until the series had attained the height which we see. if we assume one of these stories to be the growth of a year,[63] we have ocular evidence in this specimen of six years' age, for here are six successive floors. but no: for it was created complete, as we see it, this very hour. yonder goes a _medusa_, pumping its way laboriously, yet not ineffectively, just beneath the surface of the clear wave. it is a great affair, nearly a foot in diameter. have we, from merely examining its appearance and structure, any criterion by which we can guess whether it has lived an hour, or a year, or ten years? surely we have; for this mass of clear jelly is composed, like all other organic bodies, of cells, which have been gradually generated, by nutrition and assimilation, from the embryo.[64] this process must have occupied many months, if not several years; but the history of this medusa did not begin when it took its present umbrella-like form. shall we trace it back a little farther? at some time back, then, this creature detached itself as the terminal one of many little saucer-like bodies, which had been for some time previously forming by the gradual constriction of a thick fleshy stem. before the constriction began to be visible, this stem was the body of a white hydraform polype, affixed by its base, and furnished at its free extremity with thirty-two tentacles. it had lived several years in this form, developing many hydroid polypes, just like itself, by successive gemmations. before it took this shape, which it assumed gradually, its tentacles being developed in geometrical progression, 32 from 16, from 8, from 4,--it was a soft ovoid planule clothed with vibratile cilia, which swam freely in the sea, like an _infusorium_. thus the physiologist would confidently assign to this medusa an existence of several years, as an independent organism; _nor could his conclusions be controverted_, except by the knowledge of the fact that the medusa _has been but just now created_. we pass on. here is an _echinus_. let it be borne in mind still, that we have, _in idea_, the power of pursuing our researches on each creature at the moment which follows that of its creation; and that, when that actually was is of no consequence to our investigation. here then is this new-made _echinus sphæra_, a somewhat conical globe of three inches diameter, which is covered with a forest of spines, pedicellariæ, and suckers, and which glides majestically along, with an even but slow progress, over rock and reef. its vitals are enclosed in a hollow box of calcareous shell, which is built up of nearly a thousand pieces. this specimen, which is rather below than above the average size, is formed of ten meridional rows of large plates (the interambulacral), and ten of small (the ambulacral). the former series are each composed of thirty-two plates, making in all three hundred and twenty; the latter have just double that number, making six hundred and forty; thus this urchin's box is built up of nine hundred and sixty plates; every one of which is of definite shape and angle, and fits into the angles of its fellows with the accuracy of the most skilfully constructed cabinet-work. now every one of these plates is an eloquent witness to the past life-history of the sea-urchin. for the reason why the enclosing box is made of so many pieces is, that it might gradually expand and enlarge its capacity with the ever increasing requirements of the soft organs within. every plate is enveloped by a vascular flesh, from which the calcareous particles are deposited in a constant and perfectly uniform ratio; and thus all the constituent plates are continually enlarged by additions to both the internal and external surfaces (increasing their strength), and to their sutural margins (increasing their combined capacity), until the adult dimensions are attained. the size of the new-born echinus is not nearly equal to that of one of these plates, and the progressive increase of the plates by deposition on their edges has certainly taken several years to accomplish.[65] the same result is inferrible from the structure of the spines with which every plate is armed. each of these is a very long cone of calcareous matter, arranged in minute oval chambers, divided by thin glassy walls, and deposited particle by particle from the thin stratum of living flesh with which each has been invested from its first embryonic development. but of this _echinus_, as of the _medusa_ before, we find a history anterior to either box or spines. its first appearance in this stage of existence was as a barely-visible circular disk, constructed on the outside of the stomach of a singular transparent organism, much like a medusa, but of a domular form with four or six legs, stiffened by calcareous rods, and a crowning pinnacle. for some undefined time this gelatinous dome had been gliding with a stately movement through the open sea, before there was the least trace of the disk, which afterwards grew to the _echinus_. in its earliest condition the dome itself was a soft, spherical, mulberry-like _infusorium_, covered with vibratile cilia; this altered its form to that of a three-sided pyramid, and this to the vaulted dome. clearly, therefore, we have a right to infer a past history of the urchin, and that of not a few distinct stages. but no; the specimen has commenced its history within an hour! yonder feather-star (_comatula_) notice; which, having just now started into mature life at the almighty fiat of its creator, goes careering joyously through the sea, expanding and contracting its many-jointed and feathery arms, as if it had been accustomed to the alternation for a long life, and ever and anon settling itself by grasping the points of rock with its dorsal claws. you would hardly think that those flexible and slender arms were made of stone: yet they are; every joint of the stems and of their pinnæ is a vertebra of stone (precious stones, you will say--topaz and ruby--from their brilliant hues), which has been formed and deposited atom by atom, by the slow and gradual process of secretion of calcareous matter; the lime having been primarily collected from the sea-water which held it in solution. at least, such is the physiological deduction. [illustration: comatula and young.] but there was a period in the _comatula's_ history when it was not a free-swimming star, but a lily-like flower of ten slender fringed petals, seated at the summit of a long stalk, with a central columnar axis of stone. before that, the flower-head had a bud-like figure, and the petals were minute and destitute of lateral fringes; and earlier still, it was a tiny gelatinous club without any development of stone, affixed by a spreading base, and shooting forth from the top a few pellucid processes. earlier still, it was, no doubt, an infusory-like gemmule, clothed with cilia. through all these successive stages, which, of course, occupied a considerable period of time, we should certainly affirm the feather-star to have passed, did we not know that it has this very hour burst into existence. that panther, whose tawny fur studded with black rosettes appeared so beautiful as he bounded with agile grace from glade to glade just as we emerged from the forest, contains within his intestines, though you cannot see it, a mature tapeworm. the body of this parasite consists of some hundreds of square flattened segments, each of which includes a complicated generative apparatus, equal to the production of thousands of fertile ova. is not this an evidence of age? for, first of all, consider that the formation of each of these hundreds of joints has been a work of development from the anterior parts; and therefore they record as many distinct and successive processes as there are segments. and, secondly, remember that the _tænia_ did not commence existence as a _tænia_, nor in the conditions in which it now exists, within the bowels of the panther. it looks back to another form, and to another living _nidus_. there was a time when this parasitic creature had no ribbon-like body of flattened generative segments. there was, indeed, the same curious head, a tiny globose knob at the extremity of a slender neck, furnished with the same array as now, of rows of hooks and sucking disks. but in place of the segments, the neck merged into a membranous bladder distended with clear fluid. it was not a _tænia_ then, but a _cysticercus_. its home was at that time the interior of a living animal on whose vitalized juices it was sustained, but that animal was widely different from its present patron. it was an antelope, that cropped the wiry grass and aromatic shrubs of the arid plain. earlier still, the germ of this _tænia_ was an egg lying on the ground, having been discharged from the rectum of another panther, in the bowels of which it had been developed by one of the segments of a former _tænia_. let us now trace the history of this organism onwards from the point at which we have arrived in our retrograde researches. the parent _tænia_, still snugly ensconced in its obscene abode, partially matured and then separated the ultimate generative segment, containing many thousands of ova, far advanced towards perfection. the detached segment now became enclosed in the fæces of the carnivore, and was at length discharged, enveloped in the pellet. the eggs, acquiring maturity, were hatched, and the infant worms individually scattered themselves among the surrounding herbage.[66] one of these was devoured with the herbage by a grazing antelope, and having safely escaped the perilous ordeals of mastication and rumination, passed into the stomach of that ruminant, whence it soon made its way by some unknown but unerring route to the liver, in the parenchyma of which organ it rapidly developed the cyst, which gave to the present stage its proper character. the antelope fell a prey to the ferocious cat; its flesh was quickly digested in the stomach, but the gastric juice produced no effect on the _cysticercus_. this parasite had merely changed its residence for one more commodious, or at least more suitable for its further development. it presently attached itself to the walls of the intestine by means of its oral hooks and suckers, and, getting rid of its vesicular sac, with its fluid contents, probably by absorption, it began to develop, joint by joint, that immense ribbon, which it possesses now, and which constitutes it a tapeworm. such is the "strange eventful history" of this repulsive creature; a history legitimately deducible, in all its stages, from its presently-existing condition. but it is a history altogether illusory. the _tænia_ never was a _cysticercus_: the panther is as yet guiltless of capricide: it is this moment called into being, and the tapeworm begins existence within it. this lump of red sandstone that has been rolled about in the sea, till all its points and angles are worn smooth, is now roughened again by the close and firm adhesion of extraneous substance, in the form of a cluster of shelly pipes, which twine irregularly over the surface of the boulder, and then start up erect with open mouths. these are the tubes of a species of _serpula_, and the worm itself is seen now slowly emerging from one of them, and introducing its conical stopper, and elegant fans of white and scarlet filaments, to the genial daylight. observe, however, that the tubes are not of the same diameter throughout. at the point where they start up from contact with the stone, they are considerably smaller than at the tip; and if we trace back the adherent portion along its tortuous course, we find that it constantly diminishes until it is but a slender white thread of stone. now this slender extremity was formed first; and as the worm itself grew, so it progressively required a larger and yet a larger habitation; which was readily provided of the due dimensions, because the material, which is limestone, was secreted by the swollen collar of the worm, and being freely poured out as required, was moulded of the proper calibre by the rotatory motion of the animal, combined with the special use of certain tactile organs for the purpose. the shelly tubes themselves afford us ocular evidence not only of their progressive formation, but also of the successive steps by which this was effected. for at certain intervals of their length we perceive rings of the common stony substance, which mark the rim or mouth of the tube as it existed after each periodic increase. the mouth of the tube is, as we see, slightly expanded in a trumpet fashion; but as the general cylindrical figure is to be maintained, the next deposit of calcareous matter is not made at the very edge of the lip, but on a ring a little way within the margin, whence it is carried up, leaving the former margin slightly projecting. [illustration: serpula.] who could hesitate to assert that a history of past time is legibly written in the annulations of these stony tubes? and yet the creatures, with their tubes, have been but this instant created. but here is a tube of quite another construction, though inhabited by a kindred worm. it is wholly built up of sand, the inimitable architecture of the indwelling _terebella_, who has thus succeeded in performing a task which defied the efforts of that too industrious artizan,--the familiar of the renowned michael scott.[67] our worm has certainly spun a rope of sand, and one which holds together with surprising tenacity. the instrument which our little architect wrought with are the long tentacles, which, like a tangled tuft of yellow sewing-cotton, twist and twine over the floors of sandy pools. nothing at first sight seems less adequate for the purpose than those very slender, soft, and flexible threads. dr. williams shall tell us how they are used. "they consist of hollow flattened tubular filaments, furnished with strong muscular parietes. the band may be rolled longitudinally into a cylindrical form, so as to inclose a hollow cylindrical space, if the two edges of the band meet; or a semi-cylindrical space, if they only imperfectly meet. this inimitable mechanism enables each filament to take up and firmly grasp, _at any point of its length_, a molecule of sand; or, if placed in a linear series, _a row_ of molecules. but so perfect is the disposition of the muscular fibres at the extreme free end of each filament, that it is gifted with the two-fold power of acting on the sucking and on the muscular principle. when the tentacle is about to seize an object, the extremity is drawn in, in consequence of the sudden reflux of fluid in the hollow interior; by this movement a cup-shaped cavity is formed, in which the object is securely held by atmospheric pressure; this power is, however, immediately aided by the contraction of the circular muscular fibres. such, then, are the marvellous instruments by which these peaceful worms construct their habitations."[68] since the slender tentacles are the implements by which the sand-tube is thus built up, it is manifest that the existence of the tube must be subsequent to the existence of the tentacles. but the _terebella_ was at one time without tentacles; so that its history certainly reaches back to a date anterior to the existence of a tube. several stages of life have intervened between that distinguished by the present worm-form, and its infant condition, when it swam as a ciliated undivided monad. so, at least, we conclude from physiological data; but our conclusions are false, because contradicted by the fact that the mature animal with its case has been just now created. * * * * * let us forsake the ocean-shore, and walk again through the glades of the virgin forest. a white-ant (_termes_) crosses our path, and, by tracking him home, we speedily discover his dwelling, an enormous structure composed of gnawed wood cemented with an animal secretion, and formed into thin but very firm and hard layers. swarms of labourers are passing in and out; and, on our breaking away a portion of the edifice, out come crowding the warriors, with formidable jaws extended widely, ready for the fight. in the interior we find numerous chambers stored with food, and nurseries occupied by young and eggs, the number of which is every hour increasing by the oviposition of the gravid female,--the queen of the city--who is lodged in an apartment in the very centre of the whole. the entire edifice has been built around her; she is the hope of the colony, the only mother in this vast assemblage. it is therefore through her that we must look for a past history; and in her we find it. some months ago, when she was not more than one thousandth part as large as she is now, though then adult, she migrated from some other city not less populous than this is now. it was just before the periodical rains, when, at the time of the great annual swarming, myriads of winged males and females were evolved from the pupa state, and flew out from their native city. this individual female was found by some of the workers that now compose this colony, and was immediately selected to be at once their prisoner and their queen. we thus trace our great egg-laying termes to a city of last year's building, in which for a time she was in an immature condition as a nymph, and before that passed a still less-developed stage as a larva. hence her life-history goes yet farther back to an egg, originally laid by a former female in exactly the same circumstances as those in which we find this guarded and immured individual. thus we reason; but the female, with her host of attendants, and the house, which is inseparable from their present stage of existence, has been created to-day. see that creature which with loud ringing hum is whirling round and round the tassel-like blossoms of this noble _eugenia_. you would think it a bird from its massive size, but it flashes and sparkles in the sun, like a great jewel. now it suddenly alights on one of the crimson flowers, and you may perceive that it is a beetle;--a beetle of vast size, and glittering like a lump of burnished metal;--it bears the name of goliath,--a giant clad in polished armour. this is his first hour of existence; now for the first time has his nervous system responded to the stimulus of the sweet air and genial sunshine. an hour ago he had no nervous system; no system of any sort; no life; no being; no anything;--he was not until this hour. yet if we were to ask a friend conversant with entomology his opinion on the age of this insect, he would immediately give it; not, however, as an opinion, for he would repudiate the uncertainty which such a word implies, but as an indubitable fact, resting on the infallible grounds of constant observation and undeviating experience. [illustration: goliath beetle, and pupa case.] "this fine _goliathus_," he would say, "has not long, probably, emerged from a hollow case of oval form, made of particles of earth agglutinated together by a secretion from the mouth of the larva, and concealed under the surface of the ground. within that sepulchre it has left its cerements,--the shrivelled skin of the pupa, in which it had been wrapped up motionless like a mummy, for several weeks prior to its appearance as a glittering beetle. the construction of the oval cell was the last act of the larva, a thick, massy, heavy-bodied grub, which had fattened for years by feeding on the roots of plants beneath the soil. four years passed away[69] while yon beetle lay on its side, darkly labouring at this occupation; and before that it was a minute egg for some weeks. the specimen before us cannot be far short of five years old." no such thing: the witness is at fault: the _goliathus_ is not _an hour_ old. take notice of the swarm of gnats, which, like a dim cloud, are uniting in choral dance and song in the beam of the setting sun. every member of the band that "winds his shrill horn," has had an aquatic before he had an aërial existence. a week was spent, in lobster-shape, with two breathing tubes on the summit of his body, in passing alternately from the bottom to the top of yonder stagnant pool, and then back from the top to the bottom. and a month was occupied in pretty nearly the same employment, but in another mask,--in fish-like form, with the star-tipped breathing-tube projecting from the side of the tail. but for some months earlier still it was a little lenticular egg, which was agglutinated with a number of others into an oval concave boat, that floated to and fro on the surface of the pool. and there was something worth observing in that tiny skiff of eggs; for it did, in its artful construction, carry the evidence of time back to a former generation. the eggs individually and separately would have sunk to the bottom of the water; it was, however, essential to their life that they should be in contact with the air as well as with the water. hence they were so arranged in the aggregate, that the mass should swim, though the constituent individuals could not. to effect this, the parent gnat, resting on the calm surface of the pool, crossed her two hind legs, and laid an egg perpendicularly in the angle so made: others were added in succession, all maintaining the perpendicular position, all glued together by a cement that resists water, but so arranged, the crossed legs being still the mould, that the outline should be spindle-shaped, while the summits of the central eggs, being a little lower than those of the outer ones, gave a concavity to the boat. so buoyant was it when finished, and the mother's legs withdrawn, that even a drop of water falling full upon it from above, would have failed to submerge it. there it floated, week after week, and month after month, all through the winter, till the genial sun of spring hatched the fish-like larvæ to begin their wriggling existence beneath the surface. now may we not say with confidence, that the sounding-winged insect looks back to the pupa, the pupa to the larva, the larva to the egg-boat? and more, that the form of the boat,--a form so essential that it could not have lived without it,--looked back to the crossed feet of the mother-gnat, the impress of whose angle its extremities sustained? of course we might reason thus: but yet we should be at fault; for the ringing swarm of merry gnats has been this very evening created. [illustration: larva of case-fly.] the case-flies (_phryganea_) that look like delicate moths of sober-brown hue, flitting over the surface of the pond, have, like the gnats, spent a considerable time under water. when they were larvæ, they industriously collected small shells, fragments of stone, bits of reed, and the like matters, and, connecting them together with strong silk, made out of them slender tubes, in which they sheltered their soft bodies from harm, while their hard polished heads and shoulders projected from the open end. and after having lived through the winter (at least, but i rather think more than _one_ winter) in this state, each closed up the entrance of his castle, by spinning across its open end, a transverse screen of lattice-work, made of very strong and stout silk, which, while it should serve the purpose of keeping out evil-minded intruders, during the helpless inaction of the pupa, should at the same time admit the free ingress and egress of water necessary for its respiration. the life of the larva, and the exercise of these, its curious instincts, are, together with the duration of the pupa stage, inseparable precedents of the imago state in which we now observe the flying insects. no, not "inseparable;" for in this case, at least, they had no existence in time; they are prochronic developments. [illustration: melicerta.] in this pond at our feet there is an object worthy of a moment's observation, minute though it is, for it is only visible as a speck to the unassisted eye. on one of the whorl-filaments of this tuft of _myriophyllum_, there stands up a cylindrical tube, firmly adherent to the plant by its foot, but free at its upper end. small as it is, this chimney is built up of hundreds of pellets, solid, round, and yellow; placed in symmetrical order, and firmly cemented together. what has made this tube? ha! here is the little architect ready to answer for himself; he thrusts out his head and shoulders from his chimney-top, and announces his scientific cognomen as _melicerta ringens_. look! he is in the very act of building now. did you see him suddenly bow down his head and lay a brick on the top of the last course? and now he is busy making another brick; his mould is a tiny cup-shaped cavity just below his chin; his material the floating floccose atoms of vegetable refuse. cilia along his flower-like face collect these atoms into a stream, and pour them into the cup; and cilia within the cup whirl them rapidly round and round in many rotations, until with the aid of mucus they are somewhat consolidated into a round pellet. the brick is made, and nothing remains but that it be deposited next the former, in regular progression, and this is done by the tiny [greek: tektôn], suddenly bending his head forward, and bringing the chin-cup with exact precision to the spot. and how long has he been engaged in this piece of work? little more than a day. it was commenced yesterday, when the creature was not more than one-third as large as he is now. but he had lived a few hours before the commencement of his work. he was a rover before he began to be a house-keeper. in that early stage of youth and freedom, before he had made up his mind to settle in life, he had no chin-cup, no flower-like face, and of course no tube. a cylindrical gelatinous pellucid worm, he issued out of the egg, with a brush of cilia on his crown, and danced waywardly through the water. while thus occupied, his form underwent some preliminary modifications, and at length was sufficiently matured, to enable him to choose a spot for the passing of his future life, and to commence the building on which he is still engaged. not so. the pellet which he deposited when we began to look at him, was the first he had ever made; he had been created but that moment; and all the previous pellets of the case had been called into being just as we saw them. they were built up prochronically. i tear a piece of bark from the trunk of this half-decayed tree, and have disclosed amidst the rank-smelling damp and rotten wood, a large _julus_, a slow-moving creature, with some hundred-and-fifty little twinkling feet. as this specimen has attained its adult condition, it must be at least two years old; for it does not acquire its reproductive organs and perfect development till that age.[70] this creature has passed through a rather curious history of evolutions. the egg from which it was produced was lodged in a chamber excavated by the parent, a few inches below the surface of the rotten mould. from this egg proceeded a little kidney-shaped body, without limbs or motion, completely enveloped in a swathe of delicate transparent membrane. about a fortnight it remained in this helpless state, during which its organs had been forming out of the constituent cells, by repeated subdivision, and definite arrangement. at length it burst its cerement, and a minute julus appeared, not more than 1/200th of an inch in length, composed of a head with antennæ, and a body of eight segments, of which the first three carried each a pair of legs. all the multitudinous limbs which we see in this adult have been produced in successive moultings, and all the numerous segments have been produced by the subdivision of the last but one,--that is the joint preceding the anal one,--six at a time. by the time the little animal was ready for the second sloughing, that is, in about a week after the preceding, three more pairs of feet were seen, which had budded from the fourth, fifth, and sixth segments, but which were as yet closely packed down beneath the investing skin; the seventh segment also was obscurely marked into six divisions. the skin was now thrown off, and these changes were perfected; the little julus now had six pairs of feet, and thirteen segments. this process was repeated again and again; the new limbs always developing on the segments last produced, and six new segments being always formed out of the existing penultimate. and by this gradual succession of development, the animal has attained the number of limbs and segments which we now perceive. the antennæ and the eyes have likewise passed through successive stages. we have a right to infer the lapse of a period sufficient to produce these changes, for we see their indubitable results; but our inference would only lead us astray, because we have not allowed for a disturbing influence,--that of the law of creation. this is the julus's first hour of life. see, on the trunk of that towering _cedrela_, a round hole, out of which a large beetle is in the act of emerging. it is a noble _buprestis_, encased in glittering mail, of the most refulgent metallic splendour, crimson, gold, and green. can we find any clue to his age? yes: the white grab has rioted and fattened in its burrows in the timber of this tree for many years; ever gnawing away with its horny auger-like jaws the solid wood in tortuous galleries, which constantly enlarged, as it progressively grew, while its wake, as it advanced, was partially filled by its ordure. the old tree is, no doubt, perforated, through and through, by its winding corridors, as large as your middle finger. as soon as the vermin had passed this his nonage, which, as i say, may have occupied a dozen years at least,[71] he sank into his short pupa-sleep, and here we see him paying his first visit to the light of day. true; this is his first experience of daylight, and indeed of anything; for all the pupa-sleep and the larva-labour were prochronic in this case. the beetle is just created. hark to that hollow roar! there is no mistaking that majestic sound. it is the voice of the many-sounding sea. yonder through the trees we catch a glimpse of its shining face, and here we are at the verge of the cliffs, against whose feet the waves are breaking in white foam. we will clamber down to the rocks. in this weed-fringed tide-pool there is a fine specimen of the shore-crab (_carcinus moenas_). it is a male just arrived at the perfection of adult age; its carapace smooth and wholly dark-green in hue, its under parts rufous orange. its claws. are large and sharp; and the promptitude with which it presents these formidable weapons, extended to the utmost, shows how conscious it is of its warlike powers. to all appearance this crab is several years old;[72] i mean in this his present perfect or imago form. when this form was first assumed, the diameter of the carapace was not more than an eighth of an inch; it is now two inches; a great many periodical sloughings of the crust must have occurred to accomplish this sixteen-fold increase. but four distinct metamorphoses were passed before the commencement of this form. there was the grapsoid form with the outline of the carapace nearly parallel-sided, and the dentations on the sides. before this there was the megalopa form, with the carapace ovate, and the abdomen projecting behind. before this there was the zoea form, with the carapace rising into a tall erect spine, sessile eyes, no claws, and the abdomen a slender jointed cord ending in a triangular plate. and before this, there was the egg, which was laid by the mother crab, and carried by her for a considerable time attached to the false feet of her abdomen. all these evidences of age, clear and unanswerable though they are, are yet fallacious, because the crab has been created but this morning. on this sea-washed branch of a tree, which has been blown off by some tempest, and carried into the ocean, there is a single barnacle (_lepas_). it consists of a hand of many pairs of fringed fingers, protected by a shell of five pieces, and a long flexible cartilaginous stalk, by the lower extremity of which it adheres to the timber. the shelly valves are all crossed by strongly marked lines running over their surfaces in a direction parallel with each other, and with the outer margins of each valve. these, like the corresponding foliations in the tube of the _serpula_, indicate the successive stages of growth; the outlines of every valve having stood at each of these growth lines in succession. on each of the scutal valves in this individual i can count about 260 growth-lines: if we suppose one of these to be made in a week,[73] and the increase to proceed uniformly throughout the year, we must conclude the valve to have been just five years in making. [illustration: lepas.] this animal, like others we have already examined, had, moreover, a history before the first vestige of a valve was formed. it had passed through several metamorphoses; in its pupa stage it had the form of a _cypris_, and in this condition it first became adherent to the timber: before this it was a larva, having a general resemblance to another waterflea, the _cyclops_, especially in its younger stages: in this state it moulted several times. nor was this the beginning of its life; for there was the still earlier condition common to all these classes of animals, viz. that of the egg, which was laid and carried for some time by the parent barnacle, and at length hatched while within the valves of her shell. thus, through a course of several years we are able to trace back the existence of this cirriped, to its parent of a former generation. but our conclusions are altogether vitiated by the simple fact that this individual is the first of its species; it never had a parent; it never was an egg. from the rocky pool before us i have picked up a rough pebble, the surface of which is incrusted with a delicate work of stony lace. this fabric, too fine to be resolved by the unassisted eye, consists of the oval cells of a species of _lepralia_. there are some hundreds of cells in this patch, which altogether does not cover a square inch of the pebble; and they are all made after one pattern, and set in a very regular manner, in quincunx. each is a minute slipper-shaped box of stone, with the orifice set round with spines for the protection of the inmate, a transparent, elegant, and sensitive polypide, which bears on its head a coronet of ciliated tentacles. i am not going to describe the interesting structure and economy of this atom of life; but merely wish to direct your attention to one point,--the evidence which it affords of the lapse of past time. every one of these hundreds of stony cells, together with its living tenant, was normally produced by a process of gemmation; each having budded forth from the side of its predecessor as a knob of clear gelatinous flesh, in the midst of which was developed, first the cell, and then the polypide,--the latter appearing in a rudimentary condition, and gradually acquiring its proper organs, before the orifice of the cell was opened. i said every one of the cells was thus formed; but i ought to have excepted a single cell, which, though in nowise differing from the rest in form or structure, had a very different origin. this was the primal cell, and its beginning was as follows: a minute atom of a scarlet hue, and of a semi-elliptical shape, was one day whirling round and round with rapid gyrations in the open sea. it was of soft consistence, covered with strongly vibrating cilia, and furnished with some stouter setæ. after enjoying its motile instincts awhile, it settled down on this pebble, and became stationary. presently it secreted and deposited calcareous matter around at, like a coating of the thinnest glass, the red parenchyma receding from the hyaline wall towards the centre. soon an orifice with thickened edges appeared on the upper side, and minute spines grew from the edges, which quickly lengthened. it was now a _lepralia_ cell, and now the polypide was developed, and protruded its mouth from the orifice, surrounded by its elegant bell of ciliate tentacles. this solitary cell became the parent of hundreds more, by the gemmative process which i have already described. but the red swimming atom;--whence came that? well, it was shot out from the interior of a previous _lepralia_, the result not of a gemmative but of a generative act. it originated in another patch similar to the one which incrusts this pebble, and that, in like manner, and by exactly similar stages, looked back to an anterior patch, and so on. plausible as this inference is, it is false; for the little aggregation of cells and polypides has been called into existence by the divine _fiat_, this very instant. we are still at the sea-shore. within the long and narrow crevices into which these low-lying ledges of shale are split, innumerable tufts of sea-weed,--olive, purple, and green,--are perpetually waving in the wash of the sea. on one of these branching shrubs of _phyllophora_, there is adhering, apparently cast there by accident, an irregular mass of pellucid jelly. it firmly cleaves to the alga, enclosing the bases of several branches within its firm but gelatinous substance. this knob of jelly is a compound animal of the genus _botryllus_, and it has just been created as we see it. in order to understand its nature, look at it more closely. enclosed in the clear purplish-grey jelly, in the midst of scattered lighter specks, we see several star-like figures of bright hues, in which yellow and red are predominant; the symmetrical arrangement of which pleases the eye, and reminds us of some ornamental pattern designed by human art. each star is composed of several (three, seven, ten or more) pear-shaped animals, with their smaller ends meeting in the centre around a common orifice, from which a current of water is discharged. now this assemblage of animals bears evidence of progressive development. some time ago a tiny egg was discharged from a parent _botryllus_, which presently produced a little active tadpole-like larva, called a "spinule." this swam actively by means of its wriggling tail; but at length it settled head downward on this piece of sea-weed. immediately the head adhered, by an effused cement, to its support; the tail now gradually disappeared; and the round head, in the midst of a mass of jelly-like cement, began to display two orifices on its surface. it soon assumed a pear-like shape, and thus the first _botryllus_ was formed. from the side of this "pear," another was developed by gemmation, and a third on the opposite side; the smaller ends of all were in contact, and the orifices of these extremities began to merge into one; while the large ends diverged. a fourth and a fifth "pear" were successively produced in the same mode, until a star or "system" was formed. meanwhile the surrounding mass of living jelly had been commensurately enlarging, and a new _botryllus_, separate from the other star, had been produced in the jelly, which was the commencing point of a second system; and thus, by degrees, the compound mass of systems has grown to its present state of development. [illustration: botryllus. _a_, portion of one system and of a mass, on _phyllophora rubens_; _b_, an egg _c_, spinule; _d_, the same, attached; _e_, the tail absorbed; _f_, the young _botryllus_. all magnified.] this process has been one of time: the adhesion of the "spinule" took place in about sixteen hours after its escape from the egg. the appearance of the two orifices was when the little animal was four days old; and by the end of a week a second "pear" had budded. the attainment of the present condition may have occupied about six months. nay; time has been no element in this development; it is prochronic development; it is the development of creation, not of nature. behold that ruffling of the smooth surface of the water; it is caused evidently by the forcible ejection of a current from some source a little way beneath the surface. yes, it proceeds from the orifice in this mass of calcareous grit; where the protruding pipe of shell indicates the snug fortress of a _clavagella_. i will carefully break away a little of the soft stone, and we shall see the curious structure more clearly. ha! i have split off a piece which nicely exposes the whole burrow, without having materially injured the creature or his shell. you see it is a bivalve mollusk with one valve firmly imbedded and cemented into the stony wall of its chamber. but the hinder end of this valve is continued into a shelly tube, intended to protect the siphons, which is carried through the gallery forming the entrance into the chamber, and opens by a wide orifice in the free water outside. it is to this tube that i call your attention. [illustration: clavagella.] you observe that on its outer surface there are several foliated expansions of the shelly substance, surrounding it like so many frills at pretty regular intervals. each of these foliations is a permanent record of a certain epoch. the terminal one is the margin of the tube-wall everted. the one below this was at some past period the eversion of the margin at what was at that time the extremity. the third frill had in like manner terminated the tube still earlier; and so with the fourth and fifth. it is impossible to look at these expansions, and not to believe that they have been formed in succession, in this way, by the periodic growth of the tube. there was a time when, the first frill was not commenced; when the creature was a mollusk with simple valves. but even this was not the beginning of its history. it was as a swimming infusory with a broad ciliated disk, and a lashing _flagellum_, that the creature commenced its independent career; and it was doubtless in this condition[74] that it found its way into the burrow of some _saxicava_. here its tiny transparent valves were secreted; the left valve was soon cemented to the chamber; and then the creature began to secrete and form the tube around its siphons, which was progressively enlarged, and adorned at every stage of elongation by these witnessing frills--whose testimony is recorded in imperishable stone. what can be more irresistible than such evidence as this? and yet we must take exception to it on the ground that this is the very hour of the animal's creation. [illustration: dione veneris.] the elegant spinous shell-fish that we discern yonder, half-buried in the sandy floor of the sea--i mean that lilac-tinted prickly venus (_dione veneris_) needs no shelly protection for its siphons, which, as you may observe, are protruded to a great length. but a lesson not less instructive than that taught by the tube-frills of the _clavagella_, is inculcated by the valves of the _dione_. near the hinder margin of each valve there is a ridge which runs from the beak to the front edge, a ridge which bears the series of long slender shelly spines, that imparts such a charm to this shell. each of these spines records an interval in the growth of the shell. there are sixteen distinctly enumerable; each of which may possibly mark a year's growth. the increase of bivalves, however, is slow; and it may be that a longer interval than a year has intervened between spine and spine. for if we look more closely at this beautiful shell, we see that the whole exterior of both valves is marked with concentric foliated ridges, which are also indubitable lines of growth; and that these are twice or thrice as numerous as the spines, from one to five being intercalated between those which support the prolongations of the shelly substance. each of these concentric lines has a history. every line, as well as every spine, has been produced by a protrusion and eversion of the glanduligerous edge of the mantle, which then secreted and poured out a copious deposit of calcareous matter along the margin of the previously existing valve. in this species each periodic deposit took the form of a ridge slightly elevated above the general surface; and, because the turned up margin of the mantle invested the edge of the valve already formed, therefore the new layer, with its elevated ridge, was concentric with the last edge, which was concentric with the previous one, and so on, the common centre of all being the beak (_umbo_) at the back of the valve. the spines were formed in a manner essentially similar. at every second or third period of increase, the margin of the mantle, which is very versatile and protrusile, was thrust out, at the point which corresponds to the spines, into a long fleshy groove, by the reduplication of its edge. within this groove the calcareous secretion was poured out; and after it had been allowed a few moments to harden or "_set_," the mantle-groove was cautiously withdrawn, and a new spine was exposed, as a produced end to the foliated ridge. yet, though this is the normal and natural mode of production, both of the concentric line and of the spines, it would be illusory to conclude that they have been so produced in the present example. the entire formation of the _dione_ before us has been ab-normal and preter-natural: it has been _created_, not _born_: the whole development so legibly written on the shell has been prochronic. there goes the scorpion stromb (_pteroceras scorpio_), crawling over the rocks with protruded head and tentacles, and bearing his massive house on his back. this shelly house of his will afford us a good example of structural development. the great dilated lip, and the long finger-like processes of its edge, had no existence in the youthful days of the shell; they are marks of adult age: when young, the shell was simply spiral, with a thin straight lip bounding a narrow aperture. observe also a far more beautiful creature by its side, the tiger cowry (_cypræa tigris_). its shell is now entirely enveloped in the meeting wings of the great fleshy mantle, which is mottled with changing hues; and its foot or crawling disk covers a space three or four times as large as the shell. on lifting it in our hand, the whole of this array of soft flesh has been rapidly retracted, and has wholly disappeared within that very narrow orifice, bordered with toothed projections, on the under side of the shell, which we can hardly believe capable of receiving a twentieth part of the bulk that has vanished within it. and now we see nothing but the shell, with its smooth rounded back, marked with dark spots, its white inferior surface cleft by this longitudinal denticulate aperture, and its brilliant porcellanous varnish over the whole. now here is evidence of change and progress again. this cowry-shell is very unlike that of an olive, with a simple spire, an oval body, a smooth thin lip, and a wide orifice; and as unlike that of a nautilus. yet it has passed through both of these stages before it was disguised as we see it now. when it escaped from the egg-shell, it was a minute pteropod, with two great ciliated disks, inhabiting a transparent nautiloid shell, and swimming giddily about in a revolving fashion. by and by, the tiny shell increased, and the outer whorl lengthened, putting on a long-oval figure. then--that is, after a considerable period occupied in increasing the dimensions of the shell in this form--it began to assume the adult appearance. the outer lip, which had hitherto been thin, gradually thickened and encroached upon the spire, and the mantle began to secrete and deposit on the outer surface the coat of glassy enamel. at length the thickening of the lips proceeded to such an extent as almost to conceal the spire, and to reduce the aperture to a narrow line, the edges of which were now thickly plaited with the tooth-like ridges so characteristic of the genus. the lobes of the mantle now protrude through this aperture; and, expanding on each side, have deposited all over the exterior of the shell a coat of glassy enamel, studded with dark round spots or clouds, which entirely conceals the surface with the markings that were formerly visible upon it. [illustration: murex tenuispina.] yonder thorny woodcock (_murex tenuispina_) is a still more striking shell than either, and one whose periodic growths are peculiarly well marked. it is covered at regular intervals with rows of shelly spines, still longer and more numerous than those we lately admired in the _dione_. each series crowns a thickened ridge, which runs across the whorl, as regards the direction of its growth, but longitudinally as regards the general figure of the shell. now, the increase of the shell in the univalves is performed almost exactly as in the bivalves; namely, by the protrusion and eversion of the mantle on the existing edge. and, therefore, each of these thorny ridges, separated as they are by an interval of just two-thirds of a whorl, marks the termination of a new growth, the shelly matter rising up at the margin in this thickened ridge, which bristles with elongated points. in this specimen we can trace ten such ridges, whence we legitimately infer ten distinct periods through which this animal has passed, besides the nautiloid stage under which all the creatures of this class commence existence. yet, since each of these three univalves has been this day created, these inferences are deceptive. the scorpion-shell was _never_ otherwise than dilated and digitated. the cowry has _never_ had a lip that was not thickened, nor an exterior that was not porcellanous. the woodcock has _never_ known a moment in which its thorns were less numerous than they are now. notice that fine round shell carried along the floor of the sea, by means of a great fleshy tortoiseshell-coloured[75] body, which, with a head of many spreading tentacles applied to the ground, crawls with a tolerably quick progress.[76] it is the pearly nautilus. the amplitude of the beautiful nacreous shell is by no means a measure of the dimensions of the animal; for this merely sits within the shallow mouth, like a welsh fisherman in his coracle. if we remove the creature, we shall find the cavity bounded by a pearly floor, in the centre of which is a slender tube running down from it. on breaking away this floor, we expose an empty chamber, with a similar pearly floor, through which passes the shelly tube, continued through the middle of the chamber, and running down to the next. thus we should find the whole interior of the shell occupied by a series of these empty chambers, fifty or upwards in number, each less than its predecessor (rather _successor_, if we regard them in the order of development), until we can trace them no longer in the minute centre of the spire. without dwelling on the function of these chambers, farther than to say that they appear admirably contrived to make the animal with its shell either heavier or lighter than the surrounding fluid, by forcing water into them through the tube, and thus condensing the contained air, or by relaxing the pressure, and allowing the elasticity of the air to exclude the water,--our business is just with the formation of the septa, as an evidence of periodic development.[77] "the septa are formed periodically, but it must not be supposed that the shell-muscles ever become detached, or that the animal moves the distance of a chamber all at once. it is most likely that the _adductors_ grow only in front, and that a constant waste takes place behind, so that they are always moving onward, except when a new septum is to be formed; the _septa_ indicate periodic _rests_."[78] these periodic alternations of rest and action, however, it is obvious, can never have really existed in an organism which has but this instant been created. the appearances, therefore, which indicate them, are illusory, considered as testimonies to actual time. you are aware that what is often spoke of as the "bone" in this cuttlefish (_sepia officinalis_), is only a concealed shell; and i need not to dissect the animal to acquaint you that it is a highly interesting structure. a deservedly eminent physiologist shall describe it for us. "the outer shelly portion of this body consists of horny layers, alternating with calcified layers, in which last may be seen a hexagonal arrangement. the soft, friable substance, that occupies the hollow of this boat-shaped shell, is formed of a number of delicate plates, running across it from one side to the other in parallel directions, but separated by intervals several times wider than the thickness of the plates; and these intervals are in great part filled up by what appear to be fibres, or slender pillars, passing from one plate or floor to another. a more careful examination shows, however, that instead of a large number of detached pillars, there exists a comparatively small number of very thin, sinuous laminæ, which pass from one surface to the other, winding and doubling upon themselves, so that each lamina occupies a considerable space. their precise arrangement is best seen by examining the parallel plates, after the sinuous laminæ have been detached from them; the lines of junction being distinctly indicated upon these. by this arrangement, each layer is most effectually supported by those with which it is connected above and below; and the sinuosity of the thin intervening laminæ, answering exactly the same purpose as the "corrugation" given to iron plates for the sake of diminishing their flexibility, adds greatly to the strength of this curious texture, which is at the same time lightened by the large amount of space between the parallel plates that intervenes between the sinuosities of the laminæ."[79] now the delicately thin calcareous plates have all been formed in succession, "the first formed being at the outer part and posterior termination of the shell, and the succeeding new layers extending always more forwards than the edges of the old."[80] they exhibit then many hundreds of distinct deposits, each the result of a separate process, each the work of a definite period of time. the "cuttle-bone" is an autographic record, indubitably genuine, of the cuttlefish's history. yes, it is certainly genuine; it is as certainly autographic: but it is _not true_. that cuttle has been this day created. ix. parallels and precedents. (_vertebrate animals._) "the organisation of the body at each epoch may be truly said to be the _resultant_ of all the material changes which it has undergone during the preceding periods."--_dr. carpenter; human physiology_, p. 903. the _invertebrata_ then agree in one story, and that story is the same as what the plants had told us before. let us try if the vertebrate creatures bear them out. from this promontory we can look far down into the clear profundity of the still and smooth sea. what is that large object that plays hither and thither yonder, now shooting ahead, now resting on his oars, now turning on his course, now cutting the surface, now descending to the depths? it is a full-grown sword-fish, some ten feet long. we are sufficiently near him to discern that he has one short but high dorsal fin, near the head, and a minute one close to the caudal, the whole intermediate region being smooth. but this is a mark of adult age; for in early life this same species is furnished with one long and high dorsal, which is continuous from the occiput to the vicinity of the tail-fin. the remotely divided dorsal here tells of many years of life; but tells deceitfully, for the sword-fish is but just created. ha! the sword-fish has darted away, like lightning, after a finny victim. see with what doublings and windings he pursues it, and how the terrified prey uses all its powers to escape from its gigantic enemy! now they near the shore; and now the frightened quarry has leaped out of the sea upon yonder flat shelf of rock, where it lies gasping and floundering, delivered indeed from its pursuer, but only to die by being drowned _in the air_. we will descend from the cliffs, and look at it. it is a gilt-head (_chrysophrys aurata_). life is extinct now; but the brilliant colours and fine metallic reflections are scarcely dimmed--the silvery belly--the azure fins--the sides that gleam like polished steel, inlaid with bands of burnished gold! i will pluck a scale from this brilliant silvery surface. its hinder, or free edge, is beset with fine flexible crystalline points, arranged in many successive rows, overlapping each other. the front, or attached edge, is cut in a scolloped pattern, the extremities of undulations that radiate from a common point behind the centre. the whole surface, except the hinder portion that is studded with imbricated points, is covered with an immense multitude of fine concentric lines, which follow the form of the general outline. these are marks of successive increase; for every one of the lines is the margin of a lamina, the aggregation of which makes up the thickness of the scale. the laminæ can be separated by long maceration in water; and then we see that they are laid one on another in regular order, the uppermost being the smallest, and the first formed; the last made, which is the largest, being now in contact with the skin. [illustration: scale of gilthead.] every scale is therefore a document, on which is indelibly written the record of a multitude of processes, all effected in the past history of the fish. the successively deposited laminæ are exactly analogous to those of calcareous substance in the shell of the bivalve;[81] and the evidence is of exactly the same character as what we lately read off from the valve of the _dione_. but, just as in that example, too, the overruling fact of recent creation precludes our deduction of time from the evidence, since it proves the development to have been prochronic. i see yonder a more terrific tyrant of the sea than the sword-fish. it is the grisly shark (_carcharodon_). how stealthily he glides along, cutting the glittering surface of the sea with his dorsal, and now and then protruding just the tip of the upper lobe of his caudal in the wake of the other! let us go and look into his mouth; for neither animals nor elements present any impediments to these investigations of ours. is not this an awful array of knives and lancets? is not this a case of surgical instruments enough to make you shudder? what would be the amputation of your leg to this row of triangular scalpels, each an inch and a half in diameter? moved, too, by these powerful muscles? but observe the arrangement of these most formidable teeth. they are not confined to a single row as ours are, but each is succeeded by another lying behind it, that by another, and another, and another,--why, there are a dozen ranks of teeth, lying regularly packed one behind the other. the object of this arrangement is a constant supply of new teeth, as those in use become broken off, or wasted by the sloughing away of the exterior half-ossified crust of the cartilaginous jaw, to which their base is fastened by ligaments. only one row, the outer one, is in use at once, and this row stands erect; the others lie flat on each other (more and more completely as they recede from the outer row); a reserve of weapons in readiness for use, when those now employed are done with. there is a continual growth of the surface to which the teeth are fastened, from within outwards; so that each of the reserve rows will in turn be brought to the edge of the jaw, when it will be thrown up into the erect position, while the preceding, now turned out of the mouth by the gradual eversion of the surface, sloughs away and disappears as an useless incumbrance. it follows, therefore, that the teeth which we now see erect and threatening, are the successors of former ones that have passed away, and that they were once dormant like those we see behind them. but perhaps you may say, what evidence is there that these ever had any predecessors? that they were not originally the front rank as they are now? a very fair question. in the first place, the great size of the tooth indicates maturity; and is in keeping with the dimensions of the animal,--some twenty feet or so,--which are those of an adult, if not a full-grown individual. but adult age implies previous youth and infancy, and a gradual growth from the length of a few inches to this formidable size. the teeth are found in the embryo shark when not more than a foot long; and it is evident that many successive generations of teeth have passed away between those pristine lancets of a line in diameter, and these of an inch and a half. but stay; there is a peculiarity in the structure of these present teeth, which surely indicates their place to be far on in the succession. each is seen to be finely serrated on its two outer edges,--a provision which, of course, makes them more effective dividers of flesh and bone. but this structure is not found in the teeth of young individuals, which up to a period comparatively advanced, have simply cutting edges. hence we are compelled by the phenomena to infer a long past existence to this animal, which yet has been called into being within an hour. on yonder twig sits a beautiful little tree-frog, which you would be ready to mistake for a leaf of more than usually emerald hue, but for the glittering eye, and the line of yellow edged with purple that passes down the side. do you notice the frequent gulpings of the throat? those are the periodic inspirations of air, by which the creature breathes; for, having no ribs, by means of which to depress, and so to expand, the thoracic cavity, the frog swallows the air by a voluntary action. these air-gulps afford us another example of the sort of evidence we are searching for; they are so many proofs of a past history. for the tree-frog has not _always_ swallowed air; there was a period in its life when it had no lungs; when it was an aquatic animal, as exclusively a water-breather as any fish. fish-like in _form_ it was then, as well as in _habit_; it was a tadpole with a long compressed muscular tail, and with external gills of several branches, but as destitute of lungs as it was of limbs. any physiologist, looking at our little green tree-frog, would pronounce without hesitation on the stages through which it has passed; and would describe with the most perfect confidence the order in which they took place; the gradual absorption of the branchiæ, the development of the lungs, the shrinking up and final disappearance of the tail, the budding forth of the tiny rudimentary limbs, the hinder pair first, then the fore pair, and the subsequent division of their extremities into toes;--the metamorphosis of the little fish into a little batrachian, and the gradual growth and maturation of the latter,--these are facts,--the physiologist would say,--as sure both as to their actuality and as to their order, as that the frog is a frog. ah! but the physiologist is not aware of a fact, which invalidates all his conclusions based upon experience,--the fact that the little tree-frog has been created but this very instant. hark! that rattling noise is an admonition to us to tread circumspectly. it is the vibration of the horny caudal appendages of a rattlesnake. and i see the reptile coiled up under yonder shadowing leaf. but our presence is a privileged presence, and so we may handle and examine him with impunity. the organ which produces this sound is composed of a number of hollow horny capsules, each one fitting into the next, in which it is retained loosely by a protuberance of its surface. these, being agitated at the will of the animal, produce that sound which we just now heard. the capsules are developed periodically, one being added to the number already existing every year, until as many as forty are accumulated.[82] this individual, therefore, having five-and-twenty rattles, must be five-and-twenty years old. this snake, however, has had no past years; it has had no yesterday. its existence commenced this hour. here crouches, among the thick reeds, the leviathan of the rivers, the mailed crocodile. his body, invested with bony ridged plates, that rise into strong serrations along the tail, seems clothed with power; and his long rows of interlocking teeth, unveiled by lips, appear grinning with perpetual rage. an experienced herpetologist would not fail to find many evidences of age in this huge reptile. first of all, he would point to its monstrous size; then to the breadth and massive thickness of the dermal plates. "the head," he would say, "in the ruggedness of its surface, shows the same thing, for in youth it was comparatively smooth; and also in the form of its outline; for in this example its length is double its breadth, whereas in youth, these measurements were nearly equal. these conical teeth, too, are by no means the same individual teeth which existed at first. if you look at the base of one, you will see that it is hollow, and that the sides of this portion are already in process of absorption; that this hollow cone is a sheath for another tooth beneath, which is destined to replace it; as this has itself replaced its predecessor. the large size of the teeth which we see, therefore, which accords with the dimensions of the jaws, is not a condition induced by gradual growth, but by a succession of sloughings and replacements; and hence the present teeth, in their size, point conclusively to others which have preceded them, but which have disappeared." yet nothing can be more certain, than that, in this crocodile, which has been created to-day, the successive teeth thus witnessed to, are but ideal, that is prochronic, teeth; and that all the other indications of the lapse of time, in the development of this individual, are liable to the same exception. see this solemn, slow-going tortoise, shut up in his high-domed house of bones. it is the beautiful _testudo pardalis_, well named from the plates being elegantly spotted and splashed with black on a pale-yellow ground, like the fur of the panther. this is a rather large individual, and the number of concentric lines on the plates of his armour,--or may i not rather say the _tiles_ wherewith his house is roofed?--is commensurately great. you see what i mean. each of the angular plates has a small nuclear lamina, not in the centre of the area, for the development has been one-sided, but on the highest part. this was the plate in its earliest form, or at least the earliest of which any trace is left; for probably there were others yet earlier and smaller, which, on account of their thinness, have been rubbed away in the travels of the old wanderer. from this nucleus, the plate has been successively enlarged, to correspond with the general growth of the animal, by repeated additions of new laminæ to the inferior surface; each new lamina being a little wider in every direction than that which preceded it, though not _equally_ on all the margins; and thus the plates assumed the form of a very low cone, as you see, always preserving the specific outline, and manifesting the stages of increase, by the projecting edges of the successive laminæ, exactly as we saw lately in the scales of the fish. [illustration: plates of tortoise.] whether these laminæ are increased in an annual ratio, i am not sure, nor is it important. there are, i find, about forty-five concentric lines on one plate in this specimen, besides others which are evanescent. hence it would be quite legitimate to infer that this tortoise has passed through at least forty-five distinct periods of life, each of which has left a legible record of its existence. and yet, this moment, in which we look at it, is the very first moment of its life; the concentric layers are evidences of processes that never occurred, except prochronically. see yonder stately bird, nearly of the height of man, marching among the luxuriant musa-groves, and feeding on the succulent fruits. there is nothing very admirable in its coarse, black, hair-like plumage; but the rich hues of its naked neck, azure, purple, and scarlet, of the most vivid intensity, attract the gaze. the most remarkable feature in its physiognomy, is the singular, tall ridge of horn on its head, which, like the crested helmet of some mailed warrior, imparts an air of martial prowess to the bird, little in accordance with its peaceful habits. this protuberance is altogether a development of age. the skull, in the youth of the cassowary, was scarcely more elevated than that of a chicken; but in the lapse of years, the bony ridge, encased in horn, has gradually elevated itself to the height which it now possesses. here again we have a record of time, which is belied by the fact of the bird's recent creation. what is the glorious train of the peacock, all filled with eyes, but a false witness of the same kind? it leads us to infer that the bird is three years old at least, since before that period, the covert feathers, which are to form the splendid ornament of maturity, are not developed. what are the lengthened tail-plumes of most refulgent blue, that adorn the fork-tailed humming-bird (_trochilus forficatus_); what the gorgeously golden tail of the resplendent trogon; what the elegant lyre-shaped feathers of the menura; what the lustrous plumage of the birds of paradise,--all of which have been but this hour created,--but so many testimonies, unworthy of confidence, to a past history? but, further, every individual feather of this beautiful array of plumage concurs in bearing its unblushing witness to the same untruth. what says the physiologist, who is able to read off these autographic records? [illustration: growth of a feather.] "a little while ago, the tips of these feathers were seen each protruding from the extremity of a thick, opaque tube; and a little while before that, the tube itself, was a closed capsule, imbedded in a deep follicle of the skin. if you had then cut open the capsule, you would have found two concentric membranous tubes investing a highly vascular secreting pulp, abundantly supplied with nerves and blood-vessels through an orifice at the bottom of the capsule, and destined to form the substance of the coming feather. indeed, you would have seen the soft, newly-formed barbs folded round the central organized matrix; and below, the incipient quill, filled with the living pulp-cells, and their blood-vessels, which were destined subsequently to wither up and collapse into the light skinny pith which you see in the perfectly matured feather. these are stages which each of these hundreds of feathers has passed through; and these are but a single generation, which have replaced former series that have been lost in the process of moulting, every one of which had in its turn passed through exactly corresponding stages, and so on backward, till we reach the first race of feathers, which were already partly developed when the chick burst forth from its imprisoning egg-shell." so says the physiologist; but is he not most egregiously in error, since this is the day of these lovely beings' creation? there goes the great whale, the true whalebone whale, rolling and wallowing in the trough of the sea, and exposing his enormous black back like an island amidst the white foam, which he stirs up, "making the deep to be hoary." we will use our privilege and take a peep into his mouth, as we did just now into that of the shark. what a cavern! and all bristling with long black hair! why it seems as if the hair grew on the wrong side of his head--on the inside instead of the outside! nay, what you call hair is really the whale's teeth, or what represents teeth. this is the interior free fibrous margin of the _baleen_, which descends in long triangular plates from the upper jaw. there are about two hundred plates on each side, set face to face, with an interval between, and the edges outward. the inward edge runs off into those long hair-like filaments, which also extend from the slender tip. and the whole forms an effective sifting apparatus, by which the volume of sea-water, which the huge creature takes into his mouth in feeding, is drained of the sea-blubbers, the worms, the mollusks, and other small matters, which constitute the subsistence of this vast body. now each of these four hundred plates, some twelve feet in length, has grown from a minute sort of bud, in the upper jaw. its base is hollow, resting on the formative pulp which is developed from the gum. the pulp is understood to be the immediate origin of the hairy fringe, while a dense vascular substance, seated between the bases of the plates, forms the plate itself. when the plate reaches a certain length, its diameter has become greatly attenuated, and its tip is constantly breaking away, leaving the hair projecting. there is therefore a continual disappearance of the substance of the plates at the tips, and a continual growth at the base to supply the deficiency; and even more, at least during the period of adolescence, because the actual dimensions of the plates have to be increased in the ratio of the growth of the whole animal. here, again, we read a record of past history. the whale is known to be a long-lived animal; and a period of many years must have passed in bringing these plates of baleen to their present maturity. yet the vast organism before us has been created in its vastness but to-day. on the most prominent shelf of yonder precipice, a sharp buttress of naked limestone, stands an ibex, guarding, like a watchful sentinel, the herd in the sheltered valley which own his leadership. the pair of noble horns, which are at once his defence and his pride, are marked throughout their ample curve with semi-rings, or knobs, on their anterior side. these afford us an infallible criterion of the animal's age. we can count in this ibex fourteen of such prominent bosses. now the horn in these animals is not shed during life, but consists of a persistent sheath of horny substance, enveloping a bony core. until full adult age, both the core of bone and the sheath of horn are continually growing; and in the spring, when there is an unusual augmentation of vital energy in the system, the increase is more than usually rapid. at this season, the new matter deposited in the corneous sheath accumulates in the form of one of these bosses, each of which is therefore produced at the interval of a year. as the first boss appears in the second year of the animal's age, we have but to add one to the number of the bosses on each horn, and we have the number of years which it has lived. the ibex before us is just fifteen years old. [illustration: horns of stag; in their successive developments.] yon stag that is rubbing his branchy honours against a tree in the glade,--can we apply the same criterion to him? not exactly: for the horns of all the deer-tribe are of a different structure from those of the _capradæ_. they are bones of great solidity, not invested with any corneous sheath, but clothed for a certain portion of their duration with a living vascular skin, and are shed every year during life and as constantly renewed. yet the bony horns of the stag are no less sure a criterion of age, at least up to a certain period--than are those of the hollow-horned ibex. in the spring of the second year of the fawn, the horns first appear, seated on bony footstalks that spring from the frontal bone. the skin that covers these knobs begins to swell and to become turgid with blood supplied by enlarging arteries. layers of bone are now deposited, particle by particle, on the footstalks, with surprising rapidity, producing the budding horns, which grow day by day, still covered by the skin, which grows also in a corresponding ratio. this goes on till a simple rod of bone is formed, without any branches. when this is complete, the course of the arteries that supplied the skin is cut off by fresh osseous particles deposited in a thick ring around the base. the enveloping skin then dies, and is soon rubbed off. after a few months, the connexion of the now dead bone with the living is dissolved by absorption, and the horns fall off. the next spring they are renewed again, but now with a branch or antler; and the whole falls again in autumn. every spring sees them renewed, but always with an increase of development; and this increase is definite and well-known; so that the age of a stag, at least of one in the vigour of life, can be readily and certainly stated. for example, the individual stag before us, now browsing so peacefully, has each horn composed of the following elements:--the beam, or main stem; two brow-antlers; one stem-antler, and a coronet of four snags, or royal-antlers, at the summit. this condition is peculiar to the seventh development, to which if we add one year for the hornless stage of fawnhood, we obtain eight years, as, beyond all doubt, the age of this stag. both of these examples, however, the ibex and the stag, though so conclusive, and seemingly so irrefragable, are rendered nugatory by the opposing fact of a just recent creation. see this horse, a newly created, really wild horse, "wild as the wild deer, and untaught, with spur and bridle undefiled,"-his sleek coat of a dun mouse-colour, with a black stripe running down his back, and with a full black mane and tail. he has a wild spiteful glance; and his eye, and his lips now and then drawn back displaying his teeth, indicate no very amiable temper. still, we want to look at those teeth of his. please to moderate your rancour, generous dobbin, and let us make an inspection of their condition! now notice these peculiarities. the third pair of permanent incisors have appeared, and have attained the same level as their fellows; all are marked with a central hollow on the crown, the middle pair faintly: the canines have acquired considerable size; they present a regularly-convex surface outwardly, without any marks of grooving on the sides; their inner side is concave; their edges sharp; the third permanent molar has displaced its predecessor of the milk set, and the sixth is developed.[83] this condition of the teeth infallibly marks the fifth year of the horse's age. a year ago the third incisor was only just rising; the canines were small, and strongly grooved, and the third milk grinder was yet existing. a year hence, the central incisors will be worn quite flat, and their marks obliterated; the canines will be fully grown tusks, the second molar will have reached its full height, and all the teeth will be of the same level. we can then with perfect confidence assert this to be a five-year old horse. and yet, if we do so, we shall assert a palpable untruth, for the young and vigorous stallion has been created to-day. [illustration: skull of babiroussa.] in the thickets of this nutmeg grove beside us there is a babiroussa; let us examine him. here he is, almost submerged in this tepid pool. gentle swine with the circular tusk, please to open your pretty mouth! here are four incisors in the upper jaw; _at one time there were six_. the canines of the same jaw having pierced through the flesh and skin of the face, have grown upward and curved backward like horns; nay, they have nearly completed a circle, and are threatening to re-enter the skull; _once these tusks had not broken from the gums_. there are two pre-molars: _once there were four_. there are three molars, of which the first is worn quite smooth: _once this surface was crowned with four cones; but the third molar had not then appeared_. away to a broader river. here wallows and riots the huge hippopotamus. what can we make of his dentition? a strange array of teeth, indeed, is here; as uncouth and hideous a set as you may hope to see. yes, but the group is instructive. we will take them in detail. look at the lower jaw first. here are two large projecting incisors in the middle, with their tips worn away obliquely on the outer side, by the action of their opponents in the upper jaw, which are also worn inwardly. the outer incisors, both above and below, are also mutually worn in like manner. the lower canines form massive tusks, curved in the arc of a circle, ground away obliquely by the upper pair; which are short and similarly worn on their front edges. there are three pre-molars on each side, below and above, much worn: once there was a fourth, but it was shed early. lastly, we find three molars, whose crowns are ground down so as to expose two polished areas of a four-lobed figure. a little while ago, these double areas were trilobate, but at first there were no smooth areas at all; for these are but sections, more or less advanced, of the conical knobs, with which the crown of the molar was originally armed.[84] in both these examples, the polished surfaces of the teeth, worn away by mutual action, afford striking evidence of the lapse of time. some one may possibly object, however, to this: "what right have you to assume that these teeth were worn away at the moment of its creation, admitting the animal to have been created adult? may they not have been entire?" i reply, impossible: the hippopotamus's teeth would have been perfectly useless to him, except in the ground-down condition: nay, the unworn canines would have effectually prevented his jaws from closing, necessitating the keeping of the mouth wide open until the attrition was performed; long before which, of course, he would have starved. in a natural condition the mutual wearing begins as soon as the surface of the teeth come into contact with each other; that is, as soon as they have acquired a development which constitutes them fit for use. the degree of attrition is merely a question of time. there is no period that can be named, supposing the existence of the perfected teeth at all, in which the evidence of this action would not be visible. how distinct an evidence of past action, and yet, in the case of the created individual, how illusory! [illustration: skull of hippopotamus.] "trampling his path through wood and brake, and canes, which, crackling, fall before his way, and tassel-grass, whose silvery feathers play o'ertopping the young trees,- on comes the elephant, to slake his thirst at noon, in yon pellucid springs. lo! from his trunk upturn'd, aloft he flings the grateful shower: and now plucking the broad-leaf'd bough of yonder plane, with waving motion slow, fanning the languid air, he waves it to and fro." we will not be content with admiring the vast size of the fine dauntelah, and the majesty of his air and movement, and the intelligence manifested in all the actions of the "half-reasoning" beast, as he explores the amoenities of the young world to which he has but this morning been introduced. we are out on another sort of scent: let us try if we can glean any light from him on our present question. and, first, we cannot fail to notice his fine pair of tusks curving upwards almost to a semicircle. each tusk is composed of a vast number of thin cones of ivory, superimposed one on another; ever increasing by new ones formed within the interior at the base, and moulded upon the vascular pulp which fills the cavity, and by which the solid ivory is constantly secreted and deposited. each new cone pushes further and further out those previously deposited, and thus the tusk ever grows in length as it increases in age. [illustration: skull of elephant.] how many years have these tusks occupied in attaining their present diameter and length? we cannot tell: without a transverse section we cannot determine the number of layers of which each consists: and if we could, we should yet require to know what ratio exists between the deposition of a cone of ivory and a fixed period of time. the cones, however, in a tusk of these dimensions, are very numerous, for they are but thin; and it is enough for our purpose that they have occupied the same number of periods of time for their formation, though we cannot precisely indicate the length of these periods. leaving the tusks, which are the upper incisors, let us now examine the molars. and there is in these a remarkable peculiarity of development, which will assist us greatly in our chronic inquiries. before we look at them it may be as well to consider this peculiarity. the elephant has, from first to last, six, or perhaps eight, molars on each side of each jaw; but there are never more than two partially, or one wholly, in use at once. they have originally an uneven surface, produced by the extremities of a number of what may be considered as so many finger-like constituent teeth, arranged in transverse rows, covered by hard enamel, and cemented together by a bony substance. these points are gradually worn down by the process of mastication, and then the compound tooth appears crossed by narrow cartouches, or long ovals of enamel, indented at their margins. "the first set of molars, [_i. e._ the first compound molar] or milk teeth, begins to cut the jaw eight or ten days after birth, and the grinders of the upper jaw appear before those of the lower one. these milk-grinders are not shed, but are gradually worn away during the time the second set are coming forward; and as soon as the body of the grinder is nearly worn away, the fangs begin to be absorbed. from the end of the second to the beginning of the sixth year, the third set come gradually forward as the jaw lengthens, not only to fill up this additional space, but also to supply the place of this second set, which are, during the same period, gradually worn away, and have their fangs absorbed. from the beginning of the sixth to the end of the ninth year, the fourth set of grinders come forward to supply the gradual waste of the third set. in this manner to the end of life, the elephant obtains a set of new teeth, as the old ones become unfit for the mastication of its food. "the milk-grinders consist each of four teeth, or _laminæ_; the second set of grinders of eight or nine _laminæ_; the third set of twelve or thirteen; the fourth set of fifteen, and so on to the seventh or eighth set, when each grinder consists of twenty-two or twenty-three: and it may be added, that each succeeding grinder takes at least a year more than its predecessor to be completed."[85] as each tooth advances, only a small portion pierces the gum at once; one of twelve or fourteen _laminæ_, for instance, shows only two or three of these through the gum, the remainder being as yet imbedded in the jaw; and in fact the _tooth is complete at its fore part_, where it is required for mastication, _while behind it is still very incomplete_; the laminæ are successively perfected as they advance. the molar of an elephant _can never, therefore, be seen in a perfect state_: for if it is not worn in front, the back part is not fully formed and is without fangs; and when the structure of the hinder portion is perfected, _the front part is already gone_. "when the complex molar cuts the gum, the cement is first rubbed off the digital summits; then their enamel cap is worn away, and the central dentine comes into play with a prominent enamel ring; the digital processes are next ground down to their common uniting base, and a transverse tract of dentine, with its wavy border of enamel, is exposed; finally, the transverse plates themselves are abraded to their common base of dentine, and a smooth and polished tract of that substance is produced. from this basis the roots of the molar are developed, and increase in length, to keep the worn crown on the grinding level, until the reproductive force is exhausted. when the whole extent of a grinder has thus successively come into play, its last part is reduced to a long fang supporting a smooth and polished field of dentine, with sometimes a few remnants of the bottom of the enamel folds at its hinder part. then, having become useless, it is attacked by the absorbent action, by which, and the pressure of the succeeding tooth, it is finally shed."[86] with these physiological facts ascertained, let us proceed to the determination of the actual age of our noble dauntelah. the molar in present use has a length of about nine inches, and a diameter of three and a half. its crown is crossed by about eighteen enamel-plates; of which the anterior ones are much worn away, while the hinder ones can scarcely be counted with precision, as they have not wholly cut their way through the gum. these characters indicate the fifth molar (or set of molars) of the whole life-series. and the following facts will help us now to fix the actual age, at least approximately. the first molar cuts the gum at two weeks old, is in full use at three months, and is shed in the course of the second year. the second cuts the gum at about six months, and is shed in the fifth year. the third appears at two years, is in full use about the fifth year, and finally disappears about the ninth year. in the sixth year the fourth breaks from the gum, and lasts till the animal's twenty-fifth year. the fifth cuts the gum at the twentieth year, is entirely exposed soon after the fortieth, and is thrust out about the sixtieth year, by the advance of the sixth molar, which appears at about fifty years old, and probably lasts for half a century more. if others succeed this,--a seventh and even an eighth, as some assert,--these would carry on the elephant's life to two or three centuries, in accordance with an ancient opinion, which is in some degree countenanced by modern observations. to come back, then, to the case before us, since the fifth molar has its fore part much worn, and the posterior laminæ scarcely yet protruded from the gum, it follows that this elephant is now not far from the fortieth year of his life, a deduction which well agrees with the dimensions of his tusks, and his appearance of mature vigour. can you detect a flaw in this reasoning? and yet how baseless the conclusion, which assigns a past existence of forty years to a creature called into existence this very day. x. parallels and precedents. (_man._) "once, in the flight of ages past, there lived a man,--and who was he? mortal, howe'er thy lot be cast, that man resembled thee."--montgomery. we have knocked at the doors of the vegetable world, asking our questions; then at those of the lower tribes of the brute creation, and now at those of the higher forms; and we have received but one answer,--varying, indeed, in terms, but essentially the same in meaning,--from all. and now we have one more application to make; we have, still in our ideal peregrination, to seek out the newly-created form of our first progenitor, the primal head of the human race. and here we behold him; not like the beasts that perish, but- "of far nobler shape, erect and tall, godlike erect, with native honour clad, in naked majesty, as lord of all." the definitive question before us is this: does the body of the man just created present us with any evidences of a past existence, and if so, what are they? and that we may rightly judge of the matter, we will, as on former occasions, call in the aid of a skilful and experienced physiologist, to whom we will distinctly put the question. _the physiologist's report._ in replying to your inquiry concerning the proofs of a past existence in the man before me, i must treat of him as a mere animal,--a creature having an organic being. and, first, i find every part of the surface of his body possessing a nearly uniform temperature, which is higher than that of the surrounding atmosphere. there is, moreover, on all parts of the body, a tinge of redness, more or less vivid in certain regions. the heat, and the carnation tinge, alike indicate the presence of blood, arterial blood, diffused throughout, and, in particular, occupying the capillaries of the superficial parts. every drop of this blood is preceded and succeeded by other drops, every one of which has been impelled out of the heart by its constant contractions. but the very existence of this blood supposes the pre-existence of chyle and lymph, out of which it has been constructed. the chyle was formed out of chyme, changed by the action of the pancreatic and biliary secretions. chyme is food, chemically altered by the action of the gastric juice. so that the blood, now coursing through the arteries and veins, implies the previous process of the reception of food. and these pancreatic and biliary secretions, which are essential to the conversion of chyme into chyle,--and therefore into blood,--do you ask their origin? they were prepared, the one by the pancreas, the other by the liver, from blood already existing,--blood _previously formed_ of chyle with the addition of bile, &c.--and so indefinitely. again, the blood in these capillary arteries is of a bright scarlet hue, which it derives from its being charged with oxygen. this it received in the _lungs_, parting at the same time with the carbon which it had taken up in its former course. the lungs then must have existed _before_ the blood could be where and what it is, viz. arterial blood in the capillaries of the extremities; before it was driven out of the heart, since it was transmitted from the lungs through the pulmonary veins into the heart, thence to be pumped into the arterial system. but since all the tissues of the body are formed from the blood, the lungs were dependent on already-existing blood for their existence. and as the formative and nutrient power is lodged exclusively in _arterial_ blood, the very blood out of which the lungs were organized was dependent on lungs for oxygenation, without which it would have been effete and useless. here then is a cycle of which i cannot trace the beginning. but further. on the extremities of the fingers and of the toes, there are broad horny _nails_. these i trace down to the curved line where they issue from beneath the skin, and whence every particle of each nail has issued in succession. they are composed of several strata of polygonal cells, which have all grown in reduplications of the skin, forming compressed curved sheaths (_follicles_); stratum after stratum of cells having been added to the base-line, as the nail perpetually grew forwards. about three months elapse from the emergence of a given stratum of cells, before that stratum becomes terminal; and therefore each of these twenty-four fingerand toe-nails is a witness to three months' past existence. [illustration: growth of hair (_magnified_).] the head is clothed with luxuriant _hair_, composed of a multitude of individual fibres, each of which is an epidermic appendage, essentially similar to the nails. every hair is contained at its basal extremity in a delicate follicle, where it terminates around a soft vascular bulb, made up of blood-vessels and nerves. on the surface of this living bulb the horny substance is continually secreted and deposited in layers, each of which in succession pushes forward those previously made, till the tip extrudes from the follicle of the skin, after which it continues to grow in the same way, as an external hair. the tip is gradually worn away; and thus the constant growth cannot, in general, cause it to exceed a certain given length. each of the thousands of hairs with which this majestic head is clothed, bears witness to past time; and as the increase of hair is about an inch per month, and as this hair is about four inches in length, we have here thousands of witnesses to at least four months of previous history. the bones which make up the firm and stately fabric about which this human body is built, are no productions of a day. long before this they existed in the form of cartilages. in these, minute arteries began to deposit particles of phosphate of lime, around certain centres of ossification, doing their work in a determinate order, and in regular lines, so as to form continuous fibres. these fibres, aggregated, and connected by others, soon formed a texture of spicula or thin plates. now take as an example a cylindrical hollow bone, as that of the thigh. here the spicula were arranged longitudinally, parallel to the axis of the bone: preserving the general form of the cartilage which constituted its scaffolding. but the bone required a progressive increase in size. in its early state, moreover, it was not hollow, but solid. changes must have taken place to bring it to its present dimensions and condition. these were effected by the actual removal of some parts, simultaneously with the deposition of others. at a certain stage of ossification, cells were excavated by the action of the absorbent vessels, which carried away portions of bony matter lying in the axis of the cylindrical bone. their place was supplied by an oily matter, which is the marrow. as the growth proceeded, while new layers were deposited on the outside of the bone, and at the end of the long fibres, the internal layers near the centre were removed by the absorbent vessels, so that the cavity was further enlarged. in this manner the outermost layer of the young bone gradually changed its relative situation, becoming more and more deeply buried by the new layers which were successively deposited, and which covered and surrounded it; until by the removal of all the layers situated near to the centre, it became the innermost layer, and was itself destined in its turn to disappear, leaving the new bone without a single particle which had entered into the composition of the original structure.[87] these processes have been the slow and gradual work of years, of the lapse of which years the bones are themselves eloquent witnesses. within the mouth there are many _teeth_. i will not now speak of their exact number, nor of some other particulars concerning them, because i mean to return to them presently; but i look only at their general structure and origin. each tooth consists of three distinct parts, the central portion, which is _ivory_; the exceedingly hard, polished, glassy coat of the crown, which is _enamel_; and a thin layer of bone around the fang, which is the _cement_. before either of these appeared, a minute papillary process of vascular pulp was formed in a cavity of the jaw. over the pulp was spread an excessively thin membrane, which secreted from the blood, and deposited, a thin shell of bony matter, or ivory, moulded on the form of the pulp. successive layers of ivory were then added, from within; the pulp diminishing in a corresponding ratio. the cavity of the jaw at the same time deepened, and the pulp lengthened downward into the space thus provided; layers of bony substance being gradually deposited upon it, as above. [illustration: section of human tooth (_magnified_).] the cavity itself was lined with a thick vascular membrane, united to the papilla at its base. within the space lying between this membrane and the pulp, there was deposited from the wall of the former a soft, granular, non-vascular substance, known as the enamel organ. the cells on the inner surface of this substance then took the form of long, sub-parallel prisms, set in close array, perpendicular to the surface of the tooth. earthy matter was progressively deposited in them, by which they became the exceedingly dense and hard enamel of the crown. the cement of the fang was then formed by a slight modification of the process which had produced the enamel. here, then, are several distinct and important processes, effected in regular and immutable succession, each requiring time for its performance, and all undeniably witnessed-to by the structure of every tooth here seen. as i have thus proved the _fact_ of life existing in this human body for some time previous to the present moment, i now proceed to inquire how far its structure may throw light on the _actual duration_ of that past life. how far can we ascertain its chronology? the stature of the man before me is about six feet. an infant at birth is from eighteen to twenty-one inches in length. at ten years old the average stature is about four feet. six feet may be taken as the full adult height of man; and this is attained from the twenty-first to the twenty-fifth year. the stature of this individual would therefore indicate an age not less than twenty-one years. on the front of the throat i perceive a strongly-marked, angular prominence, formed by the union of the two plates of the thyroid cartilage. the prominence of this angle is due to the enlargement of the larynx; and it is accompanied by a deepening of the pitch of the voice, producing the full rich sounds that we have this instant heard, as the man chanted his song of praise. these tones, and this projection of the thyroid cartilage, are equally distinctive marks of puberty, and do not appear till about the sixteenth or seventeenth year. the chin, and sides of the face, are clothed with a dense bush of crisp hair,--the beard. this is a distinctive mark of the adolescent period, and may be taken as indicating an age not less than twenty years. on again examining the mouth, i find the teeth are thirty-two in number; viz., four incisors, two canines, four pre-molars, and six true molars, in each jaw. none of these existed (at least visibly) during the first seven years of life; in that period they were represented by the milk-teeth of infancy. the appearance of the middle pair of incisors occurred at about the eighth year; the lateral incisors at nine; the first pre-molars at ten; the second at eleven; the canines at about twelve; the second molars at thirteen or fourteen; and the third molars, or _dentes sapientiæ_, at about seventeen or eighteen. the state of the dentition, then, points to an age certainly not less than the period just named. how much more it may be, we must gather from other sources. i come now to certain phenomena which are not appreciable to us on mere external examination; but which i am able with certainty to predicate. and the first of these is the proportion of arterial to venous blood in the capillaries. in infancy, the arterial capillaries contain far more blood than the capillary veins; in old age, the proportion is exactly reversed; whereas, in maturity, the ratio is just equal. now, here there is a very small preponderance of arterial blood, indicating a period but slightly remote from maturity on the side of youth; well agreeing with the conclusion arrived at from previous premises, of some twenty to five-and-twenty years. other and more marked manifestations occur in the condition of the skeleton. in the spine, i find _the spinous and transverse processes_ of the several vertebræ are completed by separate _epiphyses_, the ossification of which does not commence till after puberty, and the final union of which with the body of the bone does not occur till about the age of twenty-five years. each _vertebra_, moreover, has attained a smooth annular _plate_ of solid bone, covering a surface that was previously rough and fissured, which is invariably added at the same period. the _ossification of the sacrum_ also has reached its culminating point. at the age of puberty, the component vertebræ began to unite from below upwards, and the two highest have now coalesced; which also marks a period of life not earlier than the twenty-fifth year. the whole united mass, moreover, is furnished on each side with thin bony plates, the appearance of which is no less characteristic of the same age. each of the _ribs_ is here furnished with two _epiphyses_, one for the head and the other for the tubercle; the ossification of these began soon after puberty; but their union with the body of the bone, as presented here, has taken several years to accomplish. to come to the limbs, we find the _shoulder-blade_ presenting three _epiphyses_, one for the _coracoid_ process, one for the _acromion_, and one for the lower angle of the bone, the ossification of which begins soon after puberty, their union with the body of the bone taking place between the ages of twenty-two and twenty-five years. the _clavicle_ has an _epiphysis_ at its sternal end, which begins to form between the eighteenth and twentieth years, and is united to the rest of the bone a few years later. the consolidation of the shoulder-bone (_humerus_) is completed rather earlier; the large piece at the upper end, which is formed by the coalescence of the ossific centres of the head and two tuberosities, unites with the shaft at about the twentieth year; whilst its lower extremity is completed by the junction of the external condyle, and of the two parts of the articulating surface (previously united with each other), at about the seventeenth year, and by that of the internal condyle in the year following. the superior _epiphyses_ of the arm-bones (_radius_ and _ulna_) unite with their respective shafts at about the age of puberty; the inferior, which are of larger size, at about the twentieth year. the _epiphyses_ of the _metacarpal_ and _phalangeal bones_ (those of the hand and fingers) are united to their principals at about the twentieth year. in the _lower extremities_, the process of ossification is completed at nearly the same periods as that of the corresponding parts of the upper. the consolidation of the hipbones (_ilium_, _ischium_, and _pubis_) to form the _os innominatum_, by the ossification of the triradiate cartilage that intervenes between them in the socket of the thigh (_acetabulum_), does not take place until after the period of puberty; and at this time additional _epiphyses_ begin to make their appearance on the crest of the _ilium_, on its anterior inferior spine, on the tuberosity of the _ischium_, and on the inner margin of the _pubes_, which are not finally joined to the bone until about the twenty-fifth year.[88] the concurrence of these conditions in the skeleton, the nearly balanced ratio of the bloods, the perfected dentition, the beard, the deepened voice, the prominent larynx, and the stature, combine to point out, with infallible precision, the age of this man, as between twenty-five and thirty years. so far, then, we can with certainty trace back the history of this being, as an independent organism; but did his history then commence? o no; we can carry him much farther back than this. what means this curious depression in the centre of the abdomen, and the corrugated knob which occupies the cavity?[89] this is the navel. the corrugation is the cicatrice left where once was attached the umbilical cord, and whence its remains, having died, sloughed away. this organ introduces us to the foetal life of man; for it was the link of connexion between, the unborn infant and the parent; the channel, through whose arteries and veins the oxygenated and the effete blood passed to and from the parental system, when as yet the unused lungs had not received one breath of vital air. and thus the life of the individual man before us passes, by a necessary retrogression, back to the life of another individual, from whose substance his own substance was formed by gemmation; one of the component cells of whose structure was the primordial cell, from which have been developed successively all the cells which now make up his mature and perfect organism. * * * * * how is it possible to avoid this conclusion? has not the physiologist irrefragable grounds for it, founded on universal experience? has not observation abundantly shown, that, wherever the bones, flesh, blood, teeth, nails, hair of man exist, the aggregate body has passed through stages exactly correspondent to those alluded to above, and has originated in the uterus of a mother, its foetal life being, so to speak, a budding out of hers? has the combined experience of mankind ever seen a solitary exception to this law? how, then, can we refuse the concession that, in the individual before us, in whom we find all the phenomena that we are accustomed to associate with adult man, repeated in the most exact verisimilitude, without a single flaw--how, i say, can we hesitate to assert that such was his origin too? and yet, in order to assert it, we must be prepared to adopt the old pagan doctrine of the eternity of matter; _ex nihilo nihil fit_. but those with whom i argue are precluded from this, by my first postulate. xi. parallels and precedents. (_germs._) "every cell, like every individual plant or animal, is the product of a previous organism of the same kind."--(dr. carpenter, _comp. physiol._ § 347.) in the preceding examples i have assumed that every organic entity was created in that stage of its being which constitutes the acme of its peculiar development; when all its faculties are in their highest perfection, and when it is best fitted to reproduce its own image. from the very nature of things i judge that this was the actual fact;[90] since, if we suppose the formation of the primitive creatures in an undeveloped or infant condition, a period would require to lapse before the increase of the species could begin; which time would be wasted. to those, indeed, who receive as authority the testimony of the holy scripture, the matter stands on more than probable ground; for its statements, as to the condition of the things created, are clear and full: they were not seeds, and germs, and eggs, and embryos,--but "the tree yielding fruit whose seed was in itself,"--"great whales,"--"winged fowl,"--"the beast of the earth,"--and "man."[91] but i do not mean to shield myself behind authority. i have begged the _fact_ of creation; but not the truth, nor even the existence, of any historic document describing it. it is essential to my argument that any such be left entirely out of the question; and, for the present, i accordingly ignore the bible. it is possible that some opponent may object to my assumption of maturity in created organisms. "your deductions may be sound enough," such an one may say, "provided your newly-created locust-tree had so many concentric cylinders of timber, your tree-fern had a well-developed stem of leaf-bases, your coral a great aggregation of polype-cells, your tortoise a carapace of many-laminated plates, your elephant a half-worn set of molars, and your man a thoroughly ossified skeleton. but how do you know that either of these organisms was created in this mature stage? i will not deny that each was created,--was called suddenly out of non-entity into entity; but i believe, or at least i choose to believe,--that each was created in the simplest form in which it can exist; as the seed, the gemmule, the ovum, the--ahem!" pray go on! you were about to say "the infant," or "the foetus," or "the embryo," probably; pray make your selection: which will you say? "well, i hardly know. because, if i choose the new-born infant, you will say, its condition implies a nine months' pre-existence, certainly; not to speak of the absurdity of a new-born infant being cast out into an open world without a parent to feed it. if i say, the foetus, or the still more incipient embryo, i involve, at once, a pre-existent mother. i am afraid you have me there!" i think i have. however, let us take up the matter orderly, and proceed on the supposition that my previous examples must be all cancelled, and the question argued _de novo_, on the assumption that each organism was created in its least developed condition. it will not be considered necessary, i suppose, to look at any intermediate condition of the organisms. the argument which is based upon the leaf-scales of the fern or the palm would essentially apply to either of these plants when it first issues from the ground. at the period when it comprises but a single frond, the botanist would no more hesitate in pronouncing that the organism had passed through stages previous to that one, than he would when it possesses an elongated stipe; though, in the latter case, the evidences of the pre-existence are more patent to the uninstructed eye. he would say, the single frond implies, with absolute necessity, a spore in the one case, a seed in the other; and we need not to see either, to be assured that this must have preceded the leaf-stage. but you go farther back still. "the plant was created as a seed." let us renew our imaginary tour at the epoch, or epochs (as many as you please), of creation, on this supposition. here is a very young plant of the curious seychelles palm or double cocoa-nut (_lodoicea sechellarum_). a single frond is all that is yet developed, and this is as yet unexpanded, the pinnæ being still folded on the midrib, like a fan. trace the frond down to its base. it springs from a thick horizontal cylindric process, which has also shot down a radicle into the soil. we trace the cylindrical stem along the surface of the soil, and find, lying on the ground, among the grass, but not buried, a great double nut, something like the two hemispheres of a human brain, or like a common cocoa-nut, half split open and healed. out of this the thick stem has issued; and we find that it is only the cotyledon of the seed, that has prolonged its base in the process of germination, in order to throw up, clear of the nut, the plumule and radicle. we look at the great nut, and find, on the woody exterior of the fibrous pericarp, at the side opposite to that whence issues the cotyledon, a broad scar. what is this? it is the _mark left by the severance of a footstalk_, which united the fruit to the parent plant. this great drupe was once a small ovary seated in the centre of a three-petaled flower, which, with many others, issued out of a great spathe, a mass of inflorescence, and hung down from the base of the leafy coronal of an adult palm-tree. this scar is an irreproachable witness of the existence of the parent palm. here, lying on the dry and dusty earth, is a brown flat bean of great hardness. this is a seed destined by and by to produce that splendid tree _erythrina crista-galli_. but it has been just created. this bean bears on one of its edges an oval scar, very distinctly marked, called the _hilum_. this was the point of attachment of a short column, by which the seed was united to one of the sutures of a long pod, in the interior of which it lay, in company with several others like itself. this great legume or pod had been the bottom of the pistil of a papilionaceous flower, crowned by a tiny stigma, lodged in a sheath formed by the united stamens, and surrounded by a corolla of refulgent scarlet petals. of course such a flower was not an independent organism; it was one of many that adorned a great tree, the history of whose life would carry us back through several generations of human years. [illustration: garden tulip. fig. 1. a flower with two petals removed, to show the ovary, _a_. fig. 2. the same ovary, more mature, divided longitudinally; _b_, the unripe seeds, packed on each other; _c_, a portion of the same carpel, from which the seeds have been removed.] this single infolding leaf, that is just shooting from the soil, so small and feeble,--what of this? there are certainly no concentric cylinders of timber here: can we trace a previous history of this? yes: by carefully removing the soil from the base, we see that it originates in a flat yellow seed--the seed of a tulip. here again we have no difficulty in detecting evidence of its former attachment. a great number of these seeds were once closely packed one on another, in each of the three carpels that constituted the capsule. and this capsule had been the oblong, three-sided ovary, which formed the body of the pistil in some beautiful tulip. do you observe these two round fleshy leaves, just peeping from the sandy earth? they are the earliest growths of a plant of _arachis hypogæa_. in this case again, to understand the true relations of this organism, we must expose it wholly to view. beneath the surface of the earth, then, i find that these seed-leaves are the two halves (_cotyledons_) of a kind of pea, which was formerly enclosed in a wrinkled skinny pod. but what is most interesting is that the pod is here, the cotyledons shooting out of it. and, attached to one end of the pod, here is a slender stalk, now withered and dry, which projects out of the ground into the air. [illustration: germination of earth-pea.] now here we have a beautiful link of connexion with the past. the plant before us does not ripen its seeds, and then drop them to care for themselves, as most plants do. "the young fruit, instead of being placed at the bottom of the calyx, as in other kinds of pulse, is found at the bottom and in the inside of a long slender tube, which looks like a flower-stalk. when the flower has withered, and the young fruit is fertilized, nothing but the bottom of the tube with its contents remains. at this period a small point projects from the summit of the young fruit, and gradually elongates, curving downwards towards the earth. at the same time the stalk of the fruit lengthens, until the small point strikes the earth, into which the now half-grown fruit is speedily forced, and where it finally ripens in what would seem a most unnatural position."[92] the young plant before us has been this moment created, and created in this incipient stage of growth: and yet there is, even here, an indubitable evidence, so far as physical phenomena can afford it, of a past history. it would be utterly impossible to select any stage in the life of the earth-pea, which did not connect itself, visibly and palpably, with a previous stage. let us return to the shore-loving mangrove. you object to my assumption that it was created as a tree, with a well-branched stem elevated upon a series of arching roots; and to my deduction of pre-lapsed years for the formation of those roots. very well. i give it up. you allow that the primitive mangrove was created in some stage, but you contend for the germ-stage, the simplest condition of the plant, whatever that might be. now, where shall we find it? in the first pair of developed leaves? they certainly point back to the cotyledons. to the cotyledons, then, let us look. lo! the young plant is germinating before its connexion with the parent is severed. it is the singular habit of this tree, that its seeds are already in a growing condition, while they hang from the twig. each seed is a long club-shaped body, with a bulbous base and a slender point, more or less produced. while it yet hangs from the branch, the radicle and crown of the root begin to grow, and gradually lengthen, until the tip reaches the soil, which it penetrates and thus roots itself; while those which depend from the higher branches, after growing for a while, drop, and, sticking in the mud, throw out roots from one end, and leaves from the other. [illustration: seed of mangrove.] what have you gained, then, in this case, by going back to the germ? the germ as decisively asserts its origination from an already existing organism--the parent tree--as the flourishing tree witnesses its gradual development from a germ. the mangrove could not by possibility have been created in any stage, consistent with the identity of the species with that which we behold now in the nineteenth century,--that did not show ocular evidence of a previous history;--evidence from the nature of things fallacious. it would be merely tiresome to go on through the vegetable kingdom. in every plant the simplest condition--viz. that of a spore or seed--depends on some development, or process, or series of processes, that have preceded it. nor does the lapse of time between the previous process and the apparent result at all destroy their necessary connexion. in the case of the curious misseltoes, the ovule does not appear till three months after the pollen has been shed; but when it does appear, its existence as an organism capable of developing the characteristic form of its species, is as truly dependent on the previous existence of the pollen, as if not an hour had intervened. supposing the essential conditions of vegetable organisms to have been at the first what they are now; in other words, supposing specific identity to have been always maintained,--which i have demanded as a postulate for this argument,--it appears to me demonstrable, that every plant in the world presented at the moment of its creation evidences _prochronic_ development, in nowise to be distinguished from those on which we firmly rely as proving the lapse of time. but is the case otherwise in the animal world? we traced back the history of our medusa through its marvellous series of gemmative developments, till we reached the minute infusory-like gemmule, which is its simplest form. now it is quite legitimate to assume that _this_, and not the pulmonigrade umbrelliform stage, was the one in which the new-created medusa began existence. have we, then, got rid of the evidence of past time, which we deduced from the successive changes through which the adult had passed? what is this ciliated planule, and whence comes it? it is the embryo discharged from the fringed ovary of a female medusa; it has already passed through several changes of colour and form. it is now of a deep yellow colour; it has been violet; it has been colourless: it is now shaped like a dumb-bell; it was a globule; it had been a mulberry-mass. yet earlier, it had been a component cell of the ovarian band, which divided the generative cavity from that of the stomach, in the parent medusa. in like manner the ciliated gemmule from which was formed the "pluteus" of the urchin, was dependent on the existence of a parent urchin; the monadiform germ from which was developed the pentacrinus of the feather-star, was originally hidden in the ovarian tubes of a parent feather-star: the infant _serpula_ that deposited the first atoms of calcareous matter as a commenced tube, had begun its own existence in the body of a parent _serpula_. it is true the evidence of the connexion between the germ and the parent is not in these low forms always patent to the eye; it is physiological. but it is not less conclusive to one who is able to appreciate its force. a physiologist is as sure that every germ, every ovum, in the invertebrate animals, was produced by an animal of a former generation, as he is of the same fact in a mammal, where his eye can see the scar of the umbilical cord. in many instances there is stronger, or rather more obvious and ordinarily appreciable, evidence of the link between the present and the past generation, than the physiological dependence. the world of insects, which, from its immensity, and from the high organic rank of its members, affords us so exhaustless a mine of economical wonders,--is rich in examples to the point. a few of these i shall cite. the eggs of many insects are not dropped anywhere, at random; for, as the newly-born young have limited powers of locomotion, and yet are in general able to subsist only on some particular kind of food, it is necessary that their birth should occur in the immediate proximity of such food: and therefore that the egg should be so placed. now this circumstance would not be specially noteworthy if the locality selected for the deposition of the egg were the same as that in which the parent insect had been accustomed to find its own private enjoyments: we should reasonably say that the eggs were placed here, because the parents happened to be here. the case, however, is very different. we never find the egg of the peacock butterfly adhering to the leaf of a cabbage, nor that of the garden white to the leaf of a nettle; but the nettle is invariably selected for the former, and a cruciferous plant for the latter. yet there is nothing in the individual wants or likings of the butterfly, in either case, to account for this. both the one and the other flutter through the sunny air, alight to drink the water of some slushy pool, rest on the expanding flowers and probe them for nectar, or suck the exuding juices of an over-ripe fruit. but when did you ever see the gorgeous-eyed peacock feeding on a nettle, or the white on a cabbage? eagerly as they seek these plants, it is solely for the purpose of depositing their eggs where instinct teaches them their unborn progeny will find suitable food. supposing, therefore, we had found the egg of either of these butterflies at the moment of its creation, we should assuredly have found it on the nettle or the cabbage (as the case might be); because to suppose it in any other situation would be equivalent to supposing it so placed as that the end of its creation--the life of the species created--would be _ipso facto_ frustrated. but, finding it so, the question naturally arises,--why here, and not elsewhere? and the only possible answer, on the ground of phenomena, is, because the parent chose this situation for it. and thus we are inevitably thrown back to an anterior generation, which is equivalent to past time. again, if we had seen the egg of the nut weevil (_balaninus nucum_) just come from the creative hand of god, we should certainly have found it within the immature soft-shelled hazel-nut, because there alone would the grub when hatched meet with "food convenient for" it. and yet if we had sought (ignorant of the fact of its recent creation) the reason of its being there, our acquaintance with entomology would have pointed to the parent beetle, who, with her jaws placed at the tip of a long slender snout, had bored a tiny hole in the tender shell, and had then projected the egg from her abdomen into the interior. the eggs of the _oestridæ_--for example, the worble of the ox (_oestrus bovis_) or the bot of the sheep (_oe. ovis_)--would be discovered in no other circumstances than beneath the skin of the former, and at the edge of the nostrils of the latter. for these are the respective situations in which the egg is always deposited, that of the worble hatching _in situ_, and forming a superficial abscess in communication with the external air, and that of the sheep-bot producing a larva which crawls up the nostrils of the poor animal, till it finds a suitable resting-place in the frontal sinuses of the skull. to suppose the egg in any other circumstances than those which i have mentioned, would be to consign it to certain destruction. yet does not its presence there bear witness to the eclectic care of the parent gadfly, whose unerring instinct knew how to seek and select the right position? if you had set yourself to look for the egg of a _pimpla manifestator_, a common cuckoo-fly, where would you have looked for it, but in the fatty tissues of a wild bee's grub, that was lodged in a deep hole in some old post? if you had sought elsewhere, you would surely have been disappointed. and would not its presence there bear testimony to the lengthened ovipositor of the well-known brisk and busy fly, and to its remarkable habits?[93] the grub of the pill chafer or tumble-dung beetle (_phanæus_) feeds on the ordure of _mammalia_. and, in order that the newly-hatched young may have a copious supply of food at hand, the parent chafer with its jaws detaches a mass of recent ordure, which it then rolls over the ground with its hind feet, until it acquires a globular form, and a coating of earth or sand. an egg is then deposited in the centre of the ball, which is rolled into a hole made in the earth to receive it. the coating of earth drying and hardening, keeps the interior of the mass fresh and moist until the young grub is hatched, when it at once begins to devour its savoury and delicate provision. it would be vain to search for the egg of a _cynips_ except within a vegetable gall, or at least within the tissues of a plant that are going to produce one. take as an example _c. quercus_, which produces the spongy excrescence well known as the common oak-apple. the female gall-fly is furnished with an ovipositor in the shape of a very fine curved needle, with which she punctures the tender bark of an oak shoot, lodging an egg in the perforation. stimulated by some fluid, probably, which is poured into the wound at the same time, the sap forms a peculiar tissue around the egg, swelling into a large ball, on which the young grub begins to feed eagerly, and in which it finds the only nutriment on which it could subsist. now, if we had found the egg of a gall-fly newly created, we should certainly have found it in a gall; and the gall would have afforded us indubitable evidence of the wounding of the vegetable tissues, and of the organ, secretion, and instinct of the tiny fly by which the process had been effected. the evidence would be irresistible, but of course it would be fallacious. let us now look at a few examples in which the egg is found in invariable association not merely with something that the parent has found for it, but with something that has proceeded from her, a part of herself. of this nature are the eggs of that beautiful, but most cacodious, lace-winged fly, _chrysopa perla_. if you had seen one of these (or more) at the instant of its creation, you would have seen a tiny oval body placed at the extremity of an elastic footstalk half-an-inch in length, and as fine as a hair, standing erect from the surface of a leaf. this thread is composed of a gummy secretion, evolved in a gland attached to the oviduct of the female lace-fly. when she deposits an egg, she first exudes a drop of this gum on the surface of a leaf, and then, elevating her abdomen, the viscid substance is drawn out in a thread, which presently hardening in the air, the egg is left at the tip of the filament. an experienced entomologist, on seeing this object, would have no hesitation in declaring the origin of the footstalk to be the gum-gland of the female _chrysopa_; and yet he would certainly have drawn a false inference in the case that i am supposing. [illustration: lace-fly and eggs.] many spiders enclose their eggs in an envelope, the produce of their own bowels. take an interesting example, as narrated by the eloquent mr. kirby. "there is a spider common under clods of earth (_lycosa saccata_), which may at once be distinguished by a white globular silken bag, about the size of a pea, in which she has deposited her eggs, attached to the extremity of her body. never miser clung to his treasure with more tenacious solicitude than this spider to her bag. though apparently a considerable incumbrance, she carries it with her everywhere. if you deprive her of it, she makes the most strenuous efforts for its recovery; and no personal danger can force her to quit the precious load. are her efforts ineffectual? a stupefying melancholy seems to seize her; and, when deprived of this first object of her cares, existence itself appears to have lost its charms. if she succeeds in regaining her bag, or you restore it to her, her actions demonstrate the excess of her joy. she eagerly seizes it, and with the utmost agility runs off with it to a place of security. "the attachment of this affectionate mother is not confined to her eggs. after the young spiders are hatched, they make their way out of the bag by an orifice which she is careful to open for them, and without which they could never escape; and then, like the young of the surinam toad (_rana pipa_), they attach themselves in clusters upon her back, belly, head, and even legs; and in this situation, where they present a very singular appearance, she carries them about with her, and feeds them until their first moult, when they are big enough to provide their own subsistence."[94] i waive the argument derived from the fact of the apparent necessity of the mother's care for the new-born young. but the mother's care is indispensable to the appearance of the young at all; not only because the eggs are the produce of her ovary, but also because the envelope which protects them is the produce of her spinning-glands. there is a furry moth, by no means uncommon, known to collectors as the gipsy (_hypogymna dispar_), the eggs of which require to be protected by an elaborate covering, either from extremes of temperature, from light, or from certain electric conditions of the atmosphere. the protection is afforded at the expense of the hair which clothed the mother herself. her ovipositor is furnished with a pair of nippers, by means of which she plucks off her own hairs, and makes with them a flat cushion on the surface of a leaf. on this she deposits her eggs in successive layers; and when the full number is laid, she covers them with a roof of hair, slanting downwards and outwards from an apex, so artfully arranged, like the thatch of a cottage, as effectually to throw off water; each layer of hairs overlapping the preceding, and all preserving the same direction, so that, when finished, the work resembles a smooth and well brushed piece of fur. if, then, a patch of eggs newly-created had been subjected to our inspection, we should have found them snugly protected by their conical roof of thatch; and when we came to examine the thatch microscopically, we should have found it composed of the hairs of _hypogymna_. and thus again we should have an indubitable and yet deceptive record of a preceding existence. the numerous species of the genus _coccus_, to which we are indebted for cochineal, lac, and other products valuable in commerce, afford me an illustration of my argument, more striking than any of the above. in the case of the lac insect (_c. lacca_), for example, the female resembles a little hemispherical scale on the twig of a tree. at a certain period of her life, a pellucid, glutinous substance begins to exude from the margins of her body, which by and by completely covers it, cementing her firmly to the branch, from which she never afterwards moves. she now proceeds to lay her eggs, which one by one as they are extruded are thrust under her, between her abdomen and the surface of the branch. the result of this is, that when the whole are laid, they occupy pretty nearly the same position in relation to the mother as they did before, with this exception, that the abdominal integuments, which before were beneath them, are now above them, and are in close contact with those of the back, so that both together make a double, but still a thin, arched roof over the heap of eggs, which are thus protected till the hatching of the young, when they eat their way out of their long dead mother. let me now make my usual application. you say the _coccus_ was created not an adult insect, which would involve the prochronic stages of its metamorphosis, but as a germ, that is an egg (for the germ of an insect is an egg, and nothing else): well, here is a batch of coccus-eggs just created, covered with the scaly roof which is necessary to their existence. but this scale is not a record of the mother, but the mother herself, _a prochronic mother_, of course! other genera of this wonderful class of animals yield us evidences of a somewhat different character, in the structures which the parents form for the reception of their eggs. one of the most complex and elaborate pieces of mechanism found in any animal organ is the ovipositor of the sawflies (_tenthredinidæ_). i cannot here describe it at length; it may suffice to say that it consists of two saw-plates, working separately and in opposite directions, the teeth of which are cut into finer teeth; and two supporting plates, very similar to the saws in shape and appearance. the whole flat side of the saw is, moreover, covered with minute sharp points, which give the action of a rasp to the instrument, in addition to that of saw. by means of this complicated apparatus the parent fly cuts a groove in the twig of the proper shrub, say, a rose-bush. when it is made, the plates are slightly separated, and an egg is laid in the groove. the saw is now withdrawn, and a frothy secretion is deposited, which appears to be intended, by its hardening, to prevent the growth of the wood from closing upon the egg, before the time of hatching arrives. if, then, any of the species of _tenthredo_ had been called into primal existence as an egg, it must have been within such a groove as this; and the groove, if carefully examined, would have presented evidences of having been formed and filled by the curious implement of the parent fly. those obscure and obscene insects, the cockroach tribe (_blattadæ_), secrete an extraordinary covering for the protection of their eggs. "instead of being laid separately, the eggs are, when deposited, enclosed in a horny case, or capsule, variable in its form in different species but generally of a more or less compressed oval shape, resembling a small bean. there is a longitudinal slit in the margin of the capsule, each side of which is defended by a narrow serrated plate, fitting closely to its fellow. the inside of this egg-case is divided into two spaces, in each of which is a row of separate compartments, every one enclosing an egg, so that the whole resembles the pod of some leguminous vegetable. this capsule, with its precious contents, is constantly carried about by the female for a week or a fortnight, and is then fastened, by means of a glutinous fluid, in some safe locality. the slit of the capsule is strongly coated with cement, so as to be even stronger than the other parts. in this capsule the young larvæ are hatched, and immediately discharge a fluid which softens the cement, and enables them to push open the slit, through which they escape; after their exit the slit shuts again so closely, that it appears as entire as before. in some species it would seem that the females themselves liberate their offspring by seizing the capsule when the larvæ are fit for escape, and tearing it with the aid of their forelegs from end to end, by which means the enclosed larvæ are set at liberty."[95] it is impossible to read this description without being reminded of the manner in which the bean or other leguminous seed links itself with a former generation by means of the dehiscent legume, itself a production of the parent plant. and the same reasoning applies to this case, as to the other;--the egg, if the _blatta_ was created in that stage, would triumphantly show in the pod with which it was covered, a record of past processes. so, once more, with the immense tribes of solitary bees, wasps, and spheges. i shall mention but one example, from my own experience. it is the dirt dauber (_pelopoeus flavipes_) of north america. the female of this elegant fly, when about to lay her eggs, builds up a tubular nest of cells with fine mud, which she makes by mingling and kneading road-dust with her saliva. each tube consists of several cells, separated by transverse partitions of the mortar; and in each, before she closes it up, she lays a single egg, which she then covers with spiders which are to constitute the food of the grub when hatched, and to last it during the whole period of its larval growth. dead spiders would not do, for their bodies would either dry up, or become putrescent long before the young grub could devour them. on the other hand, if a number of these fierce and carnivorous creatures were immured, in health, they would soon destroy one another. to obviate this, the parent-fly ingeniously stings every spider just sufficiently to paralyse, without killing it. thus nearly a score of living spiders are packed away in a cell scarcely larger than a lady's thimble; and thus they remain fresh and succulent food for the larva, not only till it is ready to begin its eating task, but even to the close of its repast. i think this a particularly instructive example. the _pelopoeus_ was indubitably created; for it exists. as indubitably it was created in some stage of its cyclical life-history. if as an imago, then i press the argument from the necessity of its previous metamorphoses. if as a pupa, or a larva, or an egg, each of these conditions of life was entirely passed as an inmate of the mud-walled cottage; which, cottage was built and stocked with food by the industry and skill of the parent-fly. the grub could not have lived without the stored spiders; the spiders could not have been stored (_normally_) without the agency of the fly. in some other instances the connexion between germ and parent is patent to the eye. the beautiful star-fish, _cribella_, passes through all its infant metamorphoses, changing from an ovum to an infusory, thence to a pluteus (or what is analogous to it), thence to a star-fish, all in the marsupium provided for the occasion, by the drawing together of the arms of the patient mother. the female _brachionus_ carries its deposited eggs attached to the hinder part of its body; and thus we can trace, through their transparent coats, the gradual development of the organs of the embryo,--the coloured eye, the rotatory cilia, the complex mastax,--and even detect the vigorous movements of these and other parts, while yet carried hither and thither by the parent. [illustration: female brachionus, with eggs.] but further, in the class from which i have taken this last illustration--that of the rotifera--there are examples of viviparous genera; and these, because of the perfect transparency of all the integuments, are peculiarly instructive and germane to my argument. in _rotifer macrurus_ the ovary with its germinal vesicles is distinctly seen occupying one side of the animal. from this one of the vesicles enlarges, until it becomes a long-oval translucent sac, nearly filling the whole left side of the visceral cavity. a kind of spasmodic movement is suddenly observed in this oblong ovum, and instantly we see, in its place, a well-developed living young; as distinctly visible as if it were excluded. it lies in a bent position, with its foot upturned; is nearly half the length of the parent; is furnished with a proboscis, with a pair of crimson eyes, with ciliary wheels, with a mastax whose toothed hemispheres frequently work vigorously, and with all the viscera proper to the species. [illustration: pregnant asplanchna. _a._ _unborn young._] in the beautiful, comparatively large, and economically singular genus, _asplanchna_, the same process of development can be watched with perfect facility through every stage. in the body of the female parent, as transparent as the clearest glass, the band-like ovary is seen floating in the visceral cavity, with several ova in various degrees of advancement. we trace one of these till it becomes a manifestly living young in the ovisac, lying along at the bottom of the parental cavity, more than one-third of whose volume is occupied by it:--supposing it to be a female infant. all its organs,--the eyes, the jaws, the stomach, the pancreatic glands, _the ovary with its nuclei_, the muscles, the rotatory cilia, &c. can be traced with the utmost distinctness long before birth, and its motions are strong and voluntary. neither in this case, nor in that of _rotifer_, does the young animal pass through any metamorphosis; the unborn young has the full development of the parent, in every respect but size. in each case, the _visible_ life-history of the individual commences not at birth, but at a period long antecedent, if indeed it can be said to commence at all, where we see it gradually developed from a nucleus, which was an integral part of the parental ovary, _even before that parent's birth_. in the case of the amusing little water-fleas (_daphnia_), we have another example of viviparous generation, which, owing to the same cause as in the rotifera,--the transparency of the integument, can be followed through all its stages by the eye of the observer. the eggs of this little crustacean are deposited in a special chamber within the valves of the parent, where they are hatched. the young remain in their receptacle for a period, which varies according to the temperature, but long enough for them to undergo important changes in structure, and to pass their first moult.[96] here, again, it is impossible to select a condition which does not take hold of a pre-existence; for the youngest independent stage is dependent on earlier stages; and these are passed in visible connexion with the parent. it is true there is in this genus, another mode of reproduction, by means of eggs which are thrown off enveloped in an organic covering, called the ephippium. if this condition be selected for the argument of my supposed opponent, i reply that it amounts to nearly the same thing; only the case will then come into the category of those animals whose earliest stages are protected by coverings formed from the body of the parent,--like the _hypogymna_, and the cockroach, already alluded to. where then, in these species, can we possibly select a stage of life, which is not inseparably and even visibly connected with a previous stage? if we come to the vertebrate creatures, the argument becomes assuredly not less convincing. the formidable shark, which we considered as a well-toothed adult ready for slaughter, let us suppose to have been created in the harmlessness of infancy. it is a slender thing, some ten or twelve inches long, bent upon itself, inclosing in the ring thus made, the vitellus or yelk-bag, the contents of which are in process of being absorbed into the abdomen. but the whole,--shark, yelk-bag, and all--is imprisoned in a brown horny capsule, that looks like a pillow-case, with long tapes appended to the four corners. this very peculiar protecting capsule points clearly to a peculiar structure in the parent. the embryo was not inclosed in the pillow-case, at its first formation; but, in the course of its descent from the ovary through the oviduct, it had to pass a region of the latter, where was a thick glandular mass,--the nidamental gland,--whose office it was to secrete a dense layer of albumen, with which, the embryo became invested. this substance took the form of the flattened purse, or pillow-case, with produced angles, above described, and on its exclusion from the duct assumed a very tough horny consistence, and a dark mahogany colour. the comparative anatomist would, therefore, without the least hesitation, refer the origin of the investing capsule to the nidamental glands of the female shark; but supposing the embryo to be but just created, his physiological science would only lead him to a false conclusion. if the tree-frog afforded us evidence of pre-existent time, in the metamorphosis which it must naturally have experienced from the tadpole to the reptilian condition, what shall we say to that strange and uncouth member of the same class,--the surinam toad (_pipa_)? little would be gained by selecting the germ-stage, as the presumed epoch of creation in this case; for, according to the extraordinary economy of this genus, the male acts as midwife, and the female as wet-nurse, to the hopeful progeny. "as fast as the female deposits her eggs, the male who attends her arranges them on her broad back, to the number of fifty or upwards. the contact of these eggs with the skin appears to produce a sort of inflammation; the skin of the back swells, and becomes covered with pits or cells, which enclose each a single egg, the surface of the back resembling the closed cells of a honeycomb. the female now betakes herself to the water; and in these cells the eggs are not only hatched, but the tadpoles undergo their metamorphosis, emerging in a perfect condition, though very small, after a lapse of _eighty-two days_ from the time in which the eggs were placed in their respective pits." to a tyro in animal physiology it might seem that the smooth rounded egg of a bird or a lizard, presents an example of an organism in the simplest possible condition, and in a stage which, if any can be, is independent of anything that went before. but is it so? let us see. here is the egg of the common fowl. i take it in my hand, and perceive nothing but an uniform, smooth, hard, white surface. this i break, and find that it is a thin layer of calcareous substance, which, on microscopical examination, proves to be composed of minute polygonal particles, so agglutinated as to leave open spaces in the interstices of their contiguous angles. below this calcareous shell i find a membrane (_membrana putaminis_), which seems, from its thinness in most parts, to be single, but which is separated into two layers at the large end of the egg. [illustration: hen's egg.] within this membrane there is another (_the chalaza_) which, closely enveloping the yelk, passes off from it towards each extremity of the egg in the form of a twisted cord. then comes a delicate membrane (_memb. vitelli_) in close contact with, and enveloping the orange-coloured yelk; which latter carries, on one point of its globular surface, the thin _blastoderm_, or germinal membrane. the yelk-globe, fastened by its twisted _chalazæ_, is suspended in a glairy fluid (albumen), which fills the space between it and the _membrana putaminis_. this fluid, though apparently homogeneous, is really composed of many layers, and the innermost of these it is which is condensed into the _chalaza_. such, then, is the complex structure of this apparently simple object. what light can it throw on our inquiry? each of these component parts bears witness to a succession of past periods. the yelk with its germ was first formed, escaping naked, or clothed only with its own excessively delicate membrane, from its ovisac into the oviduct. through the course of this tube it now slowly descended, receiving successive investments as it proceeded. the albumen was deposited layer upon layer from the mucous membrane of the upper part of the oviduct; the first depositions condensing into the _chalaza_. by and by it came down to a region of the oviduct where a tenacious secretion was poured out, which, investing the albumen, soon hardened into a substance resembling thin parchment, and formed the _membrana putaminis_; two successive layers of this were deposited, between which a bubble of gas, chiefly composed of oxygen generated in the interval, was inclosed. then it descended still farther, to a part where the lining membrane of the duct was endowed with the power of secreting calcareous matter, which, as above stated, was deposited in a thin layer of polygonal atoms. and now, having received all its components, and having arrived at the orifice of the duct, the egg was laid. here, then, there is abundant evidence of successive processes, which must have preceded the existence of this complete and perfect egg. but there is yet one more evidence which i have reserved to the last, because it is peculiarly distinct and palpable, even to the senses. the _chalaza_, we see, is twisted at each pole of the yelk-globe, until it resembles a piece of twine: what is the meaning of this? it was, as i observed, deposited as a loosely enveloping membrane in the upper part of the oviduct; the yelk-globe, however, was progressively descending; and, as it descended, _it continually revolved upon its axis_; by means of which rotation the investing membrane was gathered at each pole into a spirally twisted cord, stretching from the yelk to the ends of the _membrana putaminis_. thus it presents us with an unmistakeable record of what took place in the earlier periods of the descent. we saw distinct traces of the past in the structure of a feather. but the feathers have already begun to develop before the young bird leaves the egg. and the structure of the egg carries us back to the oviduct of the parent-fowl. at what stage of existence, then, could a bird, by possibility, have been created, which did not present distinct records of prochronic development? if we come to the mammalia, the impossibility of finding such a stage becomes only more and more obvious. for it is a law in physiology, that the higher the grade of organization assigned to any being, the more it is assisted in infancy by the parent. "this law is remarkably exemplified in the class mammalia, which unquestionably ranks at the head of the animal kingdom, in respect to degree of intelligence and general elevation of structure. it is the universal and most prominent characteristic of this class, that the young are retained within the body of the female parent, until they have made considerable progress in their development; that, whilst there, they derive their support almost immediately from her blood; and that they are afterwards nourished for some time by a secretion which she affords."[97] the foetus of the kangaroo, when expelled from the womb, is scarcely more than an inch in length. its limbs and its tail are indeed formed, but the imperfect creature has been compared to an earthworm, for the colour and semi-transparency of the integument. in this condition it is unable to find and seize the nipple, and equally unable to draw sustenance therefrom, by its own unaided efforts. the _milk is ejected_, by the _muscular action of the mother_, into the throat of the foetus, and there is a peculiar and beautiful contrivance to obviate the danger of the injected fluid's passing into the trachea instead of the oesophagus. yet, from this helpless naked condition to that of the active, well-clothed, experienced young, able to quit the maternal pouch at will, and flee to it for protection, there is a well-understood and perfectly appreciable concatenation of stages, each of which looks back to, and depends on, those previously existing. and, during the whole of these, the mother's presence is necessary to the comfort, and, for the greater part of them, to the very existence of the infant. thus, once more, there is no condition of the animal, on which we may fix, as being so simple, as to have no retrospective history. the umbilical cicatrix i have already alluded to; but i may be permitted to mention it again; because, in all the higher mammalia, at least, it exists, throughout life, an eloquent witness to the organic connexion of the individual with a mother, and therefore to her pre-existence. if it were legitimate to suppose that the first individual of the species man was created in the condition answering to that of a new-born infant, there would still be the need of maternal milk for its sustenance, and maternal care for its protection, for a considerable period; while, if we carry on the suggested stage to the period when this provision is no longer indispensable, the development of hair, nails, bones, &c., will have proceeded through many stages. and, in either condition, the navel cord or its cicatrix remains, to testify to something anterior to both. xii. the conclusion. "we have no experience in the creation of worlds." chalmers. we have passed, in review before us the whole organic world: and the result is uniform; that no example can be selected from the vast vegetable kingdom, none from the vast animal kingdom, which did not at the instant of its creation present indubitable evidences of a previous history. this is not put forth as a _hypothesis_, but as a _necessity_; i do not say that it was _probably_ so, but that it was _certainly_ so; not that it _may have been thus_, but that it _could not have been otherwise_. i do not touch the inorganic world: my acquaintance with chemistry is inadequate for this: perhaps the same law does not extend to the inorganic elements: perhaps their developments, and combinations are not, like the economy of plants and animals, essentially and exclusively cyclical: perhaps carbon and oxygen and hydrogen could be created in conditions, which obviously did not depend on any previously existing conditions. this i do not know: i neither affirm nor deny it. but i think i have demonstrated in these pages, that such a cyclical character does attach to, and is inseparable from, the history of all organic essences; and that creation can be nothing else than a series of irruptions into circles: that, supposing the irruption to have been made at what part of the circle we please, and varying this condition indefinitely at will,--we cannot avoid the conclusion that each organism was from the first marked with the records of a previous being. but since creation and previous history are inconsistent with each other; as the very idea of the creation of an organism excludes the idea of pre-existence of that organism, or of any part of it; it follows, that such records are _false_, so far as they testify to time; that the developments and processes thus recorded have been produced without time, or are what i have called _prochronic_. nor is this conclusion in the least degree affected by the actual chronology of creation. the phenomena were equally eloquent, and equally false, whether any individual organism were created six thousand years ago, or innumerable ages; whether primitively, or after the successive creations and annihilations of former organisms. the law of creation supersedes the law of nature; so far, at least, as the organic world is concerned. the law of nature, established by universal experience, is, that its phenomena depend upon certain natural antecedents: the law of creation is, that the same phenomena depend upon _no_ antecedents. the philosopher who should infer the antecedents from the phenomena alone, without having considered the law of creation, would be liable to form totally false conclusions. in order to be secure from error, he must first assure himself that creation is eliminated from the category of facts which he is investigating; and this he could do only when the facts come within the sphere of personal observation, or of historic testimony. up to such a period of antiquity as is covered by credible history, and within such a field of observation as history may be considered fairly cognisant of,--the inference of physical antecedents from physical phenomena, in the animal or vegetable world, is legitimate and true. but, beyond that period, i cannot safely deduce the same conclusion; because i cannot tell but that at any given moment included in my inquiry, creation may have occurred, and have been the absolute beginning of the circular series. the question of the actual age of any species, whether plant or animal, is one which cannot be answered, except on historic testimony. the sequence of cause and effect is not adequate to answer it; for a legitimate use of this principle, supposing it the only element of the inquiry, would inevitably lead us to the eternity of all existing organic life. one of the familiar street-exhibitions in the metropolis is a tiny coach and horses of glittering metal; which, by means of simple machinery, course round and round the margin of a circular table. let us suppose two youths of philosophical turn to come up during the process. they gaze for a while, and one asks his companion the following question. "how long do you suppose that coach has been running round?" "how long! for an indefinite period, for aught i know. i have counted twenty-two turns, and can see no change: nor can i suggest any point where the course could have begun." here a shrewd lad, carrying a grocer's basket, breaks in. "oh no; there have been only six-and-twenty turns altogether. four turns had been made when you came up. the whole began by the man taking the carriage out of a box; then he set it down out there, just opposite to us, and gave it a little push with his finger, and it has been running ever since. i saw him do it." now perhaps you will say that a glance at the machinery beneath the table would show in a moment how many turns had been made, and how many could be made. very true: but what if the tramp had locked up his clock-work, and would not let you look at it? the only evidence worth a rush is that of the lad who saw the whirligig set a-going. i wish it to be distinctly understood, that i am not proving the exact or approximate antiquity of the globe we inhabit. i am not attempting to show that it has existed for no more than six thousand years. i wish this to be distinctly stated, because i am sure i shall meet with many opponents unfair enough, or illogical enough, to misrepresent or misunderstand my argument, and sound the trumpet of victory, because i cannot demonstrate _that_. _all_ i set myself to do, is to invalidate the testimony of the witness relied on for the indefinitely remote antiquity; to show that in a very large and important field of nature, evidence exactly analogous to that relied on would inevitably lead to a false conclusion, and must, therefore, be rejected, or received only contingently; received only as indicative of probability, and that only in the absence of any positive witness to the contrary. perhaps it may be objected, that there is no sufficient analogy between the phenomena from which the past history of a single organism is inferred, and those from which the past history of a world is inferred. is there not? permit me to repeat an illustration i have already used. the geologist finds a fossil skeleton. his acquaintance with anatomy enables him to pronounce that the objects found are bones. he sees cylinders, condyles, cavities for the marrow, scars of attachment of muscles and tendons, foramina for the passage of nerves and blood-vessels; he finds the internal structure, no less than the form and surface, such as to leave not a doubt that these are real _bones_. now universal experience has taught him that bones imply the existence of flesh; that flesh implies blood; that blood implies life; that life implies time. he therefore concludes unhesitatingly, that this skeleton was once alive, and that time passed over it in that living condition. is not this process of reasoning exactly parallel to that which he would have pursued if he had examined an animal the moment after its creation, (supposing this fact to be unknown to him,) and by which he would in like manner have inferred past time? and where is the vital difference between the two cases, which would operate to make a conclusion which is manifestly false in the one case, necessarily true in the other? one of the most eminent of living botanists has set forth in striking terms the parallelism which i am suggesting. speaking of the _shoot_ as the vegetable individual, and the woody trunk as a kind of ever-accumulating ground, which supports successive generations of shoots, he uses the following comparison. "the history of the grand development of nature on the surface of our globe presents an analogy, which may perhaps serve to set this relation in a clear light. the successive geological formations superposed during the course of countless ages, present, buried in their depths, the traces of as many formations of the organic world, each of which carpeted the then superior stratum of the earth with a new life, until it found its own grave in the succeeding formation, when a new uprising of organic life took its place. in the same way, the stem of a tree is a multistratified ground, in whose layers the history of earlier growths is legibly preserved. the number of the woody layers indicates the number of the generations which have perished, _i. e._ the age of the whole tree: a distinct annual ring is the monument of a vigorous season, an indistinct one of a bad season, a sickly one (which is often found among healthy ones) indicates the unhealthiness of the foliage of that particular year. the practised woodman can decipher many facts of the past in the layers of the trunk; _e.g._ a good season for foliage or for seed, damage by frost or by insects, &c."[98] in order to perfect the analogy between an organism and the world, so as to show that the law which prevails in the one obtains also in the other, it would be necessary to prove that the development of the physical history of the world is circular, like that already shown to characterise the course of organic nature. and this i cannot prove. but neither, as i think, can the contrary be proved. the life of _the individual_ consists of a series of processes which are cyclical. in the tree this is shown by the successive growths and deaths of series of leaves: in the animal by the development and exuviation of nails, hair, epidermis, &c. the life of _the species_ consists of a series of processes which are cyclical. this has been sufficiently illustrated in the preceding pages, in the successive developments and deaths of generations of individuals. we have reason to believe that species die out, and are replaced by other species, like the individuals which belong to the species, and the organs which belong to the individual. but is the life of _the species_ a circle returning into itself? in other words, if we could take a sufficiently large view of the whole plan of nature, should we discern that the existence of species [greek: d] necessarily involved the pre-existence of species [greek: g], and must inevitably be followed by species [greek: e]? should we be able to trace the same sort of relation between the tiger of bengal and the fossil tiger of the yorkshire caves, between _elephas indicus_ and _elephas primigenius_, as subsists between the leaves of 1857 and the leaves of 1856; or between the oak now flourishing in sherwood forest and that of robin hood's day, from whose acorn it sprang?[99] i dare not say, we should; though i think it highly probable. but i think you will not dare to say, we should _not_.[100] it is certain that, when the omnipotent god proposed to create a given organism, the course of that organism was present to his idea, as an ever revolving circle, without beginning and without end. he created it at some point in the circle, and gave it thus an arbitrary beginning; but one which involved all previous rotations of the circle, though only as ideal, or, in other phrase, prochronic. is it not possible--i do not ask for more--that, in like manner, the natural course of the world was projected in his idea as a perfect whole, and that he determined to create it at some point of that course, which act, however, should involve previous stages, though only ideal or prochronic? all naturalists have speculated upon the great plan of nature; a grand array of organic essences, in which every species should be related in like ratio to its fellow species, by certain affinities, without gaps and without redundancies; the whole constituting a beautiful and perfect unity, a harmonious scheme, worthy of the infinite mind that conceived it. such a perfect plan has never been presented by any existing fauna or flora; nor is it made up by uniting the fossil faunas and floras to the recent ones; _yet the discovery of the fossil world has made a very signal approach to the filling up of the great outline_; and the more minutely this has been investigated, the more have hiatuses been bridged over, which before yawned between species and species, and links of connexion have been supplied which before were lacking.[101] it is not necessary,--at least it does not seem so to me,--that all the members of this mighty commonwealth should have an actual, a diachronic existence; anymore than that, in the creation of a man, his foetal, infantile, and adolescent stages should have an actual, diachronic existence, though these are essential to his normal life-history. nor would their diachronism be more certainly inferrible from the physical traces of them, in the one case than in the other. in the newly-created man, the proofs of successive processes requiring time, in the skin, hairs, nails, bones, &c. could in no respect be distinguished from the like proofs in a man of to-day; yet the developments to which they respectively testify are widely different from each other, so far as regards the element of time. who will say that the suggestion, _that the strata of the surface of the earth, with their fossil floras and faunas, may possibly belong to a prochronic development of the mighty plan of the life-history of this world_,--who will dare to say that such a suggestion is a self-evident absurdity? if we had no example of such a procedure, we might be justified in dealing cavalierly with the hypothesis; but it has been shown that, without a solitary exception, the whole of the vast vegetable and animal kingdoms were created,--mark! i do not say _may_ have been, but must have been created--on this principle of a prochronic development, with distinctly traceable records. it was _the law of organic creation_. it may be objected, that, to assume the world to have been created with fossil skeletons in its crust,--skeletons of animals that never really existed,--is to charge the creator with forming objects whose sole purpose was to deceive us. the reply is obvious. were the concentric timber-rings of a created tree formed merely to deceive? were the growth lines of a created shell intended to deceive? was the navel of the created man intended to deceive him into the persuasion that he had had a parent?[102] these peculiarities of structure were inseparable from the adult stage of these creatures respectively, without which they would not have been what they were. the locust-tree could not have been an adult _hymenæa_, without concentric rings;--nay, it could not have been an exogenous tree at all. the _dione_ could not have been a _dione_ without those foliations and spines that form its generic character. the man would not have been a man without a navel. to the physiologist this is obvious; but some unscientific reader may say, could not god have created plants and animals without these retrospective marks? i distinctly reply, no! not so as to preserve their specific identity with those with which we are familiar. a tree-fern without scars on the trunk! a palm without leaf-bases! a bean without a hilum! a tortoise without laminæ on its plates! a carp without concentric lines on its scales! a bird without feathers! a mammal without hairs, or claws, or teeth, or bones, or blood! a foetus without a placenta! i have indeed written the preceding pages in vain, if i have not demonstrated, in a multitude of examples, the absolute necessity of retrospective phenomena in newly-created organisms. but if it can be undeniably shown in one single example, our failure to perceive it in ninety-nine other instances would in nowise invalidate the deduction from that one. granted that you can triumphantly convict me of a _non-sequitur_, in ninety-nine out of every hundred of the cases in which i have attempted to show this connexion; still, if i have conclusively proved that in one solitary instance an animal or a plant was created with but one solitary evidence of pre-development, the principle for which i contend is established. i trust, however, it does not rest on one example, nor on twenty, nor on a hundred. it may be thought that i have multiplied my illustrations needlessly: ten times as many might have been given. i wished to show that the proof is of a cumulative character: a single good example would, indeed, have established the principle; but i wished to show how widely applicable it is; that it is, indeed, of universal application in the organic kingdoms. if, then, the existence of retrospective marks, visible and tangible proofs of processes which were prochronic, was so necessary to organic essences, that they could not have been created without them,--is it absurd to suggest the _possibility_ (i do no more) that the world itself was created under the influence of the same law, with visible tangible proofs of developments and processes, which yet were only prochronic? admit for a moment, as a hypothesis, that the creator had before his mind a projection of the whole life-history of the globe, commencing with any point which the geologist may imagine to have been a fit commencing point, and ending with some unimaginable acme in the indefinitely distant future. he determines to call this idea into actual existence, not at the supposed commencing point, but at some stage or other of its course.[103] it is clear, then, that at the selected stage it appears, exactly as it would have appeared at that moment of its history, if all the preceding eras of its history had been real. just as the new-created man was, at the first moment of his existence, a man of twenty, or five-and-twenty, or thirty years old; physically, palpably, visibly, so old, though not really, not diachronically. he appeared precisely what he would have appeared had he lived so many years. let us suppose that this present year 1857 had been the particular epoch in the projected life-history of the world, which the creator selected as the era of its actual beginning. at his fiat it appears; but in what condition? its actual condition at this moment:--whatever is now existent would appear, precisely as it does appear. there would be cities filled with swarms of men; there would be houses half-built; castles fallen into ruins; pictures on artists' easels just sketched in; wardrobes filled with half-worn garments; ships sailing over the sea; marks of birds' footsteps on the mud; skeletons whitening the desert sands; human bodies in every stage of decay in the burial-grounds. these and millions of other traces of the past would be found, _because they are found in the world now_; they belong to the present age of the world; and if it had pleased god to call into existence this globe at _this_ epoch of its life-history, the whole of which lay like a map before his infinite mind, it would certainly have presented all these phenomena; not to puzzle the philosopher, but because they are inseparable from the condition of the world at the selected moment of irruption into its history; because they constitute its condition; they make it what it is. hence the minuteness and undeniableness of the proofs of life which geologists rely on so confidently, and present with such justifiable triumph, do not in the least militate against my principle. the marks of hyænas' teeth on the bones of kirkdale cave; the infant skeletons associated with adult skeletons of the same species; the abundance of coprolites; the foot-tracks of birds and reptiles; the glacier-scratches on rocks; and hundreds of other beautiful and most irresistible evidences of pre-existence, i do not wish to undervalue, nor to explain away. on the hypothesis that the actual commencing point of the world's history was subsequent to the occurrence of such things in the perfect ideal whole, these phenomena would appear precisely as if the facts themselves had been diachronic, instead of prochronic, as was really the case.[104] perhaps some one will say, "all this might be tenable, supposing the world were an organism. your argument goes to show that organic essences in every stage of their existence present proofs of pre-existence; but what analogy is there between the lifeless inorganic globe (in which evidences of past processes are apparent, independent of the fossil organisms), and a living organic being,--plant or animal?" i answer, the point in the economy of the organic creatures, on which their prochronism rests, is not the organic, but the circular condition of their being. the problem, then, to be solved, before we can certainly determine the question of analogy between the globe and the organism, is this:--is the life-history of the globe a cycle? if it is (and there are many reasons why this is probable), then i am sure prochronism must have been evident at its creation, since there is no point in a circle which does not imply previous points. at all events, geologists cannot prove that it is not. wherever we can discern a cyclical condition, there the law of which i am treating must hold good; and it certainly obtains in other things beside organisms. when the inorganic crust of the globe was first cleft to contain rivers, whence came the water that flowed through the fissures? a river is the produce of rivulets, which issue from mountain springs; these originate in the water that percolates through the soil; and this is derived from the rains, and snows, and dews, that are deposited from the atmosphere. but there would be no deposition from the atmosphere if the water had not first been carried up by evaporation; and the vaporable fluid is obtained from the moistened soil; from the lakes and rivers; and from the seas and oceans, whose loss is perpetually recruited from the flowing rivers. here, then, we get a circle closely analogous to that of organic being. was a given drop of water created as a component particle of a running stream? its position and condition looked back to the mountain spring whence it must naturally have issued. was it called into being in the spring? it looked up to the surface, whence it must have oozed. was it formed on the surface? it looked to the clouds, whence it must have dropped. was it created in the cloud? it looked down to the surface of the lake or sea, whence it must have been raised. was it created in the lake? it looked to the river, whence it must have flowed. the chief pelagic currents, which have hitherto so often been the destruction of the navigator, but which may yet become his able and subject servants, flow in circular systems. there is such an one in the southern part of the indian ocean, known as the hurricane region; another immense one ever running round and round the north pacific; and, above all, that wondrous river of hot water--a river whose well-marked banks are not solid earth, but cold water--the gulf stream. "the fruit of trees belonging to the torrid zone of america is annually cast ashore on the western coasts of ireland and norway. pennant observes that the seeds of plants which grow in jamaica, cuba, and the adjacent countries, are collected on the shores of the hebrides. thither also barrels of french wine, the remains of vessels wrecked in the west indian seas, have been carried. in 1809 his majesty's ship _little belt_ was dismasted at halifax, nova scotia, and her bowsprit was found, eighteen months after, in the basque roads. the mainmast of the _tilbury_, buried off hispaniola in the seven years' war, was brought to our shores."[105] these facts are dependent on the eastward set of this majestic current; and so is another great physical fact of immeasurable importance to us;--the superiority in temperature of the western shores of europe over the eastern shores of north america. the harbour of st. john's, newfoundland, is frequently fast closed by ice in the month of june; yet the latitude of st. john's is considerably south of that of the port of brest, in france. impelled by the rotatory motion of the earth, and by the trade-wind,[106] the equatorial waters of the atlantic are ever urged, a broad and rapid river, into the caribbean sea, and the gulf of mexico, the narrowing shores of which compress the stream as in a funnel. the andes here present a slender but impregnable barrier to its further progress westward; and the trend of the isthmus turns it to the northward. still finding no outlet, the impatient current, like a wild-beast pacing round its cage, courses the gulf of mexico, doubles the peninsula of florida, and pursues its way first to the north-east, and then to the east, crossing the atlantic in a retrograde direction, until it laves with its warm billows the coasts of europe. here it turns to the southward, and after embracing the "fortunate" isles that lie off the african shores,--the azores, the madeiras, and the canaries,--it joins the great equatorial set beneath the trade-wind, and returns on its westward course. this mighty circulation of water must have been going on from the instant that the earth commenced rotating on its axis, or (granting this to have been chronologically subsequent) from the instant the atlantic occupied its present bed. whether sooner or later, it commenced at _some_ instant; but at that instant all the previous elements of the circle were presupposed, and a boundless succession of former circles. an intelligent stranger, looking on the movement immediately after its commencement, but ignorant of its origin, would not be able to assign any limit to its past duration. from his observation of the velocity of the current in different parts of the circle, he would say with confidence,--"these identical particles of water, which i see now urged on their ceaseless course towards the middle of the north atlantic, were, yesterday morning at this hour, in the latitude of the mouth of the chesapeake; on the morning before, off cape hatteras, on the morning before that, off cape lookout;" and so backwards interminably. whether the economy of the globe is circular, or not, i am not in a position to show. but its movements certainly are; and so are the movements of all the myriad worlds with which astronomy is conversant. asteroids, planets, satellites, comets, suns,--nay, even the stellar universe itself--obey _in their motions_, the grand universal law of circularity. take any one of these;--our moon. when its orbital motion commenced, it commenced at some point or other of the circle which it describes in its course around the earth. the pre-existence, or at least the co-existence, of the earth, and also that of the sun, are necessary to its motion. supposing it possible for a spectator, furnished with modern astronomical knowledge, to have looked at that instant on the newly-spun orb, would he not confidently have inferred, from its position at that moment, its position a week before? would he not have felt able to indicate with unhesitating certainty the solar and lunar eclipses of a century or a chiliad before, just as he now calculates the time of the eclipse that marked the death of herod the great? undoubtedly he would; for he would assume the constancy of those movements which modern science has deduced from the observations of many centuries; and, granting him the fact of their constancy, we could not invalidate his conclusions. yet _what_ would he have shown? the conditions and phenomena of bodies before they had begun to exist. the conditions are legitimately deducible; but they are prochronic conditions. the mention of the celestial orbs suggests to remembrance the famous argument for the vast antiquity of the material universe, founded on the time which is required for the propulsion of light. i believe it owes its origin to sir william herschel. speaking of the known velocity of light in connexion with the immense distance of certain nebulæ, that eminent astronomer made these remarks:-"hence it follows, that, when we... see an object of the calculated distance at which one of these very remote nebulæ may still be perceived... the rays of light which convey its image to the eye must have been more than nineteen hundred and ten thousand, that is, almost _two millions_, of years on their way; and that, consequently, so many years ago, this object must already have had an existence in the sidereal heavens, in order to send out those rays by which we now perceive it."[107] the notion has been amplified, with some interesting details, by a writer in the _scottish congregational magazine_ for _january 1847_; who thus throws the statements into a tabular form, and comments on them. "from the moon, light comes to the earth in 1-1/4 second " the sun " " in 8 minutes " jupiter " " in 52 " " uranus " " in 2 hours " a fixed star of 1st magnitude -3 to 12 years " " 2d " 20 " " " 3d " 30 " " " 4th " 45 " " " 5th " 66 " " " 6th " 96 " " " 7th " 180 " " " 12th " 4000 " "now, as we see objects by the rays of light passing from those objects to our eye, it follows that we do not perceive the heavenly bodies, _as they are_ at the moment of our seeing them, but _as they were_ at the time the rays of light by which we see them left those bodies. thus when we look at the moon, we see her, not as she is at the moment of our beholding her disc, but as she was a second and a quarter before; for instance, we see her not at the moment of her rising above the horizon, but 1-1/4 second after she has risen. the sun also when he appears to us to have just passed the meridian, has already passed it by 8 minutes. so, in like manner, of the planets and the fixed stars. we see jupiter, not as he is at the moment of our catching a sight of him, but as he was 52 minutes before. uranus appears to us, not as he is at the moment of our discovering him, but as he was 2 hours previously. and a star of the 12th magnitude presents itself to our eye as it was 4,000 years ago: so that, suppose such a star to have been annihilated 3,000 years back, it would still be visible on the earth's surface for 1,000 years to come: or, suppose a star of the same magnitude had been created at the time the israelites left egypt, it will not be perceptible on the earth for nearly 700 years from this date." beautiful, and at first sight unanswerable as this argument is, it falls to the ground before the spear-touch of our ithuriel, the doctrine of prochronism. there is nothing more improbable in the notion that the sensible undulation was created at the observer's eye, with all the pre-requisite undulations prochronic, than in the notion that blood was created in the capillaries of the first human body. the latter we have seen to be a fact: is the former an impossibility? it may perhaps be said:--"the traces of prochronism you have adduced in created organisms may be granted, because they are inseparable from the presumed condition of those organisms respectively. the blood in the vessels, the hair, the teeth, the nails, may afford evidences of past processes; but then those are only past stages of what yet exists. the case, however, is not parallel with the fossil skeletons, many of which have no connexion with anything now existing. the concentric rings of a timber-tree are essential to its adult state; but how is the existence of the _pterodactyle_ or the _megatherium_ essential to that of the recent _draco volans_, or the south american sloth? can you show in the new-formed creature any trace of some organ which does not come into its present condition of being,--of something which has quite passed away?" perhaps i can. the very concentric rings of the tree are considered by botanists as, in some sense, dead. the paradoxical dictum of schleiden,--"no tree has leaves,"[108]--is grounded on this circumstance, that the woody portion of the mass is the inert result of former generations, and that the present race of leaves is growing, not out of the woody portion of the tree, but out of its herbaceous extremities, "which grow upon the woody stem _as upon a ground_, formed by the process of vegetation. this common ground, namely, the woody stem, _which is almost lifeless_ in comparison with the herbaceous parts engaged in active growth, is annually covered with a vigorous sheath under the protecting bark; and this sheath is the ground of the nourishment of all the vegetating herbaceous extremities."[109] the polygonal plates into which the bark of the _testudinaria_ divides, not only show many superposed laminæ, at any given moment of its adult condition, but also bear witness, in the broad existent surface of each one, to former laminæ, yet older than the oldest now present, which have disintegrated and dropped off. the palm and the tree-fern show, in their trunk-scars, evidences of organs which have completely died away and disappeared; while, between these scars and the generation of living fronds, there is, at any given moment of the tree's history, a series of fronds which are quite dead and dry, but which have not yet disappeared. the _nerita_, a genus of beautiful shells from the tropical seas, dissolves away and removes, in the progress of growth, the spiral column, which originally formed the axis of development; so that, in adult age, the spiral direction of the whole testifies to the past existence of a column which has quite disappeared. in that species of _murex_,[110] which, on account of the long and slender rostellum, and the spines with which it is covered, is known to collectors as the thorny woodcock (_m. tenuispina_), the shelly spines of the earlier whorls would interfere with such as came, in process of development, to be superposed on them; for they cross the area which is to be the cavity enclosed by the advancing lip. they are, however, removed by absorption; but not so completely but that traces may still be discovered where they formerly existed: evidences of the quondam existence of what exists no longer. towards one side of the upper surface of the pretty star-fish, _cribella rosea_, (as in many other species of star-fishes,) there is a curious little mark, known as the _madreporic plate_, the use of which has greatly puzzled naturalists. sars, the norwegian zoologist, has unveiled the mystery.[111] the young larva, before it assumes the stellar form, is furnished with a sort of thick column, divided into four diverging clubbed arms, which are adhering organs, ancillary to locomotion. in the process of development, however, new locomotive organs are formed; and this four-fold column, being no longer needed, sloughs away; and that so completely, that not a trace of its existence remains, _except this scar_, or "_madreporic plate_;" which is therefore a permanent record of something that has quite passed away. but the closest parallel to the relation borne by the skeleton of an extinct species to an extant one, is presented by that of the hilum to a seed, or of the umbilicus to a mammal. each of these is a legible and undeniable, record of a being, whose individuality was totally distinct from that of the being by which it is presented, and of which all vestiges have disappeared, _save this record_. nor is the parallel founded on obscure or rare examples; both the umbilicus and the hilum are generally conspicuous; and both are extensively found in their respective kingdoms, the former pervading the viviparous vertebrata, the latter characterising the whole of the cotyledonous types of vegetation. once more. an objection may arise to the reception of the prochronic principle, on the ground that the examples i have adduced are not to be compared, in point of grandeur, with the mighty revolutions, which are presumed to have written their records in the crust of the globe; and that hence no analogy can be fairly drawn from one to the other. to the philosopher, however, there is no great or small, as there is none in the works of god. we have every reason to believe that he has wrought by the same laws in all portions of his universe: the principle on which an apple falls from the branch to the ground, is the same as that which keeps the planet neptune in the solar system. i have shown that the principle of prochronic development obtains wherever we are able to test it; that is, wherever another principle, that of _cyclicism_, exists; whether the cycle be that of a gnat's metamorphosis, or of a planet's orbit. the distinction of great or small, grand or mean, does not apply to it. if it cannot be proved to be universal, it is only because we are not sufficiently acquainted with some of the economies of nature to be able to pronounce with certainty whether they are cyclical or not. i am not aware of any natural process, in which its existence can be absolutely denied. and this makes all the difference in the world between my position and that of the old simple-minded observers, with which a superficial reader might think it to possess a good deal in common. a century ago, people used to talk of _lusus naturæ_; of a certain _plastic power_ in nature; of abortive or initiative attempts at making things which were never perfected; of imitations, in one kingdom, of the proper subjects of another, (as plants were supposed to be imitated by the frost on a window-pane, and by the dendritic forms of metals). still later, many persons have been inclined to take refuge from the conclusions of geology in the absolute sovereignty of god, asking,--"could not the omnipotent creator make the fossils in the strata, just as they now appear?" it has always been felt to be a sufficient answer to such a demand, that no reason could be adduced for such an exercise of mere power; and that it would be unworthy of the allwise god. but this is a totally different thing from that for which i am contending. i am endeavouring to show that a grand law exists, by which, in two great departments of nature at least, the analogues of the fossil skeletons were formed without pre-existence. an arbitrary acting, and an acting on fixed and general laws, have nothing in common with each other. finally, the acceptance of the principles presented in this volume, even in their fullest extent, would not, in the least degree, affect the study of scientific geology. the character and order of the strata; their disruptions and displacements and injections; the successive floras and faunas; and all the other phenomena, would be _facts_ still. they would still be, as now, legitimate subjects of examination and inquiry. i do not know that a single conclusion, now accepted, would need to be given up, except that of actual chronology. and even in respect of this, it would be rather a modification than a relinquishment of what is at present held; we might still speak of the inconceivably long duration of the processes in question, provided we understand _ideal_ instead of _actual_ time;--that the duration was projected in the mind of god, and not really existent. the zoologist would still use the fossil forms of non-existing animals, to illustrate the mutual analogies of species and groups. his recognition of their prochronism would in nowise interfere with his endeavours to assign to each its position in the scale of organic being. he would still legitimately treat it as an entity; an essential constituent of the great plan of nature; because he would recognise the plan itself as an entity, though only an ideal entity, existing only in the divine conception. he would still use the stony skeletons for the inculcation of lessons on the skill and power of god in creation; and would find them a rich mine of instruction, affording some examples of the adaptation of structure to function, which are not yielded by any extant species. such are the elongation of the little finger in _pterodactylus_, for the extension of the alar membrane; and the deflexion of the inferior incisors in _dinotherium_, for the purposes of digging or anchorage. and still would he find, in the fossil forms, evidences of that complacency in beauty, which has prompted the adorable workmaster to paint the rose in blushing hues, and to weave the fine lace of the dragonfly's wing. the whorls of the _gyroceras_, the foliaceous or zigzag sutures of the _ammonites_, and the radiating pattern of _smithia_, are not less elegant than anything of the kind in existing creation, in which, however, they have no parallels. in short, the readings of the "stone book" will be found not less worthy of god who wrote them, not less worthy of man who deciphers them, if we consider them as prochronically, than if we judge them diachronically, produced. [illustration: gyroceras.] * * * * * here i close my labours. how far i have succeeded in accomplishing the task to which i bent myself, it is not for me to judge. others will determine that; and i am quite sure it will be determined fairly, on the whole. to prevent misapprehension, however, it may be as well to enunciate what the task was, which i prescribed, especially because other (collateral, hypothetical) points have been mooted in these pages. all, then, that i consider myself responsible for is summed up in these sentences:-i. the conclusions hitherto received have been but inferences deduced from certain premises: the witness who reveals the premises does _not_ testify to the inferences. ii. the process of deducing the inferences has been liable to a vast incoming of error, arising from the operation of a _law_, proved to exist, but hitherto unrecognised. iii. the amount of the error thus produced we have no means of knowing; much less of eliminating it. iv. the whole of the facts deposed to by this witness are irrelevant to the question; and the witness is, therefore, out of court. v. the field is left clear and undisputed for the one witness on the opposite side, whose testimony is as follows:-"in six days jehovah made heaven and earth, the sea, and all that in them is." index. agave, 147. ammonites, appearance of, 58. profusion of, 65. amphibia, foot-prints of, 52, 56. anoplotherium, 69. antediluvian hypothesis, 9. untenable, 51. babbage, mr., opinions of, 25. babiroussa, 262. bamboo, 134. banyan, 164. barnacle, development of, 217. basalt, formation of, 66, 91. beaches, raised, 83. beard, 284. beetle, egg of, 310. belemnites, 58. bignonia, 168. birds, earliest, 69. gigantic, 82. feathers of, 253. blackwood, opinions of, 9. blocks, transport of, 78. blood, 275, 285. bones, structure of, 279. botryllus, metamorphoses of, 222. brachionus, eggs of, 321. bracts, development of, 166. brown, rev. j. m., opinions of, 9. bulbs, growth of, 153, 156. buprestis, 214. butterflies, eggs of, 307. butterfly-flower, 150. cabbage-palm, 144. carboniferous deposits, 44. case-flies, 209. cassowary, 252. caverns, bone, 76, 88. ceiba, 174. cephalaspis, 44. chalk formation, 64. chalmers, dr., opinions of, 19. chronology of globe, 30, 339. circularity of organic life, 113, 336, 351. clavagella, 225. coal, age of, 50. extent of, 46. origin of, 47. coccus, economy of, 315. cockburn, rev. sir w., opinions of, 14. cockroach, egg-case of, 318. conybeare, dr., opinions of, 20. coprolites, 60. coral polypes, 40, 41, 45. activity of, 86. couch-grass, 135. cow, circular life of, 121. cowry, 231. crab, metamorphosis of, 216. crag and tail, 55. formation, 75. crinoids, abundance of, 58. creation, extent of, 22. fact of, 110. law of, 337, 368. periods of, 15. what is it? 123. cribella, metamorphosis of, 321. crocodile, 248. cuckoo-fly, egg of, 309. cumbrian formations, 36. currents, oceanic, 356. cuttlefish, shell of, 237. cycads, 60. cyclicism, 336, 351. of the globe, 354. of inorganic nature, 355. of celestial orbs, 359. cysticercus, 196. daphnia, economy of, 325. dauber, economy of, 320. days of creation, 15. deductions, fallible, 2. deer, irish, 84. deltas, 85. deposits, earthy, 87. depressions and elevations, 81. development hypothesis, 111. devonian formations, 42. diachronism, 125, 346. diatomaceæ in chalk, 64. dinotherium, 72, 370. dione, 228. disturbances of strata, 54, 66. dodo, 84. double cocoa-nut, 296. earth-pea, germination of, 299. echinus, 190. eggs of fowl, 328. of insects, 306. elephant, dentition of, 266. fossil, 73. elevations and depressions, 81. encephalartos, 161. euphorbia, 164. erythrina, 297. fairholm, mr., opinions of, 12. feather, growth of, 253. feather-star, 193, 305. fig, australian, 162. indian, 164. fishes, cycloid, 68. earliest, 44. sauroid, 52. fishes, scales of, 242. foetus of kangaroo, 333. footprints, 57. foraminifera, 64, 70. frog, 57. gall-fly, egg of, 310. ganges, delta of, 85. geography, changes of, 60, 66,70. geology, in need of caution, 4. germs, hypothesis of, 294. gilt-head, 241. glaciers, theory of, 79. gladiolus, 152. globe, chronology of, 30. cyclicism of, 354. density of, 37. gnats, egg-raft of, 207. goliathus, 205. granite, 37. decomposition and reconstruction of, 38. grass-tree, 154. gray, mr., opinions of, 20. grit, 46. gulf-stream, 356. gyroceras, 371. hair, growth of, 278. harris, dr., opinions of, 19. hawkmoth, 118. hertfordshire, strata of, 33. hippopotamus, 263. fossil, 73. hitchcock, dr., opinions of, 21. horns of ibex, 257. stag, 258. horse, 260. hylæosaurus, 62. hypotheses, variety of, 27. ibex, 257. ichthyosaurus, 59. iguanodon, 62. infusoria in chalk, 64. insects, eggs of, 306. iriartea, 139. julus, 212. kangaroo, foetus of, 333. kirkdale cave, 77. labyrinthodon, 57. lace-fly, egg of, 311. lady-fern, 116. law of creation, 337, 368, 371. leaf-scars of fern, 130. lepralia, 219. lias, 58. light, velocity of, 360. lily, 156. limestone coral, 45. locust-tree. 177. london clay, 67. loranthus, 169. "_lusus naturæ_," 368. macbrair, mr., opinions of, 10. madrepore, 183. mammal, earliest, 63. mammoth, 73. man, introduction of, 83. structure of, 275. mangrove, 173. germination of, 301. marsupials, 82. mastodon, 73. medusa, 188, 304. megalosaurus, 61. melicerta, 210. miller, hugh, opinions of, 15. millepore, 183. moa, 84. moho, 84. moon, cyclicism of, 359. mosasaurus, 65. moth, eggs of, 314. mountains, upheaving of, 66, 70. murex, 233, 365. nails, growth of, 277. nature, circularity of, 113. plan of, 345, 369. nautilus, 235. navel, evidence from, 289, 334. nerita, axis of, 365. noah's flood, 6. oestridæ, economy of, 309. oolitic system, 58, 60; duration of, 63. opossum, 63. organ-pipe, 185. organic life a circle, 113, 122. organisms, earliest, 40. orchis, 152. palm-leaf, young, 145. penn, mr., opinions of, 11. phenomena, evidence of, delusive, 337. plants of london clay, 67. "plastic power," 368. plates of tortoise, 250. plesiosaurus, 59. plumularia, 119. powell, professor, opinions of, 26. prickly pear, 172. prochronism, 125, 346, 368. dependent on cyclicism, 354. "protoplast," opinions of, 23. pterodactyle, 62, 370. raindrops, 58. rattan, 145. rattlesnake, 247. reptiles, marine, 16, 59. rhinoceros, fossil, 73. roots, aerial, of fig, 163. of iriartea, 139. of mangrove, 173. of pandanus, 138. rotifera, viviparous, 322. sackcloth of palms, 141. sandstone, age of, 50. new red, 56. old red, 42. saw-fly, eggs of, 317. scale of fish, 242. scarlet-runner, economy of, 113. screw-pine, 136. scripture, efforts to reconcile with geology, 5. literal sense of, 4. sea-urchin, 191, 305. sea-pen, 182. secondary epoch, 66. sedgwick, professor, on past time, 98. opinions of, 17. selaginella, 133. senses, evidence of, 1. serpent, earliest, 68. serpula, 198, 305. sharks, 52, 58, 243. egg of, 326. shells, now fossilizing, 89. shore-crab, 216. silk-cotton tree, 174. silurian formations, 40. skeleton, human, 286. skeletons, evidence from, 105, 340. sloths, fossil, 82. smith, dr. pye, opinions of, 22. smithia, elegance of, 371. species, persistence of, 110. spider, eggs of, 313. stag, 258. star-fish, madreporic plate of, 366. stars, light from fixed, 361. stature of man, 284. strata, disturbances of, 54. number of, 37. strombus, 230. sugar-palm, 141. sumner, dr., opinions of, 19. surinam toad, 327. sword-fish, 240. tapeworm, 195. tapir, 69. teeth of babiroussa, 262. teeth of crocodile, 249. elephant, 268. hippopotamus, 263. horse, 261. man, 281, 285. shark, 243. termes, 203. terebella, 201. tertiary epoch, 66. fauna, 76. testimony, divine, 2; dear to many scientific men, 5; by some rejected, 8. testudinaria, 158. thames tunnel, strata of, 32. thyroid cartilage, 284. timber, rings of, 178, 342, 349. tortoise, 250. tour of inspection, 127. traveller's tree, 148. tree-fern, age of, 128. tree-frog, 246. trilobites, 41. truth, value of, 7. tulip, seed of, 298. tulip-tree, 165. turner, sharon, opinions of, 18. tusk of elephant, 266. ure, dr., opinions of, 10. venus, prickly, 228. "vestiges," hypothesis of, 27, 111. volcanic action, 55, 66, 86. weevil, economy of, 308. whalebone, 255. white ant, 203. world, projected history of, 351. yorkshire, strata of, 33. young, dr., opinions of, 13. * * * * * footnotes: [1] dr. lardner; museum of science and art, vol. i. p. 81. [2] as cuvier, buckland, and many others. on the question whether the phenomena of geology can be comprised within the short period formerly assigned to them, the rev. samuel charles wilts long ago observed: "buckland, sedgwick, faber, chalmers, conybeare, and many other christian geologists, strove long with themselves to believe that they could: and they did not give up the hope, or seek for a new interpretation of the sacred text, till they considered themselves driven from their position by such facts as we have stated. if, _even now, a reasonable, or we might say_ possible _solution were offered, they would_, we feel persuaded, _gladly revert_ to their original opinion."--_christian observer_, august, 1834. [3] reflections on geology. [4] geology and geologists. [5] new system of geology. [6] mineral and mosaic geologies, p. 430. [7] geology of scripture. [8] scriptural geology, _passim._ [9] letter to buckland, 15, _et seq._ [10] origen, augustine, &c. [11] testimony of the rocks, p. 144 [12] discourse (5th ed.), 115. [13] sac. hist. of world. [14] rec. of creation. [15] nat. theology. [16] pre-adamite earth. [17] harmony of scripture and geology. [18] christian observer, 1834. [19] religion of geology, lect. ii. [20] scripture and geology. [21] i am not _replying_ to any of these conflicting opinions; else, with respect to this one, i might consider it sufficient to adduce the _ipsissima verba_ of the inspired text. not a word is said of adam's being "nine hundred and thirty years _old_;" the plain statement is as follows:--"and _all the days that adam lived_ were nine hundred and thirty years." (gen. v. 5.) [22] "protoplast," pp. 58, 59; p. 325; 2d. ed. [23] unity of worlds (1856), pp. 488, 493. [24] "a geological truth must command our assent as powerfully as that of the existence of our own minds, or of the deity himself; and any revelation which stands opposed to such truths _must be false_. the geologist has therefore _nothing to do with revealed religion_ in his scientific inquiries."--_edinb. review_, xv. 16. [25] ansted's ancient world, 18. [26] ansted's ancient world, 30. [27] scripture and geology, 371. (ed. 1855.) [28] "it is by no means unlikely that some beds of coal were derived from the mass of vegetable matter present at one time on the surface, and submerged suddenly. it is only necessary to refer to the accounts of vegetation in some of the extremely moist, warm islands in the southern hemisphere, where the ground is occasionally covered with eight or ten feet of decaying vegetable matter at one time, to be satisfied that this is at least possible." [29] ansted's anc. world, 75. [30] m'culloch's system of geology, i. 506. [31] origin of coal. [32] testimony of the rocks, p. 78. [33] mr. newman suggests that they were "marsupial bats" (zoologist, p. 129). i have adopted his attitudes, but have not ventured to give them mammalian ears. [34] in tennant's "list of brit. fossils" (1847), but two species--a brachiopod and a gastropod--are mentioned as common to the chalk and the london clay. they are _terebratula striatula_, and _pyrula smithii_. [35] ansted's anc. world, 267. [36] reliquiæ diluvianæ. [37] travels through the alps, p. 19. [38] prof. owen, in his admirable account of the _mylodon_, has mentioned a fact which brings us very vividly into contact with its personal history. he shows that the animal got its living by overturning vast trees, doing the work by main strength, and feeding on the leaves. the fall of the tree might occasionally put the animal in peril; and in the specimen examined there is proof of such danger having been incurred. the skull had undergone two fractures during the life of the animal, one of which was entirely healed, and the other partially. the former exhibits the outer tables of bone broken by a fracture four inches long, near the orbit. the other is more extensive, and behind, being five inches long, and three broad, and over the brain. the inner plate had in both these cases defended the brain from any serious injury, and the animal seems to have been recovering from the latter accident at the time of its death. [39] naturalist's voyage, _passim_. [40] the indians of north america knew that the mastodon had a trunk; a fact which (though the anatomist infers it from the bones of the skull) it is difficult to imagine them to be acquainted with, except by tradition from those who had seen the living animal. [41] ansted; phys. geography, 82. [42] an interesting fact relating to the brazilian caves was communicated to dr. mantell. "m. claussen, in the course of his researches, discovered a cavern, the stalagmite floor of which was entire. on penetrating the sparry crust, he found the usual ossiferous bed; but pressing engagements compelled him to leave the deposit unexplored. after an interval of some years, m. claussen again visited the cavern, and found the excavation he had made completely filled up with stalagmite, the floor being as entire as on his first entrance. on breaking through this newly-formed incrustation, it was found to be distinctly marked with lines of dark-coloured sediment, alternating with the crystalline stalactite. reasoning on the probable cause of this appearance, m. claussen sagaciously concluded that it arose from the alternation of the wet and dry seasons. during the drought of summer, the sand and dust of the parched land were wafted into the caves and fissures, and this earthy layer was covered during the rainy season by stalagmite, from the water that percolated through the limestone, and deposited calc-spar on the floor. the number of alternate layers of spar and sediment tallied with the years that had elapsed since his first visit; and on breaking up the ancient bed of stalagmite, he found the same natural register of the annual variations of the seasons; every layer dug through presented a uniform alternation of sediment and spar; and as the botanist ascertains the age of an ancient dicotyledonous tree from the annual circles of growth, in like manner the geologist attempted to calculate the period that had elapsed since the commencement of these ossiferous deposits of the cave; and although the inference, from want of time and means to conduct the inquiry with precision, can only be accepted as a rough calculation, yet it is interesting to learn that the time indicated by this natural chronometer, since the extinct mammalian forms were interred, amounted to many thousand years."--(_petrifactions and their teachings_, p. 481.) [43] bibliothèque univers., march, 1852. [44] "it is now admitted by all competent persons, that the formation even of those strata which are _nearest the surface_, must have occupied vast periods, probably millions of years, in arriving at their present state."--babbage, _ninth bridgewater treatise_, p. 67. [45] geology of central france. [46] "though perfect knowledge is not possessed, yet there are reasons for believing that the duration of life to testacean individuals of the present race is several years. but who can state the _proportion_ which the average length of life to the individual mollusc or conchifer, bears to the duration appointed by the creator to the species? take any one of the six or seven thousand known recent species; let it be a _buccinum_, of which 120 species are ascertained, (one of which is the commonly known _whelk_;) or a _cypræa_, comprising about as many, (a well-known species is on almost every mantel-piece, the _tiger-cowry_;) or an _ostrea_ (_oyster_), of which 130 species are described. we have reason to think that the individuals have a natural life of at least six or seven years; but we have no reason to suppose that any one species has died out, since the adamic creation. may we then, for the sake of an illustrative argument, take the duration of testacean species, one with another, at one thousand times the life of the individual? may we say six thousand years? we are dealing very liberally with our opponents. yet in examining the vertical evidences of the cessations of the fossil species, marks are found of an entire change in the forms of animal life; we find such cessations and changes to have occurred many times in the thickness of but a few hundred feet of these late-rocks."--dr. j. pye smith, _scripture and geology_, 5th ed. p. 376. [47] "one of the laminated formations [in auvergne] may be said to furnish a chronometer for itself. it consists of sixty feet of siliceous and calcareous deposits, each as thin as pasteboard, and bearing upon their separating surfaces the stems and seed-vessels of small water-plants in infinite numbers; and countless multitudes of minute shells, resembling some species of our common snail-shells. these layers have been formed with evident regularity, and to each of them we may reasonably assign the term of one season, that is a year. now thirty of such layers frequently do not exceed one inch in thickness. let us average them at twenty-five. the thickness of the stratum is at least sixty feet; and thus we gain, for the whole of this formation alone, eighteen thousand years."--dr. j. p. smith, _scripture and geology_, 5th edition, p. 137. [48] "this fact has now been verified in almost all parts of the globe, and has led to a conviction that at successive periods of the past the same area of land and water has been inhabited by species of animals and plants as distinct as those which now people the antipodes, or which now co-exist in the arctic, temperate, and tropical zones. it appears that from the remotest periods there has been ever a coming in of new organic forms, and an extinction of those which pre-existed on the earth; some species having endured for a longer, others for a shorter time; but none having ever re-appeared, after once dying out."--lyell's _elements of geology_, p. 275. [49] j. pye smith, scripture and geology, 5th ed., p. 69. [50] in dr. pye smith's scripture and geology, p. 382, (ed. 1855.) [51] i would venture respectfully to suggest that the following argument by mr. babbage is vitiated throughout by a confounding of the phenomena observed with the conclusions inferred from them. "what, then, have those accomplished, who have restricted the mosaic account of the creation to that diminutive period, which is, as it were, but a span in the duration of the earth's existence, and who have imprudently rejected _the testimony of the senses_, when opposed to their philological criticisms? the very arguments which protestants have opposed to the doctrine of transubstantiation, would, if their view of the case were correct, be equally irresistible against the book of genesis. but let us consider what would be the conclusion of any reasonable being in a parallel case. let us imagine a manuscript written three thousand years ago, and professing to be a revelation from the deity, in which it was stated that the colour of the paper of the very book now in the reader's hands is _black_, and that the colour of the ink in the characters which he is now reading is _white_. with that reasonable doubt of his own individual faculties which would become the inquirer into the truth of a statement said to be derived from so high an origin, he would ask all those around him, whether to their senses the paper appeared to be _black_, and the ink to be _white_. if he found the senses of other individuals agree with his own, then he would undoubtedly pronounce the alleged revelation a forgery, and those who propounded it to be either deceived or deceivers."--_ninth bridgewater treatise_, p. 68. [52] dr. pye smith calls the hypothesis of progressive development "the crude impertinence of a few foreign sophists,"--and he states as a fact, "that all the great geologists repudiate such a notion with abhorrence, and give physical evidence of its falsehood."--_scripture and geology_, (5th ed.) p. 420. see also professor owen in "rep. brit assoc." 1842; professor sedgwick, in "discourse on stud. of camb.;" professor whewell, in "hist. of inductive sciences;" professor ansted, in "anc. world;" &c. [53] wallace's "palms of the amazon," p. 35. [54] roxburgh. [55] rumph, v. 100. [56] my observations rest on the fine specimen of this plant preserved in the british museum. dr. harvey, however, says, "the growth of the trunk in _kingia_ is very slow, and a specimen about ten feet high may probably be some hundreds of years old." report of dubl. univ. zool. and bot. assoc. for feb. 25, 1857. see the note _infra_ on page 188. [57] gaudichaud: recherches gén. sur l'organographie, p. 129. [58] on the development of _loranthus_, &c. linn. tr. xviii p. 71, (_abridged_). [59] "each and every plant is at first a cell."--"new cells can never be formed externally to, but only within, other cells already formed." (a. braun, on the veg. indiv.) "the process of the propagation of cells, by the formation of new cells in their interior, is an universal law in the vegetable kingdom." (schleiden; grundzüge). "cell-formation in plants takes place only in the cavities of older cells." (mohl, on the veg. cell) [60] see von martius, on the brazilian locusts. [61] the origin of coral-stocks is minutely described by ehrenberg, in the abhandl. for 1832, where he makes the following remarks:--"the coral mass is neither a mere structure composed of many animals arbitrarily conjoined, as ellis supposed; nor one single animal with many heads, or with simple furcations, as cavolini maintained; nor a vegetable stem with animal flowers, as linnæus expressed it; it is a body of families, a _living_ tree of consanguinity; the single animals belonging to it, and continually developing _upon the primary ancestor_, are entirely isolated within themselves, and capable of complete independence, _although unable to achieve it_." [62] this is not quite in accord with lamouroux's account; but it is more consistent with what we know of polype-growth. [63] we lack precise data on which to found conclusions as to the actual rate of growth of many animals. sir john dalyell's famous actinia, now in the possession of dr. fleming, affords us a proof that the zoophytes are long-lived, and slow in attaining maturity. it will be readily seen, however, that the argument in the text does not depend on the actual period evolved. the lapse of _a_ period of time, no matter how long, is the only essential point. [64] "all the component cells of any one organism may be considered as the descendants of the primordial cell in which it originated." (_dr. carpenter_; comp. physiol.; p. 396. 4th ed.) [65] i conclude so; because i have kept specimens of _echinus_, not full grown, in healthy condition, for nearly a year, without any perceptible increase in their dimensions. [66] i am not aware that this stage of the entozoon has been actually observed; but from what we know of its previous and subsequent history, the correctness of the statement in the text will scarcely be disputed. (see prof. owen: comp. anat. of inverteb. ed. 2. p. 74.) [67] see notes to "marmion." [68] report on brit. annelida, p. 194. [69] we have no direct observations, that i am aware of, on the larval state of the african _goliathi_; but their near ally, the _cetonia aurata_ of europe, passes four years in the grub condition, as does also the _melolontha vulgaris_, another lamellicorn beetle. the _lucanus cervus_, or stag-beetle, continues a larva for six years. [70] fabre; ann. d. sci. nat.; iii. 1855. [71] _b. splendida_, has been ascertained to have existed, as an inmate of the wood of a table, for _more than twenty_ years. (linn. trans.; x. 399.) [72] the rate of increase in dimensions shown by specimens of this species, now so frequently kept in aquaria, warrants this assertion; though _how many_ years a crab takes to attain adult size, no exact observations, so far as i know, testify. [73] the exuvia of the cirri are sloughed from the _balanidæ_ about every week in summer; and perhaps this process is coetaneous with an addition to the valves. [74] mr. broderip supposes it to have had the power of swimming freely, and of seeking its future habitation, _as a bivalve_; but lovèn had not then made known to us the embryogeny and metamorphosis of the _conchifera_. it is much more probable that the case is as i have ventured to assume in the text. [75] bennett. [76] rumphius. [77] the periodical formation of these septa in the progress of growth, is analogous to that of the projecting external plates in the wendletrap, and of the rows of spines in the _murex_; but those external processes consist of the opake calcareous layer of the shell, whilst the internal processes in the _nautilus_ consist of the nacreous layer, like the septa in the _turritella_. thus the embryo _nautilus_ at first inhabits a simple shell, like that of most univalve mollusca, and manifests, according to the usual law, the general type at the early stage of its existence; although it soon begins, and apparently before having quitted the ovum, to take on the special form.--prof. owen's _lect. on invertebrate anim._ p. 593, 2d ed. [78] woodward's "manual of the mollusca," p. 83. [79] carpenter, on the microscope, &c., p. 602. [80] grant's comp. anat., 53. [81] see jones's general outline, p. 506. (ed. 1841.) [82] such is the common statement. dr. harlan, however, observes that "the rattle is cast annually [with the sloughed skin], and, _consequently_, no inference as to the age of the animal can be drawn from the number of pieces which compose the rattles." (_journ. acad. nat. sci._; v. 368.) i confess this appears to me to be a _non sequitur_; for is it not quite possible that one may be added to the _number_ annually, without involving the actual perpetuity of the preceding ones? it is evident that the increase must take place at some time or other, and it seems to me more likely to occur at the sloughing of the skin, that is, annually, than either oftener or seldomer. [83] martin "on the horse," p. 111. [84] professor owen's "odontography:"--to which splendid work i am indebted, for the engravings of these skulls. [85] brewster's edinburgh encyclopædia. [86] owen's odontogr. p. 631. [87] penny cyclopædia; _art._ bone. [88] dr. carpenter's human physiol. p. 916. (ed. 1855.) [89] sir thomas browne, indeed, denies adam a navel; i presume, however, physiologists will rather take my view. sir thomas did not know that the prochronism which he thought absurd pervaded every part of organic structure. the following is his verdict:-"another mistake there may be in the picture of our first parents, who after the manner of theyre posteritie are bothe delineated with a navill: and this is observable not only in ordinarie and stayned peeces, but in the authenticke draughts of vrbin, angelo, and others. which, notwythstandynge, cannot be allowed, except wee impute that vnto the first cause, which we impose not on the second; or what wee deny vnto nature, wee impute vnto naturity it selfe; that is, that in the first and moste accomplyshed peece, the creator affected superfluities, or ordayned parts withoute all vse or offyce."--_pseudodoxia epidemica_, lib. v.; cap. v. [90] blackwood, in an excellent article on johnston's _physical geography_ (april, 1849), says:--"adam _must_ have been created in the full possession of manhood; for if he had been formed an infant, he must have perished through mere helplessness. when god looked on this world, and pronounced all to be 'very good,'--which implies the completion of his purpose, and the perfection of his work--is it possible to conceive that he looked only on the germs of production, on plains covered with eggs, or seas filled with spawn, or forests still buried in the capsules of seeds; on a creation utterly shapeless, lifeless and silent, instead of the myriads of delighted existence, all enjoying the first sense of being?" and an eminent geologist considers the position indisputable, as regards man:--"to the slightest rational consideration it must be evident, that the first human pair were created in the perfection of their bodily organs and mental powers."--(dr. j. p. smith; "script. and geol.;" 219.) [91] gen. i. 12, 21, 26, 27. [92] penny cyclop.; _art._ arachis. [93] linn. trans. iii. 23. [94] introd. to entom.; lett. xi. § 2. [95] jones; nat. hist. anim.; ii. 151. [96] cf. mr. lubbock (proc. roy. soc. viii. 354), with dr. baird (brit entomostr. p. 82). [97] dr. carpenter: comp. phys.; p. 615. [98] dr. alex. braun, "on the veget. individual." (ann. n. h. nov. 1855.) [99] it may be objected that _elephas primigenius_ is absolutely distinct from _e. indicus_. i answer, yes, _specifically_ distinct; and so am i distinct from my father,--_individually_ distinct. but as individual distinctness does not preclude the individual from being the exponent of a circular revolution in the life-history of the species, so specific distinctness may not preclude the species from being the exponent of a circular revolution in some higher, unnamed, life-history. [100] "we may assert of the individual, as well as of the species, that it completes the cycle of its existence in a succession of subordinate generations; while, on the other hand, we may affirm of the species, that, like the individual, it exhibits a determinate cycle of development." "the species itself may be regarded as an inferior 'momentum' of a still more comprehensive cycle of development."--_dr. a. braun_, "_on the vegetable individual._" "the species is an individual of a higher rank."--_link: elements of botanical science_, vi. 11. "species, like individuals, have a certain limited term of existence. it is the fact, that, _according to some general law_, species of animals are introduced, last for a limited period, and are then succeeded by others performing the same office."--_ansted's ancient world_, 52, 54. [101] "the unity of the plan of organization, and the regular succession of animal forms, point out a _beginning_ of this great kingdom on the surface of our globe, although the earliest stages of its development may now be effaced: and the continuity of the series though all geological epochs, and the _gradual transitions_ which _connect_ the species of one formation with those of the next in succession, distinctly indicate that they form _the parts of one creation_, and not the heterogeneous remnants of successive kingdoms begun and destroyed: so that, while they present the best records of the changes which the surface of the globe has undergone, they likewise afford the best testimony of the recent origin of the present crust of our planet, and of all its organic inhabitants."--_dr. grant, in br. sci. annual for 1839._ [102] dr. harris has the following observations:-"why might not god have created the crust of the earth, just as it is, with all its numberless stratifications, and diversified formations, complete? and the analogy for such an exercise of creative power is supposed to be found in the creation of adam, not as an infant, but as _an adult_; and in the production of the _full-sized_ trees of eden. to which the reply is direct: the maturity of the first man, and of the objects around him, could not deceive him by implying that they had slowly grown to that state. his first knowledge was the knowledge of the contrary. he lived, partly, in order to proclaim the fact of his creation. and, could his own body, or any of the objects created at the same time, have been subjected to a physiological examination, they would, no doubt, have been found to indicate their miraculous production in their very destitution of all the traces of an early growth; whereas the shell of the earth is a crowded storehouse of evidence of its gradual formation. so that the question, expressed in other language, amounts to this: might not the god of infinite truth have enclosed in the earth, at its creation, evidence of its having existed ages before its actual production? of course, the objector would disavow such a sentiment. but such appears to be the real import of the objection; and, as such, it involves its own refutation."--_pre-adamite earth_, p. 83. now this reasoning appeared, doubtless, very triumphant to the worthy doctor: and yet a very little acquaintance with physiology would have taught him that he was enunciating an absurdity. the very supposition which he considers as self-refuting, is an indubitable physiological fact. i have abundantly shown, in the text, that the _cells which compose_ the tree or the animal are as undeniable evidences of past processes as the concentric cylinders of timber, or the superposed layers of bone and scale. [103] i here assume the life-history of the globe to be represented by a straight line, because i cannot _prove_ it to be a circle. i cannot even _imagine_ its circularity. i do not mean the possibility;--i can imagine _that_: but the _mode_ i cannot conceive. this, however, does not disprove the possibility. if man's science extended not beyond the accumulated observations of his own life, he would probably be quite incompetent to conceive how the life-history of such a tree as the oak could be a circle; if he had never seen more than one individual, which was a tree when he was born, and continued to flourish till his death. [104] the existence of coprolites--the fossilized excrement of animals--has been considered a more than ordinarily triumphant proof of real pre-existence. would it not be closely parallel with the presence of fæces in the intestines of an animal at the moment of creation? yet this appears to me demonstrable. it may seem at first sight ridiculous, and will probably be represented so; but truth is truth. i have already proved that blood must have been in the arteries and veins of the newly-created man (_vide_ p. 276, _supra_), and that blood presupposes chyle and chyme; but what became of the indigestible residuum of the chyme, when the chyle was separated from it? would it not, as a matter of course, be found in the intestines? if the principle is true, that the created organism was exactly what it would have been had it reached that condition by the ordinary course of nature, then fæcal residua must have been in the intestines as certainly as chyle in the lacteals, or blood in the capillaries. [105] _blackwood_; april, 1849; p. 412. [106] strictly speaking, the current is a lagging behind of the water, which cannot keep pace with the speed communicated to the solid crust of the globe at its equatorial regions. the trade-wind is owing to the same cause. [107] philos. trans. for 1802; p. 498. [108] beitrage, p. 152. [109] dr. a. braun, on the veg. indiv. [110] see _ante_, p. 233. [111] fauna littor. norveg.; i. 47. * * * * * marine natural history class. in the summer of 1855, i met, at ilfracombe, on the coast of north devon, a small party of ladies and gentlemen, who formed themselves into a class for the study of marine natural history. there was much to be done in the way of collecting, much to be learned in the way of study. not a few species of interest, and some rarities, fell under our notice, scattered as we were over the rocks, and peeping into the pools, almost every day for a month. then the prizes were to be brought home, and kept in little aquariums for the study of their habits, their beauties to be investigated by the pocket-lens, and the minuter kinds to be examined under the microscope. an hour or two was spent on the shore every day on which the tide and the weather were suitable; and, when otherwise, the occupation was varied by an indoors' lesson, on identifying and comparing the characters of the animals obtained, the specimens themselves affording illustrations. thus the two great desiderata of young naturalists were attained simultaneously; they learned at the same time how to collect, and how to determine the names and the zoological relations of the specimens when found. a little also was effected in the way of dredging the sea-bottom, and in surface-fishing for medusæ, &c.; but our chief attention was directed to shore-collecting. altogether, the experiment was found so agreeable, that i propose to repeat it by forming a similar party every year, if spared, at some suitable part of the coast. such ladies or gentlemen as may wish to join the class should give in their names to me, early in the summer; and any preliminary inquiries about plans, terms, &c. shall meet the requisite attention. p. h. gosse. marychurch, torquay, _oct. 1857_. on the genesis of species. [illustration] on the genesis of species. by st. george mivart, f.r.s. london: macmillan and co. 1871. [_the right of translation and reproduction is reserved._] london: r. clay, sons, and taylor, printers, bread street hill. * * * * * to sir henry holland, bart., m.d., f.r.s., d.c.l., etc. etc. my dear sir henry, in giving myself the pleasure to dedicate, as i now do, this work to you, it is not my intention to identify you with any views of my own advocated in it. i simply avail myself of an opportunity of paying a tribute of esteem and regard to my earliest scientific friend--the first to encourage me in pursuing the study of nature. i remain, my dear sir henry, ever faithfully yours, st. george mivart. 7, north bank, regent's park, _december 8, 1870._ {vii} * * * * * contents. chapter i. _introductory_ the problem of the genesis of species stated.--nature of its probable solution.--importance of the question.--position here defended.--statement of the darwinian theory.--its applicability to details of geographical distribution; to rudimentary structures; to homology; to mimicry, &c.--consequent utility of the theory.--its wide acceptance.--reasons for this other than, and in addition to, its scientific value. its simplicity.--its bearing on religious questions.--_odium theologicum_ and _odium antitheologicum_.--the antagonism supposed by many to exist between it and theology neither necessary nor universal.--christian authorities in favour of evolution.--mr. darwin's "animals and plants under domestication."--difficulties of the darwinian theory enumerated ... _page_ 1 chapter ii. _the incompetency of "natural selection" to account for the incipient stages of useful structures._ mr. darwin supposes that natural-selection acts by slight variations.--these must be useful at once.--difficulties as to the giraffe; as to mimicry; as to the heads of flat-fishes; as to the origin and constancy of the vertebrate, limbs; as to whalebone; as to the young kangaroo; as to sea-urchins; as to certain processes of {viii} metamorphosis; as to the mammary gland; as to certain ape characters; as to the rattlesnake and cobra; as to the process of formation of the eye and ear; as to the fully developed condition of the eye and ear; as to the voice; as to shell-fish; as to orchids; as to ants.--the necessity for the simultaneous modification of many individuals.--summary and conclusion ... _page_ 23 chapter iii. _the co-existence of closely similar structures of diverse origin._ chances against concordant variations.--examples of discordant ones.--concordant variations not unlikely on a non-darwinian evolutionary hypothesis.--placental and implacental mammals.--birds and reptiles.--independent origins of similar sense organs.--the ear.--the eye.--other coincidences.--causes besides natural selection produce concordant variations in certain geographical regions.--causes besides natural selection produce concordant variations in certain zoological and botanical groups.--there are homologous parts not genetically related.--harmony in respect of the organic and inorganic worlds.--summary and conclusion ... _page_ 63 chapter iv. _minute and gradual modifications._ there are difficulties as to minute modifications, even if not fortuitous.--examples of sudden and considerable modifications of different kinds.--professor owen's view.--mr. wallace.--professor huxley.--objections to sudden changes.--labyrinthodont.--potto.--cetacea.--as to origin of bird's wing.--tendrils of climbing plants.--animals once supposed to be connecting links.--early specialization of structure.--macrauchenia.--glyptodon.--sabre-toothed tiger.--conclusion ... _page_ 97 {ix} chapter v. _as to specific stability._ what is meant by the phrase "specific stability;" such stability to be expected _a priori_, or else considerable changes at once.--rapidly increasing difficulty of intensifying race characters; alleged causes of this phenomenon; probably an internal cause co-operates.--a certain definiteness in variations.--mr. darwin admits the principle of specific stability in certain cases of unequal variability.--the goose.--the peacock.--the guinea fowl.--exceptional causes of variation under domestication.--alleged tendency to reversion.--instances.--sterility of hybrids.--prepotency of pollen of same species, but of different race.--mortality in young gallinaceous hybrids.--a bar to intermixture exists somewhere.--guinea-pigs.--summary and conclusion ... _page_ 113 chapter vi. _species and time._ two relations of species to time.--no evidence of past existence of minutely intermediate forms when such might be expected _a priori_.--bats, pterodactyles, dinosauria, and birds.--ichthyosauria, chelonia, and anoura.--horse ancestry.--labyrinthodonts and trilobites.--two subdivisions of the second relation of species to time.--sir william thomson's views.--probable period required for ultimate specific evolution from primitive ancestral forms.---geometrical increase of time required for rapidly multiplying increase of structural differences.--proboscis monkey.--time required for deposition of strata necessary for darwinian evolution.--high organization of silurian forms of life.--absence of fossils in oldest rocks.--summary and conclusion ... _page_ 128 chapter vii. _species and space._ the geographical distribution of animals presents difficulties.--these not insurmountable in themselves; harmonize with other difficulties.--fresh-water fishes.--forms common to africa and india; to africa and south america; to china and australia; to north america and {x} china; to new zealand and south america; to south america and tasmania; to south america and australia.--pleurodont lizards.--insectivorous mammals.--similarity of european and south american frogs.--analogy between european salmon and fishes of new zealand, &c.--an ancient antarctic continent probable.--other modes of accounting for facts of distribution.--independent origin of closely similar forms.--conclusion ... _page_ 144 chapter viii. _homologies._ animals made up of parts mutually related in various ways.--what homology is.--its various kinds.--serial homology.--lateral homology.--vertical homology.--mr. herbert spencer's explanations.--an internal power necessary, as shown by facts of comparative anatomy.---of teratology.--m. st. hilaire.--professor burt wilder.--foot-wings.--facts of pathology.--mr. james paget.--dr. william budd.--the existence of such an internal power of individual development diminishes the improbability of an analogous law of specific origination ... _page_ 155 chapter ix. _evolution and ethics._ the origin of morals an inquiry not foreign to the subject of this book.--modern utilitarian view as to that origin.--mr. darwin's speculation as to the origin of the abhorrence of incest.--cause assigned by him insufficient.--care of the aged and infirm opposed by "natural selection;" also self-abnegation and asceticism.--distinctness of the ideas right and useful.--mr. john stuart mill.--insufficiency of "natural selection" to account for the origin of the distinction between duty and profit.--distinction of moral acts into material and formal.--no ground{xi} for believing that formal morality exists in brutes.--evidence that it does exist in savages.--facility with which savages may be misunderstood.--objections as to diversity of customs.--mr. button's review of mr. herbert spencer.--anticipatory character of morals.--sir john lubbock's explanation.--summary and conclusion ... _page_ 188 chapter x. _pangenesis._ a provisional hypothesis supplementing "natural selection."--statement of the hypothesis.--difficulty as to multitude of gemmules.--as to certain modes of reproduction.--as to formations without the requisite gemmules.--mr. lewes and professor delpino.--difficulty as to developmental force of gemmules.--as to their spontaneous fission.--pangenesis and vitalism.--paradoxical reality.--pangenesis scarcely superior to anterior hypotheses.--buffon.--owen.--herbert spencer.--gemmules as mysterious as "physiological units."--conclusion ... _page_ 208 chapter xi. _specific genesis._ review of the statements and arguments of preceding chapters.--cumulative argument against predominant action of "natural selection."--whether anything positive as well as negative can be enunciated.--constancy of laws of nature does not necessarily imply constancy of specific evolution.--possible exceptional stability of existing epoch.--probability that an internal cause of change exists.--innate powers somewhere must be accepted.--symbolism of molecular action under vibrating impulses. professor owen's statement.--statement of the author's view.--it avoids the difficulties which oppose "natural selection."--it harmonizes apparently conflicting conceptions.--summary and conclusion ... _page_ 220 [page xii] chapter xii. _theology and evolution._ prejudiced opinions on the subject.--"creation" sometimes denied from prejudice.--the unknowable.--mr. herbert spencer's objections to theism; to creation.--meanings of term "creation."--confusion from not distinguishing between "primary" and "derivative" creation.--mr. darwin's objections.--bearing of christianity on evolution.--supposed opposition, the result of a misconception.--theological authority not opposed to evolution.--st. augustin.--st. thomas aquinas.--certain consequences of want of flexibility of mind.--reason and imagination.--the first cause and demonstration.--parallel between christianity and natural theology.--what evolution of species is.--professor agassiz.--innate powers must be recognized.--bearing of evolution on religious belief.--professor huxley.--professor owen.--mr. wallace.--mr. darwin.--_a priori_ conception of divine action.--origin of man.--absolute creation and dogma.--mr. wallace's view.--a supernatural origin for man's body not necessary.--two orders of being in man.--two modes of origin.--harmony of the physical, hyperphysical, and supernatural.--reconciliation of science and religion as regards evolution.--conclusion ... _page_ 243 index ... _page_ 289 {xiii} list of illustrations. leaf butterfly in flight and repose (_from mr. a. wallace's "malay archipelago"_) ... 31 walking-leaf insect ... 35 pleuronectidæ, with the peculiarly placed eye in different positions (_from dr. traquair's paper in linn. soc. trans., 1865_) ... 37, 166 mouth of whale (_from professor owen's "odontography"_) ... 40 four plates of baleen seen obliquely from within (_from professor owen's "odontography"_) ... 41 dugong ... 41, 175 echinus or sea urchin ... 43, 167 pedicellariæ of echinus very much enlarged ... 44 rattlesnake ... 49 cobra (_from sir andrew smith's "southern africa"_) ... 50 wingbones of pterodactyle, bat, and bird (_from mr. andrew murray's "geographical distribution of mammals"_) ... 64, 130, 157 skeleton of flying-dragon ... 65, 158 centipede (_from a specimen in the museum of the royal college of surgeons_) ... 66, 159 teeth of urotrichus and perameles ... 68 the archeopteryx (_from professor owen's "anatomy of vertebrata"_) ... 73, 132 {xiv} cuttle-fish ... 75, 141 skeleton of ichthyosaurus ... 78, 107, 132, 177 cytheridea torosa (_from messrs. brady and robertson's paper in ann. and mag. of nat. hist., 1870_) ... 79 a polyzoon, with bird's-head processes ... 80 bird's-head processes greatly enlarged ... 81 antechimis minutissimus and mus delicatulus (_from mr. andrew murray's "geographical distribution of mammals"_) ... 82 outlines of wings of butterflies of celebes compared with those of allied species elsewhere ... 86 great shielded grasshopper ... 89 the six-shafted bird of paradise ... 90 the long-tailed bird of paradise ... 91 the red bird of paradise ... 92 horned flies ... 93 the magnificent bird of paradise ... 93 _(the above seven figures are from mr. a. wallace's "malay archipelago"_) much enlarged horizontal section of the tooth of a labyrinthodon (_from professor owen's "odontography"_) ... 104 hand of the potto (_from life_) ... 105 skeleton of plesiosaurus ... 106, 133 the aye-aye (_from trans, of zool. soc._) ... 108 dentition of sabre-toothed tiger (_from professor owen's "odontography"_) ... 110 trilobite ... 135, 171 inner side of lower jaw of pleurodont lizard (_from professor owen's "odontography"_) ... 148 solenodon (_from berlin trans._) ... 149 tarsal bones of galago and cheirogaleus (_from proc. zool. soc._) ... 159 squilla ... 160 parts of the skeleton of the lobster ... 161 [page xv] spine of galago allenii (_from proc. zool. soc._) ... 162 vertebrae of axolotl (_from proc. zool. soc._) ... 165 annelid undergoing spontaneous fission ... 169, 211 aard-vark (_orycteropus capensis_) ... 174 pangolin (_manis_) ... 175 skeleton of manus and pes of a tailed batrachian (_from professor gegenbaur's "tarsus and carpus"_) ... 178 flexor muscles of hand of nycticetus (_from proc. zool. soc._) ... 180 the fibres of corti ... 279 {1} * * * * * the genesis of species. chapter i. _introductory._ the problem of the genesis of species stated.--nature of its probable solution.--importance of the question.--position here defended.--statement of the darwinian theory.--its applicability to details of geographical distribution; to rudimentary structures; to homology; to mimicry, &c.--consequent utility of the theory.--its wide acceptance.--reasons for this, other than, and in addition to, its scientific value.--its simplicity.--its bearing on religious questions.--_odium theologicum_ and _odium antitheologicum_.--the antagonism supposed by many to exist between it and theology neither necessary nor universal.--christian authorities in favour of evolution.--mr. darwin's "animals and plants under domestication."--difficulties of the darwinian theory enumerated. the great problem which has so long exercised the minds of naturalists, namely, that concerning the origin of different kinds of animals and plants, seems at last to be fairly on the road to receive--perhaps at no very distant future--as satisfactory a solution as it can well have. but the problem presents peculiar difficulties. the birth of a "species" has often been compared with that of an "individual." the origin, however, of even an individual animal or plant (that which determines an embryo to evolve itself,--as, _e.g._, a spider rather than a beetle, a rose-plant {2} rather than a pear) is shrouded in obscurity. _a fortiori_ must this be the case with the origin of a "species." moreover, the analogy between a "species" and an "individual" is a very incomplete one. the word "individual" denotes a concrete whole with a real, separate, and distinct existence. the word "species," on the other hand, denotes a peculiar congeries of characters, innate powers and qualities, and a certain nature realized indeed in individuals, but having no separate existence, except ideally as a thought in some mind. thus the birth of a "species" can only be compared metaphorically, and very imperfectly, with that of an "individual." individuals as _individuals_, actually and directly produce and bring forth other individuals; but no "congeries of characters" no "common nature" _as such_, can directly bring forth another "common nature," because, _per se_, it has no existence (other than ideal) apart from the individuals in which it is manifested. the problem then is, "by what combination of natural laws does a new 'common nature' appear upon the scene of realized existence?" _i.e._ how is an individual embodying such new characters produced? for the approximation we have of late made towards the solution of this problem, we are mainly indebted to the invaluable labours and active brains of charles darwin and alfred wallace. nevertheless, important as has been the impulse and direction given by those writers to both our observations and speculations, the solution will not (if the views here advocated are correct) ultimately present that aspect and character with which it has issued from the hands of those writers. neither, most certainly, will that solution agree in appearance or substance with the more or less crude conceptions which have been put forth by most of the opponents of messrs. darwin and wallace. [page 3] rather, judging from the more recent manifestations of thought on opposite sides, we may expect the development of some _tertium quid_--the resultant of forces coming from different quarters, and not coinciding in direction with any one of them. as error is almost always partial truth, and so consists in the exaggeration or distortion of one verity by the suppression of another which qualifies and modifies the former, we may hope, by the synthesis of the truths contended for by various advocates, to arrive at the one conciliating reality. signs of this conciliation are not wanting: opposite scientific views, opposite philosophical conceptions, and opposite religious beliefs, are rapidly tending by their vigorous conflict to evolve such a systematic and comprehensive view of the genesis of species as will completely harmonize with the teachings of science, philosophy, and religion. to endeavour to add one stone to this temple of concord, to try and remove a few of the misconceptions and mutual misunderstandings which oppose harmonious action, is the aim and endeavour of the present work. this aim it is hoped to attain, not by shirking difficulties, but analysing them, and by endeavouring to dig down to the common root which supports and unites diverging stems of truth. it cannot but be a gain when the labourers in the three fields above mentioned, namely, science, philosophy, and religion, shall fully recognize this harmony. then the energy too often spent in futile controversy, or withheld through prejudice, may be profitably and reciprocally exercised for the mutual benefit of all. remarkable is the rapidity with which an interest in the question of specific origination has spread. but a few years ago it scarcely occupied the minds of any but naturalists. then the crude theory put forth by lamarck, and by his english interpreter the author of the "vestiges of creation," had rather discredited than helped on a belief in organic evolution--a belief, that is, in new kinds being produced from older {4} ones by the ordinary and constant operation of natural laws. now, however, this belief is widely diffused. indeed, there are few drawing-rooms where it is not the subject of occasional discussion, and artisans and schoolboys have their views as to the permanence of organic forms. moreover, the reception of this doctrine tends actually, though by no means necessarily, to be accompanied by certain beliefs with regard to quite distinct and very momentous subject-matter. so that the question of the "genesis of species" is not only one of great interest, but also of much importance. but though the calm and thorough consideration of this matter is at the present moment exceedingly desirable, yet the actual importance of the question itself as to its consequences in the domain of theology has been strangely exaggerated by many, both of its opponents and supporters. this is especially the case with that form of the evolution theory which is associated with the name of mr. darwin; and yet neither the refutation nor the demonstration of that doctrine would be necessarily accompanied by the results which are hoped for by one party and dreaded by another. the general theory of evolution has indeed for some time past steadily gained ground, and it may be safely predicted that the number of facts which can be brought forward in its support will, in a few years, be vastly augmented. but the prevalence of this theory need alarm no one, for it is, without any doubt, perfectly consistent with strictest and most orthodox christian theology. moreover, it is not altogether without obscurities, and cannot yet be considered as fully demonstrated. the special darwinian hypothesis, however, is beset with certain scientific difficulties, which must by no means be ignored, and some of which, i venture to think, are absolutely insuperable. what darwinism or "natural selection" is, will be shortly explained; but before doing so, i think {5} it well to state the object of this book, and the view taken up and defended in it. it is its object to maintain the position that "natural selection" acts, and indeed must act, but that still, in order that we may be able to account for the production of known kinds of animals and plants, it requires to be supplemented by the action of some other natural law or laws as yet undiscovered.[1] also, that the consequences which have been drawn from evolution, whether exclusively darwinian or not, to the prejudice of religion, by no means follow from it, and are in fact illegitimate. the darwinian theory of "natural selection" may be shortly stated thus:[2]-every kind of animal and plant tends to increase in numbers in a geometrical progression. every kind of animal and plant transmits a general likeness, with individual differences, to its offspring. every individual may present minute variations of any kind and in any direction. past time has been practically infinite. every individual has to endure a very severe struggle for existence, owing to the tendency to geometrical increase of all kinds of animals and plants, while the total animal and vegetable population (man and his agency excepted) remains almost stationary. thus, every variation of a kind tending to save the life of the individual possessing it, or to enable it more surely to propagate its kind, will in the long run be preserved, and will transmit its favourable peculiarity to some of its offspring, which peculiarity will thus become intensified {6} till it reaches the maximum degree of utility. on the other hand, individuals presenting unfavourable peculiarities will be ruthlessly destroyed. the action of this law of natural selection may thus be well represented by the convenient expression "survival of the fittest."[3] now this conception of mr. darwin's is perhaps the most interesting theory, in relation to natural science, which has been promulgated during the present century. remarkable, indeed, is the way in which it groups together such a vast and varied series of biological[4] facts, and even paradoxes, which it appears more or less clearly to explain, as the following instances will show. by this theory of "natural selection," light is thrown on the more singular facts relating to the geographical distribution of animals and plants; for example, on the resemblance between the past and present inhabitants of different parts of the earth's surface. thus in australia remains have been found of creatures closely allied to kangaroos and other kinds of pouched beasts, which in the present day exist nowhere but in the australian region. similarly in south america, and nowhere else, are found sloths and armadillos, and in that same part of the world have been discovered bones of animals different indeed from existing sloths and armadillos, but yet much more nearly related to them than to any other kinds whatever. such coincidences between the existing and antecedent geographical distribution of forms are numerous. again, "natural selection" serves to explain the circumstance that often in adjacent islands we find animals closely resembling, and appearing to represent, each other; while if certain of these islands show signs (by depth of surrounding sea or what not) of more ancient separation, the animals inhabiting them exhibit a {7} corresponding divergence.[5] the explanation consists in representing the forms inhabiting the islands as being the modified descendants of a common stock, the modification being greatest where the separation has been the most prolonged. "rudimentary structures" also receive an explanation by means of this theory. these structures are parts which are apparently functionless and useless where they occur, but which represent similar parts of large size and functional importance in other animals. examples of such "rudimentary structures" are the foetal teeth of whales, and of the front part of the jaw of ruminating quadrupeds. these foetal structures are minute in size, and never cut the gum, but are reabsorbed without ever coming into use, while no other teeth succeed them or represent them in the adult condition of those animals. the mammary glands of all male beasts constitute another example, as also does the wing of the apteryx--a new zealand bird utterly incapable of flight, and with the wing in a quite rudimentary condition (whence the name of the animal). yet this rudimentary wing contains bones which are miniature representatives of the ordinary wing-bones of birds of flight. now, the presence of these useless bones and teeth is explained if they may be considered as actually being the inherited diminished representatives of parts of large size and functional importance in the remote ancestors of these various animals. again, the singular facts of "homology" are capable of a similar explanation. "homology" is the name applied to the investigation of those profound resemblances which have so often been found to underlie superficial differences between animals of very different form and habit. thus man, the horse, the whale, and the bat, all have the pectoral limb, whether it be the arm, or fore-leg, or paddle, or wing, formed on essentially the same type, though the number and proportion of parts may{8} more or less differ. again, the butterfly and the shrimp, different as they are in appearance and mode of life, are yet constructed on the same common plan, of which they constitute diverging manifestations. no _a priori_ reason is conceivable why such similarities should be necessary, but they are readily explicable on the assumption of a genetic relationship and affinity between the animals in question, assuming, that is, that they are the modified descendants of some ancient form--their common ancestor. that remarkable series of changes which animals undergo before they attain their adult condition, which is called their process of development, and during which they more or less closely resemble other animals during the early stages of the same process, has also great light thrown on it from the same source. the question as to the singularly complex resemblances borne by every adult animal and plant to a certain number of other animals and plants--resemblances by means of which the adopted zoological and botanical systems of classification have been possible--finds its solution in a similar manner, classification becoming the expression of a genealogical relationship. finally, by this theory--and as yet by this alone--can any explanation be given of that extraordinary phenomenon which is metaphorically termed _mimicry_. mimicry is a close and striking, yet superficial resemblance borne by some animal or plant to some other, perhaps very different, animal or plant. the "walking leaf" (an insect belonging to the grasshopper and cricket order) is a well-known and conspicuous instance of the assumption by an animal of the appearance of a vegetable structure (see illustration on p. 35); and the bee, fly, and spider orchids are familiar examples of a converse resemblance. birds, butterflies, reptiles, and even fish, seem to bear in certain instances a similarly striking resemblance to other birds, butterflies, reptiles, and fish, of altogether distinct kinds. the explanation of this matter which "natural selection" offers, as to animals, is that certain varieties of {9} one kind have found exemption from persecution in consequence of an accidental resemblance which such varieties have exhibited to animals of another kind, or to plants; and that they were thus preserved, and the degree of resemblance was continually augmented in their descendants. as to plants, the explanation offered by this theory might perhaps be that varieties of plants which presented a certain superficial resemblance in their flowers to insects, have thereby been helped to propagate their kind, the visit of certain insects being useful or indispensable to the fertilization of many flowers. we have thus a whole series of important facts which "natural selection" helps us to understand and co-ordinate. and not only are all these diverse facts strung together, as it were, by the theory in question; not only does it explain the development of the complex instincts of the beaver, the cuckoo, the bee, and the ant, as also the dazzling brilliancy of the humming-bird, the glowing tail and neck of the peacock, and the melody of the nightingale; the perfume of the rose and the violet, the brilliancy of the tulip and the sweetness of the nectar of flowers; not only does it help us to understand all these, but serves as a basis of future research and of inference from the known to the unknown, and it guides the investigator to the discovery of new facts which, when ascertained, it seems also able to co-ordinate.[6] nay, "natural selection" seems capable of application not only to the building up of the smallest and most insignificant organisms, but even of extension beyond the biological domain altogether, so as possibly to have relation to the stable equilibrium of the solar system{10} itself, and even of the whole sidereal universe. thus, whether this theory be true or false, all lovers of natural science should acknowledge a deep debt of gratitude to messrs. darwin and wallace, on account of its practical utility. but the utility of a theory by no means implies its truth. what do we not owe, for example, to the labours of the alchemists? the emission theory of light, again, has been pregnant with valuable results, as still is the atomic theory, and others which will readily suggest themselves. with regard to mr. darwin (with whose name, on account of the noble self-abnegation of mr. wallace, the theory is in general exclusively associated), his friends may heartily congratulate him on the fact that he is one of the few exceptions to the rule respecting the non-appreciation of a prophet in his own country. it would be difficult to name another living labourer in the field of physical science who has excited an interest so widespread, and given rise to so much praise, gathering round him, as he has done, a chorus of more or less completely acquiescing disciples, themselves masters in science, and each the representative of a crowd of enthusiastic followers. such is the darwinian theory of "natural selection," such are the more remarkable facts which it is potent to explain, and such is the reception it has met with in the world. a few words now as to the reasons for the very widespread interest it has awakened, and the keenness with which the theory has been both advocated and combated. the important bearing it has on such an extensive range of scientific facts, its utility, and the vast knowledge and great ingenuity of its promulgator, are enough to account for the heartiness of its reception by those learned in natural history. but quite other causes have concurred to produce the general and higher degree of interest felt in the theory beside the readiness with which it harmonizes with biological facts. these latter could only be appreciated by physiologists, zoologists, and botanists; whereas the darwinian theory, so novel and so startling, has found a {11} cloud of advocates and opponents beyond and outside the world of physical science. in the first place, it was inevitable that a great crowd of half-educated men and shallow thinkers should accept with eagerness the theory of "natural selection," or rather what they think to be such (for few things are more remarkable than the way in which it has been misunderstood), on account of a certain characteristic it has in common with other theories; which should not be mentioned in the same breath with it, except, as now, with the accompaniment of protest and apology. we refer to its remarkable simplicity, and the ready way in which phenomena the most complex appear explicable by a cause for the comprehension of which laborious and persevering efforts are not required, but which may be represented by the simple phrase "survival of the fittest." with nothing more than this, can, on the darwinian theory, all the most intricate facts of distribution and affinity, form, and colour, be accounted for; as well the most complex instincts and the most admirable adjustments, such as those of the human eye and ear. it is in great measure then, owing to this supposed simplicity, and to a belief in its being yet easier and more simple than it is, that darwinism, however imperfectly understood, has become a subject for general conversation, and has been able thus widely to increase a certain knowledge of biological matters; and this excitation of interest in quarters where otherwise it would have been entirely wanting, is an additional motive for gratitude on the part of naturalists to the authors of the new theory. at the same time it must be admitted that a similar "simplicity"--the apparently easy explanation of complex phenomena--also constitutes the charm of such matters as hydropathy and phrenology, in the eyes of the unlearned or half-educated public. it is indeed _the_ charm of all those seeming "short cuts" to knowledge, by which the labour of mastering scientific details is spared to those who yet believe that {12} without such labour they can attain all the most valuable results of scientific research. it is not, of course, for a moment meant to imply that its "simplicity" tells at all against "natural selection," but only that the actual or supposed possession of that quality is a strong reason for the wide and somewhat hasty acceptance of the theory, whether it be true or not. in the second place, it was inevitable that a theory appearing to have very grave relations with questions of the last importance and interest to man, that is, with questions of religious belief, should call up an army of assailants and defenders. nor have the supporters of the theory much reason, in many cases, to blame the more or less unskilful and hasty attacks of adversaries, seeing that those attacks have been in great part due to the unskilful and perverse advocacy of the cause on the part of some of its adherents. if the _odium theologicum_ has inspired some of its opponents, it is undeniable that the _odium antitheologicum_ has possessed not a few of its supporters. it is true (and in appreciating some of mr. darwin's expressions it should never be forgotten) that the theory has been both at its first promulgation and since vehemently attacked and denounced as unchristian, nay, as necessarily atheistic; but it is not less true that it has been made use of as a weapon of offence by irreligious writers, and has been again and again, especially in continental europe, thrown, as it were, in the face of believers, with sneers and contumely. when we recollect the warmth with which what he thought was darwinism was advocated by such a writer as professor vogt, one cause of his zeal was not far to seek--a zeal, by the way, certainly not "according to knowledge;" for few conceptions could have been more conflicting with true darwinism than the theory he formerly maintained, but has since abandoned, viz. that the men of the old world were descended from african and asiatic apes, while, similarly, the american apes were the progenitors of the human beings of the new world. the cause of this palpable error in a too eager disciple{13} one might hope was not anxiety to snatch up all or any arms available against christianity, were it not for the tone unhappily adopted by this author. but it is unfortunately quite impossible to mistake his meaning and intention, for he is a writer whose offensiveness is gross, while it is sometimes almost surpassed by an amazing shallowness. of course, as might fully be expected, he adopts and reproduces the absurdly trivial objections to absolute morality drawn from differences in national customs.[7] and he seems to have as little conception of the distinction between "formally" moral actions and those which are only "materially" moral, as of that between the _verbum mentale_ and the _verbum oris_. as an example of his onesidedness, it may be remarked that he compares the skulls of the american monkeys (_cebus apella_ and _c. albifrons_) with the intention of showing that man is of several distinct species, because skulls of different men are less alike than are those of these two monkeys; and he does this regardless of how the skulls of domestic animals (with which it is far more legitimate to compare races of men than with wild kinds), _e.g._ of different dogs or pigeons, tell precisely in the opposite direction. regardless also of the fact that perhaps no genus of monkeys is in a more unsatisfactory state as to the determination of its different kinds than the genus chosen by him for illustration. this is so much the case that j. a. wagner (in his supplement to schreber's great work on beasts) at first included all the kinds in a single species. as to the strength of his prejudice and his regretable coarseness, one quotation will be enough to display both. speaking of certain early christian missionaries, he says,[8] "it is not so very improbable that the new religion, before which the flourishing roman civilization relapsed into a state of barbarism, should have been introduced by people in whose {14} skulls the anatomist finds simious characters so well developed, and in which the phrenologist finds the organ of veneration so much enlarged. i shall, in the meanwhile, call these simious narrow skulls of switzerland 'apostle skulls,' as i imagine that in life they must have resembled the type of peter, the apostle, as represented in byzantine-nazarene art." in face of such a spirit, can it be wondered at that disputants have grown warm? moreover, in estimating the vehemence of the opposition which has been offered, it should be borne in mind that the views defended by religious writers are, or should be, all-important in their eyes. they could not be expected to view with equanimity the destruction in many minds of "theology, natural and revealed, psychology, and metaphysics;" nor to weigh with calm and frigid impartiality arguments which seemed to them to be fraught with results of the highest moment to mankind, and, therefore, imposing on their consciences strenuous opposition as a first duty. cool judicial impartiality in them would have been a sign perhaps of intellectual gifts, but also of a more important deficiency of generous emotion. it is easy to complain of the onesidedness of many of those who oppose darwinism in the interest of orthodoxy; but not at all less patent is the intolerance and narrow-mindedness of some of those who advocate it, avowedly or covertly, in the interest of heterodoxy. this hastiness of rejection or acceptance, determined by ulterior consequences believed to attach to "natural selection," is unfortunately in part to be accounted for by some expressions and a certain tone to be found in mr. darwin's writings. that his expressions, however, are not always to be construed literally is manifest. his frequent use metaphorically of the expressions, "contrivance," for example, and "purpose," has elicited, from the duke of argyll and others, criticisms which fail to tell against their {15} opponent, because such expressions are, in mr. darwin's writings, merely figurative--metaphors, and nothing more. it may be hoped, then, that a similar looseness of expression will account for passages of a directly opposite tendency to that of his theistic metaphors. moreover, it must not be forgotten that he frequently uses that absolutely theological term, "the creator," and that he has retained in all the editions of his "origin of species" an expression which has been much criticised. he speaks "of life, with its several powers, having been originally breathed by the creator into a few forms, or into one."[9] this is merely mentioned in justice to mr. darwin, and by no means because it is a position which this book is intended to support. for, from mr. darwin's usual mode of speaking, it appears that by such divine action he means a supernatural intervention, whereas it is here contended that throughout the whole process of physical evolution--the first manifestation of life included--_supernatural_ action is assuredly not to be looked for. again, in justice to mr. darwin, it may be observed that he is addressing the general public, and opposing the ordinary and common objections of popular religionists, who have inveighed against "evolution" and "natural selection" as atheistic, impious, and directly conflicting with the dogma of creation. still, in so important a matter, it is to be regretted that he did not take the trouble to distinguish between such merely popular views and those which repose upon some more venerable authority. mr. john stuart mill has replied to similar critics, and shown that the assertion that his philosophy is irreconcilable with theism is unfounded; and it would have been better if mr. darwin had dealt in the same manner with some of his assailants, and shown the futility of certain of their objections when {16} viewed from a more elevated religious standpoint. instead of so doing, he seems to adopt the narrowest notions of his opponents, and, far from endeavouring to expand them, appears to wish to endorse them, and to lend to them the weight of his authority. it is thus that mr. darwin seems to admit and assume that the idea of "creation" necessitates a belief in an interference with, or dispensation of, natural laws, and that "creation" must be accompanied by arbitrary and unorderly phenomena. none but the crudest conceptions are placed by him to the credit of supporters of the dogma of creation, and it is constantly asserted that they, to be consistent, must offer "creative fiats" as explanations of physical phenomena, and be guilty of numerous other such absurdities. it is impossible, therefore, to acquit mr. darwin of at least a certain carelessness in this matter; and the result is, he has the appearance of opposing ideas which he gives no clear evidence of having ever fully appreciated. he is far from being alone in this, and perhaps merely takes up and reiterates, without much consideration, assertions previously assumed by others. nothing could be further from mr. darwin's mind than any, however small, intentional misrepresentation; and it is therefore the more unfortunate that he should not have shown any appreciation of a position opposed to his own other than that gross and crude one which he combats so superfluously--that he should appear, even for a moment, to be one of those, of whom there are far too many, who first misrepresent their adversary's view, and then elaborately refute it; who, in fact, erect a doll utterly incapable of self-defence and then, with a flourish of trumpets and many vigorous strokes, overthrow the helpless dummy they had previously raised. this is what many do who more or less distinctly oppose theism in the interests, as they believe, of physical science; and they often represent, amongst other things, a gross and narrow anthropomorphism as the necessary consequence of views opposed to those which they themselves advocate. {17} mr. darwin and others may perhaps be excused if they have not devoted much time to the study of christian philosophy; but they have no right to assume or accept, without careful examination, as an unquestioned fact, that in that philosophy there is a necessary antagonism between the two ideas, "creation" and "evolution," as applied to organic forms. it is notorious and patent to all who choose to seek, that many distinguished christian thinkers have accepted and do accept both ideas, _i.e._ both "creation" and "evolution." as much as ten years ago, an eminently christian writer observed: "the creationist theory does not necessitate the perpetual search after manifestations of miraculous powers and perpetual 'catastrophes.' creation is not a miraculous interference with the laws of nature, but the very institution of those laws. law and regularity, not arbitrary intervention, was the patristic ideal of creation. with this notion, they admitted without difficulty the most surprising origin of living creatures, provided it took place by _law_. they held that when god said, 'let the waters produce,' 'let the earth produce,' he conferred forces on the elements of earth and water, which enabled them naturally to produce the various species of organic beings. this power, they thought, remains attached to the elements throughout all time."[10] the same writer quotes st. augustine and st. thomas aquinas, to the effect that, "in the institution of nature we do not look for miracles, but for the laws of nature."[11] and, again, st. basil,[12] speaks of the continued operation of natural laws in the production of all organisms. [page 18] so much for writers of early and mediæval times. as to the present day, the author can confidently affirm that there are many as well versed in theology as mr. darwin is in his own department of natural knowledge, who would not be disturbed by the thorough demonstration of his theory. nay, they would not even be in the least painfully affected at witnessing the generation of animals of complex organization by the skilful artificial arrangement of natural forces, and the production, in the future, of a fish, by means analogous to those by which we now produce urea. and this because they know that the possibility of such phenomena, though by no means actually foreseen, has yet been fully provided for in the old philosophy centuries before darwin, or even before bacon, and that their place in the system can be at once assigned them without even disturbing its order or marring its harmony. moreover, the old tradition in this respect has never been abandoned, however much it may have been ignored or neglected by some modern writers. in proof of this it may be observed that perhaps no post-mediæval theologian has a wider reception amongst christians throughout the world than suarez, who has a separate section[13] in opposition to those who maintain the distinct creation of the various kinds--or substantial forms--of organic life. but the consideration of this matter must be deferred for the present, and the question of evolution, whether darwinian or other, be first gone into. it is proposed, after that has been done, to return to this subject (here merely alluded to), and to consider at some length the bearing of "evolution," whether darwinian or non-darwinian, upon "creation and theism." now we will revert simply to the consideration of the theory of "natural selection" itself. {19} whatever may have hitherto been the amount of acceptance that this theory has met with, all, i think, anticipated that the appearance of mr. darwin's large and careful work on "animals and plants under domestication" could but further increase that acceptance. it is, however, somewhat problematical how far such anticipations will be realized. the newer book seems to add after all but little in support of the theory, and to leave most, if not all, its difficulties exactly where they were. it is a question, also, whether the hypothesis of "pangenesis"[14] may not be found rather to encumber than to support the theory it was intended to subserve. however, the work in question treats only of domestic animals, and probably the next instalment will address itself more vigorously and directly to the difficulties which seem to us yet to bar the way to a complete acceptance of the doctrine. if the theory of natural selection can be shown to be quite insufficient to explain any considerable number of important phenomena connected with the origin of species, that theory, as _the_ explanation, must be considered as provisionally discredited. if other causes than natural (including sexual) selection can be proved to have acted--if variation can in any cases be proved to be subject to certain determinations in special directions by other means than natural selection, it then becomes probable _a priori_ that it is so in others, and that natural selection depends upon, and only supplements, such means, {20} which conception is opposed to the pure darwinian position. now it is certain, _a priori_, that variation is obedient to some law and therefore that "natural selection" itself must be capable of being subsumed into some higher law; and it is evident, i believe, _a posteriori_, that natural selection is, at the very least, aided and supplemented by some other agency. admitting, then, organic and other evolution, and that new forms of animals and plants (new species, genera, &c.) have from time to time been evolved from preceding animals and plants, it follows, if the views here advocated are true, that this evolution has not taken place by the action of "natural selection" _alone_, but through it (amongst other influences) aided by the concurrent action of some other natural law or laws, at present undiscovered; and probably that the genesis of species takes place partly, perhaps mainly, through laws which may be most conveniently spoken of as special powers and tendencies existing in each organism; and partly through influences exerted on each by surrounding conditions and agencies organic and inorganic, terrestrial and cosmical, among which the "survival of the fittest" plays a certain but subordinate part. the theory of "natural selection" may (though it need not) be taken in such a way as to lead men to regard the present organic world as formed, so to speak, _accidentally_, beautiful and wonderful as is confessedly the hap-hazard result. the same may perhaps be said with regard to the system advocated by mr. herbert spencer, who, however, also relegates "natural selection" to a subordinate _rôle_. the view here advocated, on the other hand, regards the whole organic world as arising and going forward in one harmonious development similar to that which displays itself in the growth and action of each separate individual organism. it also regards each such separate organism as the expression of powers and tendencies not to be {21} accounted for by "natural selection" alone, or even by that together with merely the direct influence of surrounding conditions. the difficulties which appear to oppose themselves to the reception of "natural selection" or "the survival of the fittest," as the one explanation of the origin of species, have no doubt been already considered by mr. darwin. nevertheless, it may be worth while to enumerate them, and to state the considerations which appear to give them weight; and there is no doubt but that a naturalist so candid and careful as the author of the theory in question, will feel obliged, rather than the reverse, by the suggestion of all the doubts and difficulties which can be brought against it. what is to be brought forward may be summed up as follows:-that "natural selection" is incompetent to account for the incipient stages of useful structures. that it does not harmonize with the co-existence of closely similar structures of diverse origin. that there are grounds for thinking that specific differences may be developed suddenly instead of gradually. that the opinion that species have definite though very different limits to their variability is still tenable. that certain fossil transitional forms are absent, which might have been expected to be present. that some facts of geographical distribution supplement other difficulties. that the objection drawn from the physiological difference between "species" and "races" still exists unrefuted. that there are many remarkable phenomena in organic forms upon which "natural selection" throws no light whatever, but the explanations of which, if they could be attained, might throw light upon specific origination. [page 22] besides these objections to the sufficiency of "natural selection," others may be brought against the hypothesis of "pangenesis," which, professing as it does to explain great difficulties, seems to do so by presenting others not less great--almost to be the explanation of _obscurum per {23} obscurius_. * * * * * chapter ii. the incompetency of "natural selection" to account for the incipient stages of useful structures. mr. darwin supposes that natural selection acts by slight variations.--these must be useful at once.--difficulties as to the giraffe; as to mimicry; as to the heads of flat-fishes; as to the origin and constancy of the vertebrate limbs; as to whalebone; as to the young kangaroo; as to sea-urchins; as to certain processes of metamorphosis; as to the mammary gland; as to certain ape characters; as to the rattlesnake and cobra; as to the process of formation of the eye and ear; as to the fully developed condition of the eye and ear; as to the voice; as to shell-fish; as to orchids; as to ants.--the necessity for the simultaneous modification of many individuals.--summary and conclusion. "natural selection," simply and by itself, is potent to explain the maintenance or the further extension and development of favourable variations, which are at once sufficiently considerable to be useful from the first to the individual possessing them. but natural selection utterly fails to account for the conservation and development of the minute and rudimentary beginnings, the slight and infinitesimal commencements of structures, however useful those structures may afterwards become. now, it is distinctly enunciated by mr. darwin, that the spontaneous variations upon which his theory depends are individually slight, minute, and insensible. he says,[15] "slight individual differences, however, {24} suffice for the work, and are probably the sole differences which are effective in the production of new species." and again, after mentioning the frequent sudden appearances of domestic varieties, he speaks of "the false belief as to the similarity of natural species in this respect."[16] in his work on the "origin of species," he also observes, "natural selection acts only by the preservation and accumulation of small inherited modifications."[17] and "natural selection, if it be a true principle, will banish the belief ... of any great and sudden modification in their structure."[18] finally, he adds, "if it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down."[19] now the conservation of minute variations in many instances is, of course, plain and intelligible enough; such, _e.g._, as those which tend to promote the destructive faculties of beasts of prey on the one hand, or to facilitate the flight or concealment of the animals pursued on the other; provided always that these minute beginnings are of such a kind as really to have a certain efficiency, however small, in favour of the conservation of the individual possessing them; and also provided that no unfavourable peculiarity in any other direction accompanies and neutralizes, in the struggle for life, the minute favourable variation. but some of the cases which have been brought forward, and which have met with very general acceptance, seem less satisfactory when carefully analysed than they at first appear to be. amongst these we may mention "the neck of the giraffe." at first sight it would seem as though a better example in support of "natural selection" could hardly have been chosen. let the fact of the {25} occurrence of occasional, severe droughts in the country which that animal has inhabited be granted. in that case, when the ground vegetation has been consumed, and the trees alone remain, it is plain that at such times only those individuals (of what we assume to be the nascent giraffe species) which were able to reach high up would be preserved, and would become the parents of the following generation, some individuals of which would, of course, inherit that high-reaching power which alone preserved their parents. only the high-reaching issue of these high-reaching individuals would again, _cæteris paribus_, be preserved at the next drought, and would again transmit to their offspring their still loftier stature; and so on, from period to period, through æons of time, all the individuals tending to revert to the ancient shorter type of body, being ruthlessly destroyed at the occurrence of each drought. (1.) but against this it may be said, in the first place, that the argument proves too much; for, on this supposition, many species must have tended to undergo a similar modification, and we ought to have at least several forms, similar to the giraffe, developed from different ungulata.[20] a careful observer of animal life, who has long resided in south africa, explored the interior, and lived in the giraffe country, has assured the author that the giraffe has powers of locomotion and endurance fully equal to those possessed by any of the other ungulata of that continent. it would seem, therefore, that some of these other ungulates ought to have developed in a similar manner as to the neck, under pain of being starved, when the long neck of the giraffe was in its incipient stage. to this criticism it has been objected that different kinds of animals are preserved, in the struggle for life, in very different ways, and even {26} that "high reaching" may be attained in more modes than one--as, for example, by the trunk of the elephant. this is, indeed, true, but then none of the african ungulata[21] have, nor do they appear ever to have had, any proboscis whatsoever; nor have they acquired such a development as to allow them to rise on their hind limbs and graze on trees in a kangaroo-attitude, nor a power of climbing, nor, as far as known, any other modification tending to compensate for the comparative shortness of the neck. again, it may perhaps be said that leaf-eating forms are exceptional, and that therefore the struggle to attain high branches would not affect many ungulates. but surely, when these severe droughts necessary for the theory occur, the ground vegetation is supposed to be exhausted; and, indeed, the giraffe is quite capable of feeding from off the ground. so that, in these cases, the other ungulata _must_ have taken to leaf eating or have starved, and thus must have had any accidental long-necked varieties favoured and preserved exactly as the long-necked varieties of the giraffe are supposed to have been favoured and preserved. the argument as to the different modes of preservation has been very well put by mr. wallace,[22] in reply to the objection that "colour, being dangerous, should not exist in nature." this objection appears similar to mine; as i say that a giraffe neck, being needful, there should be many animals with it, while the objector noticed by mr. wallace says, "a dull colour being needful, all animals should be so coloured." and mr. wallace shows in reply how porcupines, tortoises and mussels, very hard-coated bombadier beetles, stinging insects and nauseous-tasted caterpillars, can afford to be brilliant by the various means of active defence or passive protection they possess, other than obscure colouration. he says "the {27} attitudes of some insects may also protect them, as the habit of turning up the tail by the harmless rove-beetles (staphylinidæ) no doubt leads other animals, besides children, to the belief that they can sting. the curious attitude assumed by sphinx caterpillars is probably a safeguard, as well as the blood-red tentacles which can suddenly be thrown out from the neck by the caterpillars of all the true swallow-tailed butterflies." but, because many different kinds of animals can elude the observation or defy the attack of enemies in a great variety of ways, it by no means follows that there are any similar number and variety of ways for attaining vegetable food in a country where all such food, other than the lofty branches of trees, has been for a time destroyed. in such a country we have a number of vegetable-feeding ungulates, all of which present minute variations as to the length of the neck. if, as mr. darwin contends, the natural selection of these favourable variations has alone lengthened the neck of the giraffe by preserving it during droughts; similar variations, in similarly-feeding forms, at the same times, ought similarly to have been preserved and so lengthened the neck of some other ungulates by similarly preserving them during the same droughts. (2.) it may be also objected, that the power of reaching upwards, acquired by the lengthening of the neck and legs, must have necessitated a considerable increase in the entire size and mass of the body (larger bones requiring stronger and more voluminous muscles and tendons, and these again necessitating larger nerves, more capacious blood-vessels, &c.), and it is very problematical whether the disadvantages thence arising would not, in times of scarcity, more than counterbalance the advantages. for a considerable increase in the supply of food would be requisite on account of this increase in size and mass, while at the same time there would be a certain decrease in strength; for, as mr. herbert spencer {28} says,[23] "it is demonstrable that the excess of absorbed over expended nutriment must, other things equal, become less as the size of an animal becomes greater. in similarly-shaped bodies, the masses vary as the cubes of the dimensions; whereas the strengths vary as the squares of the dimensions.".... "supposing a creature which a year ago was one foot high, has now become two feet high, while it is unchanged in proportions and structure--what are the necessary concomitant changes that have taken place in it? it is eight times as heavy; that is to say, it has to resist eight times the strain which gravitation puts on its structure; and in producing, as well as in arresting, every one of its movements, it has to overcome eight times the inertia. meanwhile, the muscles and bones have severally increased their contractile and resisting powers, in proportion to the areas of their transverse sections; and hence are severally but four times as strong as they were. thus, while the creature has doubled in height, and while its ability to overcome forces has quadrupled, the forces it has to overcome have grown eight times as great. hence, to raise its body through a given space, its muscles have to be contracted with twice the intensity, at a double cost of matter expended." again, as to the cost at which nutriment is distributed through the body, and effete matters removed from it, "each increment of growth being added at the periphery of an organism, the force expended in the transfer of matter must increase in a rapid progression--a progression more rapid than that of the mass." there is yet another point. vast as may have been the time during which the process of evolution has continued, it is nevertheless not infinite. yet, as every kind, on the darwinian hypothesis, varies slightly but indefinitely in every organ and every part of every organ, how very generally must favourable variations as to the length of the neck have {29} been accompanied by some unfavourable variation in some other part, neutralizing the action of the favourable one, the latter, moreover, only taking effect during these periods of drought! how often must not individuals, favoured by a slightly increased length of neck, have failed to enjoy the elevated foliage which they had not strength or endurance to attain; while other individuals, exceptionally robust, could struggle on yet further till they arrived at vegetation within their reach. however, allowing this example to pass, many other instances will be found to present great difficulties. let us take the cases of mimicry amongst lepidoptera and other insects. of this subject mr. wallace has given a most interesting and complete account,[24] showing in how many and strange instances this superficial resemblance by one creature to some other quite distinct creature acts as a safeguard to the first. one or two instances must here suffice. in south america there is a family of butterflies, termed _heliconidæ_, which are very conspicuously coloured and slow in flight, and yet the individuals abound in prodigious numbers, and take no precautions to conceal themselves, even when at rest, during the night. mr. bates (the author of the very interesting work "the naturalist on the river amazons," and the discoverer of "mimicry") found that these conspicuous butterflies had a very strong and disagreeable odour; so much so that any one handling them and squeezing them, as a collector must do, has his fingers stained and so infected by the smell, as to require time and much trouble to remove it. it is suggested that this unpleasant quality is the cause of the abundance of the heliconidæ; mr. bates and other observers reporting that they have never seen them attacked by the birds, reptiles, or insects which prey upon other lepidoptera. now it is a curious fact that very different south american butterflies{30} put on, as it were, the exact dress of these offensive beauties and mimic them even in their mode of flight. in explaining the mode of action of this protecting resemblance mr. wallace observes:[25] "tropical insectivorous birds very frequently sit on dead branches of a lofty tree, or on those which overhang forest paths, gazing intently around, and darting off at intervals to seize an insect at a considerable distance, with which they generally return to their station to devour. if a bird began by capturing the slow-flying conspicuous heliconidæ, and found them always so disagreeable that it could not eat them, it would after a very few trials leave off catching them at all; and their whole appearance, form, colouring, and mode of flight is so peculiar, that there can be little doubt birds would soon learn to distinguish them at a long distance, and never waste any time in pursuit of them. under these circumstances, it is evident that any other butterfly of a group which birds were accustomed to devour, would be almost equally well protected by closely resembling a heliconia externally, as if it acquired also the disagreeable odour; always supposing that there were only a few of them among a great number of heliconias." "the approach in colour and form to the heliconidæ, however, would be at the first a positive, though perhaps a slight, advantage; for although at short distances this variety would be easily distinguished and devoured, yet at a longer distance it might be mistaken for one of the uneatable group, and so be passed by and gain another day's life, which might in many cases be sufficient for it to lay a quantity of eggs and leave a numerous progeny, many of which would inherit the peculiarity which had been the safeguard of their parent." [illustration: leaf butterfly in flight and repose. (_from mr. wallace's_ "_malay archipelago._")] as a complete example of mimicry mr. wallace refers to a common indian butterfly. he says:[26] "but the most wonderful and undoubted case of protective resemblance in a butterfly, which i have ever seen, is that {31} of the common indian _kallima inachis_, and its malayan ally, _kallima paralekta_. the upper surface of these is very striking and showy, as they are of a large size, and are adorned with a broad band of rich orange {32} on a deep bluish ground. the under side is very variable in colour, so that out of fifty specimens no two can be found exactly alike, but every one of them will be of some shade of ash, or brown, or ochre, such as are found among dead, dry, or decaying leaves. the apex of the upper wings is produced into an acute point, a very common form in the leaves of tropical shrubs and trees, and the lower wings are also produced into a short narrow tail. between these two points runs a dark curved line exactly representing the midrib of a leaf, and from this radiate on each side a few oblique lines, which serve to indicate the lateral veins of a leaf. these marks are more clearly seen on the outer portion of the base of the wings, and on the inner side towards the middle and apex, and it is very curious to observe how the usual marginal and transverse striæ of the group are here modified and strengthened so as to become adapted for an imitation of the venation of a leaf." ... "but this resemblance, close as it is, would be of little use if the habits of the insect did not accord with it. if the butterfly sat upon leaves or upon flowers, or opened its wings so as to expose the upper surface, or exposed and moved its head and antennæ as many other butterflies do, its disguise would be of little avail. we might be sure, however, from the analogy of many other cases, that the habits of the insect are such as still further to aid its deceptive garb; but we are not obliged to make any such supposition, since i myself had the good fortune to observe scores of _kallima paralekta_, in sumatra, and to capture many of them, and can vouch for the accuracy of the following details. these butterflies frequent dry forests, and fly very swiftly. they were seen to settle on a flower or a green leaf, but were many times lost sight of in a bush or tree of dead leaves. on such occasions they were generally searched for in vain, for while gazing intently at the very spot where one had disappeared, it would often suddenly dart out, and again vanish twenty or fifty yards further on. on one or two occasions the insect was detected{33} reposing, and it could then be seen how completely it assimilates itself to the surrounding leaves. it sits on a nearly upright twig, the wings fitting closely back to back, concealing the antennæ and head, which are drawn up between their bases. the little tails of the hind wing touch the branch, and form a perfect stalk to the leaf, which is supported in its place by the claws of the middle pair of feet, which are slender and inconspicuous. the irregular outline of the wings gives exactly the perspective effect of a shrivelled leaf. we thus have size, colour, form, markings, and habits, all combining together to produce a disguise which may be said to be absolutely perfect; and the protection which it affords is sufficiently indicated by the abundance of the individuals that possess it." beetles also imitate bees and wasps, as do some lepidoptera; and objects the most bizarre and unexpected are simulated, such as dung and drops of dew. some insects, called bamboo and walking-stick insects, have a most remarkable resemblance to pieces of bamboo, to twigs and branches. of these latter insects mr. wallace says:[27] "some of these are a foot long and as thick as one's finger, and their whole colouring, form, rugosity, and the arrangement of the head, legs, and antennæ, are such as to render them absolutely identical in appearance with dry sticks. they hang loosely about shrubs in the forest, and have the extraordinary habit of stretching out their legs unsymmetrically, so as to render the deception more complete." now let us suppose that the ancestors of these various animals were all destitute of the very special protections they at present possess, as on the darwinian hypothesis we must do. let it also be conceded that small deviations from the antecedent colouring or form would tend to make some of their ancestors escape destruction by causing them more or less frequently to be passed over, or mistaken by their persecutors. yet the deviation {34} must, as the event has shown, in each case be in some definite direction, whether it be towards some other animal or plant, or towards some dead or inorganic matter. but as, according to mr. darwin's theory, there is a constant tendency to indefinite variation, and as the minute incipient variations will be in _all directions_, they must tend to neutralize each other, and at first to form such unstable modifications that it is difficult, if not impossible, to see how such indefinite oscillations of infinitesimal beginnings can ever build up a sufficiently appreciable resemblance to a leaf, bamboo, or other object, for "natural selection" to seize upon and perpetuate. this difficulty is augmented when we consider--a point to be dwelt upon hereafter--how necessary it is that many individuals should be similarly modified simultaneously. this has been insisted on in an able article in the _north british review_ for june 1867, p. 286, and the consideration of the article has occasioned mr. darwin to make an important modification in his views.[28] in these cases of mimicry it seems difficult indeed to imagine a reason why variations tending in an _infinitesimal degree_ in any special direction should be preserved. all variations would be preserved which tended to obscure the perception of an animal by its enemies, whatever direction those variations might take, and the common preservation of conflicting tendencies would greatly favour their mutual neutralization and obliteration if we may rely on the many cases recently brought forward by mr. darwin with regard to domestic animals. [illustration: the walking-leaf insect.] mr. darwin explains the imitation of some species by others more or less nearly allied to it, by the common origin of both the mimic and the mimicked species, and the consequent possession by both (according to the theory of "pangenesis") of gemmules tending to reproduce ancestral characters, which characters the mimic must be assumed first to have {35} lost and then to have recovered. mr. darwin says,[29] "varieties of one species frequently mimic distinct species, a fact in perfect harmony with the foregoing cases, and explicable _only on the theory of descent_." but this at the best is but a partial and very incomplete explanation. it is one, moreover, which mr. wallace does not accept.[30] it is very incomplete, because it has no bearing on some of the most striking cases, and of course mr. darwin does not pretend that it has. we should have to go back far indeed to reach the common ancestor of the mimicking {36} walking-leaf insect and the real leaf it mimics, or the original progenitor of both the bamboo insect and the bamboo itself. as these last most remarkable cases have certainly nothing to do with heredity,[31] it is unwarrantable to make use of that explanation for other protective resemblances, seeing that its inapplicability, in certain instances, is so manifest. again, at the other end of the process it is as difficult to account for the last touches of perfection in the mimicry. some insects which imitate leaves extend the imitation even to the very injuries on those leaves made by the attacks of insects or of fungi. thus, speaking of one of the walking-stick insects, mr. wallace says:[32] "one of these creatures obtained by myself in borneo (_ceroxylus laceratus_) was covered over with foliaceous excrescences of a clear olive-green colour, so as exactly to resemble a stick grown over by a creeping moss or jungermannia. the dyak who brought it me assured me it was grown over with moss although alive, and it was only after a most minute examination that i could convince myself it was not so." again, as to the leaf butterfly, he says:[33] "we come to a still more extraordinary part of the imitation, for we find representations of leaves in every stage of decay, variously blotched, and mildewed, and pierced with holes, and in many cases irregularly covered with powdery black dots, gathered into patches and spots, so closely resembling the various kinds of minute fungi that grow on dead leaves, that it is impossible to avoid thinking at first sight that the butterflies themselves have been attacked by real fungi." here imitation has attained a development which seems utterly beyond the power of the mere "survival of the fittest" to produce. how this double mimicry can importantly aid in the struggle for life seems puzzling indeed, but much more so how the first faint beginnings of the imitation of {37} such injuries in the leaf can be developed in the animal into such a complete representation of them--_a fortiori_ how simultaneous and similar first beginnings of imitations of such injuries could ever have been developed in several individuals, out of utterly indifferent and indeterminate infinitesimal variations in all conceivable directions. [illustration: pleuronectidæ, with the peculiarly placed eye in different positions. (_from dr. traquair's paper in the "transactions of the linnean society, 1865."_)] another instance which may be cited is the asymmetrical condition of the heads of the flat-fishes (pleuronectidæ), such as the sole, the flounder, the brill, the turbot, &c. in all these fishes the two eyes, which in the young are situated as usual one on each side, come to be placed, in the adult, both on the same side of the head. if this condition had appeared at once, if in the hypothetically fortunate common ancestor of these fishes an eye had suddenly become thus transferred, then the perpetuation of such a transformation by the action of "natural selection" is conceivable enough. such sudden changes, however, are not those favoured by the darwinian theory, and indeed the accidental occurrence of such a spontaneous transformation is hardly conceivable. but if this is not so, if the transit was gradual, then how such transit of one eye a minute fraction of the {38} journey towards the other side of the head could benefit the individual is indeed far from clear. it seems, even, that such an incipient transformation must rather have been injurious. another point with regard to these flat-fishes is that they appear to be in all probability of recent origin--_i.e._ geologically speaking. there is, of course, no great stress to be laid on the mere absence of their remains from the secondary strata, nevertheless that absence is noteworthy, seeing that existing fish families, _e.g._ sharks (squalidæ), have been found abundantly even down so far as the carboniferous rocks, and traces of them in the upper silurian. another difficulty seems to be the first formation of the limbs of the higher animals. the lowest vertebrata[34] are perfectly limbless, and if, as most darwinians would probably assume, the primeval vertebrate creature was also apodal, how are the preservation and development of the first rudiments of limbs to be accounted for--such rudiments being, on the hypothesis in question, infinitesimal and functionless? in reply to this it has been suggested that a mere flattening of the end of the body has been useful, such, _e.g._, as we see in sea-snakes,[35] which may be the rudiment of a tail formed strictly to aid in swimming. also that a mere _roughness_ of the skin might be useful to a swimming animal by holding the water better, that thus minute processes might be selected and preserved, and that, in the same way, these might be gradually increased into limbs. but it is, to say the least, very questionable whether a roughness of the skin, or minute processes, would be useful to a {39} swimming animal; the motion of which they would as much impede as aid, unless they were at once capable of a suitable and appropriate action, which is against the hypothesis. again, the change from mere indefinite and accidental processes to two regular pairs of symmetrical limbs, as the result of merely fortuitous, favouring variations, is a step the feasibility of which hardly commends itself to the reason, seeing the very different positions assumed by the ventral fins in different fishes. if the above suggestion made in opposition to the views here asserted be true, then the general constancy of position of the limbs of vertebrata may be considered as due to the position assumed by the primitive rugosities from which those limbs were generated. clearly only two pairs of rugosities were so preserved and developed, and all limbs (on this view) are descendants of the same two pairs, as all have so similar a fundamental structure. yet we find in many fishes the pair of fins, which correspond to the hinder limbs of other animals, placed so far forwards as to be either on the same level with, or actually in front of, the normally anterior pair of limbs; and such fishes are from this circumstance called "thoracic," or "jugular" fishes respectively, as the weaver fishes and the cod. this is a wonderful contrast to the fixity of position of vertebrate limbs generally. if then such a change can have taken place in the comparatively short time occupied by the evolution of these special fish forms, we might certainly expect other and far more bizarre structures would (did not some law forbid) have been developed, from other rugosities, in the manifold exigencies of the multitudinous organisms which must (on the darwinian hypothesis) have been gradually evolved during the enormous period intervening between the first appearance of vertebrate life and the present day. yet, with these exceptions, the position of the limbs is constant from the lower fishes up to man, there being always an anterior pectoral pair placed in front of a posterior or pelvic pair when both are present, and in no single {40} instance are there more than these two pairs. [illustration: mouth of a whale.] the development of whalebone (baleen) in the mouth of the whale is another difficulty. a whale's mouth is furnished with very numerous horny plates, which hang down from the palate along each side of the mouth. they thus form two longitudinal series, each plate of which is placed transversely to the long axis of the body, and all are very close together. on depressing the lower lip the free outer edges of these plates come into view. their inner edges are furnished with numerous coarse hair-like processes, consisting of some of the constituent fibres of the horny plates--which, as it were, fray out--and the mouth is thus lined, except below, by a network of countless fibres formed by the inner edges of the two series of plates. this network acts as a sort of sieve. when the whale feeds it takes {41} into its mouth a great gulp of water, which it drives out again through the intervals of the horny plates of baleen, the fluid thus traversing the sieve of horny fibres, which retains the minute creatures on which these marine monsters subsist. now it is obvious, that if this baleen had once attained such a size and development as to be at all useful, then its preservation and augmentation within serviceable limits, would be promoted by "natural selection" alone. but how to obtain the beginning of such useful development? there are indeed certain animals of exclusively aquatic habits (the dugong and manatee) which also possess more or less horn on the palate, and at first sight this might be taken as a mitigation of the difficulty; but it is not so, and the fact does not help us one step further along the road: for, in the first place, these latter animals differ so importantly in structure from whales and porpoises that they form an altogether distinct order, and cannot be thought to approximate to the whale's progenitors. they are vegetarians, the whales feed on animals; the former never have the ribs articulated in the mode in which they are in some of the latter; the former have pectoral mammæ, and the latter are {42} provided with two inguinal mammary glands, and have the nostrils enlarged into blowers, which the former have not. the former thus constitute the order sirenia, while the latter belong to the cetacea. in the second place, the horny matter on the palates of the dugong and manatee has not, even initially, that "strainer" action, which is the characteristic function of the cetacean "baleen." [illustration: four plates of baleen seen obliquely from within.] [illustration: dugong.] there is another very curious structure, the origin or the disappearance of which it seems impossible to account for on the hypothesis of minute indefinite variations. it is that of the mouth of the young kangaroo. in all mammals, as in ourselves, the air-passage from the lungs opens in the floor of the mouth behind the tongue, and in front of the opening of the gullet, so that each particle of food as it is swallowed passes over the opening, but is prevented from falling into it (and thus causing death from choking) by the action of a small cartilaginous shield (the epiglottis), which at the right moment bends back and protects the orifice. now the kangaroo is born in such an exceedingly imperfect and undeveloped condition, that it is quite unable to suck. the mother therefore places the minute blind and naked young upon the nipple, and then injects milk into it by means of a special muscular envelope of the mammary gland. did no special provision exist, the young one must infallibly be choked by the intrusion of the milk into the windpipe. but there _is_ a special provision. the larynx is so elongated that it rises up into the posterior end of the nasal passage, and is thus enabled to give free entrance to the air for the lungs, while the milk passes harmlessly on each side of this elongated larynx, and so safely attains the gullet behind it. now, on the darwinian hypothesis, either all mammals descended from marsupial progenitors, or else the marsupials, sprung from animals having in most respects the ordinary mammalian structure. [page 43] on the first alternative, how did "natural selection" remove this (at least perfectly innocent and harmless) structure in almost all other mammals, and, having done so, again reproduce it in precisely those forms which alone require it, namely, the cetacea? that such a harmless structure _need not_ be removed any darwinian must confess, since a structure exists in both the crocodiles and gavials, which enables the former to breathe themselves while drowning the prey which they hold in their mouths. on mr. darwin's hypothesis it could only have been developed where useful, therefore not in the gavials(!) which feed on fish, but which yet retain, as we might expect, this, in them superfluous but harmless formation. on the second alternative, how did the elongated larynx itself arise, seeing that if its development lagged behind that of the maternal structure, the young primeval kangaroo must be choked: while without the injecting power in the mother, it must be starved? the struggle by the sole action of which such a form was developed must indeed have been severe! [illustration: an echinus, or sea-urchin (the spines removed from one-half.)] the sea-urchins (echinus) present us also with structures the origin of which it seems impossible to explain by the action of "natural {44} selection" only. these lowly animals belong to that group of the star-fish class (echinodermata), the species of which possess generally spheroidal bodies, built up of multitudinous calcareous plates, and constitute the order echinoidea. they are also popularly known as sea-eggs. utterly devoid of limbs, the locomotion of these creatures is effected by means of rows of small tubular suckers (which protrude through pores in the calcareous plates) and by moveable spines scattered over the body. [illustration: pedicellariæ. (immensely enlarged.)] besides these spines and suckers there are certain very peculiar structures, termed "pedicellariæ." each of these consists of a long slender stalk, ending in three short limbs--or rather jaws--the whole supported by a delicate internal skeleton. the three limbs (or jaws), which start from a common point at the end of the stalk, are in the constant habit of opening and closing together again with a snapping action, while the stalk itself sways about. the utility of these appendages is, even now, problematical. it may be that they remove from the surface of the animal's body foreign substances which would be prejudicial to it, and which it cannot otherwise get rid of. but granting this, what would be the utility of the _first rudimentary beginnings_ of such structures, and how could such incipient buddings have ever preserved the life of a single echinus? it is true that on darwinian principles the ancestral form from which the sea-urchin developed was different, and must not be conceived merely as an echinus devoid of pedicellariæ; but this makes the difficulty none the less. it is equally hard to imagine that the first rudiments of such structures could have been useful to _any_ animal from which the echinus might have been{45} derived. moreover, not even the _sudden_ development of the snapping action could have been beneficial without the freely moveable stalk, nor could the latter have been efficient without the snapping jaws, yet no minute merely indefinite variations could simultaneously evolve these complex co-ordinations of structure; to deny this seems to do no less than to affirm a startling paradox. mr. darwin explains the appearance of some structures, the utility of which is not apparent, by the existence of certain "laws of correlation." by these he means that certain parts or organs of the body are so related to other organs or parts, that when the first are modified by the action of "natural selection," or what not, the second are simultaneously affected, and increase proportionally or possibly so decrease. examples of such are the hair and teeth in the naked turkish dog, the general deafness of white cats with blue eyes, the relation between the presence of more or less down on young birds when first hatched, and the future colour of their plumage,[36] with many others. but the idea that the modification of any internal or external part of the body of an echinus carries with it the effect of producing elongated, flexible, triradiate, snapping processes, is, to say the very least, fully as obscure and mysterious as what is here contended for, viz. the efficient presence of an unknown internal natural law or laws conditioning the evolution of new specific forms from preceding ones, modified by the action of surrounding conditions, by "natural selection" and by other controlling influences. the same difficulty seems to present itself in other examples of exceptional structure and action. in the same echinus, as in many allied forms, and also in some more or less remote ones, a very peculiar mode of development exists. the adult is not formed from the egg directly, but {46} the egg gives rise to a creature which swims freely about, feeds, and is even somewhat complexly organized. soon a small lump appears on one side of its stomach; this enlarges, and, having established a communication with the exterior, envelopes and appropriates the creature's stomach, with which it swims away and develops into the complete adult form, while the dispossessed individual perishes. again, certain flies present a mode of development equally bizarre, though quite different. in these flies, the grub is, as usual, produced from the ovum, but this grub, instead of growing up into the adult in the ordinary way, undergoes a sort of liquefaction of a great part of its body, while certain patches of formative tissue, which are attached to the ramifying air tubes, or tracheæ (and which patches bear the name of "imaginal disks"), give rise to the legs, wings, eyes, &c., respectively; and these severally formed parts grow together, and build up the head and body by their mutual approximation. such a process is unknown outside the class of insects, and inside that class it is only known in a few of the two-winged flies. now, how "natural selection," or any "laws of correlation," can account for the gradual development of such an exceptional process of development--so extremely divergent from that of other insects--seems nothing less than inconceivable. mr. darwin himself[37] gives an account of a very peculiar and abnormal mode of development of a certain beetle, the sitaris, as described by m. fabre. this insect, instead of at first appearing in its grub stage, and then, after a time, putting on the adult form, is at first active and furnished with six legs, two long antennæ, and four eyes. hatched in the nests of bees, it at first attaches itself to one of the males, and then crawls, when the opportunity offers, upon a female bee. when the female bee lays her eggs, the young sitaris springs upon them and devours them. then, losing its eyes, legs, and antennæ, and {47} becoming rudimentary, it sinks into an ordinary grub-like form, and feeds on honey, ultimately undergoing another transformation, re-acquiring its legs, &c., and emerging a perfect beetle! that such a process should have arisen by the accumulation of minute accidental variations in structure and habit, appears to many minds, quite competent to form an opinion on the subject, absolutely incredible. it may be objected, perhaps, that these difficulties are _difficulties of ignorance_--that we cannot explain them because we do not know _enough_ of the animals. but it is here contended that this is not the case; it is not that we merely fail to see how natural selection acted, but that there is a positive incompatibility between the cause assigned and the results. it will be stated shortly what wonderful instances of co-ordination and of unexpected utility mr. darwin has discovered in orchids. the discoveries are not disputed or undervalued, but the explanation of their _origin_ is deemed thoroughly unsatisfactory--utterly insufficient to explain the incipient, infinitesimal beginnings of structures which are of utility only when they are considerably developed. let us consider the mammary gland, or breast. is it conceivable that the young of any animal was ever saved from destruction by accidentally sucking a drop of scarcely nutritious fluid from an accidentally hypertrophied cutaneous gland of its mother? and even if one was so, what chance was there of the perpetuation of such a variation? on the hypothesis of natural selection itself, we must assume that up to that time the race had been well adapted to the surrounding conditions; the temporary and accidental trial and change of conditions, which caused the so-sucking young one to be the "fittest to survive" under the supposed circumstances, would soon cease to act, and then the progeny of the mother, with the accidentally hypertrophied, sebaceous glands, would have no tendency to survive the {48} far outnumbering descendants of the normal ancestral form. if, on the other hand, we assume the change of conditions not to have been temporary but permanent, and also assume that this permanent change of conditions was accidentally synchronous with the change of structure, we have a coincidence of very remote probability indeed. but if, again, we accept the presence of some harmonizing law simultaneously determining the two changes, or connecting the second with the first by causation, then, of course, we remove the accidental character of the coincidence. again, how explain the external position of the male sexual glands in certain mammals? the utility of the modification, when accomplished, is problematical enough, and no less so the incipient stages of the descent. as was said in the first chapter, mr. darwin explains the brilliant plumage of the peacock or the humming-bird by the action of sexual selection: the more and more brilliant males being selected by the females (which are thus attracted) to become the fathers of the next generation, to which generation they tend to communicate their own bright nuptial vesture. but there are peculiarities of colour and of form which it is exceedingly difficult to account for by any such action. thus, amongst apes, the female is notoriously weaker, and is armed with much less powerful canine tusks than the male. when we consider what is known of the emotional nature of these animals, and the periodicity of its intensification, it is hardly credible that a female would often risk life or limb through her admiration of a trifling shade of colour, or an infinitesimally greater though irresistibly fascinating degree of wartiness.[38] {49} [illustration: rattlesnake.] yet the males of some kinds of ape are adorned with quite exceptionally brilliant local decoration, and the male orang is provided with remarkable, projecting, warty lumps of skin upon the cheeks. as we have said, the weaker female can hardly be supposed to have developed these by persevering and long-continued selection, nor can they be thought to tend to the preservation of the individual. on the contrary, the presence of this enlarged appendage must occasion a slight increase in the need of nutriment, and in so far must be a detriment, although its detrimental effect would not be worth speaking of except in relation to "darwinism," according to which, "selection" has acted through unimaginable ages, {50} and has ever tended to suppress any useless development by the struggle for life.[39] [illustration: cobra. (_copied, by permission, from sir andrew smith's "reptiles of south africa."_)] in poisonous serpents, also, we have structures which, at all events at first sight, seem positively hurtful to those reptiles. such are the rattle of the rattlesnake, and the expanding neck of the cobra, the former seeming to warn the ear of the intended victim, as the latter warns the eye. it is true we cannot perhaps demonstrate that the victims are alarmed and warned, but, on darwinian principles, they certainly ought to be so. for the {51} rashest and most incautious of the animals preyed on would always tend to fall victims, and the existing individuals being the long-descended progeny of the timid and cautious, ought to have an inherited tendency to distrust, amongst other things, both "rattling" and "expanding" snakes. as to any power of fascination exercised by means of these actions, the most distinguished naturalists, certainly the most distinguished erpetologists, entirely deny it, and it is opposed to the careful observations of those known to us.[40] the mode of formation of both the eye and the ear of the highest animals is such that, if it is (as most darwinians assert processes of development to be) a record of the actual steps by which such structures were first evolved in antecedent forms, it almost amounts to a demonstration that those steps were never produced by "natural selection." the eye is formed by a simultaneous and corresponding ingrowth of one part and outgrowth of another. the skin in front of the future eye becomes depressed, the depression increases and assumes the form of a sac, which changes into the aqueous humour and lens. an outgrowth of brain substance, on the other hand, forms the retina, while a third process is a lateral ingrowth of connective tissue, which afterwards changes into the vitreous humour of the eye. the internal ear is formed by an involution of the integument, and not by an outgrowth of the brain. but tissue, in connexion with it, becomes in part changed, thus forming the auditory nerve, which places the tegumentary sac in direct communication with the brain itself. {52} now, these complex and simultaneous co-ordinations could never have been produced by infinitesimal beginnings, since, until so far developed as to effect the requisite junctions, they are useless. but the eye and ear when fully developed present conditions which are hopelessly difficult to reconcile with the mere action of "natural selection." the difficulties with regard to the eye have been well put by mr. murphy, especially that of the concordant result of visual development springing from different starting-points and continued on by independent roads. he says,[41] speaking of the beautiful structure of the perfect eye, "the higher the organization, whether of an entire organism or of a single organ, the greater is the number of the parts that co-operate, and the more perfect is their co-operation; and consequently, the more necessity there is for corresponding variations to take place in all the co-operating parts at once, and the more useless will be any variation whatever unless it is accompanied by corresponding variations in the co-operating parts; while it is obvious that the greater the number of variations which are needed in order to effect an improvement, the less will be the probability of their all occurring at once. it is no reply to this to say, what is no doubt abstractedly true, that whatever is possible becomes probable, if only time enough be allowed. there are improbabilities so great that the common sense of mankind treats them as impossibilities. it is not, for instance, in the strictest sense of the word, impossible that a poem and a mathematical proposition should be obtained by the process of shaking letters out of a box; but it is improbable to a degree that cannot be distinguished from impossibility; and the improbability of obtaining an improvement in an organ by means of several spontaneous variations, all occurring together, is an improbability of the same kind. if we suppose that any single variation occurs on the average once in _m_ times, the probability of {53} that variation occurring in any individual will be 1/_m_; and suppose that _x_ variations must concur in order to make an improvement, then the probability of the necessary variations all occurring together will be 1/_m_^x. now suppose, what i think a moderate proposition, that the value of _m_ is 1,000, and the value of _x_ is 10, then 1/_m_^x = 1/1000^{10} = 1/10^{30}. a number about ten thousand times as great as the number of waves of light that have fallen on the earth since historical time began. and it is to be further observed, that no improvement will give its possessor a _certainty_ of surviving and leaving offspring, but only an _extra chance_, the value of which it is quite impossible to estimate." this difficulty is, as mr. murphy points out, greatly intensified by the undoubted fact that the wonderfully complex structure has been arrived at quite independently in beasts on the one hand and in cuttle-fishes on the other; while creatures of the insect and crab division present us with a third and quite separately developed complexity. as to the ear, it would take up too much space to describe its internal structure;[42] it must suffice to say that in its interior there is an immense series of minute rod-like bodies, termed _fibres of corti_, having the appearance of a key-board, and each fibre being connected with a filament of the auditory nerve, these nerves being like strings to be struck by the keys, _i.e._ by the fibres of corti. moreover, this apparatus is supposed to be a key-board in function as well as in appearance, the{54} vibration of each one fibre giving rise, it is believed, to the sensation of one particular tone, and combinations of such vibrations producing chords. it is by the action of this complex organ then, that all the wonderful intricacy and beauty of beethoven and mozart come, most probably, to be perceived and appreciated. now it can hardly be contended that the preservation of any race of men in the struggle for life ever depended on such an extreme delicacy and refinement of the internal ear,--a perfection only exercised in the enjoyment and appreciation of the most perfect musical performances. how, then, could either the minute incipient stages, or the final perfecting touches of this admirable structure, have been brought about by vague, aimless, and indefinite variations in all conceivable directions of an organ, suitable to enable the rudest savage to minister to his necessities, but no more? mr. wallace[43] makes an analogous remark with regard to the organ of voice in man--the human larynx. he says of singing: "the habits of savages give no indication of how this faculty could have been developed by natural selection, because it is never required or used by them. the singing of savages is a more or less monotonous howling, and the females seldom sing at all. savages certainly never choose their wives for fine voices, but for rude health, and strength, and physical beauty. sexual selection could not therefore have developed this wonderful power, which only comes into play among civilized people." reverting once more to beauty of form and colour, there is one manifestation of it for which no one can pretend that sexual selection can possibly account. the instance referred to is that presented by bivalve shell-fish.[44] here we meet with charming tints and elegant forms and markings of no direct use to their possessors[45] in the struggle for {55} life, and of no indirect utility as regards sexual selection, for fertilization takes place by the mere action of currents of water, and the least beautiful individual has fully as good a chance of becoming a parent as has the one which is the most favoured in beauty of form and colour. again, the peculiar outline and coloration of certain orchids--notably of our own bee, fly, and spider orchids--seem hardly explicable by any action of "natural selection." mr. darwin says very little on this singular resemblance of flowers to insects, and what he does say seems hardly to be what an advocate of "natural selection" would require. surely, for minute accidental indefinite variations to have built up such a striking resemblance to insects, we ought to find that the preservation of the plant, or the perpetuation of its race, depends almost constantly on relations between bees, spiders, and flies respectively and the bee, spider, and fly orchids.[46] this process must have continued for ages constantly and perseveringly, and yet what is the fact? mr. darwin tells us, in his work on the fertilization of orchids, that neither the spider nor the fly orchids are much visited by insects, while, with regard to the bee orchid, he says, "i have never seen an insect visit these flowers." and he shows how this species is even wonderfully and specially modified to effect self-fertilization. in the work just referred to mr. darwin gives a series of the most wonderful and minute contrivances by which the visits of insects are utilized for the fertilization of orchids,--structures so wonderful {56} that nothing could well be more so, except the attribution of their origin to minute, fortuitous, and indefinite variation. the instances are too numerous and too long to quote, but in his "origin of species"[47] he describes two which must not be passed over. in one (_coryanthes_) the orchid has its lower lip enlarged into a bucket, above which stand two water-secreting horns. these latter replenish the bucket from which, when half-filled, the water overflows by a spout on one side. bees visiting the flower fall into the bucket and crawl out at the spout. by the peculiar arrangement of the parts of the flower, the first bee which does so carries away the pollen-mass glued to his back, and then when he has his next involuntary bath in another flower, as he crawls out the pollen-mass attached to him comes in contact with the stigma of that second flower and fertilizes it. in the other example (_catasetum_), when a bee gnaws a certain part of the flower, he inevitably touches a long delicate projection, which mr. darwin calls the antenna. "this antenna transmits a vibration to a certain membrane, which is instantly ruptured; this sets free a spring by which the pollen-mass is shot forth like an arrow in the right direction, and adheres by its viscid extremity to the back of the bee!" another difficulty, and one of some importance, is presented by those communities of ants which have not only a population of sterile females, or workers, but two distinct and very different castes of such. mr. darwin believes that he has got over this difficulty by having found individuals intermediate in form and structure[48] between the two working castes; others may think that we have in this belief of mr. darwin, an example {57} of the unconscious action of volition upon credence. a vast number of difficulties similar to those which have been mentioned might easily be cited--those given, however, may suffice. there remains, however, to be noticed a very important consideration, which was brought forward in the _north british review_ for june 1867, p. 286, namely, the necessity for the simultaneous modification of _many individuals_. this consideration seems to have escaped mr. darwin, for at p. 104 of his last (fifth) edition of "natural selection," he admits, with great candour, that until reading this article he did not "appreciate how rarely single variations, whether slight or strongly marked, could be perpetuated." the _north british review_ (speaking of the supposition that a species is changed by the survival of a few individuals in a century through a similar and favourable variation) says: "it is very difficult to see how this can be accomplished, even when the variation is eminently favourable indeed; and still more difficult when the advantage gained is very slight, as must generally be the case. the advantage, whatever it may be, is utterly outbalanced by numerical inferiority. a million creatures are born; ten thousand survive to produce offspring. one of the million has twice as good a chance as any other of surviving; but the chances are fifty to one against the gifted individuals being one of the hundred survivors. no doubt the chances are twice as great against any one other individual, but this does not prevent their being enormously in favour of _some_ average individual. however slight the advantage may be, if it is shared by half the individuals produced, it will probably be present in at least fifty-one of the survivors, and in a larger proportion of their offspring; but the chances are against the preservation of any one 'sport' (_i.e._ sudden, marked variation) in a numerous tribe. the vague use of an imperfectly understood doctrine of chance has led darwinian supporters, first, to confuse the two cases above distinguished; and, secondly, to imagine {58} that a very slight balance in favour of some individual sport must lead to its perpetuation. all that can be said is that in the above example the favoured sport would be preserved once in fifty times. let us consider what will be its influence on the main stock when preserved. it will breed and have a progeny of say 100; now this progeny will, on the whole, be intermediate between the average individual and the sport. the odds in favour of one of this generation of the new breed will be, say one and a half to one, as compared with the average individual; the odds in their favour will, therefore, be less than that of their parents; but owing to their greater number, the chances are that about one and a half of them would survive. unless these breed together, a most improbable event, their progeny would again approach the average individual; there would be 150 of them, and their superiority would be, say in the ratio of one and a quarter to one; the probability would now be that nearly two of them would survive, and have 200 children, with an eighth superiority. rather more than two of these would survive; but the superiority would again dwindle, until after a few generations it would no longer be observed, and would count for no more in the struggle for life than any of the hundred trifling advantages which occur in the ordinary organs. an illustration will bring this conception home. suppose a white man to have been wrecked on an island inhabited by negroes, and to have established himself in friendly relations with a powerful tribe, whose customs he has learnt. suppose him to possess the physical strength, energy, and ability of a dominant white race, and let the food and climate of the island suit his constitution; grant him every advantage which we can conceive a white to possess over the native; concede that in the struggle for existence his chance of a long life will be much superior to that of the native chiefs; yet from all these admissions, there does not follow the conclusion that, after a limited or unlimited {59} number of generations, the inhabitants of the island will be white. our shipwrecked hero would probably become king; he would kill a great many blacks in the struggle for existence; he would have a great many wives and children." ... "in the first generation there will be some dozens of intelligent young mulattoes, much superior in average intelligence to the negroes. we might expect the throne for some generations to be occupied by a more or less yellow king; but can any one believe that the whole island will gradually acquire a white, or even a yellow, population?" "darwin says that in the struggle for life a grain may turn the balance in favour of a given structure, which will then be preserved. but one of the weights in the scale of nature is due to the number of a given tribe. let there be 7000 a's and 7000 b's, representing two varieties of a given animal, and let all the b's, in virtue of a slight difference of structure, have the better chance of life by 1/7000 part. we must allow that there is a slight probability that the descendants of b will supplant the descendants of a; but let there be only 7001 a's against 7000 b's at first, and the chances are once more equal, while if there be 7002 a's to start, the odds would be laid on the a's. true, they stand a greater chance of being killed; but then they can better afford to be killed. the grain will only turn the scales when these are very nicely balanced, and an advantage in numbers counts for weight, even as an advantage in structure. as the numbers of the favoured variety diminish, so must its relative advantages increase, if the chance of its existence is to surpass the chance of its extinction, until hardly any conceivable advantage would enable the descendants of a single pair to exterminate the descendants of many thousands if they and their descendants are supposed to breed freely with the inferior variety, and so gradually lose their ascendency." mr. darwin himself says of the article quoted: "the justice of these remarks cannot, i think, be disputed. if, for instance, a bird of some {60} kind could procure its food more easily by having its beak curved, and if one were born with its beak strongly curved, and which consequently flourished, nevertheless there would be a very poor chance of this one individual perpetuating its kind to the exclusion of the common form." this admission seems almost to amount to a change of front in the face of the enemy! these remarks have been quoted at length because they so greatly intensify the difficulties brought forward in this chapter. if the most favourable variations have to contend with such difficulties, what must be thought as to the chance of preservation of the slightly displaced eye in a sole or of the incipient development of baleen in a whale? summary and conclusion. it has been here contended that a certain few facts, out of many which might have been brought forward, are inconsistent with the origination of species by "natural selection" only or mainly. mr. darwin's theory requires minute, indefinite, fortuitous variations of all parts in all directions, and he insists that the sole operation of "natural selection" upon such is sufficient to account for the great majority of organic forms, with their most complicated structures, intricate mutual adaptations and delicate adjustments. to this conception has been opposed the difficulties presented by such a structure as the form of the giraffe, which ought not to have been the solitary structure it is; also the minute beginnings and the last refinements of protective mimicry equally difficult or rather impossible to account for by "natural selection." again the difficulty as to the heads of flat-fishes has been insisted on, as also the origin, and at the same time the constancy, of the limbs of the highest animals. reference has also been made to the whalebone of whales, and to the impossibility of {61} understanding its origin through "natural selection" only; the same as regards the infant kangaroo, with its singular deficiency of power compensated for by maternal structures on the one hand, to which its own breathing organs bear direct relation on the other. again, the delicate and complex pedicellariæ of echinoderms, with a certain process of development (through a secondary larva) found in that class, together with certain other exceptional modes of development, have been brought forward. the development of colour in certain apes, the hood of the cobra, and the rattle of the rattlesnake have also been cited. again, difficulties as to the process of formation of the eye and ear, and as to the fully developed condition of those complex organs, as well as of the voice, have been considered. the beauty of certain shell-fish; the wonderful adaptations of structure, and variety of form and resemblance, found in orchids; together with the complex habits and social conditions of certain ants, have been hastily passed in review. when all these complications are duly weighed and considered, and when it is borne in mind how necessary it is for the permanence of a new variety that many individuals in each case should be simultaneously modified, the cumulative argument seems irresistible. the author of this book can say that though by no means disposed originally to dissent from the theory of "natural selection," if only its difficulties could be solved, he has found each successive year that deeper consideration and more careful examination have more and more brought home to him the inadequacy of mr. darwin's theory to account for the preservation and intensification of incipient, specific, and generic characters. that minute, fortuitous, and indefinite variations could have brought about such special forms and modifications as have been enumerated in this chapter, seems to contradict not imagination, but reason. [page 62] that either many individuals amongst a species of butterfly should be simultaneously preserved through a similar accidental and minute variation in one definite direction, when variations in many other directions would also preserve; or that one or two so varying should succeed in supplanting the progeny of thousands of other individuals, and that this should by no other cause be carried so far as to produce the appearance (as we have before stated) of spots of fungi, &c.--are alternatives of an improbability so extreme as to be practically equal to impossibility. in spite of all the resources of a fertile imagination, the darwinian, pure and simple, is reduced to the assertion of a paradox as great as any he opposes. in the place of a mere assertion of our ignorance as to the way these phenomena have been produced, he brings forward, as their explanation, a cause which it is contended in this work is demonstrably insufficient. of course in this matter, as elsewhere throughout nature, we have to do with the operation of fixed and constant natural laws, and the knowledge of these may before long be obtained by human patience or human genius; but there is, it is believed, already enough evidence to show that these as yet unknown natural laws or law will never be resolved into the action of "natural selection," but will constitute or exemplify a mode and condition of organic action of which the darwinian theory takes no account whatsoever. [page 63] * * * * * chapter iii. the co-existence of closely similar structures of diverse origin. chances against concordant variations.--examples of discordant ones.--concordant variations not unlikely on a non-darwinian evolutionary hypothesis.--placental and implacental mammals.--birds and reptiles.--independent origins of similar sense organs.--the ear.--the eye.--other coincidences.--causes besides natural selection produce concordant variations in certain geographical regions.--causes besides natural selection produce concordant variations in certain zoological and botanical groups.--there are homologous parts not genetically related.--harmony in respect of the organic and inorganic worlds.--summary and conclusion. the theory of "natural selection" supposes that the varied forms and structure of animals and plants have been built up merely by indefinite, fortuitous,[49] minute variations in every part and in all directions--those variations only being preserved which are directly or indirectly useful to the individual possessing them, or necessarily correlated with such useful variations. [illustration: wingbones of pterodactyle, bat, and bird. (_copied, by permission, from mr. andrew murray's "geographical distribution of mammals."_)] on this theory the chances are almost infinitely great against the independent, accidental occurrence and preservation of two similar series of minute variations resulting in the independent development of two closely similar forms. in all cases, no doubt (on this same theory), _some_ adaptation to habit or need would gradually be evolved, but that {64} adaptation would surely be arrived at by different roads. the organic world supplies us with multitudes of examples of similar functional results being attained by the most diverse means. thus the body is sustained in the air by birds and by bats. in the first case it is so sustained by a limb in which the bones of the hand are excessively reduced, but which is provided with immense outgrowths from the skin--namely, the feathers of the wing. in the second case, however, the body is sustained in the air by a limb in which the bones of the hand are enormously increased in length, and so sustain a great expanse of naked skin, which is the flying membrane of the bat's wing. certain fishes and certain reptiles can also flit and take very prolonged jumps in the air. the flying-fish, however, takes these by means of a great elongation of the rays of the pectoral fins--parts which cannot be said to be of the same nature as the constituents of the wing of either the bat or the bird. the little lizard, which enjoys the formidable name of "flying-dragon," flits by means of a structure altogether peculiar--namely, by the liberation and great elongation of some of the ribs which support a fold of skin. in the extinct pterodactyles--which were _truly_ flying {65} reptiles--we meet with an approximation to the structure of the bat, but in the pterodactyle we have only one finger elongated in each hand: a striking example of how the very same function may be provided for by a modification similar in principle, yet surely manifesting the independence of its origin. when we go to lower animals, we find flight produced by organs, as the wings of insects, which are not even modified limbs at all; or we find even the function sometimes subserved by quite artificial means, as in the aërial spiders, which use their own threads to float with in the air. in the vegetable kingdom the atmosphere is often made use of for the scattering of seeds, by their being furnished with special structures of very different kinds. the diverse modes by which such seeds are dispersed are well expressed by mr. darwin. he says:[50] "seeds are disseminated {66} by their minuteness,--by their capsule being converted into a light balloon-like envelope,--by being embedded in pulp or flesh, formed of the most diverse parts, and rendered nutritious, as well as conspicuously coloured, so as to attract and be devoured by birds,--by having hooks and grapnels of many kinds and serrated awns, so as to adhere to the fur of quadrupeds,--and by being furnished with wings and plumes, as different in shape as elegant in structure, so as to be wafted by every breeze." [illustration: skeleton of the flying-dragon. (showing the elongated ribs which support the flitting organ.)] again, if we consider the poisoning apparatus possessed by different animals, we find in serpents a perforated--or rather very deeply channelled--tooth. in wasps and bees the sting is formed of modified parts, accessory in reproduction. in the scorpion, we have the median terminal process of the body specially organized. in the spider, we have a specially constructed antenna; and finally in the centipede a pair of modified thoracic limbs. [illustration: a centipede.] it would be easy to produce a multitude of such instances of similar ends being attained by dissimilar means, and it is here contended that by "the action of natural selection" _only_ it is so improbable as to be practically impossible for two exactly similar structures to have ever been independently developed. it is so because the number of possible {67} variations is indefinitely great, and it is therefore an indefinitely great number to one against a similar series of variations occurring and being similarly preserved in any two independent instances. the difficulty here asserted applies, however, only to pure darwinism, which makes use _only_ of indirect modifications through the survival of the fittest. other theories (for example, that of mr. herbert spencer) admit the _direct_ action of conditions upon animals and plants--in ways not yet fully understood--there being conceived to be at the same time a certain peculiar but limited power of response and adaptation in each animal and plant so acted on. such theories have not to contend against the difficulty proposed, and it is here urged that even very complex extremely similar structures have again and again been developed quite independently one of the other, and this because the process has taken place not by merely haphazard, indefinite variations in all directions, but by the concurrence of some other and internal natural law or laws co-operating with external influences and with natural selection in the evolution of organic forms. it must never be forgotten that to admit any such constant operation of any such unknown natural cause is to deny the purely darwinian theory, which relies upon the survival of the fittest by means of minute fortuitous indefinite variations. amongst many other obligations which the author has to acknowledge to professor huxley, are the pointing out of this very difficulty, and the calling his attention to the striking resemblance between certain teeth of the dog and of the thylacine as one instance, and certain ornithic peculiarities of pterodactyles as another. mammals[51] are divisible into one great group, which comprises the {68} immense majority of kinds termed, from their mode of reproduction, _placental mammals_, and into another very much smaller group comprising the pouched-beasts or marsupials (which are the kangaroos, bandicoots, phalangers, &c., of australia), and the true opossums of america, called _implacental mammals_. now the placental mammals are subdivided into various orders, amongst which are the flesh-eaters (carnivora, _i.e._ cats, dogs, otters, weasels, &c.), and the insect-eaters (insectivora, _i.e._ moles, hedgehogs, shrew-mice, &c.). the marsupial mammals also present a variety of forms (some of which are carnivorous beasts, whilst others are insectivorous), so marked that it has been even proposed to divide them into orders parallel to the orders of placental beasts. the resemblance, indeed, is so striking as, on darwinian principles, to suggest the probability of genetic affinity; and it even led professor huxley, in his hunterian lectures, in 1866, to promulgate the notion that a vast and widely-diffused marsupial fauna may have existed anteriorly to the development of the ordinary placental, non-pouched beasts, and that the carnivorous, insectivorous, and herbivorous placentals may have respectively descended from the carnivorous, insectivorous, and herbivorous marsupials. [illustration: teeth of urotrichus and perameles.] amongst other points professor huxley called attention to the resemblance between the anterior molars of the placental dog with those of the marsupial thylacine. these, indeed, are strikingly similar, but there are better examples still of this sort of coincidence. thus it has often {69} been remarked that the insectivorous marsupials, _e.g. perameles_, wonderfully correspond, as to the form of certain of the grinding teeth, with certain insectivorous placentals, _e.g. urotrichus_. again, the saltatory insectivores of africa (_macroscelides_) not only resemble the kangaroo family (_macropodidæ_) in their jumping habits and long hind legs, but also in the structure of their molar teeth, and even further, as i have elsewhere[52] pointed out, in a certain similarity of the upper cutting teeth, or incisors. now these correspondences are the more striking when we bear in mind that a similar dentition is often put to very different uses. the food of different kinds of apes is very different, yet how uniform is their dental structure! again, who, looking at the teeth of different kinds of bears, would ever suspect that one kind was frugivorous, and another a devourer exclusively of animal food? the suggestion made by professor huxley was therefore one which had much to recommend it to darwinians, though it has not met with any notable acceptance, and though he seems himself to have returned to the older notion, namely, that the pouched-beasts, or marsupials, are a special ancient offshoot from the great mammalian class. but whichever view may be the correct one, we have in either case a number of forms similarly modified in harmony with surrounding conditions, and eloquently proclaiming some natural plastic power, other than mere fortuitous variation with survival of the fittest. if, however, the reader thinks that teeth are parts peculiarly qualified for rapid variation (in which view the author cannot concur), he is requested to suspend his judgment till he has considered the question of the independent evolution of the _highest organs of sense_. if this seems to establish the {70} existence of some other law than that of "natural selection," then the operation of that other law may surely be also traced in the harmonious co-ordinations of dental form. the other difficulty, kindly suggested to me by the learned professor, refers to the structure of birds, and of extinct reptiles more or less related to them. the class of birds is one which is remarkably uniform in its organization. so much is this the case, that the best mode of subdividing the class is a problem of the greatest difficulty. existing birds, however, present forms which, though closely resembling in the greater part of their structure, yet differ importantly the one from the other. one form is exemplified by the ostrich, rhea, emeu, cassowary, apteryx, dinornis, &c. these are the _struthious_ birds. all other existing birds belong to the second division, and are called (from the keel on the breast-bone) _carinate_ birds. now birds and reptiles have such and so many points in common, that darwinians must regard the former as modified descendants of ancient reptilian forms. but on darwinian principles it is impossible that the class of birds so uniform and homogeneous should have had a double reptilian origin. if one set of birds sprang from one set of reptiles, and another set of birds from another set of reptiles, the two sets could never, by "natural selection" only, have grown into such a perfect similarity. to admit such a phenomenon would be equivalent to abandoning the theory of "natural selection" as the sole origin of species. now, until recently it has generally been supposed by evolutionists that those ancient flying reptiles, the pterodactyles, or forms allied to them, were the progenitors of the class of birds; and certain parts of their structure especially support this view. allusion is here made to the bladebone (scapula), and the bone which passes down from the shoulder-joint to the breast-bone (viz. the coracoid). these bones are such remarkable anticipations of the same parts in ordinary (_i.e._ carinate) birds {71} that it is hardly possible for a darwinian not to regard the resemblance as due to community of origin. this resemblance was carefully pointed out by professor huxley in his "hunterian course" for 1867, when attention was called to the existence in _dimorphodon macronyx_ of even that small process which in birds gives attachment to the upper end of the merrythought. also mr. seeley[53] has shown that in pterodactyles, as in birds, the optic lobes of the brain were placed low down on each side--"lateral and depressed." nevertheless, the view has been put forward and ably maintained by the same professor,[54] as also by professor cope in the united states, that the line of descent from reptiles to birds has not been from ordinary reptiles, through pterodactyle-like forms, to ordinary birds, but to the struthious ones from certain extinct reptiles termed dinosauria; one of the most familiarly known of which is the iguanodon of the wealden formation. in these dinosauria we find skeletal characters unlike those of ordinary (_i.e._ carinate) birds, but closely resembling in certain points the osseous structure of the struthious birds. thus a difficulty presents itself as to the explanation of the three following relationships:--(1) that of the pterodactyles with carinate birds; (2) that of the dinosauria with struthious birds; (3) that of the carinate and struthious birds with each other. either birds must have had two distinct origins whence they grew to their present conformity, or the very same skeletal, and probably cerebral characters must have spontaneously and independently arisen. here is a dilemma, either horn of which bears a threatening aspect to the exclusive supporter of "natural selection," and between which it seems somewhat {72} difficult to choose. it has been suggested to me that this difficulty may be evaded by considering pterodactyles and carinate birds as independent branches from one side of an ancient common trunk, while similarly the dinosauria and struthious birds are taken to be independent branches from the other side of the same common trunk; the two kinds of birds resembling each other so much on account of their later development from that trunk as compared with the development of the reptilian forms. but to this it may be replied that the ancient common stock could not have had at one and the same time a shoulder structure of _both kinds_. it must have been that of the struthious birds or that of the carinate birds, or something different from both. if it was that of the struthious birds, how did the pterodactyles and carinate birds independently arrive at the very same divergent structure? if it was that of the carinate birds, how did the struthious birds and dinosauria independently agree to differ? finally, if it was something different from either, how did the carinate birds and pterodactyles take on independently one special common structure when disagreeing in so many; while the struthious birds, agreeing in many points with the dinosauria, agree yet more with the carinate birds? indeed by no arrangement of branches from a stem can the difficulty be evaded. professor huxley seems inclined[55] to cut the gordian knot by considering the shoulder structure of the pterodactyle as independently educed, and having relation to physiology only. this conception is one which harmonizes completely with the views here advocated, and with those of mr. herbert spencer, who also calls in direct modification to the aid of "natural selection." that merely minute, indefinite variations in all directions should unaided have independently built up the shoulder structure of {73} the pterodactyles and carinate birds, and have laterally depressed their optic lobes, at a time so far back as the deposition of the oolite strata,[56] is a coincidence of the highest improbability; but that an innate power and evolutionary law, aided by the corrective action of "natural selection," should have furnished like needs with like aids, is not at all improbable. the difficulty does not tell against the theory of evolution, but only against the specially darwinian form of it. now this form has never been expressly adopted by professor huxley; so far from it, in his lecture on this subject at the royal institution before referred to, he observes,[57] "i can testify, from personal experience, it is possible to have a complete faith in the general doctrine of evolution, and yet to hesitate in accepting the nebular, or the uniformitarian, or the darwinian hypotheses in all their integrity and fulness." [illustration: the archeopteryx (of the oolite strata).] it is quite consistent, then, in the professor to explain the {74} difficulty as he does; but it would not be similarly so with an absolute and pure darwinian. yet stronger arguments of an analogous kind are, however, to be derived from the highest organs of sense. in the most perfectly organized animals--those namely which, like ourselves, possess a spinal column--the internal organs of hearing consist of two more or less complex membranous sacs (containing calcareous particles--otoliths), which are primitively or permanently lodged in two chambers, one on each side of the cartilaginous skull. the primitive cartilaginous cranium supports and protects the base of the brain, and the auditory nerves pass from that brain into the cartilaginous chambers to reach the auditory sacs. these complex arrangements of parts could not have been evolved by "natural selection," _i.e._ by minute accidental variations, except by the action of such through a vast period of time; nevertheless, it was fully evolved at the time of the deposition of the upper silurian rocks. cuttle-fishes (_cephalopoda_) are animals belonging to the molluscous primary division of the animal kingdom, which division contains animals formed upon a type of structure utterly remote from that on which the animals of the higher division provided with a spinal column are constructed. and indeed no transitional form (tending even to bridge over the chasm between these two groups) has ever yet been discovered, either living or in a fossilized condition.[58] nevertheless, in the two-gilled cephalopods (_dibranchiata_) we find the brain supported and protected by a cartilaginous cranium. in the base of this cranium are two cartilaginous chambers. in each chamber is a membranous sac containing an otolith, and the auditory nerves pass from the cerebral ganglia into the cartilaginous chambers to reach the auditory sacs. moreover, it has been suggested by professor owen that {75} sinuosities between processes projecting from the inner wall of each chamber "seem to be the first rudiments of those which, in the higher classes (_i.e._ in animals with a spinal column), are extended in the form of canals and spiral chambers, within the substance of the dense nidus of the labyrinth."[59] [illustration: cuttle-fish. a. ventral aspect. b. dorsal aspect.] here, then, we have a wonderful coincidence indeed; two highly complex auditory organs, marvellously similar in structure, but which must nevertheless have been developed in entire and complete independence one of the other! it would be difficult to calculate the odds against the independent occurrence and conservation of two such complex series of merely accidental and minute haphazard variations. and it can never be {76} maintained that the sense of hearing could not be efficiently subserved otherwise than by such sacs, in cranial cartilaginous capsules so situated in relation to the brain, &c. our wonder, moreover, may be increased when we recollect that the two-gilled cephalopods have not yet been found below the lias, where they at once abound; whereas the four-gilled cephalopods are silurian forms. moreover, the absence is in this case significant in spite of the imperfection of the geological record, because when we consider how many individuals of various kinds of four-gilled cephalopods have been found, it is fair to infer that at the least a certain small percentage of dibranchs would also have left traces of their presence had they existed. thus it is probable that some four-gilled form was the progenitor of the dibranch cephalopods. now the four-gilled kinds (judging from the only existing form, the nautilus) had the auditory organ in a very inferior condition of development to what we find in the dibranch; thus we have not only evidence of the independent high development of the organ in the former, but also evidence pointing towards a certain degree of comparative rapidity in its development. such being the case with regard to the organ of hearing, we have another yet stronger argument with regard to the organ of sight, as has been well pointed out by mr. j. j. murphy.[60] he calls attention to the fact that the eye must have been perfected in at least "three distinct lines of descent," alluding not only to the molluscous division of the animal kingdom, and the division provided with a spinal column, but also to a third primary division, namely, that which includes all insects, spiders, crabs, &c., which are spoken of as annulosa, and the type of whose structure is as distinct from that of the molluscous type on the one hand, as it is from that of the type with a spinal column (_i.e._ the vertebrate type) on the other. {77} in the cuttle-fishes we find an eye even more completely constructed on the vertebrate type than is the ear. sclerotic, retina, choroid, vitreous humour, lens, aqueous humour, all are present. the correspondence is wonderfully complete, and there can hardly be any hesitation in saying that for such an exact, prolonged, and correlated series of similar structures to have been brought about in two independent instances by merely indefinite and minute accidental variations, is an improbability which amounts practically to impossibility. moreover, we have here again the same imperfection of the four-gilled cephalopod, as compared with the two-gilled, and therefore (if the latter proceeded from the former) a similar indication of a certain comparative rapidity of development. finally, and this is perhaps one of the most curious circumstances, the process of formation appears to have been, at least in some respects, the same in the eyes of these molluscous animals as in the eyes of vertebrates. for in these latter the cornea is at first perforated, while different degrees of perforation of the same part are presented by different adult cuttle-fishes--large in the calamaries, smaller in the octopods, and reduced to a minute foramen in the true cuttle-fish sepia. some may be disposed to object that the conditions requisite for effecting vision are so rigid that similar results in all cases must be independently arrived at. but to this objection it may well be replied that nature herself has demonstrated that there is no such necessity as to the details of the process. for in the higher annulosa, such as the dragon-fly, we meet with an eye of an unquestionably very high degree of efficiency, but formed on a type of structure only remotely comparable with that of the fish or the cephalopod. the last-named animal might have had an eye as efficient as that of a vertebrate, but formed on a distinct type, instead of being another edition, as it were, of the very same structure. in the beginning of this chapter examples have been given of the very {78} diverse mode in which similar results have in many instances been arrived at; on the other hand, we have in the fish and the cephalopod not only the eye, but at one and the same time the ear also similarly evolved, yet with complete independence. thus it is here contended that the similar and complex structures of both the highest organs of sense, as developed in the vertebrates on the one hand, and in the mollusks on the other, present us with residuary phenomena for which "natural selection" alone is quite incompetent to account. and that these same phenomena must therefore be considered as conclusive evidence for the action of some other natural law or laws conditioning the simultaneous and independent evolution of these harmonious and concordant adaptations. provided with this evidence, it may be now profitable to enumerate other correspondences, which are not perhaps in themselves inexplicable by natural selection, but which are more readily to be explained by the action of the unknown law or laws referred to--which action, as its necessity has been demonstrated in one case, becomes _a priori_ probable in the others. [illustration: skeleton of an ichthyosaurus.] thus the great oceanic mammalia--the whales--show striking resemblances to those prodigious, extinct, marine reptiles, the ichthyosauria, and this not only in structures readily referable to similarity of habit, but in such matters as greatly elongated premaxillary bones, together with the concealment of certain bones of the skull by other cranial bones. [page 79] again, the aërial mammals, the bats, resemble those flying reptiles of the secondary epoch, the pterodactyles; not only to a certain extent in the breast-bone and mode of supporting the flying membrane, but also in the proportions of different parts of the spinal column and the hinder (pelvic) limbs. also bivalve shell-fish (_i.e._ creatures of the mussel, cockle, and oyster class, which receive their name from the body being protected by a double shell, one valve of which is placed on each side) have their two shells united by one or two powerful muscles, which pass directly across from one shell to the other, and which are termed "adductor muscles" because by their contraction they bring together the valves and so close the shell. [illustration: cytheridea torosa. [an ostracod (crustacean), externally like a bivalve shell-fish (lamellibranch).] now there are certain animals which belong to the crab and lobster class (crustacea)--a class constructed on an utterly different type from that on which the bivalve shell-fish are constructed--which present a very curious approximation to both the form and, in a certain respect, the structure of true bivalves. allusion is here made to certain small crustacea--certain phyllopods and ostracods--which have the hard outer coat of their thorax so modified as to look wonderfully like a bivalve shell, although its {80} nature and composition are quite different. but this is by no means all,--not only is there this external resemblance between the thoracic armour of the crustacean and the bivalve shell, but the two sides of the ostracod and phyllopod thorax are connected together also by an adductor muscle! [illustration: a polyzoon with bird's-head processes.] {81} the pedicellariæ of the echinus have been already spoken of, and the difficulty as to their origin from minute, fortuitous, indefinite variations has been stated. but structures essentially similar (called avicularia, or "bird's-head processes") are developed from the surface of the compound masses of certain of the highest of the polyp-like animals (viz. the polyzoa or, as they are sometimes called, the bryozoa). these compound animals have scattered over the surface of their bodies minute processes, each of which is like the head of a bird, with an upper and lower beak, the whole supported on a slender neck. the beak opens and shuts at intervals, like the jaws of the pedicellariæ of the echinus, and there is altogether, in general principle, a remarkable similarity between the structures. yet the echinus can have, at the best, none but the most distant genetic relationship with the polyzoa. we have here again therefore complex and similar organs of diverse and independent origin. [illustration: bird's-head processes very greatly enlarged.] in the highest class of animals (the mammalia) we have almost always a placental mode of reproduction, _i.e._ the blood of the foetus is placed in nutritive relation with the blood of the mother by means of vascular prominences. no trace of such a structure exists in any bird or in any reptile, and yet it crops out again in certain sharks. there indeed it might well be supposed to end, but, marvellous as it seems, it reappears in very lowly creatures; namely, in certain of the ascidians, sometimes called tunicaries or sea-squirts. [page 82] now, if we were to concede that the ascidians were the common ancestors[61] of both these sharks and of the higher mammals, we should be little, if any, nearer to an explanation of the phenomenon by means of "natural selection," for in the sharks in question the vascular prominences are developed from one foetal structure (the umbilical vesicle), while in the higher mammals they are developed from quite another part, viz. the allantois. [illustration: upper figure--antechinus minutissimus (_implacental_). lower figure--mus delicatulus (_placental_).] so great, however, is the number of similar, but apparently independent, structures, that we suffer from a perfect _embarras de richesses_. thus, for example, we have the convoluted windpipe of the sloth, reminding us{83} of the condition of the windpipe in birds; and in another mammal, allied to the sloth, namely the great ant-eater (myrmecophaga), we have again an ornithic character in its horny gizzard-like stomach. in man and the highest apes the cæcum has a vermiform appendix, as it has also in the wombat! also the similar forms presented by the crowns of the teeth in some seals, in certain sharks, and in some extinct cetacea may be referred to; as also the similarity of the beak in birds, some reptiles, in the tadpole, and cuttle-fishes. as to entire external form, may be adduced the wonderful similarity between a true mouse (_mus delicatulus_) and a small marsupial, pointed out by mr. andrew murray in his work on the "geographical distribution of mammals," p. 53, and represented in the frontispiece by figures copied from gould's "mammals of australia;" but instances enough for the present purpose have been already quoted. additional reasons for believing that similarity of structure is produced by other causes than merely by "natural selection" are furnished by certain facts of zoological geography, and by a similarity in the mode of variation being sometimes extended to several species of a genus, or even to widely different groups; while the restriction and the limitation of such similarity are often not less remarkable. thus mr. wallace says,[62] as to local influence: "larger or smaller districts, or even single islands, give a special character to the majority of their papilionidæ. for instance:--1. the species of the indian region (sumatra, java, and borneo) are almost invariably smaller than the allied species inhabiting celebes and the moluccas. 2. the species of new guinea and australia are also, though in a less degree, smaller than the nearest species or varieties of the moluccas. 3. in the moluccas themselves the species of amboyna are the largest. 4. the species of celebes equal or even surpass in size those of amboyna. {84} 5. the species and varieties of celebes possess a striking character in the form of the anterior wings, different from that of the allied species and varieties of all the surrounding islands. 6. tailed species in india or the indian region become tailless as they spread eastward through the archipelago. 7. in amboyna and ceram the females of several species are dull-coloured, while in the adjacent islands they are more brilliant." again:[63] "in amboyna and ceram the female of the large and handsome _ornithoptera helena_ has the large patch on the hind wings constantly of a pale dull ochre or buff colour; while in the scarcely distinguishable varieties from the adjacent islands, of bouru and new guinea, it is of a golden yellow, hardly inferior in brilliancy to its colour in the male sex. the female of _ornithoptera priamus_ (inhabiting amboyna and ceram exclusively) is of a pale dusky brown tint, while in all the allied species the same sex is nearly black, with contracted white markings. as a third example, the female of _papilio ulysses_ has the blue colour obscured by dull and dusky tints, while in the closely allied species from the surrounding islands, the females are of almost as brilliant an azure blue as the males. a parallel case to this is the occurrence, in the small islands of goram, matabello, ké, and aru, of several distinct species of euploea and diadema, having broad bands or patches of white, which do not exist in any of the allied species from the larger islands. these facts seem to indicate some local influence in modifying colour, as unintelligible and almost as remarkable as that which has resulted in the modifications of form previously described." after endeavouring to explain some of the facts in a way to be noticed directly, mr. wallace adds:[64] "but even the conjectural explanation now given fails us in the other cases of local modification. why the species of the western islands should be smaller than those further east; why those of amboyna should exceed in size those of gilolo and new guinea; why the {85} tailed species of india should begin to lose that appendage in the islands, and retain no trace of it on the borders of the pacific; and why, in three separate cases, the females of amboyna species should be less gaily attired than the corresponding females of the surrounding islands, are questions which we cannot at present attempt to answer. that they depend, however, on some general principle is certain, because analogous facts have been observed in other parts of the world. mr. bates informs me that, in three distinct groups, papilios, which, on the upper amazon, and in most other parts of south america, have spotless upper wings, obtain pale or white spots at pará and on the lower amazon, and also that the æneas group of papilios never have tails in the equatorial regions and the amazon valley, but gradually acquire tails in many cases as they range towards the northern or southern tropic. even in europe we have somewhat similar facts, for the species and varieties of butterflies peculiar to the island of sardinia are generally smaller and more deeply coloured than those of the mainland, and the same has been recently shown to be the case with the common tortoiseshell butterfly in the isle of man; while _papilio hospiton_, peculiar to the former island, has lost the tail, which is a prominent feature of the closely allied _p. machaon_. "facts of a similar nature to those now brought forward would no doubt be found to occur in other groups of insects, were local faunas carefully studied in relation to those of the surrounding countries; and they seem to indicate that climate and other physical causes have, in some cases, a very powerful effect in modifying specific form and colour, and thus directly aid in producing the endless variety of nature." [illustration: outlines of wings of butterflies of celebes compared with those of allied species elsewhere. outer outline, _papilio gigon_, of celebes. inner outline, _p. demolion_, of singapore and java.--2. outer outline, _p. miletus_, of celebes. inner outline, _p. sarpedon_, india.--3. outer outline, _tachyris zarinda_, celebes. inner outline, _t. nero_.] with regard to butterflies of celebes belonging to different families, they present "a peculiarity of outline which distinguishes them at a glance from those of any other part of the world:"[65] it is that the upper wings {86} are generally more elongated and the anterior margin more curved. moreover, there is, in most instances, near the base an abrupt bend or elbow, which in some species is very conspicuous. mr. wallace endeavours to explain {87} this phenomenon by the supposed presence at some time of special persecutors of the modified forms, supporting the opinion by the remark that small, obscure, very rapidly flying and mimicked kinds have not had the wing modified. such an enemy occasioning increased powers of flight, or rapidity in turning, he adds, "one would naturally suppose to be an insectivorous bird; but it is a remarkable fact that most of the genera of fly-catchers of borneo and java on the one side, and of the moluccas on the other, are almost entirely absent from celebes. their place seems to be supplied by the caterpillar-catchers, of which six or seven species are known from celebes, and are very numerous in individuals. we have no positive evidence that these birds pursue butterflies on the wing, but it is highly probable that they do so when other food is scarce. mr. bates suggested to me that the larger dragon-flies prey upon butterflies, but i did not notice that they were more abundant in celebes than elsewhere."[66] now, every opinion or conjecture of mr. wallace is worthy of respectful and attentive consideration, but the explanation suggested and before referred to hardly seems a satisfactory one. what the past fauna of celebes may have been is as yet conjectural. mr. wallace tells us that now there is a remarkable _scarcity_ of fly-catchers, and that their place is supplied by birds of which it can only be said that it is "highly probable" that they chase butterflies "when other food is scarce." the quick eye of mr. wallace failed to detect them in the act, as also to note any unusual abundance of other insectivorous forms, which therefore, considering mr. wallace's zeal and powers of observation, we may conclude do not exist. moreover, even if there ever has been an abundance of such, it is by no means certain that they would have succeeded in producing the conformation in question, for the effect of this peculiar curvature on flight is by no means clear. we have here, then, a structure hypothetically explained by an uncertain {88} property induced by a cause the presence of which is only conjectural. surely it is not unreasonable to class this instance with the others before given, in which a common modification of form or colour coexists with a certain geographical distribution quite independently of the destructive agencies of animals. if physical causes connected with locality can abbreviate or annihilate the tails of certain butterflies, why may not similar causes produce an elbow-like prominence on the wings of other butterflies? there are many such instances of simultaneous modification. mr. darwin himself[67] quotes mr. gould as believing that birds of the same species are more brightly coloured under a clear atmosphere, than when living on islands or near the coast. mr. darwin also informs us that wollaston is convinced that residence near the sea affects the colour of insects; and finally, that moquin-tandon gives a list of plants which, when growing near the sea-shore, have their leaves in some degree fleshy, though not so elsewhere. in his work on "animals and plants under domestication,"[68] mr. darwin refers to m. costa as having (in _bull. de la soc. imp. d'acclimat_. tome viii. p. 351) stated "that young shells taken from the shores of england and placed in the mediterranean at once altered their manner of growth, and formed prominent diverging rays _like those on the shells of the proper mediterranean oyster_;" also to mr. meehan, as stating (_proc. acad. nat. sc. of philadelphia_, jan. 28, 1862) "that twenty-nine kinds of american trees all differ from their nearest european allies in _a similar manner_, leaves less toothed, buds and seeds smaller, fewer branchlets," &c. these are striking examples indeed! but cases of simultaneous and similar modifications abound on all sides. even as regards our own species there is a very generally admitted opinion that a new type has been developed in the united states, and this in about a couple of centuries only, and in a vast multitude of individuals of {89} diverse ancestry. the instances here given, however, must suffice, though more could easily be added. [illustration: the great shielded grasshopper.] it may be well now to turn to groups presenting similar variations, not through, but independently of, geographical distribution, and, as far as we know, independently of conditions other than some peculiar nature and tendency (as yet unexplained) common to members of such groups, which nature and tendency seem to induce them to vary in certain definite lines or directions which are different in different groups. thus with regard to the group of insects, of which the walking leaf is a member, mr. wallace observes:[69] "the _whole family_[70] of the phasmidæ, or spectres, to which this insect belongs, is more or less imitative, and a great number of the species are called 'walking-stick insects,' from their singular {90} resemblance to twigs and branches." [illustration: the six-shafted bird of paradise.] again, mr. wallace[71] tells us of no less than four kinds of orioles, which birds mimic, more or less, four species of a genus of honey-suckers, the weak orioles finding their profit in being mistaken by certain birds of prey for the strong, active, and gregarious honey-suckers. now, many other birds would be benefited by similar mimicry, which is none the less confined, in this part of the world, to the oriole genus. it is true that the absence of mimicry in other forms may be explained by their possessing some other (as yet unobserved) means of preservation. but it is nevertheless remarkable, not so much that one species should mimic, as that no less than four should do so in different ways and degrees, all these{91} four belonging to _one and the same genus_. [illustration: the long-tailed bird of paradise.] in other cases, however, there is not even the help of protective action to account for the phenomenon. thus we have the wonderful birds of paradise,[72] which agree in developing plumage unequalled in beauty, but a beauty which, as to details, is of different kinds, and produced in different ways in different species. to develop "beauty and singularity of plumage" is a character of the group, but not of any one definite kind, to be explained merely by inheritance. {92} [illustration] again, we have the very curious horned flies,[73] which agree indeed in a common peculiarity, but in one singularly different in detail, in different species and not known to have any protecting effect. amongst plants, also, we meet with the same peculiarity. the great group of orchids presents a number of species which offer strange and bizarre {93} approximations to different animal forms, and which have often the appearance of cases of mimicry, as it were in an incipient stage. [illustration: horned flies.] [illustration: the magnificent bird of paradise.] the number of similar instances which could be brought forward from amongst animals and plants is very great, but the examples given are, it is {94} hoped, amply sufficient to point towards the conclusion which other facts will, it is thought, establish, viz. that there are causes operating (in the evocation of these harmonious diverging resemblances) other than "natural selection," or heredity, and other even than merely geographical, climatal, or any simply external conditions. many cases have been adduced of striking likenesses between different animals, not due to inheritance; but this should be the less surprising, in that the very same individual presents us with likenesses between different parts of its body (_e.g._, between the several joints of the backbone), which are certainly not so explicable. this, however, leads to a rather large subject, which will be spoken of in the eighth chapter of the present work. here it will be enough to affirm (leaving the proof of the assertion till later) that parts are often homologous which have no direct genetic relationship,--a fact which harmonizes well with the other facts here given, but which "natural selection," pure and simple, seems unable to explain. but surely the independent appearance of similar organic forms is what we might expect, _a priori_, from the independent appearance of similar inorganic ones. as mr. g. h. lewes well observes,[74] "we do not suppose the carbonates and phosphates found in various parts of the globe--we do not suppose that the families of alkaloids and salts have any nearer kinship than that which consists in the similarity of their elements, and the conditions of their combination. hence, in organisms, as in salts, morphological identity may be due to a community of causal connexion, rather than community of descent. "mr. darwin justly holds it to be incredible that individuals identically the same should have been produced through natural selection from parents _specifically distinct_, but he will not deny that identical forms may issue from parents _genetically distinct_, when these parent forms and {95} the conditions of production are identical. to deny this would be to deny the law of causation." professor huxley has, however, suggested[75] that such mineral identity may be explained by applying also to minerals a law of descent; that is, by considering such similar forms as the descendants of atoms which inhabited one special part of the primitive nebular cosmos, each considerable space of which may be supposed to have been under the influence of somewhat different conditions. surely, however, there can be no real parity between the relationship of existing minerals to nebular atoms, and the relationship of existing animals and plants to the earliest organisms. in the first place, the latter have produced others by generative multiplication, which mineral atoms never did. in the second, existing animals and plants spring from the living tissues of preceding animals and plants, while existing minerals spring from the chemical affinity of separate elements. carbonate of soda is not formed, by a process of reproduction, from other carbonate of soda, but directly by the suitable juxtaposition of carbon, oxygen, and sodium. instead of approximating animals and minerals in the mode suggested, it may be that they are to be approximated in quite a contrary fashion; namely, by attributing to mineral species an internal innate power. for, as we must attribute to each elementary atom an innate power and tendency to form (under the requisite external conditions) certain unions with other atoms, so we may attribute to certain mineral species--as crystals--an innate power and tendency to exhibit (the proper conditions being supplied) a definite and symmetrical external form. the distinction between animals and vegetables on the one hand, and minerals on the other, is that, while in the organic world close similarity is the result sometimes of inheritance, sometimes of direct production independently of parental action, in the{96} inorganic world the latter is the constant and only mode in which such similarity is produced. when we come to consider the relations of species to space--in other words, the geographical distribution of organisms--it will be necessary to return somewhat to the subject of the independent origin of closely similar forms, in regard to which some additional remarks will be found towards the end of the seventh chapter. in this third chapter an effort has been made to show that while on the darwinian theory concordant variations are extremely improbable, yet nature presents us with abundant examples of such; the most striking of which are, perhaps, the higher organs of sense. also that an important influence is exercised by conditions connected with geographical distribution, but that a deeper-seated influence is at work, which is hinted at by those special tendencies in definite directions, which are the properties of certain groups. finally, that these facts, when taken together, afford strong evidence that "natural selection" has not been the exclusive or predominant cause of the various organic structural peculiarities. this conclusion has also been re-enforced by the consideration of phenomena presented to us by the inorganic world. [page 97] * * * * * chapter iv. minute and gradual modifications. there are difficulties as to minute modifications, even if not fortuitous.--examples of sudden and considerable modifications of different kinds.--professor owen's view.--mr. wallace.--professor huxley.--objections to sudden changes.--labyrinthodont.--potto.--cetacea.--as to origin of bird's wing.--tendrils of climbing plants.--animals once supposed to be connecting links.--early specialization of structure.--macrauchenia.--glyptodon.--sabre-toothed tiger.--conclusion. not only are there good reasons against the acceptance of the exclusive operation of "natural selection" as the one means of specific origination, but there are difficulties in the way of accounting for such origination by the sole action of modifications which are infinitesimal and minute, whether fortuitous or not. arguments may yet be advanced in favour of the view that new species have from time to time manifested themselves with suddenness, and by modifications appearing at once (as great in degree as are those which separate _hipparion_ from _equus_), the species remaining stable in the intervals of such modifications: by stable being meant that their variations only extend for a certain degree in various directions, like oscillations in a stable equilibrium. this is the conception of mr. galton,[76] who compares the development of species with a many {98} facetted spheroid tumbling over from one facet, or stable equilibrium, to another. the existence of internal conditions in animals corresponding with such facets is denied by pure darwinians, but it is contended in this work, though not in this chapter, that something may also be said for their existence. the considerations brought forward in the last two chapters, namely, the difficulties with regard to incipient and closely similar structures respectively, together with palæontological considerations to be noticed later, appear to point strongly in the direction of sudden and considerable changes. this is notably the case as regards the young oysters already mentioned, which were taken from the shores of england and placed in the mediterranean, and at once altered their mode of growth and formed prominent diverging rays, _like those of the proper mediterranean oyster_; as also the twenty-nine kinds of american trees, all differing from their nearest european allies _similarly_--"leaves less toothed, buds and seeds smaller, fewer branchlets," &c. to these may be added other facts given by mr. darwin. thus he says, "that climate, to a certain extent, directly modifies the form of dogs."[77] the rev. r. everett found that setters at delhi, though most carefully paired, yet had young with "nostrils more contracted, noses more pointed, size inferior, and limbs more slender." again, cats at mombas, on the coast of africa, have short stiff hairs instead of fur, and a cat at algoa bay, when left only eight weeks at mombas, "underwent a complete metamorphosis, having parted with its sandy-coloured fur."[78] the conditions of life seem to produce a considerable effect on horses, and instances are given by mr. darwin of pony breeds[79] having independently arisen in different parts of the world, possessing a certain similarity in their physical {99} conditions. also changes due to climate may be brought about at once in a second generation, though no appreciable modification is shown by the first. thus "sir charles lyell mentions that some englishmen, engaged in conducting the operations of the real del monte company in mexico, carried out with them some greyhounds of the best breed to hunt the hares which abound in that country. it was found that the greyhounds could not support the fatigues of a long chase in this attenuated atmosphere, and before they could come up with their prey they lay down gasping for breath; but these same animals have produced whelps, which have grown up, and are not in the least degree incommoded by the want of density in the air, but run down the hares with as much ease as do the fleetest of their race in this country."[80] we have here no action of "natural selection;" it was not that certain puppies happened accidentally to be capable of enduring more rarefied air, and so survived, but the offspring were directly modified by the action of surrounding conditions. neither was the change elaborated by minute modifications in many successive generations, but appeared at once in the second. with regard once more to sudden alterations of form, nathusius is said to state positively as to pigs,[81] that the result of common experience and of his experiments was that rich and abundant food, given during youth, tends by some direct action to make the head broader and shorter. curious jaw appendages often characterize normandy pigs, according to m. eudes deslongchamps. richardson figures these appendages on the old "irish greyhound pig," and they are said by nathusius to appear occasionally in all the long-eared races. mr. darwin observes,[82] "as no wild pigs are known to have analogous appendages, we have at present no reason to {100} suppose that their appearance is due to reversion; and if this be so, we are forced to admit that somewhat complex, though apparently useless structures may be suddenly developed without the aid of selection." again, "climate directly affects the thickness of the skin and hair" of cattle.[83] in the english climate an individual porto santo rabbit[84] recovered the proper colour of its fur in rather less than four years. the effect of the climate of india on the turkey is considerable. mr. blyth[85] describes it as being much degenerated in size, "utterly incapable of rising on the wing," of a black colour, and "with long pendulous appendages over the beak enormously developed." mr. darwin again tells us that there has suddenly appeared in a bed of common broccoli a peculiar variety, faithfully transmitting its newly acquired and remarkable characters;[86] also that there have been a rapid transformation and transplantation of american varieties of maize with a european variety;[87] that certainly "the ancon and manchamp breeds of sheep," and that (all but certainly) niata cattle, turnspit and pug dogs, jumper and frizzled fowls, short-faced tumbler pigeons, hook-billed ducks, &c., and a multitude of vegetable varieties, have suddenly appeared in nearly the same state as we now see them.[88] lastly, mr. darwin tells us, that there has been an occasional development (in five distinct cases) in england of the "japanned" or "black-shouldered peacock" (_pavo nigripennis_), a distinct species, according to dr. sclater,[89] yet arising in sir j. trevelyan's flock composed entirely of the common kind, and increasing, "_to the extinction of the previously existing breed_."[90] mr. darwin's only explanation of the phenomena (on the supposition of the species being distinct) is by{101} reversion, owing to a supposed ancestral cross. but he candidly admits, "i have heard of no other such case in the animal or vegetable kingdom." on the supposition of its being only a variety, he observes, "the case is the most remarkable ever recorded of the abrupt appearance of a new form, which so closely resembles a true species, that it has deceived one of the most experienced of living ornithologists." as to plants, m. c. naudin[91] has given the following instances of the sudden origination of apparently permanent forms. "the first case mentioned is that of a poppy, which took on a remarkable variation in its fruit--a crown of secondary capsules being added to the normal central capsule. a field of such poppies was grown, and m. göppert, with seed from this field, obtained still this monstrous form in great quantity. deformities of ferns are sometimes sought after by fern-growers. they are now always obtained by taking spores from the abnormal parts of the monstrous fern; from which spores ferns presenting the same peculiarities invariably grow.... the most remarkable case is that observed by dr. godron, of nancy. in 1861 that botanist observed, amongst a sowing of _datura tatula_, the fruits of which are very spinous, a single individual of which the capsule was perfectly smooth. the seeds taken from this plant all furnished plants having the character of this individual. the fifth and sixth generations are now growing without exhibiting the least tendency to revert to the spinous form. more remarkable still, when crossed with the normal _datura tatula_, hybrids were produced, which, in the second generation, reverted to the original types, as true hybrids do." there are, then, abundant instances to prove that considerable {102} modifications may suddenly develop themselves, either due to external conditions or to obscure internal causes in the organisms which exhibit them. moreover, these modifications, from whatever cause arising, are capable of reproduction--the modified individuals "breeding true." the question is whether new species have been developed by non-fortuitous variations which are insignificant and minute, or whether such variations have been comparatively sudden, and of appreciable size and importance? either hypothesis will suit the views here maintained equally well (those views being opposed only to fortuitous, indefinite variations), but the latter is the more remote from the darwinian conception, and yet has much to be said in its favour. professor owen considers, with regard to specific origination, that natural history "teaches that the change would be sudden and considerable: it opposes the idea that species are transmitted by minute and slow degrees."[92] "an innate tendency to deviate from parental type, operating through periods of adequate duration," being "the most probable nature, or way of operation of the secondary law, whereby species have been derived one from the other."[93] now, considering the number of instances adduced of sudden modifications in domestic animals, it is somewhat startling to meet with mr. darwin's dogmatic assertion that it is "a _false belief_" that natural species have often originated in the same abrupt manner. the belief _may_ be false, but it is difficult to see how its falsehood can be positively asserted. it is demonstrated by mr. darwin's careful weighings and measurements, that, though little used parts in domestic animals get reduced in weight and somewhat in size, yet that they show no inclination to become truly "rudimentary structures." accordingly he asserts[94] that such {103} rudimentary parts are formed "suddenly, by arrest of development" in domesticated animals, but in wild animals slowly. the latter assertion, however, is a _mere assertion_; necessary, perhaps, for the theory of "natural selection," but as yet unproved by facts. but why should not these changes take place suddenly in a state of nature? as mr. murphy says,[95] "it may be true that we have no evidence of the origin of wild species in this way. but this is not a case in which negative evidence proves anything. we have never witnessed the origin of a wild species by any process whatever; and if a species were to come suddenly into being in the wild state, as the ancon sheep did under domestication, how could you ascertain the fact? if the first of a newly-begotten species were found, the fact of its discovery would tell nothing about its origin. naturalists would register it as a very rare species, having been only once met with, but they would have no means of knowing whether it were the first or the last of its race." to this mr. wallace has replied (in his review of mr. murphy's work in _nature_[96]), by objecting that sudden changes could very rarely be useful, because each kind of animal is a nicely balanced and adjusted whole, any one sudden modification of which would in most cases be hurtful unless accompanied by other simultaneous and harmonious modifications. if, however, it is not unlikely that there is an innate tendency to deviate at certain times, and under certain conditions, it is no more unlikely that that innate tendency should be an harmonious one, calculated to simultaneously adjust the various parts of the organism to their new relations. the objection as to the sudden abortion of rudimentary organs may be similarly met. professor huxley seems now disposed to accept the, at least {104} occasional, intervention of sudden and considerable variations. in his review of professor kölliker's[97] criticisms, he himself says,[98] "we greatly suspect that she" (_i.e._ nature) "does make considerable jumps in the way of variation now and then, and that these saltations give rise to some of the gaps which appear to exist in the series of known forms." [illustration: much enlarged horizontal section of the tooth of a labyrinthodon.] in addition to the instances brought forward in the second chapter against the minute action of natural selection, may be mentioned such {105} structures as the wonderfully folded teeth of the labyrinthodonts. the marvellously complex structure of these organs is not merely unaccountable as due to natural "selection," but its production by insignificant increments of complexity is hardly less difficult to comprehend. similarly the aborted index of the potto (_perodicticus_) is a structure not likely to have been induced by minute changes; while, as to "natural selection," the reduction of the fore-finger to a mere rudiment is inexplicable indeed! "how this mutilation can have aided in the struggle for life, we must confess, baffles our conjectures on the subject; for that any very appreciable gain to the individual can have resulted from the slightly lessened degree of required nourishment thence resulting (_i.e._ from the suppression), seems to us to be an almost absurd proposition."[99] [illustration: hand of the potto (perodicticus), from life.] again, to anticipate somewhat, the great group of whales (cetacea) was fully developed at the deposition of the eocene strata. on the other hand, we may pretty safely conclude that these animals were absent as late as the latest secondary rocks, so that their development could not have been so very slow, unless geological time is (although we shall presently see there are grounds to believe it is not) practically infinite. it is quite true that it is, in general, very unsafe to infer the absence of any animal forms during a certain geological period, because no remains of them {106} have as yet been found in the strata then deposited: but in the case of the cetacea it is safe to do so; for, as sir charles lyell remarks,[100] they are animals, the remains of which are singularly likely to have been preserved had they existed, in the same way that the remains were preserved of the ichthyosauri and plesiosauri, which appear to have represented the cetacea during the secondary geological period. [illustration: skeleton of a plesiosaurus.] as another example, let us take the origin of wings, such as exist in birds. here we find an arm, the bones of the hand of which are atrophied and reduced in number, as compared with those of most other vertebrates. now, if the wing arose from a terrestrial or subaërial organ, this abortion of the bones could hardly have been serviceable--hardly have preserved individuals in the struggle for life. if it arose from an aquatic organ, like the wing of the penguin, we have then a singular divergence from the ordinary vertebrate fin-limb. in the ichthyosaurus, in the plesiosaurus, in the whales, in the porpoises, in the seals, and in others, we have shortening of the bones, but no reduction in the number either of the fingers or of their joints, which are, on the contrary, multiplied in cetacea and the ichthyosaurus. and even in the turtles we have eight carpal bones and five digits, while no finger has less than two phalanges. it{107} is difficult, then, to believe that the avian limb was developed in any other way than by a comparatively sudden modification of a marked and important kind. [illustration: skeleton of an ichthyosaurus.] how, once more, can we conceive the peculiar actions of the tendrils of some climbing plants to have been produced by minute modifications? these, according to mr. darwin,[101] oscillate till they touch an object, and then embrace it. it is stated by that observer, "that a thread weighing no more than the thirty-second of a grain, if placed on the tendril of the _passiflora gracilis_, will cause it to bend; and merely to touch the tendril with a twig causes it to bend; but if the twig is at once removed, the tendril soon straightens itself. but the contact of other tendrils of the plant, or of the falling of drops of rain, do not produce these effects."[102] but some of the zoological and anatomical discoveries of late years tend rather to diminish than to augment the evidence in favour of minute and gradual modification. thus all naturalists now admit that certain animals, which were at one time supposed to be connecting links between groups, belong altogether to one group, and not at all to the other. for example, the aye-aye[103] (_chiromys madagascariensis_). {108} was till lately considered to be allied to the squirrels, and was often classed with them in the rodent order, principally on account of its dentition; at the same time that its affinities to the lemurs and apes were admitted. the thorough investigation into its anatomy that has now been made, demonstrates that it has no more essential affinity to rodents than any other lemurine creature has. [illustration: the aye-aye.] bats were, by the earliest observers, naturally supposed to have a close relationship to birds, and cetaceans to fishes. it is almost superfluous to observe that all now agree that these mammals make not even an approach to either one or other of the two inferior classes. {109} in the same way it has been recently supposed that those extinct flying saurians, the pterodactyles, had an affinity with birds more marked than any other known animals. now, however, as has been said earlier, it is contended that not only had they no such close affinity, but that other extinct reptiles had a far closer one. the _amphibia_ (_i.e._ frogs, toads, and efts) were long considered (and are so still by some) to be reptiles, showing an affinity to fishes. it now appears that they form with the latter one great group--the ichthyopsida of professor huxley--which differs widely from reptiles; while its two component classes (fishes and amphibians) are difficult to separate from each other in a thoroughly satisfactory manner. if we admit the hypothesis of gradual and minute modification, the succession of organisms on this planet must have been a progress from the more general to the more special, and no doubt this has been the case in the majority of instances. yet it cannot be denied that some of the most recently formed fossils show a structure singularly more generalized than any exhibited by older forms; while others are more specialized than are any allied creatures of the existing creation. a notable example of the former circumstance is offered by macrauchenia--a hoofed animal, which was at first supposed to be a kind of great llama (whence its name)--the llama being a ruminant, which, like all the rest, has two toes to each foot. now hoofed animals are divisible into two very distinct series, according as the number of functional toes on each hind foot is odd or even. and many other characters are found to go with this obvious one. even the very earliest ungulata show this distinction, which is completely developed and marked even in the eocene palæotherium and anoplotherium found in paris by cuvier. the former of these has the toes odd (perissodactyle), the other has them even (artiodactyle). now, the macrauchenia, from the first relics of it which were found, {110} was thought to belong, as has been said, to the even-toed division. subsequent discoveries, however, seemed to give it an equal claim to rank amongst the perissodactyle forms. others again inclined the balance of probability towards the artiodactyle. finally, it appears that this very recently extinct beast presents a highly generalized type of structure, uniting in one organic form both artiodactyle and perissodactyle characters, and that in a manner not similarly found in any other known creature living, or fossil. at the same time the differentiation of artiodactyle and perissodactyle forms existed as long ago as in the period of the eocene ungulata, and that in a marked degree, as has been before observed. again, no armadillo _now living_ presents nearly so remarkable a speciality of structure as was possessed by the _extinct_ glyptodon. in that singular animal the spinal column had most of its joints fused together, forming a rigid cylindrical rod, a modification, as far as yet known, absolutely peculiar to it. [illustration: dentition of the sabre-toothed tiger (machairodus).] in a similar way the _extinct_ machairodus, or sabre-toothed tiger, is characterized by a more highly differentiated and specially carnivorous dentition than is shown by any predacious beast of the _present day_. {111} the specialization is of this kind. the grinding teeth (or molars) of beasts are divided into premolars and true molars. the premolars are molars which have deciduous vertical predecessors (or milk teeth), and any which are in front of such, _i.e._ between such and the canine tooth. the true molars are those placed behind the molars having deciduous vertical predecessors. now, as a dentition becomes more distinctly carnivorous, so the hindmost molars and the foremost premolars disappear. in the existing cats this process is carried so far that in the upper jaw only one true molar is left on each side. in the machairodus there is no upper true molar at all, while the premolars are reduced to two, there being only these two teeth above, on each side, behind the canine. now, with regard to these instances of early specialization, as also with regard to the changed estimate of the degrees of affinity between forms, it is not pretended for a moment that such facts are irreconcilable with "natural selection." nevertheless, they point in an opposite direction. of course not only is it conceivable that certain antique types arrived at a high degree of specialization and then disappeared; but it is manifest they did do so. still the fact of this early degree of excessive specialization tells to a certain, however small, extent against a progress through excessively minute steps, whether fortuitous or not; as also does the distinctness of forms formerly supposed to constitute connecting links. for, it must not be forgotten, that if species have manifested themselves generally by gradual and minute modifications, then the absence, not in one but in _all cases_, of such connecting links, is a phenomenon which remains to be accounted for. it appears then that, apart from fortuitous changes, there are certain difficulties in the way of accepting extremely minute modifications of any kind, although these difficulties may not be insuperable. something, at all events, is to be said in favour of the opinion that sudden and {112} appreciable changes have from time to time occurred, however they may have been induced. marked _races_ have undoubtedly so arisen (some striking instances having been here recorded), and it is at least conceivable that such may be the mode of _specific_ manifestation generally, the possible conditions as to which will be considered in a later chapter. [page 113] * * * * * chapter v. as to specific stability. what is meant by the phrase "specific stability;" such stability to be expected _a priori_, or else considerable changes at once.--rapidly increasing difficulty of intensifying race characters; alleged causes of this phenomenon; probably an internal cause co-operates.--a certain definiteness in variations.--mr. darwin admits the principle of specific stability in certain cases of unequal variability.--the goose.--the peacock.--the guinea fowl.--exceptional causes of variation under domestication.--alleged tendency to reversion.--instances.--sterility of hybrids.--prepotency of pollen of same species, but of different race.--mortality in young gallinaceous hybrids.--a bar to intermixture exists somewhere.--guinea-pigs.--summary and conclusion. as was observed in the preceding chapters, arguments may yet be advanced in favour of the opinion that species are stable (at least in the intervals of their comparatively sudden successive manifestations); that the organic world consists, according to mr. galton's before-mentioned conception, of many facetted spheroids, each of which can repose upon any one facet, but, when too much disturbed, rolls over till it finds repose in stable equilibrium upon another and distinct facet. something, it is here contended, may be urged, in favour of the existence of such facets--of such intermitting conditions of stable equilibrium. a view as to the stability of species, in the intervals of change, has been well expressed in an able article, before quoted from, as follows:[104]--"a given animal or plant appears to be contained, as it were, within a {114} sphere of variation: one individual lies near one portion of the surface; another individual, of the same species, near another part of the surface; the average animal at the centre. any individual may produce descendants varying in any direction, but is more likely to produce descendants varying towards the centre of the sphere, and the variations in that direction will be greater in amount than the variations towards the surface." this might be taken as the representation of the normal condition of species (_i.e._ during the periods of repose of the several facets of the spheroids), on that view which, as before said, may yet be defended. judging the organic world from the inorganic, we might expect, _a priori_, that each species of the former, like crystallized species, would have an approximate limit of form, and even of size, and at the same time that the organic, like the inorganic forms, would present modifications in correspondence with surrounding conditions; but that these modifications would be, not minute and insignificant, but definite and appreciable, equivalent to the shifting of the spheroid on to another facet for support. mr. murphy says,[105] "crystalline formation is also dependent in a very remarkable way on the medium in which it takes place." "beudant has found that common salt crystallizing from pure water forms cubes, but if the water contains a little boracic acid, the angles of the cubes are truncated. and the rev. e. craig has found that carbonate of copper, crystallizing from a solution containing sulphuric acid, forms hexagonal tubular prisms; but if a little ammonia is added, the form changes to that of a long rectangular prism, with secondary planes in the angles. if a little more ammonia is added, several varieties of rhombic octahedra appear; if a little nitric acid is added, the rectangular prism appears again. the changes take place not by the addition of new crystals, but by changing the growth of the original ones." these, however, may be said{115} to be the same species, after all; but recent researches by dr. h. charlton-bastian seem to show that modifications in the conditions may result in the evolution of forms so diverse as to constitute different organic species. mr. murphy observes[106] that "it is scarcely possible to doubt that the various forms of fungi which are characteristic of particular situations are not really distinct species, but that the same germ will develop into different forms, according to the soil on which it falls;" but it is possible to interpret the facts differently, and it may be that these are the manifestations of really different and distinct species, developed according to the different and distinct circumstances in which each is placed. mr. murphy quotes dr. carpenter[107] to the effect that "no _puccinia_ but the _puccinia rosæ_ is found upon rose bushes, and this is seen nowhere else; _omygena exigua_ is said to be never seen but on the hoof of a dead horse; and _isaria felina_ has only been observed upon the dung of cats, deposited in humid and obscure situations." he adds, "we can scarcely believe that the air is full of the germs of distinct species of fungi, of which one never vegetates until it falls on the hoof of a dead horse, and another till it falls on cat's dung in a damp and dark place." this is true, but it does not quite follow that they are necessarily the same species if, as dr. bastian seems to show, thoroughly different and distinct organic forms[108] can be evolved one from another by modifying the conditions. this observer has brought forward arguments and facts from which it would appear that such definite, sudden, and considerable transformations may take place in the lowest organisms. if such is really the case, we might expect, _a priori_, to find in the highest organisms a tendency (much more impeded and rare in its manifestations) to {116} similarly appreciable and sudden changes, under certain stimuli; but a tendency to continued stability, under normal and ordinary conditions. the proposition that species have, under ordinary circumstances, a definite limit to their variability, is largely supported by facts brought forward by the zealous industry of mr. darwin himself. it is unquestionable that the degrees of variation which have been arrived at in domestic animals have been obtained more or less readily in a moderate amount of time, but that further development in certain desired directions is in some a matter of extreme difficulty, and in others appears to be all but, if not quite, an impossibility. it is also unquestionable that the degree of divergence which has been attained in one domestic species is no criterion of the amount of divergence which has been attained in another. it is contended on the other side that we have no evidence of any limits to variation other than those imposed by physical conditions, such, _e.g._, as those which determine the greatest degree of speed possible to any animal (of a given size) moving over the earth's surface; also it is said that the differences in degree of change shown by different domestic animals depend in great measure upon the abundance or scarcity of individuals subjected to man's selection, together with the varying direction and amount of his attention in different cases; finally, it is said that the changes found in nature are within the limits to which the variation of domestic animals extends,--it being the case that when changes of a certain amount have occurred to a species under nature, it becomes _another species_, or sometimes _two or more other species_ by divergent variations, each of these species being able again to vary and diverge in any useful direction. but the fact of the rapidly increasing difficulty found in producing by ever such careful selection, any further extreme in some charge already carried very far (such as the tail of the "fan-tailed pigeon" or the crop of the "pouter"), is certainly, so far as it goes, on the side of the {117} existence of definite limits to variability. it is asserted in reply, that physiological conditions of health and life may bar any such further development. thus, mr. wallace says[109] of these developments: "variation seems to have reached its limits in these birds. but so it has in nature. the fantail has not only more tail-feathers than any of the three hundred and forty existing species of pigeons, but more than any of the eight thousand known species of birds. there is, of course, some limit to the number of feathers of which a tail useful for flight can consist, and in the fantail we have probably reached that limit. many birds have the oesophagus or the skin of the neck more or less dilatable, but in no known bird is it so dilatable as in the pouter pigeon. here again the possible limit, compatible with a healthy existence, has probably been reached. in like manner, the differences in the size and form of the beak in the various breeds of the domestic pigeon, is greater than that between the extreme forms of beak in the various genera and sub-families of the whole pigeon tribe. from these facts, and many others of the same nature, we may fairly infer, that if rigid selection were applied to any organ, we could in a comparatively short time produce a much greater amount of change than that which occurs between species and species in a state of nature, since the differences which we do produce are often comparable with those which exist between distinct genera or distinct families." but in a domestic bird like the fantail where natural selection does not come into play, the tail-feathers could hardly be limited by "utility for flight," yet two more tail-feathers could certainly exist in a fancy breed if "utility for flight" were the only obstacle. it seems probable that the real barrier is an _internal_ one in the nature of the organism, and the existence of such is just what is contended for in this chapter. as to{118} the differences between domestic races being greater than those between species or even genera, that is not enough for the argument. for upon the theory of "natural selection" all birds have a common origin, from which they diverged by infinitesimal changes, so that we ought to meet with sufficient changes to warrant the belief that a hornbill could be produced from a humming-bird, proportionate time being allowed. but not only does it appear that there are barriers which oppose change in certain directions, but that there are positive tendencies to development along certain special lines. in a bird which has been kept and studied like the pigeon, it is difficult to believe that any remarkable spontaneous variations would pass unnoticed by breeders, or that they would fail to be attended to and developed by some one fancier or other. on the hypothesis of _indefinite_ variability, it is then hard to say why pigeons with bills like toucans, or with certain feathers lengthened like those of trogans, or those of birds of paradise, have never been produced. this, however, is a question which may be settled by experiment. let a pigeon be bred with a bill like a toucan's, and with the two middle tail-feathers lengthened like those of the king bird of paradise, or even let individuals be produced which exhibit any marked tendency of the kind, and indefinite variability shall be at once conceded. as yet all the changes which have taken place in pigeons are of a few definite kinds only, such as may be well conceived to be compatible with a species possessed of a certain inherent capacity for considerable yet definite variation, a capacity for the ready production of certain degrees of abnormality, which then cannot be further increased. mr. darwin himself has already acquiesced in the proposition here maintained, inasmuch as he distinctly affirms the existence of a marked internal barrier to change in certain cases. and if this is admitted in one case, the _principle_ is conceded, and it immediately becomes probable that such internal barriers exist in all, although enclosing a much larger {119} field for variation in some cases than in others. mr. darwin abundantly demonstrates the variability of dogs, horses, fowls, and pigeons, but he none the less shows clearly the _very small_ extent to which the goose, the peacock, and the guinea-fowl have varied.[110] mr. darwin attempts to explain this fact as regards the goose by the animal being valued only for food and feathers, and from no pleasure having been felt in it on other accounts. he adds, however, at the end the striking remark,[111] which concedes the whole position, "but the goose seems to have _a singularly inflexible organization_." this is not the only place in which such expressions are used. he elsewhere makes use of phrases which quite harmonize with the conception of a normal specific constancy, but varying greatly and suddenly at intervals. thus he speaks[112] of a _whole organization seeming to have become plastic, and tending to depart from the parental type_. that different organisms should have different degrees of variability, is only what might have been expected _a priori_ from the existence of parallel differences in inorganic species, some of these having but a single form, and others being polymorphic. to return to the goose, however, it may be remarked that it is at least as probable that its fixity of character is the cause of the neglect, as the reverse. it is by no means unfair to assume that _had_ the goose shown a tendency to vary similar in degree to the tendency to variation of the fowl or pigeon, it would have received attention at once on that account. as to the peacock it is excused on the pleas (1), that the individuals maintained are so few in number, and (2) that its beauty is so great it can hardly be improved. but the individuals maintained _have not been too few_ for the independent origin of the black-shouldered form, or for the supplanting of the commoner one by it. as to any neglect in selection,{120} it can hardly be imagined that with regard to this bird (kept as it is all but exclusively for its beauty), any spontaneous beautiful variation in colour or form would have been neglected. on the contrary, it would have been seized upon with avidity and preserved with anxious care. yet apart from the black-shouldered and white varieties, no tendency to change has been known to show itself. as to its being too beautiful for improvement, that is a proposition which can hardly be maintained. many consider the javan bird as much handsomer than the common peacock, and it would be easy to suggest a score of improvements as regards either species. the guinea-fowl is excused, as being "no general favourite, and scarcely more common than the peacock;" but mr. darwin himself shows and admits that it is a noteworthy instance of constancy under very varied conditions. these instances alone (and there are yet others) seem sufficient to establish the assertion, that degree of change is different in different domestic animals. it is, then, somewhat unwarrantable in any darwinian to assume that _all_ wild animals have a capacity for change similar to that existing in _some_ of the domestic ones. it seems more reasonable to assert the opposite, namely, that if, as mr. darwin says, the capacity for change is different in different domestic animals, it must surely be limited in those which have it least, and _a fortiori_ limited in wild animals. indeed, it cannot be reasonably maintained that wild species certainly vary as much as do domestic races; it is possible that they may do so, but at least this has not been yet shown. indeed, the much greater degree of variation amongst domestic animals than amongst wild ones is asserted over and over again by mr. darwin, and his assertions are supported by an overwhelming mass of facts and instances. of course, it may be asserted that a tendency to indefinite change exists in all cases, and that it is only the circumstances and conditions of {121} life which modify the effects of this tendency to change so as to produce such different results in different cases. but assertion is not proof, and this assertion has not been proved. indeed, it may be equally asserted (and the statement is more consonant with some of the facts given), that domestication in certain animals induces and occasions a capacity for change which is wanting in wild animals--the introduction of new causes occasioning new effects. for, though a certain degree of variability (normally, in all probability, only oscillation) exists in all organisms, yet domestic ones are exposed to new and different causes of variability, resulting in such striking divergencies as have been observed. not even in this latter case, however, is it necessary to believe that the variability is indefinite, but only that the small oscillations become in certain instances intensified into large and conspicuous ones. moreover, it is possible that some of our domestic animals have been in part chosen and domesticated through possessing variability in an eminent degree. that each species exhibits certain oscillations of structure is admitted on all hands. mr. darwin asserts that this is the exhibition of a tendency to vary which is absolutely indefinite. if this indefinite variability _does_ exist, of course no more need be said. but we have seen that there are arguments _a priori_ and _a posteriori_ against it, while the occurrence of variations in certain domestic animals greater in degree than the differences between many wild species, is no argument in favour of its existence, until it can be shown that the causes of variability in the one case are the same as in the other. an argument against it, however, may be drawn from the fact, that certain animals, though placed under the influence of those exceptional causes of variation to which domestic animals are subject, have yet never been known to vary, even in a degree equal to that in which certain wild kinds have been ascertained to vary. in addition to this immutability of character in some animals, it is {122} undeniable, that domestic varieties have little stability, and much tendency to reversion, whatever be the true explanation of such phenomena. in controverting the generally received opinion as to "reversion," mr. darwin has shown that it is not all breeds which in a few years revert to the original form; but he has shown no more. thus, the feral rabbits of porto santo, jamaica, and the falkland islands, have not yet so reverted in those several localities.[113] nevertheless, a porto santo rabbit brought to england reverted in a manner the most striking, recovering the proper colour of its fur "in rather less than four years."[114] again, the white silk fowl, in our climate, "reverts to the ordinary colour of the common fowl in its skin and bones, due care having been taken to prevent any cross."[115] this reversion taking place in spite of careful selection, is very remarkable. numerous other instances of reversion are given by mr. darwin, both as regards plants and animals; amongst others, the singular fact of bud reversion.[116] the curiously recurring development of black sheep, in spite of the most careful breeding, may also be mentioned, though, perhaps, reversion has no part in the phenomenon. these facts seem certainly to tell in favour of limited variability, while the cases of non-reversion do not contradict it, as it is not contended that all species have the same tendency to revert, but rather that their capacities in this respect, as well as for change, are different in different kinds, so that often reversion may only show itself at the end of very long periods indeed. yet some of the instances given as probable or possible causes of reversion by mr. darwin, can hardly be such. he cites, for example, the occasional presence of supernumerary digits in man.[117] for this notion, however, he is not responsible, as he rests his remark on the authority of a {123} passage published by professor owen. again, he refers[118] to "the greater frequency of a monster proboscis in the pig than in any other animal." but with the exception of the peculiar muzzle of the saiga (or european antelope), the only known proboscidian ungulates are the elephants and tapirs, and to neither of these has the pig any close affinity. it is rather in the horse than in the pig that we might look for the appearance of a reversionary proboscis, as both the elephants and the tapirs have the toes of the hind foot of an odd number. it is true that the elephants are generally considered to form a group apart from both the odd and the even-toed ungulata. but of the two, their affinities with the odd-toed division are more marked.[119] another argument in favour of the, at least intermitting, constancy of specific forms and of sudden modification, may be drawn from the absence of minute transitional forms, but this will be considered in the next chapter. it remains now to notice in favour of specific stability, that the objection drawn from physiological difference between "species" and "races" still exists unrefuted. mr. darwin freely admits difficulties regarding the sterility of different species when crossed, and shows satisfactorily that it could never have arisen from the action of "natural selection." he remarks[120] also: "with some few exceptions, in the case of plants, domesticated varieties, such as those of the dog, fowl, pigeon, several fruit trees, and culinary vegetables, which differ from each other in external characters more than many species, are perfectly fertile when crossed, or even fertile in {124} excess, whilst closely allied species are almost invariably in some degree sterile." again, after speaking of "the general law of good being, derived from the intercrossing of distinct individuals of the same species," and the evidence that the pollen of a distinct _variety_ or race is prepotent over a flower's own pollen, adds the very significant remark,[121] "when distinct _species_ are crossed, the case is directly the reverse, for a plant's own pollen is almost always prepotent over foreign pollen." again he adds:[122] "i believe from observations communicated to me by mr. hewitt, who has had great experience in hybridizing pheasants and fowls, that the early death of the embryo is a very frequent cause of sterility in first crosses. mr. salter has recently given the results of an examination of about 500 eggs produced from various crosses between three species of gallus and their hybrids. the majority of these eggs had been fertilized, and in the majority of the fertilized eggs the embryos either had been partially developed and had then aborted, or had become nearly mature, but the young chickens had been unable to break through the shell. of the chickens which were born, more than four-fifths died within the first few days, or at latest weeks, 'without any obvious cause, apparently from mere inability to live,' so that from 500 eggs only twelve chickens were reared. the early death of hybrid embryos probably occurs in like manner with plants, at least it is known that hybrids raised from very distinct species are sometimes weak and dwarfed, and perish at an early age, of which fact max wichura has recently given some striking cases with hybrid willows." mr. darwin objects to the notion that there is any special sterility imposed to check specific intermixture and change, saying,[123] "to grant to species the special power of producing hybrids, and then to stop {125} their further propagation by different degrees of sterility, not strictly related to the facility of the first union between their parents, seems a strange arrangement." but this only amounts to saying that the author himself would not have so acted had he been the creator. a "strange arrangement" must be admitted anyhow, and all who acknowledge teleology at all, must admit that the strange arrangement was designed. mr. darwin says, as to the sterility of species, that the cause lies exclusively in their sexual constitution; but all that need be affirmed is that sterility is brought about somehow, and it is undeniable that "crossing" _is_ checked. all that is contended for is that there _is_ a bar to the intermixture of _species_, but not of _breeds_; and if the conditions of the generative products are that bar, it is enough for the argument, no special kind of barring action being contended for. he, however, attempts to account for the modification of the sexual products of species as compared with those of varieties, by the exposure of the former to more uniform conditions during longer periods of time than those to which varieties are exposed, and that as wild animals, when captured, are often rendered sterile by captivity, so the influence of union with another species may produce a similar effect. it seems to the author an unwarrantable assumption that a cross with what, on the darwinian theory, can only be a slightly diverging descendant of a common parent, should produce an effect equal to that of captivity, and consequent change of habit, as well as considerable modification of food. no clear case has been given by mr. darwin in which mongrel animals, descended from the same undoubted species, have been persistently infertile _inter se_; nor any clear case in which hybrids between animals, generally admitted to be distinct species, have been continuously fertile _inter se_. it is true that facts are brought forward tending to establish the probability of the doctrine of pallas, that species may sometimes be {126} rendered fertile by domestication. but even if this were true, it would be no approximation towards proving the converse, _i.e._ that races and varieties may become sterile when wild. and whatever may be the preference occasionally shown by certain breeds to mate with their own variety, no sterility is recorded as resulting from unions with other varieties. indeed, mr. darwin remarks,[124] "with respect to sterility from the crossing of domestic races, i know of no well-ascertained case with animals. this fact (seeing the great difference in structure between some breeds of pigeons, fowls, pigs, dogs, &c.) is extraordinary when contrasted with the sterility, of many closely-allied natural species when crossed." it has been alleged that the domestic and wild guinea-pig do not breed together, but the specific identity of these forms is very problematical. mr. a. d. bartlett, superintendent of the zoological gardens, whose experience is so great, and observation so quick, believes them to be decidedly distinct species. thus, then, it seems that a certain normal specific stability in species, accompanied by occasional sudden and considerable modifications, might be expected _a priori_ from what we know of crystalline inorganic forms and from what we may anticipate with regard to the lowest organic ones. this presumption is strengthened by the knowledge of the increasing difficulties which beset any attempt to indefinitely intensify any race characteristics. the obstacles to this indefinite intensification, as well as to certain lines of variation in certain cases, appear to be not only external, but to depend on internal causes or an internal cause. we have seen that mr. darwin himself implicitly admits the principle of specific stability in asserting the singular inflexibility of the organization of the goose. we have also seen that it is not fair to conclude that all wild races can vary as much as the most variable domestic ones. it has also been shown {127} that there are grounds for believing in a tendency to reversion generally, as it is distinctly present in certain instances. also that specific stability is confirmed by the physiological obstacles which oppose themselves to any considerable or continued intermixture of species, while no such barriers oppose themselves to the blending of varieties. all these considerations taken together may fairly be considered as strengthening the belief that specific manifestations are relatively stable. at the same time the view advocated in this book does not depend upon, and is not identified with, any such stability. all that the author contends for is that specific manifestation takes place along certain lines, and according to law, and not in an exceedingly minute, indefinite, and fortuitous manner. finally, he cannot but feel justified, from all that has been brought forward, in reiterating the opening assertion of this chapter that something is still to be said for the view which maintains that species are stable, at least in the intervals of their comparatively rapid successive {128} manifestations. * * * * * chapter vi. species and time. two relations of species to time.--no evidence of past existence of minutely intermediate forms when such might be expected _a priori_.--bats, pterodactyles, dinosauria, and birds.--ichthyosauria, chelonia, and anoura.--horse ancestry.--labyrinthodonts and trilobites.--two subdivisions of the second relation of species to time.--sir william thomson's views.---probable period required for ultimate specific evolution from primitive ancestral forms.--geometrical increase of time required for rapidly multiplying increase of structural differences.--proboscis monkey.--time required for deposition of strata necessary for darwinian evolution.--high organization of silurian forms of life.--absence of fossils in oldest rocks.--summary and conclusion. two considerations present themselves with regard to the necessary relation of species to time if the theory of "natural selection" is valid and sufficient. the first is with regard to the evidences of the past existence of intermediate form, their duration and succession. the second is with regard to the total amount of time required for the evolution of all organic forms from a few original ones, and the bearing of other sciences on this question of time. as to the first consideration, evidence is as yet against the modification of species by "natural selection" alone, because not only are minutely transitional forms generally absent, but they are absent in cases where we might certainly _a priori_ have expected them to be present. [page 129] now it has been said:[125] "if mr. darwin's theory be true, the number of varieties differing one from another a very little must have been indefinitely great, so great indeed as probably far to exceed the number of individuals which have existed of any one variety. if this be true, it would be more probable that no two specimens preserved as fossils should be of one variety than that we should find a great many specimens collected from a very few varieties, provided, of course, the chances of preservation are equal for all individuals." "it is really strange that vast numbers of perfectly similar specimens should be found, the chances against their perpetuation as fossils are so great; but it is also very strange that the specimens should be so exactly alike as they are, if, in fact, they came and vanished by a gradual change." mr. darwin attempts[126] to show cause why we should believe _a priori_ that intermediate varieties would exist in lesser numbers than the more extreme forms; but though they would doubtless do so sometimes, it seems too much to assert that they would do so generally, still less universally. now little less than universal and very marked inferiority in numbers would account for the absence of certain series of minutely intermediate fossil specimens. the mass of palæontological evidence is indeed overwhelmingly against minute and gradual modification. it is true that when once an animal has obtained powers of flight its means of diffusion are indefinitely increased, and we might expect to find many relics of an aërial form and few of its antecedent state--with nascent wings just commencing their suspensory power. yet had such a slow mode of origin, as darwinians contend for, operated exclusively in all cases, it is absolutely incredible that birds, bats, and pterodactyles should have left the remains they have, and yet not a single relic be preserved in any one instance{130} of any of these different forms of wing in their incipient and relatively imperfect functional condition! [illustration: wing-bones of pterodactyle, bat, and bird.] whenever the remains of bats have been found they have presented the exact type of existing forms, and there is as yet no indication of the conditions of an incipient elevation from the ground. the pterodactyles, again, though a numerous group, are all true and perfect pterodactyles, though surely _some_ of the many incipient forms, which on the darwinian theory have existed, must have had a good chance of preservation. as to birds, the only notable instance in which discoveries recently made appear to fill up an important hiatus, is the interpretation given by professor huxley[127] to the remains of dinosaurian reptiles, and which were noticed in the third chapter of this work. the learned professor has (as also has professor cope in america) shown that in very important {131} and significant points the skeletons of the iguanodon and of its allies approach very closely to that existing in the ostrich, emeu, rhea, &c. he has given weighty reasons for thinking that the line of affinity between birds and reptiles passes to the birds last named from the dinosauria rather than from the pterodactyles, through archeopteryx-like forms to the ordinary birds. finally, he has thrown out the suggestion that the celebrated footsteps left by some extinct three-toed creatures on the very ancient sandstone of connecticut were made, not, as hitherto supposed, by true birds, but by more or less ornithic reptiles. but even supposing all that is asserted or inferred on this subject to be fully proved, it would not approach to a demonstration of specific origin by _minute_ modification. and though it harmonizes well with "natural selection," it is equally consistent with the rapid and sudden development of new specific forms of life. indeed, professor huxley, with a laudable caution and moderation too little observed by some teutonic darwinians, guarded himself carefully from any imputation of asserting dogmatically the theory of "natural selection," while upholding fully the doctrine of evolution. but, after all, it is by no means certain, though very probable, that the connecticut footsteps were made by very ornithic reptiles, or extremely sauroid birds. and it must not be forgotten that a completely carinate[128] bird (the archeopteryx) existed at a time, when, as yet, we have no evidence of some of the dinosauria having come into being. moreover, if the remarkable and minute similarity of the coracoid of a pterodactyle to that of a bird be merely the result of function and no sign of genetic affinity, it is not inconceivable that pelvic and leg resemblances of dinosauria to birds may be functional likewise, though such an explanation is, of {132} course, by no means necessary to support the view maintained in this book. [illustration: the archeopteryx (of the oolite strata).] [illustration: skeleton of an ichthyosaurus.] but the number of forms represented by many individuals, yet by _no transitional ones_, is so great that only two or three can be selected as examples. thus those remarkable fossil reptiles, the ichthyosauria and plesiosauria, extended, through the secondary period, probably over the greater part of the globe. yet no single transitional form has yet been met with in spite of the multitudinous individuals preserved. again, with their modern representatives the cetacea, one or two aberrant forms alone {133} have been found, but no series of transitional ones indicating minutely the line of descent. this group, the whales, is a very marked one, and it is curious, on darwinian principles, that so few instances tending to indicate its mode of origin should have presented themselves. here, as in the bats, we might surely expect that some relics of unquestionably incipient stages of its development would have been left. [illustration: skeleton of a plesiosaurus.] the singular order chelonia, including the tortoises, turtles, and terrapins (or fresh-water tortoises), is another instance of an extreme form without any, as yet known, transitional stages. another group may be finally mentioned, viz. the frogs and toads, anourous batrachians, of which we have at present no relic of any kind linking them on to the eft group on the one hand, or to reptiles on the other. the only instance in which an approach towards a series of nearly related forms has been obtained is the existing horse, its predecessor hipparion and other extinct forms. but even here there is no proof whatever of modification by minute and infinitesimal steps; _a fortiori_ no approach to a proof of modification by "natural selection," acting upon indefinite fortuitous variations. on the contrary, the series is an admirable example of successive modification in one special direction along one beneficial line, and the teleologist must here be allowed to consider that one {134} motive of this modification (among probably an indefinite number of motives inconceivable to us) was the relationship in which the horse was to stand to the human inhabitants of this planet. these extinct forms, as professor owen, remarks,[129] "differ from each other in a greater degree than do the horse, zebra, and ass," which are not only good _zoological_ species as to form, but are species _physiologically_, _i.e._ they cannot produce a race of hybrids fertile _inter se_. as to the mere action of surrounding conditions, the same professor remarks:[130] "any modification affecting the density of the soil might so far relate to the changes of limb-structure, as that a foot with a pair of small hoofs dangling by the sides of the large one, like those behind the cloven hoof of the ox, would cause the foot of hipparion, _e.g._, and _a fortiori_ the broader based three-hoofed foot of the palæothere, to sink less deeply into swampy soil, and be more easily withdrawn than the more concentratively simplified and specialized foot of the horse. rhinoceroses and zebras, however, tread together the arid plains of africa in the present day; and the horse has multiplied in that half of america where two or more kinds of tapir still exist. that the continents of the eocene or miocene periods were less diversified in respect of swamp and sward, pampas or desert, than those of the pliocene period, has no support from observation or analogy." not only, however, do we fail to find any traces of the incipient stages of numerous very peculiar groups of animals, but it is undeniable that there are instances which appeared at first to indicate a _gradual transition_, yet which instances have been shown by further investigation and discovery not to indicate truly anything of the kind. thus at one time the remains of labyrinthodonts, which up till then had been discovered, seemed to justify the opinion that as time went on, forms had successively appeared with{135} more and more complete segmentation and ossification of the backbone, which in the earliest forms was (as it is in the lowest fishes now) a soft continuous rod or notochord. now, however, it is considered probable that the soft back-boned labyrinthodont archegosaurus, was an immature or larval form,[131] while labyrinthodonts with completely developed vertebræ have been found to exist amongst the very earliest forms yet discovered. the same may be said regarding the eyes of the trilobites, some of the oldest forms having been found as well furnished in that respect as the very last of the group which has left its remains accessible to observation. [illustration: trilobite.] such instances, however, as well as the way in which marked and special forms (as the pterodactyles, &c., before referred to) appear at once in and similarly disappear from the geological record, are of course explicable on the darwinian theory, provided a sufficiently enormous amount of past time be allowed. the alleged extreme, and probably great, imperfection of that record may indeed be pleaded in excuse. but it _is_ an excuse.[132] {136} nor is it possible to deny the _a priori_ probability of the preservation of at least a few _minutely transitional_ forms in some instances if _every_ species without exception has arisen exclusively by such minute and gradual transitions. it remains, then, to turn to the other considerations with regard to the relation of species to time: namely (1) as to the total amount of time allowable by other sciences for organic evolution; and (2) the proportion existing, on darwinian principles, between the time anterior to the earlier fossils, and the time since; as evidenced by the proportion between the amount of evolutionary change during the latter epoch and that which must have occurred anteriorly. sir william thomson has lately[133] advanced arguments from three distinct lines of inquiry, and agreeing in one approximate result. the three lines of inquiry were--1. the action of the tides upon the earth's rotation. 2. the probable length of time during which the sun has illuminated this planet; and 3. the temperature of the interior of the earth. the result arrived at by these investigations is a conclusion that the existing state of things on the earth, life on the earth, all geological history showing continuity of life, must be limited within some such period of past time as one hundred million years. the first question which suggests itself, supposing sir w. thomson's views to be correct, is, is this period anything like enough for the evolution of all organic forms by "natural selection"? the second is, is this period anything like enough for the deposition of the strata which must have been deposited if all organic forms have been evolved by _minute_ steps, according to the darwinian theory? in the first place, as to sir william thomson's views, the author of this book cannot presume to advance any opinion; but the fact that they have not been refuted, pleads strongly in their favour when we consider how {137} much they tell against the theory of mr. darwin. the last-named author only remarks that "many of the elements in the calculation are more or less doubtful,"[134] and professor huxley[135] does not attempt to _refute_ sir w. thomson's arguments, but only to show cause for suspense of judgment, inasmuch as the facts _may be_ capable of other explanations. mr. wallace, on the other hand,[136] seems more disposed to accept them, and, after considering sir william's objections and those of mr. croll, puts the probable date of the beginning of the cambrian deposits[137] at only twenty-four million years ago. on the other hand, he seems to consider that specific change has been more rapid than generally supposed, and exceptionally stable during the last score or so of thousand years. now, first, with regard to the time required for the evolution of all organic forms by merely accidental, minute, and fortuitous variations, the useful ones of which have been preserved: mr. murphy[138] is distinctly of opinion that there has not been time enough. he says, "i am inclined to think that geological time is too short for the evolution of the higher forms of life out of the lower by that accumulation of imperceptibly slow variations, to which alone darwin ascribes the whole process." "darwin justly mentions the greyhound as being equal to any natural species in the perfect co-ordination of its parts, 'all adapted for extreme fleetness and for running down weak prey.'" "yet it is an artificial species (and not _physiologically_ a species _at all_), formed by long-continued selection under domestication; and there is no reason to suppose that any of the variations which have been selected to form it have been other than gradual and almost imperceptible. suppose that it has {138} taken five hundred years to form the greyhound out of his wolf-like ancestor. this is a mere guess, but it gives the order of the magnitude." now, if so, "how long would it take to obtain an elephant from a protozoon, or even from a tadpole-like fish? ought it not to take much more than a million times as long?"[139] mr. darwin[140] would compare with the natural origin of a species "unconscious selection, that is, the preservation of the most useful or beautiful animals, with no intention of modifying the breed." he adds: "but by this process of unconscious selection, various breeds have been sensibly changed in the course of two or three centuries." "sensibly changed!" but not formed into "new species." mr. darwin, of course, could not mean that species _generally_ change so rapidly, which would be strangely at variance with the abundant evidence we have of the stability of animal forms as represented on egyptian monuments and as shown by recent deposits. indeed, he goes on to say,--"species, however, probably change much more slowly, and within the same country only a few change at the same time. this slowness follows from all the inhabitants of the same country being already so well adapted to each other, that places in the polity of nature do not occur until after long intervals, when changes of some kind in the physical conditions, or through immigration, have occurred, and individual differences and variations of the right nature, by which some of the inhabitants might be better fitted to their new places under altered circumstances, might not at once occur." this is true, and not only will these changes occur at distant intervals, but it must be borne in mind that in tracing back an animal to a remote ancestry, we pass through modifications of such rapidly increasing number and importance that a geometrical progression can alone indicate the increase of periods {139} which such profound alterations would require for their evolution through "natural selection" only. thus let us take for an example the proboscis monkey of borneo (_semnopithecus nasalis_). according to mr. darwin's own opinion, this form might have been "sensibly changed" in the course of two or three centuries. according to this, to evolve it as a true and perfect species one thousand years would be a very moderate period. let ten thousand years be taken to represent approximately the period of substantially constant conditions during which no considerable change would be brought about. now, if one thousand years may represent the period required for the evolution of the species _s. nasalis_, and of the other species of the genus semnopithecus; ten times that period should, i think, be allowed for the differentiation of that genus, the african cercopithecus and the other genera of the family simiidæ--the differences between the genera being certainly more than tenfold greater than those between the species of the same genus. again we may perhaps interpose a period of ten thousand years' comparative repose. for the differentiation of the families simiidæ and cebidæ--so very much more distinct and different than any two genera of either family--a period ten times greater should, i believe, be allowed than that required for the evolution of the subordinate groups. a similarly increasing ratio should be granted for the successive developments of the difference between the lemuroid and the higher forms of primates; for those between the original primate and other root-forms of placental mammals; for those between primary placental and implacental mammals, and perhaps also for the divergence of the most ancient stock of these and of the monotremes, for in all these cases modifications of structure appear to increase in complexity in at least that ratio. finally, a vast period must be granted for the development of the lowest mammalian type from the primitive stock of the whole vertebrate sub-kingdom. supposing this primitive stock to have {140} arisen directly from a very lowly organized animal indeed (such as a nematoid worm, or an ascidian, or a jelly-fish), yet it is not easy to believe that less than two thousand million years would be required for the totality of animal development by no other means than minute, fortuitous, occasional, and intermitting variations in all conceivable directions. if this be even an approximation to the truth, then there seem to be strong reasons for believing that geological time is not sufficient for such a process. the second question is, whether there has been time enough for the deposition of the strata which must have been deposited, if all organic forms have been evolved according to the darwinian theory? now this may at first seem a question for geologists only, but, in fact, in this matter geology must in some respects rather take its time from zoology than the reverse; for if mr. darwin's theory be true, past time down to the deposition of the upper silurian strata can have been but a very small fraction of that during which strata have been deposited. for when those upper silurian strata were formed, organic evolution had already run a great part of its course, perhaps the longest, slowest, and most difficult part of that course. at that ancient epoch not only were the vertebrate, molluscous, and arthropod types distinctly and clearly differentiated, but highly developed forms had been produced in each of these sub-kingdoms. thus in the vertebrata there were fishes not belonging to the lowest but to the very highest groups which are known to have ever been developed, namely, the elasmobranchs (the highly organized sharks and rays) and the ganoids, a group now poorly represented, but for which the sturgeon may stand as a type, and which in many important respects more nearly resemble higher vertebrata than do the ordinary or osseous fishes. fishes in which the ventral fins are placed in front of the pectoral ones (_i.e._ jugular fishes) have been generally considered to be comparatively modern forms. but professor huxley has kindly informed me that he has discovered a {141} jugular fish in the permian deposits. amongst the molluscous animals we have members of the very highest known class, namely, the cephalopods, or cuttle-fish class; and amongst articulated animals we find trilobites and eurypterida, which do not belong to any incipient worm-like group, but are distinctly differentiated crustacea of no low form. [illustration: cuttle-fish. a. ventral aspect. b. dorsal aspect.] we have in all these animal types nervous systems differentiated on distinctly different patterns, fully formed organs of circulation, digestion, excretion, and generation, complexly constructed eyes and other sense organs; in fact, all the most elaborate and complete animal structures built up, and not only once, for in the fishes and mollusca we have (as described in the third chapter of this work) the coincidence of the independently developed organs of sense attaining a nearly similar complexity in two quite distinct forms. if, then, so small an advance {142} has been made in fishes, molluscs, and arthropods since the upper silurian deposits, it will probably be within the mark to consider that the period before those deposits (during which all these organs would, on the darwinian theory, have slowly built up their different perfections and complexities) occupied time at least a hundredfold greater. now it will be a moderate computation to allow 25,000,000 years for the deposition of the strata down to and including the upper silurian. if, then, the evolutionary work done during this deposition, only represents a hundredth part of the sum total, we shall require 2,500,000,000 (two thousand five hundred million) years for the complete development of the whole animal kingdom to its present state. even one quarter of this, however, would far exceed the time which physics and astronomy seem able to allow for the completion of the process. finally, a difficulty exists as to the reason of the absence of rich fossiliferous deposits in the oldest strata--if life was then as abundant and varied as, on the darwinian theory, it must have been. mr. darwin himself admits[141] "the case at present must remain inexplicable; and may be truly urged as a valid argument against the views" entertained in his book. thus, then, we find a wonderful (and on darwinian principles an all but inexplicable) absence of minutely transitional forms. all the most marked groups, bats, pterodactyles, chelonians, ichthyosauria, anoura, &c., appear at once upon the scene. even the horse, the animal whose pedigree has been probably best preserved, affords no conclusive evidence of specific origin by infinitesimal, fortuitous variations; while some forms, as the labyrinthodonts and trilobites, which seemed to exhibit gradual change, are shown by further investigation to do nothing of the sort. as regards the time required for evolution (whether estimated by the probably minimum{143} period required for organic change or for the deposition of strata which accompanied that change), reasons have been suggested why it is likely that the past history of the earth does not supply us with enough. first, because of the prodigious increase in the importance and number of differences and modifications which we meet with as we traverse successively greater and more primary zoological groups; and, secondly, because of the vast series of strata necessarily deposited if the period since the lower silurian marks but a small fraction of the period of organic evolution. finally, the absence or rarity of fossils in the oldest rocks is a point at present inexplicable, and not to be forgotten or neglected. now all these difficulties are avoided if we admit that new forms of animal life of all degrees of complexity appear from time to time with comparative suddenness, being evolved according to laws in part depending on surrounding conditions, in part internal--similar to the way in which crystals (and, perhaps from recent researches, the lowest forms of life) build themselves up according to the internal laws of their component substance, and in harmony and correspondence with all environing influences and conditions. [page 144] * * * * * chapter vii. species and space. the geographical distribution of animals presents difficulties.--these not insurmountable in themselves; harmonize with other difficulties.--fresh-water fishes.--forms common to africa and india; to africa and south america; to china and australia; to north america and china; to new zealand and south america; to south america and tasmania; to south america and australia.--pleurodont lizards.--insectivorous mammals.--similarity of european and south american frogs--analogy between european salmon and fishes of new zealand, &c. an ancient antarctic continent probable.--other modes of accounting for facts of distribution.--independent origin of closely similar forms.--conclusion. the study of the distribution of animals over the earth's surface presents us with many facts having certain not unimportant bearings on the question of specific origin. amongst these are instances which, at least at first sight, appear to conflict with the darwinian theory of "natural selection." it is not, however, here contended that such facts do by any means constitute by themselves obstacles which cannot be got over. indeed it would be difficult to imagine any obstacles of the kind which could not be surmounted by an indefinite number of terrestrial modifications of surface--submergences and emergences--junctions and separations of continents in all directions and combinations of any desired degree of frequency. all this being supplemented by the intercalation of armies of enemies, multitudes of ancestors of all kinds, and myriads of connecting forms, whose _raison d'être_ may be simply their utility or necessity {145} for the support of the theory of "natural selection." nevertheless, when brought in merely to supplement and accentuate considerations and arguments derived from other sources, in that case difficulties connected with the geographical distribution of animals are not without significance, and are worthy of mention even though, by themselves, they constitute but feeble and more or less easily explicable puzzles which could not alone suffice either to sustain or to defeat any theory of specific origination. many facts as to the present distribution of animal life over the world are very readily explicable by the hypothesis of slight elevations and depressions of larger and smaller parts of its surface, but there are others the existence of which it is much more difficult so to explain. the distribution either of animals possessing the power of flight, or of inhabitants of the ocean, is, of course, easily to be accounted for; the difficulty, if there is really any, must mainly be with strictly terrestrial animals of moderate or small powers of locomotion and with inhabitants of fresh water. mr. darwin himself observes,[142] "in regard to fish, i believe that the same species never occur in the fresh waters of distant continents." now, the author is enabled, by the labours and through the kindness of dr. günther, to show that this belief cannot be maintained; he having been so obliging as to call attention to the following facts with regard to fish-distribution. these facts show that though only one species which is absolutely and exclusively an inhabitant of fresh water is as yet known to be found in distant continents, yet that in several other instances the same species _is_ found in the fresh water of distant continents, and that very often the same _genus_ is so distributed. the genus _mastacembelus_ belongs to a family of fresh-water indian {146} fishes. eight species of this genus are described by dr. günther in his catalogue.[143] these forms extend from java and borneo on the one hand, to aleppo on the other. nevertheless, a new species (_m. cryptacanthus_) has been described by the same author,[144] which is an inhabitant of the camaroon country of _western_ africa. he observes, "the occurrence of indian forms on the west coast of africa, such as _periophthalmus_, _psettus_, _mastacembelus_, is of the highest interest, and an almost new fact in our knowledge of the geographical distribution of fishes." _ophiocephalus_, again, is a truly indian genus, there being no less than twenty-five species,[145] all from the fresh waters of the east indies. yet dr. günther informs me that there is a species in the upper nile and in west africa. the acanthopterygian family (_labyrinthici_) contains nine freshwater genera, and these are distributed between the east indies and south and central africa. the carp fishes (cyprinoids) are found in india, africa, and madagascar, but there are none in south america. thus existing fresh-water fishes point to an immediate connexion between africa and india, harmonizing with what we learn from miocene mammalian remains. on the other hand, the characinidæ (a family of the physostomous fishes) are found in africa and south america, and not in india, and even its component groups are so distributed,--namely, the _tetragonopterina_[146] and the _hydrocyonina_.[147] again, we have similar phenomena in that almost exclusively fresh-water group the siluroids. thus the genera _clarias_[148] and _heterobranchus_[149] are found {147} both in africa and the east indies. _plotosus_ is found in africa, india, and australia, and the species _p. anguillaris_[150] has been brought from both china and moreton bay. here, therefore, we have the same species in two distinct geographical regions. it is however a coast fish, which, though entering rivers, yet lives in the sea. _eutropius_[151] is an african genus, but _e. obtusirostris_ comes from india. on the other hand, _amiurus_ is a north american form; but one species, _a. cantonensis_,[152] comes from china. the genus _galaxias_[153] has at least one species common to new zealand and south america, and one common to south america and tasmania. in this genus we thus have an absolutely and completely fresh-water form _of the very same species_ distributed between different and distinct geographical regions. of the lower fishes, a lamprey, _mordacia mordax_,[154] is common to south australia and chile; while another form of the same family, namely, _geotria chilensis_,[155] is found not only in south america and australia, but in new zealand also. these fishes, however, probably pass part of their lives in the sea. we thus certainly have several species which _are_ common to the fresh waters of distant continents, although it cannot be certainly affirmed that they are exclusively and entirely fresh-water fishes throughout all their lives except in the case of _galaxias_. existing forms point to a close union between south america and africa on the one hand, and between south america, australia, tasmania, and new zealand on the other; but these unions were not synchronous any more than the unions indicated between india and australia, china and australia, china and north america, and india and africa. pleurodont lizards are such as have the teeth attached by their sides {148} to the inner surface of the jaw, in contradistinction to acrodont lizards, which have the bases of their teeth anchylosed to the summit of the margin of the jaw. now pleurodont iguanian lizards abound in the south american region; but nowhere else, and are not as yet known to inhabit any part of the present continent of africa. yet pleurodont lizards, strange to say, are found in madagascar. this is the more remarkable, inasmuch as we have no evidence yet of the existence in madagascar of fresh-water fishes common to africa and south america. [illustration: inner side of lower jaw of pleurodont lizard. (showing the teeth attached to the inner surface of its side.)] again, that remarkable island madagascar is the home of very singular and special insectivorous beasts of the genera centetes, ericulus, and echinops; while the only other member of the group to which they belong is solenodon, which is a resident in the west indian islands, cuba and hayti. the connexion, however, between the west indies and madagascar must surely have been at a time when the great lemurine group was absent; for it is difficult to understand the spread of such a form as solenodon, and at the same time the non-extension of the active lemurs, or their utter extirpation, in such a congenial locality as the west indian archipelago. the close connexion of south america and australia is demonstrated (on the darwinian theory), not only from the marsupial fauna of both, but also from the frogs and toads which respectively inhabit those regions. a truly remarkable similarity and parallelism exist, however, between certain of the same animals inhabiting south western america and europe. thus dr.{149} günther has described[156] a frog from chile by the name of cacotus, which singularly resembles the european bombinator. [illustration: solenodon.] again of the salmons, two genera from south america, new zealand, and australia, are analogous to european salmons. in addition to this may be mentioned a quotation from professor dana, given by mr. darwin,[157] to the effect that "it is certainly a wonderful fact that new zealand should have a closer resemblance in its crustacea to great britain, its antipode, than to any other part of the world:" and mr. darwin adds "sir j. richardson also speaks of the reappearance on the shores of new zealand, tasmania, &c. of northern forms of fish. dr. hooker informs me that twenty-five species of algæ are common to new zealand and to {150} europe, but have not been found in the intermediate tropical seas." many more examples of the kind could easily be brought, but these must suffice. as to the last-mentioned cases mr. darwin explains them by the influence of the glacial epoch, which he would extend actually across the equator, and thus account, amongst other things, for the appearance in chile of frogs having close genetic relations with european forms. but it is difficult to understand the persistence and preservation of such exceptional forms with the extirpation of all the others which probably accompanied them, if so great a migration of northern kinds had been occasioned by the glacial epoch. mr. darwin candidly says,[158] "i am far from supposing that all difficulties in regard to the distribution and affinities of the identical and allied species, which now live so widely separated in the north and south, and sometimes on the intermediate mountain-ranges, are removed." ... "we cannot say why certain species and not others have migrated; why certain species have been modified and have given rise to new forms, whilst others have remained unaltered." again he adds, "various difficulties also remain to be solved; for instance, the occurrence, as shown by dr. hooker, of the same plants at points so enormously remote as kerguelen land, new zealand, and fuegia; but icebergs, as suggested by lyell, may have been concerned in their dispersal. the existence, at these and other distant points of the southern hemisphere, of species which, though distinct, belong to genera exclusively confined to the south, is a more remarkable case. some of these species are so distinct that we cannot suppose that there has been time since the commencement of the last glacial period for their migration and subsequent modification to the necessary degree." mr. darwin goes on to account for these facts by the probable existence of a rich antarctic flora in a warm period anterior to the last glacial {151} epoch. there are indeed many reasons for thinking that a southern continent, rich in living forms, once existed. one such reason is the way in which struthious birds are, or have been, distributed around the antarctic region: as the ostrich in africa, the rhea in south america, the emeu in australia, the apteryx, dinornis, &c. in new zealand, the epiornis in madagascar. still the existence of such a land would not alone explain the various geographical cross relations which have been given above. it would not, for example, account for the resemblance between the crustacea or fishes of new zealand and of england. it would, however, go far to explain the identity (specific or generic) between fresh water and other forms now simultaneously existing in australia and south america, or in either or both of these, and new zealand. again, mutations of elevation small and gradual (but frequent and intermitting), through enormous periods of time--waves, as it were, of land rolling many times in many directions--might be made to explain many difficulties as to geographical distribution, and any cases that remained would probably be capable of explanation, as being isolated but allied animal forms, now separated indeed, but being merely remnants of extensive groups which, at an earlier period, were spread over the surface of the earth. thus none of the facts here given are any serious difficulty to the doctrine of "evolution," but it is contended in this book that if other considerations render it improbable that the manifestation of the successive forms of life has been brought about by minute, indefinite, and fortuitous variations, then these facts as to geographical distribution intensify that improbability, and are so far worthy of attention. all geographical difficulties of the kind would be evaded if we could concede the probability of the independent origin, in different localities, of the same organic forms in animals high in the scale of nature. {152} similar causes must produce similar results, and new reasons have been lately adduced for believing, as regards the _lowest organisms_, that the same forms can arise and manifest themselves independently. the difficulty as to higher animals is, however, much greater, as (on the theory of evolution) one acting force must always be the ancestral history in each case, and this force must always tend to go on acting in the same groove and direction in the future as it has in the past. so that it is difficult to conceive that individuals, the ancestral history of which is very different, can be acted upon by all influences, external and internal, in such diverse ways and proportions that the results (unequals being added to unequals) shall be equal and similar. still, though highly improbable, this cannot be said to be impossible; and if there _is_ an innate law of any kind helping to determine specific evolution, this may more or less, or entirely, neutralize or even reverse the effect of ancestral habit. thus, it is quite conceivable that a pleurodont lizard might have arisen in madagascar in perfect independence of the similarly-formed american lacertilia: just as certain teeth of carnivorous and insectivorous marsupial animals have been seen most closely to resemble those of carnivorous and insectivorous placental beasts; just as, again, the paddles of the cetacea resemble, in the fact of a multiplication in the number of the phalanges, the many-jointed feet of extinct marine reptiles, and as the beak of the cuttle-fish or of the tadpole resembles that of birds. we have already seen (in chapter iii.) that it is impossible, upon any hypothesis, to escape admitting the independent origins of closely similar forms, it may be that they are both more frequent and more important than is generally thought. that closely similar structures may arise without a genetic relationship has been lately well urged by mr. ray lankester.[159] he has brought {153} this notion forward even as regards the bones of the skull in osseous fishes and in mammals. he has done so on the ground that the probable common ancestor of mammals and of osseous fishes was a vertebrate animal of so low a type that it could not be supposed to have possessed a skull differentiated into distinct bony elements--even if it was bony at all. if this was so, then the cranial bones must have had an independent origin in each class, and in this case we have the most strikingly harmonious and parallel results from independent actions. for the bones of the skull in an osseous fish are so closely conformed to those of a mammal, that "both types of skull exhibit many bones in common," though "in each type some of these bones acquire special arrangements and very different magnitudes."[160] and no investigator of homologies doubts that a considerable number of the bones which form the skull of any osseous fish are distinctly homologous with the cranial bones of man. the occipital, the parietal, and frontal, the bones which surround the internal ear, the vomer, the premaxilla, and the quadrate bones, may be given as examples. now, if such close relations of homology can be brought about independently of any but the most remote genetic affinity, it would be rash to affirm dogmatically that there is any impossibility in the independent origin of such forms as centetes and solenodon, or of genetically distinct batrachians, as similar to each other as are some of the frogs of south america and of europe. at the same time such phenomena must at present be considered as very improbable, from the action of ancestral habit, as before stated. we have seen, then, that the geographical distribution of animals presents difficulties, though not insuperable ones, for the darwinian hypothesis. if, however, other reasons against it appear of any weight--if, especially, there is reason to believe that geological time has not been {154} sufficient for it, then it will be well to bear in mind the facts here enumerated. these facts, however, are not opposed to the doctrine of evolution; and if it could be established that closely similar forms had really arisen in complete independence one of the other, they would rather tend to strengthen and to support that theory. [page 155] * * * * * chapter viii. homologies. animals made-up of parts mutually related in various ways.--what homology is.--its various kinds.--serial homology.--lateral homology.--vertical homology.--mr. herbert spencer's explanations.--an internal power necessary, as shown by facts of comparative anatomy.--of teratology.--m. st. hilaire.--professor burt wilder.--foot-wings.--facts of pathology.--mr. james paget.--dr. william budd.--the existence of such an internal power of individual development diminishes the improbability of an analogous law of specific origination. that concrete whole which is spoken of as "an individual" (such, _e.g._, as a bird or a lobster) is formed of a more or less complex aggregation of parts which are actually (from whatever cause or causes) grouped, together in a harmonious interdependency, and which have a multitude of complex relations amongst themselves. the mind detects a certain number of these relations as it contemplates the various component parts of an individual in one or other direction--as it follows up different lines of thought. these perceived relations, though subjective, _as relations_, have nevertheless an objective foundation as real parts, or conditions of parts, of real wholes; they are, therefore, true relations, such, _e.g._, as those between the right and left hand, between the hand and the foot, &c. the component parts of each concrete whole have also a relation of resemblance to the parts of other concrete wholes, whether of the same{156} or of different kinds, as the resemblance between the hands of two men, or that between the hand of a man and the fore-paw of a cat. now, it is here contended that the relationships borne one to another by various component parts, imply the existence of some innate, internal condition, conveniently spoken of as a power or tendency, which is quite as mysterious as is any innate condition, power, or tendency, resulting in the orderly evolution of successive specific manifestations. these relationships, as also this developmental power, will doubtless, in a certain sense, be somewhat further explained as science advances. but the result will be merely a shifting of the inexplicability a point backwards, by the intercalation of another step between the action of the internal condition or power and its external result. in the meantime, even if by "natural selection" we could eliminate the puzzles of the "origin of species," yet other phenomena, not less remarkable (namely, those noticed in this chapter), would still remain unexplained and as yet inexplicable. it is not improbable that, could we arrive at the causes conditioning all the complex inter-relations between the several parts of one animal, we should at the same time obtain the key to unlock the secrets of specific origination. it is desirable, then, to see what facts there are in animal organization which point to innate conditions (powers and tendencies), as yet unexplained, and upon which the theory of "natural selection" is unable to throw any explanatory light. the facts to be considered are the phenomena of "homology," and especially of serial, bilateral, and vertical homology. the word "homology" indicates such a relation between two parts that they may be said in some sense to be "the same," or at least "of similar nature." this similarity, however, does not relate to the _use_ to which parts are put, but only to their relative position with regard to other parts, or to their mode of origin. there are many kinds of {157} homology,[161] but it is only necessary to consider the three kinds above enumerated. [illustration: wingbones of pterodactyle, bat, and bird.] the term "homologous" may be applied to parts in two individual animals of different kinds, or to different parts of the same individual. thus "the right and left hands," or "joints of the backbone," or "the teeth of the two jaws," are homologous parts of the same individual. but the arm of a man, the fore-leg of the horse, the paddle of the whale, and the wing of the bat and the bird are all also homologous parts, yet of another kind, _i.e._ they are the same parts existing in animals of different species. on the other hand, the wing of the humming-bird and the wing of the humming-bird moth are not homologous at all, or in any sense; for the resemblance between them consists solely in the use to which they are put, and is therefore only a relation of _analogy_. there is no relation of _homology_ between them, because they have no common resemblance as to their relations to surrounding parts, or as to their mode of origin. similarly, there is no homology between the wing of the bat and that {158} of the flying-dragon, for the latter is formed of certain ribs, and not of limb bones. [illustration: skeleton of the flying dragon. (showing the elongated ribs which support the flitting organ.)] homology may be further distinguished into (1) a relationship which, on evolutionary principles, would be due to descent from a common ancestor, as the homological relation between the arm-bone of the horse and that of the ox, or between the singular ankle bones of the two lemurine genera, cheirogaleus and galago, and which relation has been termed by mr. ray lankester "homogeny;"[162] and (2) a relationship induced, not derived--such as exists between parts closely similar in relative position, but with no genetic affinity, or only a remote one, as the homological relation between the chambers of the heart of a bat and those of a {159} bird, or the similar teeth of the thylacine and the dog before spoken of. for this relationship mr. bay lankester has proposed the term "homoplasy." [illustration: tarsal bones of different lemuroids. (right tarsus of galago; left tarsus of cheirogaleus.)] [illustration: a centipede.] "serial homology" is a relation of resemblance existing between two or more parts placed in series one behind the other in the same individual. examples of such homologues are the ribs, or joints of the backbone of{160} a horse, or the limbs of a centipede. the latter animal is a striking example of serial homology. the body (except at its two ends) consists of a longitudinal series of similar segments. each segment supports a pair of limbs, and the appendages of all the segments (except as before) are completely alike. [illustration: squilla.] a less complete case of serial homology is presented by crustacea (animals of the crab class), notably by the squilla and by the common lobster. in the latter animal we have a six-jointed abdomen (the so-called tail), {161} in front of which is a large solid mass (the cephalo-thorax), terminated anteriorly by a jointed process (the rostrum). on the under surface of the body we find a quantity of moveable appendages. such are, _e.g._, feelers (fig. 9), jaws (figs. 6, 7, and 8), foot-jaws (fig. 5), claws and legs (figs. 3 and 4), beneath the cephalo-thorax; and flat processes (fig. 2), called "swimmerets," beneath the so-called tail or abdomen. [illustration: part of the skeleton of the lobster.] now, these various appendages are distinct and different enough as we {162} see them in the adult, but they all appear in the embryo as buds of similar form and size, and the thoracic limbs at first consist each of two members, as the swimmerets always do. this shows what great differences may exist in size, in form, and in function, between parts which are developmentally the same, for all these appendages are modifications of one common kind of structure, which becomes differently modified in different situations; in other words, they are serial homologues. the segments of the body, as they follow one behind the other, are also serially alike, as is plainly seen in the abdomen or tail. in the cephalo-thorax of the lobster, however, this is disguised. it is therefore very interesting to find that in the other crustacean before mentioned, the squilla, the segmentation of the body is more completely preserved, and even the first three segments, which go to compose the head, remain permanently distinct. [illustration: spine of galago allenii.] such an obvious and unmistakeable serial repetition of parts does not obtain in the highest, or backboned animals, the vertebrata. thus in man and other mammals, nothing of the kind is _externally_ visible, and we have to penetrate to his skeleton to find such a series of homologous parts. there, indeed, we discover a number of pairs of bones, each pair so obviously resembling the others, that they all receive a common name--the ribs. there also (_i.e._ in the skeleton) we find a still more remarkable series of similar parts, the joints of the spine or backbone (vertebræ), which are admitted by all to possess a certain community of structure.{163} it is in their limbs, however, that the vertebrata present the most obvious and striking serial homology--almost the only serial homology noticeable externally. the facts of serial homology seem hardly to have excited the amount of interest they certainly merit. very many writers, indeed, have occupied themselves with investigations and speculations as to what portions of the leg and foot answer to what parts of the arm and hand, a question which has only recently received a more or less satisfactory solution through the successive concordant efforts of professor humphry,[163] professor huxley,[164] the author of this work,[165] and professor flower.[166] very few writers, however, have devoted much time or thought to the question of serial homology in general. mr. herbert spencer, indeed, in his very interesting "first principles of biology," has given forth ideas on this subject, which are well worthy careful perusal and consideration, and some of which apply also to the other kinds of homology mentioned above. he would explain the serial homologies of such creatures as the lobster and centipede thus: animals of a very low grade propagate themselves by spontaneous fission. if certain creatures found benefit from this process of division remaining incomplete, such creatures (on the theory of "natural selection") would transmit their selected tendency to such incomplete division to their posterity. in this way, it is conceivable, that animals might arise in the form of long chains of similar segments, each of which chains would consist of a number of imperfectly separated individuals, and be equivalent to a series of separate individuals belonging to kinds in which the fission was complete. in other words, mr. spencer would explain it as the coalescence of {164} organisms of a lower degree of aggregation in one longitudinal series, through survival of the fittest aggregations. this may be so. it is certainly an ingenious speculation, but facts have not yet been brought forward which demonstrate it. had they been so, this kind of serial homology might be termed "homogenetic." the other kind of serial repetitions, namely, those of the vertebral column, are explained by mr. spencer as the results of alternate strains and compressions acting on a primitively homogeneous cylinder. the serial homology of the fore and hind limbs is explained by the same writer as the result of a similarity in the influences and conditions to which they are exposed. serial homologues so formed might be called, as mr. ray lankester has proposed, "homoplastic." but there are, it is here contended, abundant reasons for thinking that the predominant agent in the production of the homologies of the limbs is an _internal_ force or tendency. and if such a power can be shown to be necessary in this instance, it may also be legitimately used to explain such serial homologies as those of the centipede's segments and of the joints of the backbone. at the same time it is not, of course, pretended that external conditions do not contribute their own effects in addition. the presence of this internal power will be rendered more probable if valid arguments can be brought forward against the explanations which mr. herbert spencer has offered. _lateral homology_ (or bilateral symmetry) is the resemblance between the right and left sides of an animal, or of part of an animal; as, _e.g._, between our right hand and our left. it exists more or less at one or other time of life in all animals, except some very lowly organized creatures. in the highest animals this symmetry is laid down at the very dawn of life, the first trace of the future creature being a longitudinal streak--the embryonic "primitive groove." this kind of homology is explained by mr. spencer as the result of the similar way in which conditions affect {165} the right and left sides respectively. [illustration: vertebræ of axolotl.] _vertical homology_ (or vertical symmetry) is the resemblance existing between parts which are placed one above the other beneath. it is much less general and marked than serial, or lateral homology. nevertheless, it is plainly to be seen in the tail region of most fishes, and in the far-extending dorsal (back) and ventral (belly) fins of such kinds as the sole and the flounder. it is also strikingly shown in the bones of the tail of certain efts, as in _chioglossa_, where the complexity of the upper (neural) arch is closely repeated by the inferior one. again, in _spelerpes rubra_, where almost vertically ascending articular processes above are repeated by almost vertically descending articular processes below. also in the axolotl, where there are douple pits, placed side by side, not only superiorly but at the same time inferiorly.[167] this kind of homology is also explained by mr. spencer as the result of the similarity of conditions affecting the two parts. thus he explains the very general absence of symmetry between the dorsal and ventral surfaces of animals by the different conditions to which these two surfaces are respectively exposed, and in the same way he explains the asymmetry of the flat-fishes (_pleuronectidæ_), of snails, &c. now, first, as regards mr. spencer's explanation of animal forms by means of the influence of external conditions, the following observations may be made. abundant instances are brought forward by him of admirable adaptation of structure to circumstances, but as to the immense majority of these it is very difficult, if not impossible, to see _how_ external conditions{166} can have produced, or even tended to have produced them. for example, we may take the migration of one eye of the sole to the other side of its head. what is there here either in the darkness, or the friction, or in any other conceivable external cause, to have produced the first beginning of such an unprecedented displacement of the eye? mr. spencer has beautifully illustrated that correlation which all must admit to exist between the forms of organisms and their surrounding external conditions, but by no means proved that the latter are _the cause_ of the former. [illustration: pleuronectidæ, with the peculiarly placed eye in different positions.] some internal conditions (or in ordinary language some internal power and force) must be conceded to living organisms, otherwise incident forces must act upon them and upon non-living aggregations of matter in the same way and with similar effects. if the mere presence of these incident forces produces so ready a response in animals and plants, it must be that there are, in their case, conditions disposing and enabling them so to respond, according to the old maxim, _quicquid recipitur, recipitur ad modum recipientis_, as the same rays of light which bleach a piece of silk, blacken nitrate of silver. if, therefore, we attribute the forms of organisms to the action of {167} external conditions, _i.e._ of incident forces on their modifiable structure, we give but a partial account of the matter, removing a step back, as it were, the action of the internal condition, power, or force which must be conceived as occasioning such ready modifiability. but indeed it is not at all easy to see how the influence of the surface of the ground or any conceivable condition or force can produce the difference which exists between the ventral and dorsal shields of the carapace of a tortoise, or by what differences of merely external causes the ovaries of the two sides of the body can be made equal in a bat and unequal in a bird. [illustration: an echinus, or sea-urchin. (the spines removed from one-half.)] there is, on the other hand, an _a priori_ reason why we should expect to find that the symmetrical forms of all animals are due to internal causes. this reason is the fact that the symmetrical forms of minerals are undoubtedly due to such causes. it is unnecessary here to do more than allude to the beautiful and complex forms presented by inorganic structures. with regard to organisms, however, the wonderful acanthometræ and the polycystina may be mentioned as presenting complexities of form which can hardly be thought to be due to other than _internal_ causes. the same may be said of the great group of echinoderms, with their amazing{168} variety of component parts. if then internal forces can so build up the most varied structures, they are surely capable of producing the serial, lateral, and vertical symmetries which higher animal forms exhibit. mr. spencer is the more bound to admit this, inasmuch as in his doctrine of "physiological units" he maintains that these organic atoms of his have an innate power of building up and evolving the whole and perfect animal from which they were in each case derived. to build up and evolve the various symmetries here spoken of is not one whit more mysterious. directly to refute mr. spencer's assertion, however, would require the bringing forward of examples of organisms which are ill-adapted to their positions, and out of harmony with their surroundings--a difficult task indeed.[168] secondly, as regards the last-mentioned author's explanation of such serial homology as exists in the centipede and its allies, the very groundwork is open to objection. multiplication by spontaneous fission seems from some recent researches to be much less frequent than has been supposed, and more evidence is required as to the fact of the habitual propagation of _any_ planariæ in this fashion.[169] but even if this were as asserted, {169} nevertheless it fails to explain the peculiar condition presented by _syllis_ and some other annelids, where a new head is formed at intervals in certain segments of the body. here there is evidently an innate tendency to the development at intervals of a complex whole. it is not the budding out or spontaneous fission of certain segments, but the transformation in a definite and very peculiar manner of parts which already exist into other and more complex parts. again, the processes of development presented by some of these creatures do not by any means point to an origin through{170} the linear coalescence of primitively distinct animals by means of imperfect segmentation. thus in certain diptera (two winged flies) the legs, wings, eyes, &c., are derived from masses of formative tissue (termed imaginal disks), which by their mutual approximation together build up parts of the head and body,[170] recalling to mind the development of echinoderms. [illustration: an annelid dividing spontaneously. (a new head having been formed towards the hinder end of the body of the parent.)] again, nicholas wagner found in certain other diptera, the hessian flies, that the larva gives rise to secondary larvæ within it, which develop and burst the body of the primary larva. the secondary larvæ give rise, similarly, to another set within them, and these again to another[171] set. again, the fact that in _tænia echinococcus_ one egg produces numerous individuals, tends to invalidate the argument that the increase of segments during development is a relic of specific genesis. mr. h. spencer seems to deny serial homology to the mollusca, but it is difficult to see why the shell segments of chiton are not such homologues because the segmentation is superficial. similarly the external processes of eolis, doris, &c., are good examples of serial homology, as also are plainly the successive chambers of the orthoceratidæ. nor are parts of a series less serial, because arranged spirally, as in most gasteropods. mr. spencer observes of the molluscous as of the vertebrate animal, "you cannot cut it into transverse slices, each of which contains a digestive organ, a respiratory organ, a reproductive organ, &c."[172] but the same may be said of every single arthropod and annelid if it be meant that all these organs are not contained in every possible slice. while if it be meant that parts of all such organs are contained in certain slices, then some of the mollusca may also be included. another objection to mr. spencer's speculation is derived from considerations which have already been stated, as to past time. for if{171} the annulose animals have been formed by aggregation, we ought to find this process much less perfect in the oldest form. but a complete development, such as already obtains in the lobster, &c., was reached by the eurypterida and trilobites of the palæozoic strata; and annelids, probably formed mainly like those of the present day, abounded during the deposition of the oldest fossiliferous rocks. [illustration: trilobite.] thirdly, and lastly, as regards such serial homology as is exemplified by the backbone of man, there are also several objections to mr. spencer's mechanical explanation. on the theory of evolution most in favour, the first vertebrata were aquatic. now, as natation is generally effected by repeated and vigorous lateral flexions of the body, we ought to find the segmentation much more complete laterally than on the dorsal and ventral aspects of the spinal column. nevertheless, in those species which, taken together, constitute a series of more and more distinctly segmented forms, the segmentation gradually increases _all round_ the central part of the spinal column. mr. spencer[173] thinks it probable that the sturgeon has retained the notochordal (that is, the primitive, unsegmented) structure because it{172} is sluggish. but dr. günther informs me that the sluggishness of the common tope (_galeus vulgaris_) is much like that of the sturgeon, and yet the bodies of its vertebræ are distinct and well-ossified. moreover, the great salamander of japan is much more inert and sluggish than either, and yet it has a well-developed, bony spine. i can learn nothing of the habits of the sharks _hexanchus_, _heptanchus_, and _echinorhinus_, but müller describes them as possessing a persistent _chorda dorsalis_.[174] it may be they have the habits of the tope, but other sharks are amongst the very swiftest and most active of fishes. in the bony pike (_lepidosteus_), the rigidity of the bony scales by which it is completely enclosed must prevent any excessive flexion of the body, and yet its vertebral column presents a degree of ossification and vertebral completeness greater than that found in any other fish whatever. mr. spencer supports his argument by the non-segmentation of the anterior end of the skeletal axis, _i.e._ by the non-segmentation of the skull. but in fact the skull _is_ segmented, and, according to the quasi-vertebral theory of the skull put forward by professor huxley,[175] is probably formed of a number of coalesced segments, of some of which the trabeculæ cranii and the mandibular and hyoidean arches are indications. what is, perhaps, most remarkable however is, that the segmentation of the skull--its separation into the three occipital, parietal, and frontal elements--is most complete and distinct in the highest class, and this can have nothing, however remotely, to do with the cause suggested by mr. spencer. thus, then, there is something to be said in opposition to both the aggregational and the mechanical explanations of serial homology. the explanations suggested are very ingenious, yet repose upon a very {173} small basis of fact. not but that the process of vertebral segmentation may have been sometimes assisted by the mechanical action suggested. it remains now to consider what are the evidences in support of the existence of an internal power, by the action of which these homological manifestations are evolved. it is here contended that there _is_ good evidence of the existence of some such special internal power, and that not only from facts of comparative anatomy, but also from those of teratology[176] and pathology. these facts appear to show, not only that there are homological internal relations, but that they are so strong and energetic as to re-assert and re-exhibit themselves in creatures which, on the darwinian theory, are the descendants of others in which they were much less marked. they are, in fact, sometimes even more plain and distinct in animals of the highest types than in inferior forms, and, moreover, this deep-seated tendency acts even in diseased and abnormal conditions. mr. darwin recognizes[177] these homological relations, and does "not doubt that they may be mastered more or less completely by natural selection." he does not, however, give any explanation of these phenomena other than the imposition on them of the name "laws of correlation;" and indeed he says, "the nature of the bond of correlation is frequently quite obscure." now, it is surely more desirable to make use, if possible, of one conception than to imagine a number of, to all appearance, separate and independent "laws of correlation" between different parts of each animal. [illustration: the aard-vark (orycteropus).] [illustration: the pangolin (manis).] but even some of these alleged laws hardly appear well founded. thus mr. darwin, in support of such a law of concomitant variation as regards hair and teeth, brings forward the case of julia pastrana,[178] and a man {174} of the burmese court, and adds,[179] "these cases and those of the hairless dogs forcibly call to mind the fact that the two orders of mammals, namely, the edentata and cetacea, which are the most abnormal in their dermal covering, are likewise the most abnormal either by deficiency or redundancy of teeth." the assertion with regard to these orders is certainly true, but it should be borne in mind at the same time that the armadillos, which are much more abnormal than are the american anteaters as regards their dermal covering, in their dentition are less so. the cape ant-eater, on the other hand, the aard-vark (orycteropus), has teeth formed on a type quite different from that existing in any other mammal; yet its hairy coat is not known to exhibit any such strange peculiarity. again, those remarkable scaly ant-eaters of the old world--the pangolins (manis)--stand alone amongst mammals as regards their dermal covering; having been classed {175} with lizards by early naturalists on account of their clothing of scales, yet their mouth is like that of the hairy ant-eaters of the new world. on the other hand, the duck-billed platypus of australia (ornithorhynchus) is the only mammal which has teeth formed of horn, yet its furry coat is normal and ordinary. again, the dugong and manatee are dermally alike, yet extremely different as regards the structure and number of their teeth. the porcupine also, in spite of its enormous armature of quills, is furnished with as good a supply of teeth as are the hairy members of the same family, but not with a better one; and in spite of the deficiency of teeth in the hairless dogs, no converse redundancy of teeth has, it is believed, been remarked in angora cats and rabbits. to say the least, then, this law {176} of correlation presents numerous and remarkable exceptions. [illustration: dugong.] to return, however, to the subject of homological relations: it is surely inconceivable that indefinite variation with survival of the fittest can ever have built up these serial, bilateral, and vertical homologies, without the action of some special innate power or tendency so to build up, possessed by the organism itself in each case. by "special tendency" is meant one the laws and conditions of which are as yet unknown, but which is analogous to the innate power and tendency possessed by crystals similarly, to build up certain peculiar and very definite forms. first, with regard to comparative anatomy. the correspondence between the thoracic and pelvic limbs is notorious. professor gegenbaur has lately endeavoured[180] to explain this resemblance by the derivation of each limb from a primitive form of fin. this fin is supposed to have had a marginal external (radial) series of cartilages, each of which supported a series of secondary cartilages, starting from the inner (ulnar) side of the distal part of the supporting marginal piece. the root marginal piece would become the humerus or femur, as the case might be: the second marginal piece, with the piece attached to the inner side of the distal end of the root marginal piece, would together form either the radius and ulna or the tibia and fibula, and so on. now there is little doubt (from _a priori_ considerations) but that the special differentiation of the limb bones of the higher vertebrates has been evolved from anterior conditions existing in some fish-like form or other. but the particular view advocated by the learned professor is open to criticism. thus, it may be objected against this view, first, that it takes no account of the radial ossicle which becomes so enormous in the mole; secondly, that it does not explain the extra series of ossicles {177} which are formed on the _outer_ (radial or marginal) side of the paddle in the ichthyosaurus; and thirdly, and most importantly, that even if this had been the way in which the limbs had been differentiated, it would not be at all inconsistent with the possession of an innate power of producing, and an innate tendency to produce similar and symmetrical homological resemblances. it would not be so because resemblances of the kind are found to exist, which, on the darwinian theory, must be subsequent and secondary, not primitive and ancestral. thus we find in animals of the eft kind (certain amphibians), in which the tarsus is cartilaginous, that the carpus is cartilaginous likewise. and we shall see in cases of disease and of malformation what a tendency there is to a similar affection of homologous parts. in efts, as professor gegenbaur himself has pointed out,[181] there is a striking correspondence between the bones or cartilages supporting the arm, wrist, and fingers, and those sustaining the leg, ankle, and toes, with the exception that the toes exceed the fingers in number by one. [illustration: skeleton of an ichthyosaurus.] [illustration: a. skeleton of anterior extremity of an eft. b. skeleton of posterior extremity of the same.] yet these animals are far from being the root-forms from which all the vertebrata have diverged, as is evidenced from the degree of specialization which their structure presents. if they have descended from such {178} primitive forms as professor gegenbaur imagines, then they have built up a secondary serial homology--a repetition of similar modifications--fully as remarkable as if it were primary. the plesiosauria--those extinct marine reptiles of the secondary period, with long necks, small heads, and paddle-like limbs--are of yet higher organization than are the efts and other amphibia. nevertheless they present us with a similarity of structure between the fore and hind limb, which is so great as almost to be {179} identity. but the amphibia and plesiosauria, though not themselves primitive vertebrate types, may be thought by some to have derived their limb-structure by direct descent from such. tortoises, however, must be admitted to be not only highly differentiated organisms, but to be far indeed removed from primeval vertebrate structure. yet certain tortoises[182] (notably _chelydra temminckii_) exhibit such a remarkable uniformity in fore and hind limb structure (extending even up to the proximal ends of the humerus and femur) that it is impossible to doubt its independent development in these forms. [illustration: skeleton of a plesiosaurus.] again in the potto (perodicticus) there is an extra bone in the foot, situated in the transverse ligament enclosing the flexor tendons. it is noteworthy that in the _hand_ of the same animal a serially homologous structure should also be developed.[183] in the allied form called the slow lemur (nycticebus) we have certain arrangements of the muscles and tendons of the hand which reproduce in great measure those of the foot and _vice versâ_.[184] and in the hyrax another myological resemblance appears.[185] it is, however, needless to multiply instances which can easily be produced in large numbers if required. secondly, with regard to teratology, it is notorious that similar abnormalities are often found to co-exist in both the pelvic and thoracic limbs. m. isidore geoffroy st. hilaire remarks,[186] "l'anomalie se répète d'un membre thoracique au membre abdominal du même côté." and he afterwards quotes from weitbrecht,[187] who had "observé dans un cas l'absence simultanée aux deux mains et aux deux pieds, de quelques doigts, de {180} quelques metacarpiens et metatarsiens, enfin de quelques os du carpe et du tarse." [illustration: long flexor muscles and tendons of the hand. _p.t._ pronator teres. _f.s._ flexor sublimis digitorum. _f.p._ flexor profundus digitorum. _f.l.p._ flexor longus pollicis.] professor burt g. wilder, in his paper on extra digits,[188] has {181} recorded no less than twenty-four cases where such excess coexisted in both little fingers; also one case in which the right little finger and little toe were so affected; six in which it was both the little fingers and both the little toes; and twenty-two other cases more or less the same, but in which the details were not accurately to be obtained. mr. darwin cites[189] a remarkable instance of what he is inclined to regard as the development in the foot of birds of a sort of representation of the wing-feathers of the hand. he says: "in several distinct breeds of the pigeon and fowl the legs and the two outer toes are heavily feathered, so that, in the trumpeter pigeon, they appear like little wings. in the feather-legged bantam, the 'boots,' or feathers, which grow from the outside of the leg, and generally from the two outer toes, have, according to the excellent authority of mr. hewitt, been seen to exceed the wing-feathers in length, and in one case were actually nine and a half inches in length! as mr. blyth has remarked to me, these leg-feathers resemble the primary wing-feathers, and are totally unlike the fine down which naturally grows on the legs of some birds, such as grouse and owls. hence it may be suspected that excess of food has first given redundancy to the plumage, and then that the law of homologous variation has led to the development of feathers on the legs, in a position corresponding with those on the wing, namely, on the outside of the tarsi and toes. i am strengthened in this belief by the following curious case of correlation, which for a long time seemed to me utterly inexplicable,--namely, that in pigeons of any breed, if the legs are feathered, the two outer toes are partially connected by skin. these two outer toes correspond with our third and fourth toes. now, in the wing of the pigeon, or any other bird, the first and fifth digits are wholly aborted; the second is rudimentary, and carries the so-called 'bastard wing;' whilst the third and fourth {182} digits are completely united and enclosed by skin, together forming the extremity of the wing. so that in feather-footed pigeons not only does the exterior surface support a row of long feathers like wing-feathers, but the very same digits which in the wing are completely united by skin become partially united by skin in the feet; and thus, by the law of the correlated variation of homologous parts, we can understand the curious connexion of feathered legs and membrane between the outer toes." irregularities in the circulating system are far from uncommon, and sometimes illustrate this homological tendency. my friend and colleague mr. george g. gascoyen, assistant surgeon at st. mary's hospital, has supplied me with two instances of symmetrical affections which have come under his observation. in the first of these the brachial artery bifurcated almost at its origin, the two halves re-uniting at the elbow-joint, and then dividing into the radial and ulnar arteries in the usual manner. in the second case an aberrant artery was given off from the radial side of the brachial artery, again almost at its origin. this aberrant artery anastomosed below the elbow-joint with the radial side of the radial artery. in each of these cases the right and left sides varied in precisely the same manner. thirdly, as to pathology. mr. james paget,[190] speaking of symmetrical diseases, says: "a certain morbid change of structure on one side of the body is repeated in the exactly corresponding part of the other side." he then quotes and figures a diseased lion's pelvis from the college of surgeons museum, and says of it: "multiform as the pattern is in which the new bone, the product of some disease comparable with a human rheumatism, is deposited--a pattern more complex and irregular than the spots upon a map--there is not one spot or line on one side which is not represented, as exactly as it would be in a mirror, on the other. the likeness has more than daguerreotype exactness." he goes on to observe: "i need not {183} describe many examples of such diseases. any out-patients' room will furnish abundant instances of exact symmetry in the eruptions of eczema, lepra, and psoriasis; in the deformities of chronic rheumatism, the paralyses from lead; in the eruptions excited by iodide of potassium or copaiba. and any large museum will contain examples of equal symmetry in syphilitic ulcerations of the skull; in rheumatic and syphilitic deposits on the tibiæ and other bones; in all the effects of chronic rheumatic arthritis, whether in the bones, the ligaments, or the cartilages; in the fatty and earthy deposits in the coats of arteries."[191] he also considered it to be proved that, "next to the parts which are symmetrically placed, none are so nearly identical in composition as those which are homologous. for example, the backs of the hands and of the feet, or the palms and soles, are often not only symmetrically, but similarly, affected with psoriasis. so are the elbows and the knees; and similar portions of the thighs and the arms may be found affected with ichthyosis. sometimes also specimens of fatty and earthy deposits in the arteries occur, in which exact similarity is shown in the plan, though not in the degree, with which the disease affects severally the humeral and femoral, the radial and peroneal, the ulnar and posterior tibial arteries." dr. william budd[192] gives numerous instances of symmetry in disease, both lateral and serial. thus, amongst others, we have one case (william godfrey), in which the hands and feet were distorted. "the distortion of the right hand is greater than that of the left, of the right foot greater than that of the left foot." in another (elizabeth alford) lepra affected the extensor surfaces of the thoracic and pelvic limbs. again, in the case of skin disease illustrated in plate iii., "the analogy between the {184} elbows and knees is clearly expressed in the fact that these were the only parts affected with the disease."[193] professor burt wilder,[194] in his paper on "pathological polarities," strongly supports the philosophical importance of these peculiar relations, adding arguments in favour of antero-posterior homologies, which it is here unnecessary to discuss, enough having been said, it is believed, to thoroughly demonstrate the existence of these deep internal relations which are named lateral and serial homologies. what explanation can be offered of these phenomena? to say that they exhibit a "nutritional relation" brought about by a "balancing of forces" is merely to give a new denomination to the unexplained fact. the changes are, _of course_, brought about by a "nutritional" process, and the symmetry is undoubtedly the result of a "balance of forces," but to say so is a truism. the question is, what is the cause of this "nutritional balancing"? it is here contended that it must be due to an internal cause which at present science is utterly incompetent to explain. it is an internal property possessed by each living organic whole as well as by each non-living crystalline mass, and that there is such internal power or tendency, which may be spoken of as a "polarity," seems to be demonstrated by the instances above given, which can easily be multiplied indefinitely. mr. herbert spencer[195] (speaking of the reproduction, by budding, of a begonia-leaf) recognizes a power of the kind. he says, "we have, therefore, no alternative but to say that the living particles composing one of these fragments have an innate tendency to arrange themselves into the shape of the organism to which they belong. we must infer that a plant or animal of any species is made up of special units, in all of which there dwells the intrinsic aptitude to aggregate into the form of that species; just as{185} in the atoms of a salt, there dwells the intrinsic aptitude to crystallize in a particular way. it seems difficult to conceive that this can be so; but we see that it _is_ so." ... "for this property there is no fit term. if we accept the word polarity as a name for the force by which inorganic units are aggregated into a form peculiar to them, we may apply this word to the analogous force displayed by organic limits." dr. jeffries wyman,[196] in his paper on the "symmetry and homology of limbs," has a distinct chapter on the "analogy between symmetry and polarity," illustrating it by the effects of magnets on "particles in a polar condition." mr. j. j. murphy, after noticing[197] the power which crystals have to repair injuries inflicted on them and the modifications they undergo through the influence of the medium in which they may be formed, goes on to say:[198] "it needs no proof that in the case of spheres and crystals the forms and the structures are the effect, and not the cause, of the formative principles. attraction, whether gravitative or capillary, produces the spherical form; the spherical form does not produce attraction. and crystalline polarities produce crystalline structure and form; crystalline structure and form do not produce crystalline polarities. the same is not quite so evident of organic forms, but it is equally true of them also." ... "it is not conceivable that the microscope should reveal peculiarities of structure corresponding to peculiarities of habitual tendency in the embryo, which at its first formation has no structure whatever;"[199] and he adds that "there is something quite inscrutable and mysterious" in the formation of a new individual from the germinal {186} matter of the embryo. in another place[200] he says: "we know that in crystals, notwithstanding the variability of form within the limits of the same species, there are definite and very peculiar formative laws, which cannot possibly depend on anything like organic functions, because crystals have no such functions; and it ought not to surprise us if there are similar formative or morphological laws among organisms, which, like the formative laws of crystallization, cannot be referred to any relation of form or structure to function. especially, i think, is this true of the lowest organisms, many of which show great beauty of form, of a kind that appears to be altogether due to symmetry of growth; as the beautiful star-like rayed forms of the _acanthometræ_, which are low animal organisms not very different from the foraminifera." their "definiteness of form does not appear to be accompanied by any corresponding differentiation of function between different parts; and, so far as i can see, the beautiful regularity and symmetry of their radiated forms are altogether due to unknown laws of symmetry of growth, just like the equally beautiful and somewhat similar forms of the compound six-rayed, star-shaped crystals of snow." altogether, then, it appears that each organism has an innate tendency to develop in a symmetrical manner, and that this tendency is controlled and subordinated by the action of external conditions, and not that this symmetry is superinduced only _ab externo_. in fact, that each organism has its own internal and special laws of growth and development. if, then, it is still necessary to conceive an internal law or "substantial form," moulding each organic being,[201] and directing its development{187} as a crystal is built up, only in an indefinitely more complex manner, it is congruous to imagine the existence of some internal law accounting at the same time for specific divergence as well as for specific identity. a principle regulating the successive evolution of different organic forms is not one whit more mysterious than is the mysterious power by which a particle of structureless sarcode develops successively into an egg, a grub, a chrysalis, a butterfly, when all the conditions, cosmical, physical, chemical, and vital, are supplied, which are the requisite accompaniments to determine such evolution. [page 188] * * * * * chapter ix. evolution and ethics. the origin of morals an inquiry not foreign to the subject of this book.--modern utilitarian view as to that origin.--mr. darwin's speculation as to the origin of the abhorrence of incest.--cause assigned by him insufficient.--care of the aged and infirm opposed by "natural selection;" also self-abnegation and asceticism.--distinctness of the ideas "right" and "useful."--mr. john stuart mill.--insufficiency of "natural selection" to account for the origin of the distinction between duty and profit.---distinction of moral acts into "material" and "formal."--no ground for believing that formal morality exists in brutes.--evidence that it does exist in savages.--facility with which savages may be misunderstood.--objections as to diversity of customs.--mr. hutton's review of mr. herbert spencer.--anticipatory character of morals.--sir john lubbock's explanation.--summary and conclusion. any inquiry into the origin of the notion of "morality"--the conception of "right"--may, perhaps, be considered as somewhat remote from the question of the genesis of species; the more so, since mr. darwin, at one time, disclaimed any pretension to explain the origin of the higher psychical phenomena of man. his disciples, however, were never equally reticent, and indeed he himself is now not only about to produce a work on man (in which this question must be considered), but he has distinctly announced the extension of the application of his theory to the very phenomena in question. he says:[202] "in the distant future i see open fields for {189} far more important researches. psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. light will be thrown on the origin of man and his history." it may not be amiss then to glance slightly at the question, so much disputed, concerning the origin of ethical conceptions and its bearing on the theory of "natural selection." the followers of mr. john stuart mill, of mr. herbert spencer, and apparently, also, of mr. darwin, assert that in spite of the great _present_ difference between the ideas "useful" and "right," yet that they are, nevertheless, one in _origin_, and that that origin consisted ultimately of pleasurable and painful sensations. they say that "natural selection" has evolved moral conceptions from perceptions of what was useful, _i.e._ pleasurable, by having through long ages preserved a predominating number of those individuals who have had a natural and spontaneous liking for practices and habits of mind useful to the race, and that the same power has destroyed a predominating number of those individuals who possessed a marked tendency to contrary practices. the descendants of individuals so preserved have, they say, come to inherit such a liking and such useful habits of mind, and that at last (finding this inherited tendency thus existing in themselves, distinct from their tendency to conscious self-gratification) they have become apt to regard it as fundamentally distinct, _innate_, and independent of all experience. in fact, according to this school, the idea of "right" is only the result of the gradual accretion of useful predilections which, from time to time, arose in a series of ancestors naturally selected. in this way, "morality" is, as it were, the congealed past experience of the race, and "virtue" becomes no more than a sort of "retrieving," which the thus improved human animal practises by a perfected and inherited habit, regardless of self-gratification, just as the brute animal has acquired the habit of seeking prey and bringing it to his master, instead of devouring it {190} himself. though mr. darwin has not as yet expressly advocated this view, yet some remarks made by him appear to show his disposition to sympathise with it. thus, in his work on "animals and plants under domestication,"[203] he asserts that "the savages of australia and south america hold the crime of incest in abhorrence;" but he considers that this abhorrence has probably arisen by "natural selection," the ill effects of close interbreeding causing the less numerous and less healthy offspring of incestuous unions to disappear by degrees, in favour of the descendants (greater both in number and strength) of individuals who naturally, from some cause or other, as he suggests, preferred to mate with strangers rather than with close blood-relations; this preference being transmitted and becoming thus instinctive, or habitual, in remote descendants. but on mr. darwin's own ground, it maybe objected that this notion fails to account for "abhorrence," and "moral reprobation;" for, as no stream can rise higher than its source, the original "slight feeling" which was _useful_ would have been perpetuated, but would never have been augmented beyond the degree requisite to ensure this beneficial preference, and therefore would not certainly have become magnified into "abhorrence." it will not do to assume that the union of males and females, each possessing the required "slight feeling," must give rise to offspring with an intensified feeling of the same kind; for, apart from reversion, mr. darwin has called attention to the unexpected modifications which sometimes result from the union of _similarly_ constituted parents. thus, for example, he tells us:[204] "if two top-knotted canaries are matched, the young, instead of having very fine top-knots, are generally bald." from examples of this kind, it is fair, on darwinian principles, to infer that the union of {191} parents who possessed a similar inherited aversion might result in phenomena quite other than the augmentation of such aversion, even if the two aversions should be altogether similar; while, very probably, they might be so different in their nature as to tend to neutralize each other. besides, the union of parents so similarly emotional would be rare indeed amongst savages, where marriages would be owing to almost anything rather than to congeniality of mind between the spouses. mr. wallace tells us,[205] that they choose their wives for "rude health and physical beauty," and this is just what might be naturally supposed. again, we must bear in mind the necessity there is that _many individuals_ should be similarly and simultaneously affected with this aversion from consanguineous unions; as we have seen in the second chapter, how infallibly variations presented by only a few individuals, tend to be eliminated by mere force of numbers. mr. darwin indeed would throw back this aversion, if possible, to a pre-human period; since he speculates as to whether the gorillas or orang-utans, in effecting their matrimonial relations, show any tendency to respect the prohibited degrees of affinity.[206] no tittle of evidence, however, has yet been adduced pointing in any such direction, though surely if it were of such importance and efficiency as to result (through the aid of "natural selection" alone) in that "abhorrence" before spoken of, we might expect to be able to detect unmistakeable evidence of its incipient stages. on the contrary, as regards the ordinary apes (for with regard to the highest there is no evidence of the kind) as we see them in confinement, it would be difficult to name any animals less restricted, by even a generic bar, in the gratification of the sexual instinct. and although the conditions under which they have been observed are abnormal, yet these are hardly the animals to present us in a state of nature, with an extraordinary and exceptional sensitiveness in such matters. [page 192] to take an altogether different case. care of, and tenderness towards, the aged and infirm are actions on all hands admitted to be "right;" but it is difficult to see how such actions could ever have been so useful to a community as to have been seized on and developed by the exclusive action of the law of the "survival of the fittest." on the contrary, it seems probable that on strict utilitarian principles the rigid political economy of tierra del fuego would have been eminently favoured and diffused by the impartial action of "natural selection" alone. by the rigid political economy referred to, is meant that destruction and utilization of "useless mouths" which mr. darwin himself describes in his highly interesting "journal of researches."[207] he says: "it is certainly true, that when pressed in winter by hunger, they kill and devour their old women before they kill their dogs. the boy being asked why they did this, answered, 'doggies catch otters, old women no.' they often run away into the mountains, but they are pursued by the men and brought back to the slaughter-house at their own firesides." mr. edward bartlett, who has recently returned from the amazons, reports that at one indian village where the cholera made its appearance, the whole population immediately dispersed into the woods, leaving the sick to perish uncared for and alone. now, had the indians remained, undoubtedly far more would have died; as doubtless, in tierra del fuego, the destruction of the comparatively useless old women has often been the means of preserving the healthy and reproductive young. such acts surely must be greatly favoured by the stern and unrelenting action of exclusive "natural selection." in the same way that admiration which all feel for acts of self-denial done for the good of others, and tending even towards the destruction of the actor, could hardly be accounted for on darwinian principles alone; for self-immolators must but rarely leave direct descendants, while the community they benefit must by their destruction tend, so far, to {193} morally deteriorate. but devotion to others of the same community is by no means _all_ that has to be accounted for. devotion to the whole human race, and devotion to god--in the form of asceticism--have been and are very generally recognized as "good;" and the author contends that it is simply impossible to conceive that such ideas and sanctions should have been developed by "natural selection" alone, from only that degree of unselfishness necessary for the preservation of brutally barbarous communities in the struggle for life. that degree of unselfishness once attained, further improvement would be checked by the mutual opposition of diverging moral tendencies and spontaneous variations in all directions. added to which, we have the principle of reversion and atavism, tending powerfully to restore and reproduce that more degraded anterior condition whence the later and better state painfully emerged. very few, however, dispute the complete distinctness, here and now, of the ideas of "duty" and "interest" whatever may have been the origin of those ideas. no one pretends that ingratitude may, in any past abyss of time, have been a virtue, or that it may be such now in arcturus or the pleiades. indeed, a certain eminent writer of the utilitarian school of ethics has amusingly and very instructively shown how radically distinct even in his own mind are the two ideas which he nevertheless endeavours to identify. mr. john stuart mill, in his examination of "sir william hamilton's philosophy," says,[208] if "i am informed that the world is ruled by a being whose attributes are infinite, but what they are we cannot learn, nor what the principles of his government, except that 'the highest human morality which we are capable of conceiving' does not sanction them; convince me of it, and i will bear my fate as i may. but when i am told that i must believe this, and at the same time call this being by the {194} names which express and affirm the highest human morality, i say in plain terms that i will not. whatever power such a being may have over me, there is one thing which he shall not do: he shall not compel me to worship him. i will call no being good, who is not what i mean when i apply that epithet to my fellow-creatures; and if such a being can sentence me to hell for not so calling him, to hell i will go." this is unquestionably an admirable sentiment on the part of mr. mill (with which every absolute moralist will agree), but it contains a complete refutation of his own position, and is a capital instance[209] of the vigorous life of moral intuition in one who professes to have eliminated any fundamental distinction between the "right" and the "expedient." for if an action is morally good, and to be done, merely in proportion to the amount of pleasure it secures, and morally bad and to be avoided as tending to misery, and if it could be _proved_ that by calling god good--whether he is so or not, in our sense of the term,--we could secure a maximum of pleasure, and by refusing to do so we should incur endless torment, clearly, on utilitarian principles, the flattery would be good. mr. mill, of course, must also mean that, in the matter in question, all men would do well to act with him. therefore, he must mean that it would be well for all to accept (on the hypothesis above given) infinite and final misery for all as the result of the pursuit of happiness as the only end. it must be recollected that in consenting to worship this unholy god, mr. mill is not asked to do harm to his neighbour, so that his refusal reposes simply on his perception of the immorality of the requisition. it is also noteworthy that an omnipotent deity is supposed incapable of altering mr. mill's mind and moral perceptions. mr. mill's decision is right, but it is difficult indeed to see how, {195} without the recognition of an "absolute morality," he can justify so utter and final an abandonment of all utility in favour of a clear and distinct moral perception. these two ideas, the "right" and the "useful," being so distinct here and now, a greater difficulty meets us with regard to their origin from some common source, than met us before when considering the first beginnings of certain bodily structures. for the distinction between the "right" and the "useful" is so fundamental and essential that not only does the idea of benefit not enter into the idea of duty, but we see that the very fact of an act _not_ being beneficial to us makes it the more praiseworthy, while gain tends to diminish the merit of an action. yet this idea, "right," thus excluding, as it does, all reference to utility or pleasure, has nevertheless to be constructed and evolved from utility and pleasure, and ultimately from pleasurable sensations, if we are to accept pure darwinianism: if we are to accept, that is, the evolution of man's psychical nature and highest powers, by the exclusive action of "natural selection," from such faculties as are possessed by brutes; in other words, if we are to believe that the conceptions of the highest human morality arose through minute and fortuitous variations of brutal desires and appetites in all conceivable directions. it is here contended, on the other hand, that no conservation of any such variations could ever have given rise to the faintest beginning of any such moral perceptions; that by "natural selection" alone the maxim _fiat justitia, ruat coelum_ could never have been excogitated, still less have found a widespread acceptance; that it is impotent to suggest even an approach towards an explanation of the _first beginning_ of the idea of "right." it need hardly be remarked that acts may be distinguished not only as pleasurable, useful, or beautiful, but also as good in two different senses: (1) _materially_ moral acts, and (2) acts which are _formally_ moral. the first are acts good in themselves, _as acts_, apart from any intention of the agent which may or may not have been directed towards{196} "right." the second are acts which are good not only in themselves, as acts, but also in the deliberate _intention_ of the agent who recognizes his actions as being "right." thus acts may be _materially_ moral or immoral, in a very high degree, without being in the least _formally_ so. for example, a person may tend and minister to a sick man with scrupulous care and exactness, having in view all the time nothing but the future reception of a good legacy. another may, in the dark, shoot his own father, taking him to be an assassin, and so commit what is _materially_ an act of parricide, though _formally_ it is only an act of self-defence of more or less culpable rashness. a woman may innocently, because ignorantly, marry a married man, and so commit a _material_ act of adultery. she may discover the facts, and persist, and so make her act _formal_ also. actions of brutes, such as those of the bee, the ant, or the beaver, however materially good as regards their relation to the community to which such animals belong, are absolutely destitute of the most incipient degree of real, _i.e._ formal "goodness," because unaccompanied by mental acts of conscious will directed towards the fulfilment of duty. apology is due for thus stating so elementary a distinction, but the statement is not superfluous, for confusion of thought, resulting from confounding together these very distinct things, is unfortunately far from uncommon. thus some darwinians assert that the germs of morality exist in brutes, and we have seen that mr. darwin himself speculates on the subject as regards the highest apes. it may safely be affirmed, however, that there is no trace in brutes of any actions simulating morality which are not explicable by the fear of punishment, by the hope of pleasure, or by personal affection. no sign of moral reprobation is given by any brute, and yet had such existed in germ through darwinian abysses of past time, some evidence of its existence must surely have been rendered perceptible through "survival of the fittest" in other forms besides man, if that {197} "survival" has alone and exclusively produced it in him. abundant examples may, indeed, be brought forward of useful acts which simulate morality, such as parental care of the young, &c. but did the most undeviating habits guide all brutes in such matters, were even aged and infirm members of a community of insects or birds carefully tended by young which benefited by their experience, such acts would not indicate even the faintest rudiment of real, _i.e._ formal, morality. "natural selection" would, of course, often lead to the prevalence of acts beneficial to a community, and to acts _materially_ good; but unless they can be shown to be _formally_ so, they are not in the least to the point, they do not offer any explanation of the origin of an altogether new and fundamentally different motive and conception. it is interesting, on the other hand, to note mr. darwin's statement as to the existence of a distinct moral feeling, even in, perhaps, the very lowest and most degraded of all the human races known to us. thus in the same "journal of researches"[210] before quoted, bearing witness to the existence of moral reprobation on the part of the fuegians, he says: "the nearest approach to religious feeling which i heard of was shown by york minster (a fuegian so named), who, when mr. bynoe shot some very young ducklings as specimens, declared in the most solemn manner, 'oh, mr. bynoe, much rain, snow, blow much.' this was evidently a retributive punishment for wasting human food." mr. wallace gives the most interesting testimony, in his "malay archipelago," to the existence of a very distinct, and in some instances highly developed moral sense in the natives with whom he came in contact. in one case,[211] a papuan who had been paid in advance for bird-skins and who had not been able to fulfil his contract before mr. wallace was on{198} the point of starting, "came running down after us holding up a bird, and saying with great satisfaction, 'now i owe you nothing!'" and this though he could have withheld payment with complete impunity. mr. wallace's observations and opinions on this head seem hardly to meet with due appreciation in sir john lubbock's recent work on primitive man.[212] but considering the acute powers of observation and the industry of mr. wallace, and especially considering the years he passed in familiar and uninterrupted intercourse with natives, his opinion and testimony should surely carry with it great weight. he has informed the author that he found a strongly marked and widely diffused modesty, in sexual matters, amongst all the tribes with which he came in contact. in the same way mr. bonwick, in his work on the tasmanians, testifies to the modesty exhibited by the naked females of that race, who by the decorum of their postures gave evidence of the possession in germ of what under circumstances would become the highest chastity and refinement. hasty and incomplete observations and inductions are prejudicial enough to physical science, but when their effect is to degrade untruthfully our common humanity, there is an additional motive to regret them. a hurried visit to a tribe, whose language, traditions and customs are unknown, is sometimes deemed sufficient for "smart" remarks as to "ape characters," &c., which are as untrue as irrelevant. it should not be forgotten how extremely difficult it is to enter into the ideas and feelings of an alien race. if in the nineteenth century a french theatrical audience can witness with acquiescent approval, as a type of english manners and ideas, the representation of a marquis who sells his wife at smithfield, &c. &c., it is surely no wonder if the ideas of a tribe of newly visited savages {199} should be more or less misunderstood. to enter into such ideas requires long and familiar intimacy, like that experienced by the explorer of the malay archipelago. from him, and others, we have abundant evidence that moral ideas exist, at least in germ, in savage races of men, while they sometimes attain even a highly developed state. no amount of evidence as to acts of moral depravity is to the point, as the object here aimed at is to establish that moral intuitions _exist_ in savages, not that their actions are good. objections, however, are sometimes drawn from the different notions as to the moral value of certain acts, entertained by men of various countries or of different epochs; also from the difficulty of knowing what particular actions in certain cases are the right ones, and from the effects which prejudice, interest, passion, habit, or even, indirectly, physical conditions, may have upon our moral perceptions. thus sir john lubbock speaks[213] of certain feejeeans, who, according to the testimony of mr. hunt,[214] have the custom of piously choking their parents under certain circumstances, in order to insure their happiness in a future life. should any one take such facts as telling _against_ the belief in an absolute morality, he would show a complete misapprehension of the point in dispute; for such facts tell in _favour_ of it. were it asserted that man possesses a distinct innate power and faculty by which he is made intuitively aware what acts considered in and by themselves are right and what wrong,--an infallible and universal internal code,--the illustration would be to the point. but all that need be contended for is that the intellect perceives not only truth, but also a quality of "higher" which ought to be followed, and of "lower" which ought to be avoided; when two lines of conduct are presented to the will for choice, the intellect so acting being the conscience. {200} this has been well put by mr. james martineau in his excellent essay on whewell's morality. he says,[215] "if moral good were a quality resident in each action, as whiteness in snow, or sweetness in fruits; and if the moral faculty was our appointed instrument for detecting its presence; many consequences would ensue which are at variance with fact. the wide range of differences observable in the ethical judgments of men would not exist; and even if they did, could no more be reduced and modified by discussion than constitutional differences of hearing or of vision. and, as the quality of moral good either must or must not exist in every important operation of the will, we should discern its presence or absence separately in each; and even though we never had the conception of more than one insulated action, we should be able to pronounce upon its character. this, however, we have plainly no power to do. every moral judgment is relative, and involves a comparison of two terms. when we praise what _has been_ done, it is with the coexistent conception of something _else_ that _might have been_ done; and when we resolve on a course as right, it is to the exclusion of some other that is wrong. this fact, that every ethical decision is in truth a _preference_, an election of one act as higher than another, appears of fundamental importance in the analysis of the moral sentiments." from this point of view it is plain how trifling are arguments drawn from the acts of a savage, since an action highly immoral in us might be one exceedingly virtuous in him--being the highest presented to his choice in his degraded intellectual condition and peculiar circumstances. it need only be contended, then, that there _is_ a perception of "right" incapable of further analysis; not that there is any infallible internal guide as to all the complex actions which present themselves for {201} choice. the _principle_ is given in our nature, the _application_ of the principle is the result of a thousand educational influences. it is no wonder, then, that, in complex "cases of conscience," it is sometimes a matter of exceeding difficulty to determine which of two courses of action is the less objectionable. this no more invalidates the truth of moral principles than does the difficulty of a mathematical problem cast doubt on mathematical principles. habit, education, and intellectual gifts facilitate the correct application of both. again, if our moral insight is intensified or blunted by our habitual wishes or, indirectly, by our physical condition, the same may be said of our perception of the true relations of physical facts one to another. an eager wish for marriage has led many a man to exaggerate the powers of a limited income, and a fit of dyspepsia has given an unreasonably gloomy aspect to more than one balance-sheet. considering that moral intuitions have to do with _insensible_ matters, they cannot be expected to be more clear than the perception of physical facts. and if the latter perceptions may be influenced by volition, desire, or health, our moral views may also be expected to be so influenced, and this in a higher degree because they so often run counter to our desires. a bottle or two of wine may make a sensible object appear double; what wonder, then, if our moral perceptions are sometimes warped and distorted by such powerful agencies as an evil education or an habitual absence of self-restraint. in neither case does occasional distortion invalidate the accuracy of normal and habitual perception. the distinctness here and now of the ideas of "right" and "useful" is however, as before said, fully conceded by mr. herbert spencer, although he contends that these conceptions are one in root and origin. his utilitarian genesis of morals, however, has been recently combated{202} by mr. richard holt hutton in a paper which appeared in _macmillan's magazine_.[216] this writer aptly objects an _argumentum ad hominem_, applying to morals the same argument that has been applied in this work to our sense of musical harmony, and by mr. wallace to the vocal organs of man. mr. herbert spencer's notions on the subject are thus expressed by himself: "to make my position fully understood, it seems needful to add that, corresponding to the fundamental propositions of a developed moral science, there have been, and still are developing in the race certain fundamental moral intuitions; and that, though these moral intuitions are the result of accumulated experiences of utility gradually organized and inherited, they have come to be quite independent of conscious experience. just in the same way that i believe the intuition of space possessed by any living individual to have arisen from organized and consolidated experiences of all antecedent individuals, who bequeathed to him their slowly developed nervous organizations; just as i believe that this intuition, requiring only to be made definite and complete by personal experiences, has practically become a form of thought quite independent of experience;--so do i believe that the experiences of utility, organized and consolidated through all past generations of the human race, have been producing corresponding nervous modifications which, by continued transmissions and accumulation, have become in us certain faculties of moral intuition, active emotions responding to right and wrong conduct, which have no apparent basis in the individual experiences of utility. i also hold that, just as the space intuition responds to the exact demonstrations of geometry, and has its rough conclusions interpreted and verified by them, so will moral intuitions respond to the demonstrations of moral science, and will have their rough conclusions interpreted and verified by them." {203} against this view of mr. herbert spencer, mr. hutton objects--"1. that even as regards mr. spencer's illustration from geometrical intuitions, his process would be totally inadequate, since you could not deduce the necessary space intuition of which he speaks from any possible accumulations of familiarity with space relations.... we cannot _inherit_ more than our fathers _had_: no amount of experience of facts, however universal, can give rise to that particular characteristic of intuitions and _a priori_ ideas, which compels us to deny the possibility that in any other world, however otherwise different, our experience (as to space relations) could be otherwise. "2. that the case of moral intuitions is very much stronger. "3. that if mr. spencer's theory accounts for anything, it accounts not for the deepening of a sense of utility and inutility into right and wrong, but for the drying up of the sense of utility and inutility into mere inherent tendencies, which would exercise over us not _more_ authority but _less_, than a rational sense of utilitarian issues. "4. that mr. spencer's theory could not account for the intuitional sacredness now attached to _individual_ moral rules and principles, without accounting _a fortiori_ for the general claim of the greatest happiness principle over us as the final moral intuition---which is conspicuously contrary to the fact, as not even the utilitarians themselves plead any instinctive or intuitive sanction for their great principle. "5. that there is no trace of positive evidence of any single instance of the transformation of a utilitarian rule of right into an intuition, since we find no utilitarian principle of the most ancient times which is now an accepted moral intuition, nor any moral intuition, however sacred, which has not been promulgated thousands of years ago, and which has not constantly had to stop the tide of utilitarian _objections_ to its authority--and this age after age, in our own day quite as much as in days gone by.... surely, if anything is remarkable in the history of {204} morality, it is the _anticipatory_ character, if i may use the expression, of moral principles--the intensity and absoluteness with which they are laid down ages before the world has approximated to the ideal thus asserted." sir john lubbock, in his work on primitive man before referred to, abandons mr. spencer's explanation of the genesis of morals while referring to mr. hutton's criticisms on the subject. sir john proposes to substitute "deference to authority" instead of "sense of interest" as the origin of our conception of "duty," saying that what has been found to be beneficial has been traditionally inculcated on the young, and thus has become to be dissociated from "interest" in the mind, though the inculcation itself originally sprung from that source. this, however, when analysed, turns out to be a distinction without a difference. it is nothing but utilitarianism, pure and simple, after all. for it can never be intended that authority is obeyed because of an intuition that it _should be deferred to_, for that would be to admit the very principle of absolute morality which sir john combats. it must be meant, then, that authority is obeyed through fear of the consequences of disobedience, or through pleasure felt in obeying the authority which commands. in the latter case we have "pleasure" as the end and no rudiment of the conception "duty." in the former we have fear of punishment, which appeals directly to the sense of "utility to the individual," and no amount of such a sense will produce the least germ of "ought" which is a conception different _in kind_, and in which the notion of "punishment" has no place. thus, sir john lubbock's explanation only concerns a _mode_ in which the sense of "duty" may be stimulated or appealed to, and makes no approximation to an explanation of its origin. could the views of mr. herbert spencer, of mr. mill, or of mr. darwin on this subject be maintained, or should they come to be generally accepted, the consequences would be disastrous indeed! were it really the case that virtue was a _mere kind of "retrieving,"_ then certainly we should {205} have to view with apprehension the spread of intellectual cultivation, which would lead the human "retrievers" to regard from a new point of view their fetching and carrying. we should be logically compelled to acquiesce in the vociferations of some continental utilitarians, who would banish altogether the senseless words "duty" and "merit;" and then, one important influence which has aided human progress being withdrawn, we should be reduced to hope that in this case the maxim _cessante causa cessat ipse effectus_ might through some incalculable accident fail to apply. it is true that mr. spencer tries to erect a safeguard against such moral disruption, by asserting that for every immoral act, word, or thought, each man during this life receives minute and exact retribution, and that thus a regard for individual self-interest will effectually prevent any moral catastrophe. but by what means will he enforce the acceptance of a dogma which is not only incapable of proof, but is opposed to the commonly received opinion of mankind in all ages? ancient literature, sacred and profane, teems with protests against the successful evil-doer, and certainly, as mr. hutton observes,[217] "honesty must have been associated by our ancestors with many unhappy as well as many happy consequences, and we know that in ancient greece dishonesty was openly and actually associated with happy consequences.... when the concentrated experience of previous generations was held, _not_ indeed to justify, but to excuse by utilitarian considerations, craft, dissimulation, sensuality, selfishness." this dogma is opposed to the moral consciousness of many as to the events of their own lives; and the author, for one, believes that it is absolutely contrary to fact. history affords multitudes of instances, but an example may be selected from one of the most critical periods of modern times. let it be {206} granted that lewis the sixteenth of france and his queen had all the defects attributed to them by the most hostile of serious historians; let all the excuses possible be made for his predecessor, lewis the fifteenth, and also for madame de pompadour, can it be pretended that there are grounds for affirming that the vices of the two former so far exceeded those of the latter, that their respective fates were plainly and evidently just? that while the two former died in their beds, after a life of the most extreme luxury, the others merited to stand forth through coming time as examples of the most appalling and calamitous tragedy? this theme, however, is too foreign to the immediate matter in hand to be further pursued, tempting as it is. but a passing protest against a superstitious and deluding dogma may stand,--a dogma which may, like any other dogma, be vehemently asserted and maintained, but which is remarkable for being destitute, at one and the same time, of both authoritative sanction and the support of reason and observation. to return to the bearing of moral conceptions on "natural selection," it seems that, from the reasons given in this chapter, we may safely affirm--1. that "natural selection" could not have produced, from the sensations of pleasure and pain experienced by brutes, a higher degree of morality than was useful; therefore it could have produced any amount of "beneficial habits," but not abhorrence of certain acts as impure and sinful. 2. that it could not have developed that high esteem for acts of care and tenderness to the aged and infirm which actually exists, but would rather have perpetuated certain low social conditions which obtain in some savage localities. 3. that it could not have evolved from ape sensations the noble virtue of a marcus aurelius, or the loving but manly devotion of a st. lewis. 4. that, alone, it could not have given rise to the maxim _fiat justitia, ruat coelum_. [page 207] 5. that the interval between material and formal morality is one altogether beyond its power to traverse. also, that the anticipatory character of moral principles is a fatal bar to that explanation of their origin which is offered to us by mr. herbert spencer. and, finally, that the solution of that origin proposed recently by sir john lubbock is a mere version of simple utilitarianism, appealing to the pleasure or safety of the individual, and therefore utterly incapable of solving the riddle it attacks. such appearing to be the case as to the power of "natural selection," we, nevertheless, find moral conceptions--_formally_ moral ideas--not only spread over the civilized world, but manifesting themselves unmistakeably (in however rudimentary a condition, and however misapplied) amongst the lowest and most degraded of savages. if from amongst these, individuals can be brought forward who seem to be destitute of any moral conception, similar cases also may easily be found in highly civilized communities. such cases tell no more against moral intuitions than do cases of colour-blindness or idiotism tell against sight and reason. we have thus a most important and conspicuous fact, the existence of which is fatal to the theory of "natural selection," as put forward of late by mr. darwin and his most ardent followers. it must be remarked, however, that whatever force this fact may have against a belief in the origination of man from brutes by minute, fortuitous variations, it has no force whatever against the conception of the orderly evolution and successive manifestation of specific forms by ordinary natural law--even if we include amongst such the upright frame, the ready hand and massive brain of man himself. [page 208] * * * * * chapter x. pangenesis. a provisional hypothesis supplementing "natural selection."--statement of the hypothesis.--difficulty as to multitude of gemmules.--as to certain modes of reproduction.--as to formations without the requisite gemmules.--mr. lewes and professor delpino.--difficulty as to developmental force of gemmules.--as to their spontaneous fission.--pangenesis and vitalism.--paradoxical reality.--pangenesis scarcely superior to anterior hypotheses.--buffon.--owen.--herbert spencer.--"gemmules" as mysterious as "physiological units."--conclusion. in addition to the theory of "natural selection," by which it has been attempted to account for the origin of species, mr. darwin has also put forward what he modestly terms "a provisional hypothesis" (that of _pangenesis_), by which to account for the origin of each and every individual form. now, though the hypothesis of pangenesis is no necessary part of "natural selection," still any treatise on specific origination would be incomplete if it did not take into consideration this last speculation of mr. darwin. the hypothesis in question may be stated as follows: that each living organism is ultimately made up of an almost infinite number of minute particles, or organic atoms, termed "gemmules," each of which has the power of reproducing its kind. moreover, that these particles circulate freely about the organism which is made up of them, and are derived from all the parts of all the organs of the less remote ancestors of each such {209} organism during all the states and stages of such several ancestors' existence; and therefore of the several states of each of such ancestors' organs. that such a complete collection of gemmules is aggregated in each ovum and spermatozoon in most animals, and in each part capable of reproducing by gemmation (budding) in the lowest animals and in plants. therefore in many of such lower organisms such a congeries of ancestral gemmules must exist in every part of their bodies, since in them every part is capable of reproducing by gemmation. mr. darwin must evidently admit this, since he says: "it has often been said by naturalists that each cell of a plant has the actual or potential capacity of reproducing the whole plant; but it has this power only in virtue of containing gemmules _derived from every part_."[218] moreover, these gemmules are supposed to tend to aggregate themselves, and to reproduce in certain definite relations to other gemmules. thus, when the foot of an eft is cut off, its reproduction is explained by mr. darwin as resulting from the aggregation of those floating gemmules which come next in order to those of the cut surface, and the successive aggregations of the other kinds of gemmules which come after in regular order. also, the most ordinary processes of repair are similarly accounted for, and the successive development of similar parts and organs in creatures in which such complex evolutions occur is explained in the same way, by the independent action of separate gemmules. in order that each living creature may be thus furnished, the number of such gemmules in each must be inconceivably great. mr. darwin says:[219] "in a highly organized and complex animal, the gemmules thrown off from each different cell or unit throughout the body must be inconceivably numerous and minute. each unit of each part, as it changes during development--and we know that some insects undergo at least twenty {210} metamorphoses--must throw off its gemmules. all organic beings, moreover, include many dormant gemmules derived from their grandparents and more remote progenitors, but not from all their progenitors. these _almost infinitely numerous_ and minute gemmules must be included in each bud, ovule, spermatozoon, and pollen grain." we have seen also that in certain cases a similar multitude of gemmules must be included also in every considerable part of the whole body of each organism, but where are we to stop? there must be gemmules not only from every organ, but from every component part of such organ, from every subdivision of such component part, and from every cell, thread, or fibre entering into the composition of such subdivision. moreover, not only from all these, but from each and every successive stage of the evolution and development of such successively more and more elementary parts. at the first glance this new atomic theory has charms from its apparent simplicity, but the attempt thus to follow it out into its ultimate limits and extreme consequences seems to indicate that it is at once insufficient and cumbrous. mr. darwin himself is, of course, fully aware that there must be _some_ limit to this aggregation of gemmules. he says:[220] "excessively minute and numerous as they are believed to be, an infinite number derived, during a long course of modification and descent, from each cell of each progenitor, could not be supported and nourished by the organism." but apart from these matters, which will be more fully considered further on, the hypothesis not only does not appear to account for certain phenomena which, in order to be a valid theory, it ought to account for; but it seems absolutely to conflict with patent and notorious facts. how, for example, does it explain the peculiar reproduction which is {211} found to take place in certain marine worms--certain annelids? [illustration: an annelid dividing spontaneously. (a new head having been formed towards the hinder end of the body of the parent.)] in such creatures we see that, from time to time, one of the segments of the body gradually becomes modified till it assumes the condition of a head, and this remarkable phenomenon is repeated again and again, the body of the worm thus multiplying serially into new individuals which successively detach themselves from the older portion. the development of such a mode of reproduction by "natural selection" seems not less inexplicable than does its continued performance through the aid of {212} "pangenesis." for how can gemmules attach themselves to others to which they do not normally or generally succeed? scarcely less difficult to understand is the process of the stomach-carrying-off mode of metamorphosis before spoken of as existing in the echinoderms. next, as to certain patent and notorious facts: on the hypothesis of pangenesis, no creature can develop an organ unless it possesses the component gemmules which serve for its formation. no creature can possess such gemmules unless it inherits them from its parents, grandparents, or its less remote ancestors. now, the jews are remarkably scrupulous as to marriage, and rarely contract such a union with individuals not of their own race. this practice has gone on for thousands of years, and similarly also for thousands of years the rite of circumcision has been unfailingly and carefully performed. if then the hypothesis of pangenesis is well founded, that rite ought to be now absolutely or nearly superfluous from the necessarily continuous absence of certain gemmules through so many centuries and so many generations. yet it is not at all so, and this fact seems to amount almost to an experimental demonstration that the hypothesis of pangenesis is an insufficient explanation of individual evolution. two exceedingly good criticisms of mr. darwin's hypothesis have appeared. one of these is by mr. g. h. lewes,[221] the other by professor delpino of florence.[222] the latter gentleman gives a report of an observation made by him upon a certain plant, which observation adds force to what has just been said about the jewish race. he says:[223] "if we examine and compare the numerous species of the genus _salvia_, commencing with _salvia officinalis_, which may pass as the main state of the genus, and {213} concluding with _salvia verticillata_, which may be taken as the most highly developed form, and as the most distant from the type, we observe a singular phenomenon. the lower cell of each of the two fertile anthers, which is much reduced and different from the superior even in _salvia officinalis_, is transmuted in other _salviæ_ into an organ (nectarotheca) having a very different form and function, and finally disappears entirely in _salvia verticillata_. "now, on one occasion, in a flower belonging to an individual of _salvia verticillata_, and only on the left stamen, i observed a perfectly developed and pollinigerous lower cell, perfectly homologous with that which is normally developed in _salvia officinalis_. this case of atavism is truly singular. according to the theory of pangenesis, it is necessary to assume that all the gemmules of this anomalous formation, and therefore the mother-gemmule of the cell, and the daughter-gemmules of the special epidermic tissue, and of the very singular subjacent tissue of the endothecium, have been perpetuated, and transmitted from parent to offspring in a dormant state, and through a number of generations, such as startles the imagination, and leads it to refuse its consent to the theory of pangenesis, however seductive it may be." this seems a strong confirmation of what has been here advanced. the main objection raised against mr. darwin's hypothesis is that it (pangenesis) requires so many subordinate hypotheses for its support, and that some of these are not tenable. professor delpino considers[224] that as many as eight of these subordinate hypotheses are required, namely, that-"1. the emission of the gemmules takes place, or may take place in all states of the cell. "2. the quantity of gemmules emitted from every cell is very great. "3. the minuteness of the gemmules is extreme. {214} "4. the gemmules possess two sorts of affinity, one of which might be called _propagative_, and the other _germinative_ affinity. "5. by means of the propagative affinity all the gemmules emitted by all the cells of the individual flow together and become condensed in the cells which compose the sexual organs, whether male or female (embryonal vesicle, cells of the embryo, pollen grains, fovilla, antherozoids, spermatozoids), and likewise flow together and become condensed in the cells which constitute the organs of a sexual or agamic reproduction (buds, spores, bulbilli, portions of the body separated by scission, &c.). "6. by means of the germinative affinity, every gemmule (except in cases of anomalies or monstrosities) can be developed only in cells homologous with the mother-cells of the cell from which they originated. in other words, the gemmules from any cell can only be developed in unison with the cell preceding it in due order of succession, and whilst in a nascent state. "7. of each kind of gernmule a great number perishes; a great number remains in a dormant state through many generations in the bodies of descendants; the remainder germinate and reproduce the mother-cell. "8. every gemmule may multiply itself by a process of scission into any number of equivalent gemmules." mr. darwin has published a short notice in reply to professor delpino, in _scientific opinion_ of october 20, 1869, p. 426. in this reply he admits the justice of professor delpino's attack, but objects to the alleged necessity of the first subordinate hypothesis, namely, that the emission of gemmules takes place in all states of the cell. but if this is not the case, then a great part of the utility and distinction of pangenesis is destroyed, or as mr. lewes justly says,[225] "if gemmules produce whole cells, we have the very power which was pronounced mysterious in larger organisms." {215} mr. darwin also does not see the force of the objection to the power of self-division which must be asserted of the gemmules themselves if pangenesis be true. the objection, however, appears to many to be formidable. to admit the power of spontaneous division and multiplication in such rudimentary structures, seems a complete contradiction. the gemmules, by the hypothesis of pangenesis, are the ultimate organized components of the body, the absolute organic atoms of which each body is composed; how then _can_ they be divisible? any part of a gemmule would be an impossible (because a _less_ than possible) quantity. if it is divisible into still smaller organic wholes, as a germ-cell is, it must be made up as the germ-cell is, of subordinate component atoms, which are then the _true_ gemmules. this process may be repeated _ad infinitum_, unless we get to true organic atoms, the true gemmules, whatever they may be, and they necessarily will be incapable of any process of spontaneous fission. it is remarkable that mr. darwin brings forward in support of gemmule fission, the observation that "thuret has seen the zoospore of an alga divide itself, and both halves germinate." yet on the hypothesis of pangenesis, the zoospore of an alga must contain gemmules from all the cells of the parent algæ, and from all the parts of all their less remote ancestors in all their stages of existence. what wonder then that such an excessively complex body should divide and multiply; and what parity is there between such a body and a gemmule? a steam-engine and a steel-filing might equally well be compared together. professor delpino makes a further objection which, however, will only be of weight in the eyes of vitalists. he says,[226] pangenesis is not to be received because "it leads directly to the negation of a specific vital principle, co-ordinating and regulating all the movements, acts, and functions of the individuals in which it is incarnated. for pangenesis of the individual is a term without meaning. if, in contemplating an {216} animal of high organization, we regard it purely as an aggregation of developed gemmules, although these gemmules have been evolved successively one after the other, and one within the other, notwithstanding they elude the conception of the _real and true individual_, these problematical and invisible gemmules must be regarded as so many individuals. now, that real, true, living individuals exist in nature, is a truth which is persistently attested to us by our consciousness. but how, then, can we explain that a great quantity of dissimilar elements, like the atoms of matter, can unite to form those perfect unities which we call individuals, if we do not suppose the existence of a specific principle, proper to the individual but foreign to the component atoms, which aggregates these said atoms, groups them into molecules, and then moulds the molecules into cells, the cells into tissues, the tissues into organs, and the organs into apparatus?" "but, it may be urged in opposition by the pangenesists, your vital principle is an unknown and irresolute _x_. this is true; but, on the other hand, let us see whether pangenesis produces a clearer formula, and one free from unknown elements. the existence of the gemmules is a first unknown element; the propagative affinity of the gemmules is a second; their germinative affinity is a third; their multiplication by fission is a fourth--and what an unknown element!" "thus, in pangenesis, everything proceeds by force of unknown elements, and we may ask whether it is more logical to prefer a system which assumes a multitude of unknown elements to a system which assumes only a single one?" mr. darwin appears, by "natural selection," to destroy the reality of species, and by pangenesis that of the individual. mr. lewes observes[227] of the individual that "this whole is only a subjective conception which summarizes the parts, and that in point of fact it is the parts which {217} are reproduced." but the parts are also, from the same point of view, merely subjective until we come to the absolute organic atoms. these atoms, on the other hand, are utterly invisible, intangible; indeed, in the words of mr. darwin, inconceivable. thus, then, it results from the theories in question, that the organic world is reduced to utter unreality as regards all that can be perceived by the senses or distinctly imagined by the mind; while the only reality consists of the invisible, the insensible, the inconceivable; in other words, nothing is known that really is, and only the nonexistent can be known. a somewhat paradoxical outcome of the speculations of those who profess to rely exclusively on the testimony of sense. "_les extrêmes se touchent_," and extreme sensationalism shakes hands with the "das seyn ist das nichts" of hegel. altogether the hypothesis of pangenesis seems to be little, if at all, superior to anterior hypotheses of a more or less similar nature. apart from the atoms of democritus, and apart also from the speculations of mediæval writers, the molecules of bonnet and of buffon almost anticipated the hypothesis of pangenesis. according to the last-named author,[228] organic particles from every part of the body assemble in the sexual secretions, and by their union build up the embryo, each particle taking its due place, and occupying in the offspring a similar position to that which it occupied in the parents. in 1849 professor owen, in his treatise on "parthenogenesis," put forward another conception. according to this, the cells resulting from the subdivision of the germ-cell preserve their developmental force, unless employed in building up definite organic structures. in certain creatures, and in certain parts of other creatures, germ-cells unused are stored up, and by their agency lost limbs and {218} other mutilations are repaired. such unused products of the germ-cell are also supposed to become located in the generative products. according to mr. herbert spencer, in his "principles of biology," each living organism consists of certain so-called "physiological units." each of these units has an innate power and capacity, by which it tends to build up and reproduce the entire organism of which it forms a part, unless in the meantime its force is exhausted by its taking part in the production of some distinct and definite tissue--a condition somewhat similar to that conceived by professor owen. now, at first sight, mr. darwin's atomic theory appears to be more simple than any of the others. it has been objected that while mr. spencer's theory requires the assumption of an innate power and tendency in each physiological unit, mr. darwin's, on the other hand, requires nothing of the kind, but explains the evolution of each individual by purely mechanical conceptions. in fact, however, it is not so. each gemmule, according to mr. darwin, is really the seat of powers, elective affinities, and special tendencies as marked and mysterious as those possessed by the physiological unit of mr. spencer, with the single exception that the former has no tendency to build up the whole living, complex organism of which it forms a part. some may think this an important distinction, but it can hardly be so, for mr. darwin considers that his gemmule has the innate power and tendency to build up and transform itself into the whole living, complex cell of which it forms a part; and the one tendency is, in principle, fully as difficult to understand, fully as mysterious, as is the other. the difference is but one of degree, not of kind. moreover, the one mystery in the case of the "physiological unit" explains all, while with regard to the gemmule, as we have seen, it has to be supplemented by other powers and tendencies, each distinct, and each in itself inexplicable and profoundly mysterious. [page 219] that there should be physiological units possessed of the power attributed to them, harmonizes with what has recently been put forward by dr. h. charlton bastian; who maintains that under fit conditions the simplest organisms develop themselves into relatively large and complex ones. this is not supposed by him to be due to any inheritance of ancestral gemmules, but to direct growth and transformation of the most minute and the simplest organisms, which themselves, by all reason and analogy, owe their existence to immediate transformation from the inorganic world. thus, then, there are grave difficulties in the way of the reception of the hypothesis of pangenesis, which moreover, if established, would leave the evolution of individual organisms, when thoroughly analysed, little if at all less mysterious or really explicable than it is at present. as was said at the beginning of this chapter, "pangenesis" and "natural selection" are quite separable and distinct hypotheses. the fall of one of these by no means necessarily includes that of the other. nevertheless, mr. darwin has associated them closely together, and, therefore, the refutation of pangenesis may render it advisable for those who have hitherto accepted "natural selection" to reconsider that theory. [page 220] * * * * * chapter xi. specific genesis. review of the statements and arguments of preceding chapters.--cumulative argument against predominant action of "natural selection."--whether anything positive as well as negative can be enunciated.--constancy of laws of nature does not necessarily imply constancy of specific evolution.--possible exceptional stability of existing epoch.--probability that an internal cause of change exists.--innate powers must be conceived as existing somewhere or other.--symbolism of molecular action under vibrating impulses.--professor owen's statement.--statement of the author's view.--it avoids the difficulties which oppose "natural selection."--it harmonizes apparently conflicting conceptions.--summary and conclusion. having now severally reviewed the principal biological facts which bear upon specific manifestation, it remains to sum up the results, and to endeavour to ascertain what, if anything, can be said _positively_, as well as negatively, on this deeply interesting question. in the preceding chapters it has been contended, in the first place, that no mere survival of the fittest accidental and minute variations can account for the incipient stages of useful structures, such as, _e.g._, the heads of flat-fishes, the baleen of whales, vertebrate limbs, the laryngeal structures of the newborn kangaroo, the pedicellariæ of echinoderms, or for many of the facts of mimicry, and especially those last touches of mimetic perfection, where an insect not only mimics a leaf, but one worm-eaten and attacked by fungi. [page 221] also, that structures like the hood of the cobra and the rattle of the rattlesnake seem to require another explanation. again, it has been contended that instances of colour, as in some apes; of beauty, as in some shell-fish; and of utility, as in many orchids, are examples of conditions which are quite beyond the power of natural selection to originate and develop. next, the peculiar mode of origin of the eye (by the simultaneous and concurrent modification of distinct parts), with the wonderful refinement of the human ear and voice, have been insisted on; as also, that the importance of all these facts is intensified through the necessity (admitted by mr. darwin) that many individuals should be similarly and simultaneously modified in order that slightly favourable variations may hold their own in the struggle for life, against the overwhelming force and influence of mere number. again, we have considered, in the third chapter, the great improbability that from minute variations in all directions alone and unaided, save by the survival of the fittest, closely similar structures should independently arise; though, on a non-darwinian evolutionary hypothesis, their development might be expected _a priori_. we have seen, however, that there are many instances of wonderfully close similarity which are not due to genetic affinity; the most notable instance, perhaps, being that brought forward by mr. murphy, namely, the appearance of the same eye-structure in the vertebrate and molluscous sub-kingdoms. a curious resemblance, though less in degree, has also been seen to exist between the auditory organs of fishes and of cephalopods. remarkable similarities between certain placental and implacental mammals, between the bird's-head processes of polyzoa and the pedicellariæ of echinoderms, between ichthyosauria and cetacea, with very many other similar coincidences, have also been pointed out. evidence has also been brought forward to show that similarity is sometimes directly induced by very obscure conditions, at present quite {222} inexplicable, _e.g._ by causes immediately connected with geographical distribution; as in the loss of the tail in certain forms of lepidoptera and in simultaneous modifications of colour in others, and in the direct modification of young english oysters, when transported to the shore of the mediterranean. again, it has been asserted that certain groups of organic forms seem to have an innate tendency to remarkable developments of some particular kind, as beauty and singularity of plumage in the group of birds of paradise. it has also been contended that there is something to be said in favour of sudden, as opposed to exceedingly minute and gradual, modifications, even if the latter are not fortuitous. cases were brought forward, in chapter iv., such as the bivalve just mentioned, twenty-seven kinds of american trees simultaneously and similarly modified, also the independent production of pony breeds, and the case of the english greyhounds in mexico, the offspring of which produced directly acclimated progeny. besides these, the case of the normandy pigs, of _datura tatula_, and also of the black-shouldered peacock, have been spoken of. the teeth of the labyrinthodon, the hand of the potto, the whalebone of whales, the wings of birds, the climbing tendrils of some plants, &c. have also been adduced as instances of structures, the origin and production of which are probably due rather to considerable modifications than to minute increments. it has also been shown that certain forms which were once supposed to be especially transitional and intermediate (as, _e.g._, the aye-aye) are really by no means so; while the general rule, that the progress of forms has been "from the more general to the more special," has been shown to present remarkable exceptions, as, _e.g._, macrauchenia, the glyptodon, and the sabre-toothed tiger (machairodus). next, as to specific stability, it has been seen that there may be a {223} certain limit to normal variability, and that if changes take place they may be expected _a priori_ to be marked and considerable ones, from the facts of the inorganic world, and perhaps also of the lowest forms of the organic world. it has also been seen that with regard to minute spontaneous variations in races, there is a rapidly increasing difficulty in intensifying them, in any one direction, by ever such careful breeding. moreover, it has appeared that different species show a tendency to variability in special directions, and probably in different degrees, and that at any rate mr. darwin himself concedes the existence of an internal barrier to change when he credits the goose with "a singularly inflexible organization;" also, that he admits the presence of an _internal_ proclivity to change when he speaks of "a whole organization seeming to have become plastic, and tending to depart from the parental type." we have seen also that a marked tendency to reversion does exist, inasmuch as it sometimes takes place in a striking manner, as exemplified in the white silk fowl in england, _in spite of_ careful selection in breeding. again, we have seen that a tendency exists in nature to eliminate hybrid races, by whatever means that elimination is effected, while no similar tendency bars the way to an indefinite blending of varieties. this has also been enforced by statements as to the prepotency of certain pollen of identical species, but of distinct races. to all the preceding considerations have been added others derived from the relations of species to past time. it has been contended that we have as yet no evidence of minutely intermediate forms connecting uninterruptedly together undoubtedly distinct species. that while even "horse ancestry" fails to supply such a desideratum, in very strongly marked and exceptional kinds (such as the ichthyosauria, chelonia, and anoura), the absence of links is very important and significant. for if every species, without{224} exception, has arisen by minute modifications, it seems incredible that a small percentage of such transitional forms should not have been preserved. this, of course, is especially the case as regards the marine ichthyosauria and plesiosauria, of which such numbers of remains have been discovered. sir william thomson's great authority has been seen to oppose itself to "natural selection," by limiting, on astronomical and physical grounds, the duration of life on this planet to about one hundred million years. this period, it has been contended, is not nearly enough on the one hand for the evolution of all organic forms by the exclusive action of mere minute, fortuitous variations; on the other hand, for the deposition of all the strata which must have been deposited, if minute fortuitous variation was the manner of successive specific manifestation. again, the geographical distribution of existing animals has been seen to present difficulties which, though not themselves insurmountable, yet have a certain weight when taken in conjunction with all the other objections. the facts of homology, serial, bilateral and vertical, have also been passed in review. such facts, it has been contended, are not explicable without admitting the action of what may most conveniently be spoken of as an _internal_ power, the existence of which is supported by facts not only of comparative anatomy but of teratology and pathology also. "natural selection" also has been shown to be impotent to explain these phenomena, while the existence of such an internal power of homologous evolution diminishes the _a priori_ improbability of an analogous law of specific origination. all these various considerations have been supplemented by an endeavour to show the utter inadequacy of mr. darwin's theory with regard to the higher psychical phenomena of man (especially the evolution of moral conceptions), and with regard to the evolution of individual organisms by the action{225} of pangenesis. and it was implied that if mr. darwin's latter hypothesis can be shown to be untenable, an antecedent doubt is thus thrown upon his other conception, namely, the theory of "natural selection." a cumulative argument thus arises against the prevalent action of "natural selection," which, to the mind of the author, is conclusive. as before observed, he was not originally disposed to reject mr. darwin's fascinating theory. reiterate endeavours to solve its difficulties have, however, had the effect of convincing him that that theory as the one or as the leading explanation of the successive evolution and manifestation of specific forms, is untenable. at the same time he admits fully that "natural selection" acts and must act, and that it plays in the organic world a certain though a secondary and subordinate part. the one _modus operandi_ yet suggested having been found insufficient, the question arises, can another be substituted in its place? if not, can anything that is positive, and if anything, what, be said as to the question of specific origination? now, in the first place, it is of course axiomatic that the laws which conditioned the evolution of extinct and of existing species are of as much efficacy at this moment as at any preceding period, that they _tend_ to the manifestation of new forms as much now as ever before. it by no means necessarily follows, however, that this tendency is actually being carried into effect, and that new species of the higher animals and plants are actually now produced. they may be so or they may not, according as existing circumstances favour, or conflict with, the action of those laws. it is possible that lowly organized creatures may be continually evolved at the present day, the requisite conditions being more or less easily supplied. there is, however, no similar evidence at present as to higher forms; while, as we have seen in chapter vii., there are _a priori_ considerations which militate against their being similarly evolved. {226} the presence of wild varieties and the difficulty which often exists in the determination of species are sometimes adduced as arguments that high forms are now in process of evolution. these facts, however, do not necessarily prove more than that some species possess a greater variability than others, and (what is indeed unquestionable) that species have often been unduly multiplied by geologists and botanists. it may be, for example, that wagner was right, and that all the american monkeys of the genus cebus may be reduced to a single species or to two. with regard to the lower organisms, and supposing views recently advanced to become fully established, there is no reason to think that the forms said to be evolved were new species, but rather reappearances of definite kinds which had appeared before and will appear again under the same conditions. in the same way, with higher forms similar conditions must educe similar results, but here practically similar conditions can rarely obtain because of the large part which "descent" and "inheritance" always play in such highly organized forms. still it is conceivable that different combinations at different times may have occasionally the same outcome just as the multiplications of different numbers may have severally the same result. there are reasons, however, for thinking it possible that the human race is a witness of an exceptionally unchanging and stable condition of things, if the calculations of mr. croll are valid as to how far variations in the eccentricity in the earth's orbit together with the precession of the equinoxes have produced changes in climate. mr. wallace has pointed out[229] that the last 60,000 years having been exceptionally unchanging as regards these conditions, specific evolution may have been {227} exceptionally rare. it becomes then possible to suppose that for a similar period stimuli to change in the manifestation of animal forms may have been exceptionally few and feeble,--that is, if the conditions of the earth's orbit have been as exceptional as stated. however, even if new species are actually now being evolved as actively as ever, or if they have been so quite recently, no conflict thence necessarily arises with the view here advocated. for it by no means follows that if some examples of new species have recently been suddenly produced from individuals of antecedent species, we ought to be able to put our fingers on such cases; as mr. murphy well observes[230] in a passage before quoted, "if a species were to come suddenly into being in the wild state, as the ancon sheep did under domestication, how could we ascertain the fact? if the first of a newly-born species were found, the fact of its discovery would tell nothing about its origin. naturalists would register it as a very rare species, having been only once met with, but they would have no means of knowing whether it were the first or the last of its race." but are there any grounds for thinking that in the genesis of species an _internal_ force or tendency interferes, co-operates with and controls the action of external conditions? it is here contended that there are such grounds, and that though inheritance, reversion, atavism, natural selection, &c., play a part not unimportant, yet that such an internal power is a great, perhaps the main, determining agent. it will, however, be replied that such an entity is no _vera causa_; that if the conception is accepted, it is no real explanation; and that it is merely a roundabout way of saying that the facts are as they are, while the cause remains unknown. to this it may be rejoined that for all who believe in the existence of the abstraction "force" at all, other than will, {228} this conception of an internal force must be accepted and located somewhere--cannot be eliminated altogether; and that therefore it may as reasonably be accepted in this mode as in any other. it was urged at the end of the third chapter that it is congruous to credit mineral species with an internal power or force. by such a power it may be conceived that crystals not only assume their external symmetry, but even repair it when injured. ultimate chemical elements must also be conceived as possessing an innate tendency to form certain unions, and to cohere in stable aggregations. this was considered towards the end of chapter viii. turning to the organic world, even on the hypothesis of mr. herbert spencer or that of mr. darwin, it is impossible to escape the conception of innate internal forces. with regard to the physiological units of the former, mr. spencer himself, as we have seen, distinctly attributes to them "an _innate_ tendency" to evolve the parent form from which they sprang. with regard to the gemmules of mr. darwin, we have seen, in chapter x., with how many innate powers, tendencies, and capabilities they must each be severally endowed, to reproduce their kind, to evolve complex organisms or cells, to exercise germinative affinity, &c. if then (as was before said at the end of chapter viii.) such innate powers must be attributed to chemical atoms, to mineral species, to gemmules, and to physiological units, it is only reasonable to attribute such to each individual organism. the conception of such internal and latent capabilities is somewhat like that of mr. galton, before mentioned, according to which the organic world consists of entities, each of which is, as it were, a spheroid with many facets on its surface, upon one of which it reposes in stable equilibrium. when by the accumulated action of incident forces this equilibrium is {229} disturbed, the spheroid is supposed to turn over until it settles on an adjacent facet once more in stable equilibrium. the internal tendency of an organism to certain considerable and definite changes would correspond to the facets on the surface of the spheroid. it may be objected that we have no knowledge as to how terrestrial, cosmical and other forces can affect organisms so as to stimulate and evolve these latent, merely potential forms. but we have had evidence that such mysterious agencies _do_ affect organisms in ways as yet inexplicable, in the very remarkable effects of geographical conditions which were detailed in the third chapter. it is quite conceivable that the material organic world may be so constituted that the simultaneous action upon it of all known forces, mechanical, physical, chemical, magnetic, terrestrial, and cosmical, together with other as yet unknown forces which probably exist, may result in changes which are harmonious and symmetrical, just as the internal nature of vibrating plates causes particles of sand scattered over them to assume definite and symmetrical figures when made to oscillate in different ways by the bow of a violin being drawn along their edges. the results of these combined internal powers and external influences might be represented under the symbol of complex series of vibrations (analogous to those of sound or light) forming a most complex harmony or a display of most varied colours. in such a way the reparation of local injuries might be symbolized as a filling up and completion of an interrupted rhythm. thus also monstrous aberrations from typical structure might correspond to a discord, and sterility from crossing be compared with the darkness resulting from the interference of waves of light. such symbolism will harmonize with the peculiar reproduction, before mentioned, of heads in the body of certain annelids, with the facts of serial homology, as well as those of bilateral and vertical symmetry. {230} also, as the atoms of a resonant body may be made to give out sound by the juxtaposition of a vibrating tuning-fork, so it is conceivable that the physiological units of a living organism may be so influenced by surrounding conditions (organic and other) that the accumulation of these conditions may upset the previous rhythm of such units, producing modifications in them--a fresh chord in the harmony of nature--a new species! but it may be again objected that to say that species arise by the help of an innate power possessed by organisms is no explanation, but is a reproduction of the absurdity, _l'opium endormit parcequ'il a une vertu soporifique_. it is contended, however, that this objection does not apply, even if it be conceded that there is that force in molière's ridicule which is generally attributed to it.[231] much, however, might be said in opposition to more than one of that brilliant dramatist's smart philosophical epigrams, just as to the theological ones of voltaire, or to the biological one of that other frenchman who for a time discredited a cranial skeletal theory by the phrase "vertèbre pensante."[232] in fact, however, it is a real explanation of how a man lives to say that he lives independently, on his own income, instead of being supported by his relatives and friends. in the same way, there is fully as real a distinction between the production of new specific manifestations entirely _ab externo_, and by the production of the same through an innate force and tendency, the determination of which into action is occasioned by {231} external circumstances. to say that organisms possess this innate power, and that by it new species are from time to time produced, is by no means a mere assertion that they _are_ produced, and in an unknown mode. it is the negation of that view which deems external forces alone sufficient, and at the same time the assertion of something positive, to be arrived at by the process of _reductio ad absurdum_. all physical explanations result ultimately in such conceptions of innate power, or else in that of will force. the far-famed explanation of the celestial motions ends in the conception that every particle of matter has the innate power of attracting every other particle directly as the mass, and inversely as the square of the distance. we are logically driven to this positive conception if we do not accept the view that there is no force but volition, and that all phenomena whatever are the immediate results of the action of intelligent and self-conscious will. we have seen that the notion of sudden changes--saltatory actions in nature--has received countenance from professor huxley.[233] we must conceive that these jumps are orderly, and according to law, inasmuch as the whole cosmos is such. such orderly evolution harmonizes with a teleology derived, not indeed from external nature directly, but from the mind of man. on this point, however, more will be said in the next chapter. but, once more, if new species are not manifested by the action of external conditions upon minute indefinite individual differences, in what precise way may we conceive that manifestation to have taken place? are new species now evolving, as they have been from time to time evolved? if so, in what way and by what conceivable means? {232} in the first place, they must be produced by natural action in pre-existing material, or by supernatural action. for reasons to be given in the next chapter, the second hypothesis need not be considered. if, then, new species are and have been evolved from pre-existing material, must that material have been organic or inorganic? as before said, additional arguments have lately been brought forward to show that individual organisms _do_ arise from a basis of _in_-organic material only. as, however, this at the most appears to be the case, if at all, only with the lowest and most minute organisms exclusively, the process cannot be observed, though it may perhaps be fairly inferred. we may therefore, if for no other reason, dismiss the notion that highly organized animals and plants can be suddenly or gradually built up by any combination of physical forces and natural powers acting externally and internally upon and in merely inorganic material as a base. but the question is, how have the highest kinds of animals and plants arisen? it seems impossible that they can have appeared otherwise than by the agency of antecedent organisms not greatly different from them. a multitude of facts, ever increasing in number and importance, all point to such a mode of specific manifestation. one very good example has been adduced by professor flower in the introductory lecture of his first hunterian course.[234] it is the reduction in size, to a greater or less degree, of the second and third digits of the foot in australian marsupials, and this, in spite of the very different form and function of the foot in different groups of those animals. a similarly significant evidence of relationship is afforded by processes of the zygomatic region of the skull in certain edentates existing and extinct. {233} again, the relation between existing and recent faunas of the different regions of the world, and the predominating (though by no means exclusive) march of organization, from the more general to the more special, point in the same direction. almost all the facts brought forward by the patient industry of mr. darwin in support of his theory of "natural selection," are of course available as evidence in favour of the agency of pre-existing and similar animals in specific evolution. now the new forms must be produced by changes taking place in organisms in, after or before their birth, either in their embryonic, or towards or in their adult, condition. examples of strange births are sufficiently common, and they may arise either from direct embryonic modifications or apparently from some obscure change in the parental action. to the former category belong the hosts of instances of malformation through arrest of development, and perhaps generally monstrosities of some sort are the result of such affections of the embryo. to the second category belong all cases of hybridism, of cross breed, and in all probability the new varieties and forms, such as the memorable one of the black-shouldered peacock. in all these cases we do not have abortions or monstrosities, but more or less harmonious forms often of great functional activity, endowed with marked viability and generative prepotency, except in the case of hybrids, when we often find even a more marked generative impotency. it seems probable therefore that new species may arise from some constitutional affection of parental forms--an affection mainly, if not exclusively, of their generative system. mr. darwin has carefully collected[235] numerous instances to show how excessively sensitive to various influences this system is. he says:[236] "sterility is independent of general health, and is often accompanied by excess of size, or {234} great luxuriance," and, "no one can tell, till he tries; whether any particular animal will breed under confinement, or any exotic plant seed freely under culture." again, "when a new character arises, whatever its nature may be, it generally tends to be inherited, at least in a temporary and sometimes in a most persistent manner."[237] yet the obscure action of conditions will alter characters long inherited, as the grandchildren of aylesbury ducks, removed to a distant part of england, completely lost their early habit of incubation, and hatched their eggs at the same time with the common ducks of the same place.[238] mr. darwin quotes mr. bartlett as saying: "it is remarkable that lions breed more freely in travelling collections than in the zoological gardens; probably the constant excitement and irritation produced by moving from place to place, or change of air, may have considerable influence in the matter."[239] mr. darwin also says: "there is reason to believe that insects are affected by confinement like the higher animals," and he gives examples.[240] again, he gives examples of change of plumage in the linnet, bunting, oriole, and other birds, and of the temporary modification of the horns of a male deer during a voyage.[241] finally, he adds that these changes cannot be attributed to loss of health or vigour, "when we reflect how healthy, long-lived, and vigorous many animals are under captivity, such as parrots, and hawks when used for hawking, chetahs when used for hunting, and elephants. the reproductive organs themselves are not diseased; and the diseases from which animals in menageries usually perish, are not those which in any way affect their fertility. no domestic animal is more subject to disease than the sheep, yet it is remarkably prolific.... it would appear that any change in {235} the habits of life, whatever these habits may be, if great enough, tends to affect in an inexplicable manner the powers of reproduction." such, then, is the singular sensitiveness of the generative system. as to the means by which that system is affected, we see that a variety of conditions affect it; but as to the modes in which they act upon it, we have as yet little if any clue. we have also seen the singular effects (in tailed lepidoptera, &c.) of causes connected with geographical distribution, the mode of action of which is as yet quite inexplicable; and we have also seen the innate tendency which there appears to be in certain groups (birds of paradise, &c.) to develop peculiarities of a special kind. it is, to say the least, probable that other influences exist, terrestrial and cosmical, as yet un-noted. the gradually accumulating or diversely combining actions of all these on highly sensitive structures, which are themselves possessed of internal responsive powers and tendencies, may well result in occasional repeated productions of forms harmonious and vigorous, and differing from the parental forms in proportion to the result of the combining or conflicting action of all external and internal influences. if, in the past history of this planet, more causes ever intervened, or intervened more energetically than at present, we might _a priori_ expect a richer and more various evolution of forms more radically differing than any which could be produced under conditions of more perfect equilibrium. at the same time, if it be true that the last few thousand years have been a period of remarkable and exceptional uniformity as regards this planet's astronomical relations, there are then some grounds for thinking that organic evolution may have been exceptionally depressed during the same epoch. now, as to the fact that sudden changes and sudden developments have {236} occurred, and as to the probability that such changes are likely to occur, evidence was given in chapter iv. in chapter v. we also saw that minerals become modified suddenly and considerably by the action of incident forces--as, _e.g._, the production of hexagonal tabular crystals of carbonate of copper by sulphuric acid, and of long rectangular prisms by ammonia, &c. we have thus a certain antecedent probability that if changes are produced in specific manifestation through incident forces, these changes will be sensible and considerable, not minute and infinitesimal. consequently, it is probable that new species have appeared from time to time with comparative suddenness, and that they still continue so to arise if all the conditions necessary for specific evolution now obtain. this probability will be increased if the observations of dr. bastian are confirmed by future investigation. according to his report, when the requisite conditions were supplied, the transformations which appeared to take place (from very low to higher organisms) were sudden, definite, and complete. therefore, if this is so, there must probably exist in higher forms a similar tendency to such change. that tendency may indeed be long suppressed, and ultimately modified by the action of heredity--an action which would increase in force with the increase in the perfection and complexity of the organism affected. still we might expect that such changes as do take place would be also sudden, definite, and complete. moreover, as the same causes produce the same effects, several individual parent forms must often have been similarly and simultaneously affected. that they should be so affected--at least that several similarly modified individuals should simultaneously arise--has been seen to be a generally necessary circumstance for the permanent duration of such new modifications. it is also conceivable that such new forms may be endowed with {237} excessive constitutional strength and viability, and with generative prepotency, as was the case with the black-shouldered peacock in sir j. trevelyan's flock. this flock was entirely composed of the common kind, and yet the new form rapidly developed itself "_to the extinction of the previously existing breed_."[242] indeed, the notion accepted by both mr. darwin and mr. herbert spencer, and which is plainly the fact (namely, that changes of conditions and incident forces, within limits, augment the viability and fertility of individuals), harmonizes well with the suggested possibility as to an augmented viability and prepotency in new organic forms evolved by peculiar consentaneous actions of conditions and forces, both external and internal. the remarkable series of changes noted by dr. bastian were certainly not produced by external incident forces _only_, but by these acting on a peculiar _materia_, having special properties and powers. therefore, the changes were induced by the consentaneous action of internal and external forces.[243] in the same way then, we may expect changes in higher forms to be evolved by similar united action of internal and external forces. one other point may here be alluded to. when the remarkable way in which structure and function simultaneously change, is borne in mind; when those numerous instances in which nature has supplied similar wants by similar means, as detailed in chapter iii., are remembered; when also all the wonderful contrivances of orchids, of mimicry, and the strange complexity of certain instinctive actions are considered: then the conviction forces itself on many minds that the organic world is the expression of an intelligence of some kind. this view has been well advocated by mr. joseph john murphy, in his recent work so often here referred to. {238} this intelligence, however, is evidently not altogether such as ours, or else has other ends in view than those most obvious to us. for the end is often attained in singularly roundabout ways, or with a prodigality of means which seems out of all proportion with the result: not with the simple action directed to one end which generally marks human activity. organic nature then speaks clearly to many minds of the action of an intelligence resulting, on the whole and in the main, in order, harmony, and beauty, yet of an intelligence the ways of which are not such as ours. this view of evolution harmonizes well with theistic conceptions; not, of course, that this harmony is brought forward as an argument in its favour generally, but it will have weight with those who are convinced that theism reposes upon solid grounds of reason as _the_ rational view of the universe. to such it may be observed that, thus conceived, the divine action has that slight amount of resemblance to, and that wide amount of divergence from what human action would be, which might be expected _a priori_--might be expected, that is, from a being whose nature and aims are utterly beyond our power to imagine, however faintly, but whose truth and goodness are the fountain and source of our own perceptions of such qualities. the view of evolution maintained in this work, though arrived at in complete independence, yet seems to agree in many respects with the views advocated by professor owen in the last volume of his "anatomy of vertebrates," under the term "derivation." he says:[244] "derivation holds that every species changes in time, by virtue of inherent tendencies thereto. 'natural selection' holds that no such change can take place without the influence of altered external circumstances.[245] {239} 'derivation' sees among the effects of the innate tendency to change irrespective of altered circumstances, a manifestation of creative power in the variety and beauty of the results; and, in the ultimate forthcoming of a being susceptible of appreciating such beauty, evidence of the pre-ordaining of such relation of power to the appreciation. 'natural selection' acknowledges that if ornament or beauty, in itself, should be a purpose in creation, it would be absolutely fatal to it as a hypothesis." "'natural selection' sees grandeur in the view of life, with its several powers, having been originally breathed by the creator into a few forms or into one. 'derivation' sees therein a narrow invocation of a special miracle and an unworthy limitation of creative power, the grandeur of which is manifested daily, hourly, in calling into life many forms, by conversion of physical and chemical into vital modes of force, under as many diversified conditions of the requisite elements to be so combined." the view propounded in this work allows, however, a greater and more important part to the share of external influences, it being believed by the author, however, that these external influences equally with the internal ones are the results of one harmonious action underlying the whole of nature, organic and inorganic, cosmical, physical, chemical, terrestrial, vital, and social. according to this view, an internal law presides over the actions of every part of every individual, and of every organism as a unit, and of the entire organic world as a whole. it is believed that this conception of an internal innate force will ever remain necessary, however much its subordinate processes and actions may become explicable: that by such a force, from time to time, new species are manifested by ordinary generation just as _pavo nigripennis_ appeared suddenly, these new forms not being monstrosities but harmonious self-consistent wholes. that thus, as specific distinctness is manifested by obscure sexual {240} conditions, so in obscure sexual modifications specific distinctions arise. that these "jumps" are considerable in comparison with the minute variations of "natural selection"--are in fact sensible steps, such as discriminate species from species. that the latent tendency which exists to these sudden evolutions is determined to action by the stimulus of external conditions. that "natural selection" rigorously destroys monstrosities, and abortive and feeble attempts at the performance of the evolutionary process. that "natural selection" removes the antecedent species rapidly when the new one evolved is more in harmony with surrounding conditions. that "natural selection" favours and develops useful variations, though it is impotent to originate them or to erect the physiological barrier which seems to exist between species. by some such conception as this, the difficulties here enumerated, which beset the theory of "natural selection" pure and simple, are to be got over. thus, for example, the difficulties discussed in the first chapter--namely, those as to the origins and first beginnings of certain structures--are completely evaded. again, as to the independent origin of closely similar structures, such as the eyes of the vertebrata and cuttle-fishes, the difficulty is removed if we may adopt the conception of an innate force similarly directed in each case, and assisted by favourable external conditions. specific stability, limitation to variability, and the facts of reversion, all harmonize with the view here put forward. the same may be said with regard to the significant facts of homology, and of organic symmetry; and our consideration of the hypothesis of pangenesis in chapter x., has seemed to result in a view as to innate powers which accords well with what is here advocated. [page 241] the evolutionary hypothesis here advocated also serves to explain all those remarkable facts which were stated in the first chapter to be explicable by the theory of natural selection, namely, the relation of existing to recent faunas and floras; the phenomena of homology and of rudimentary structures; also the processes gone through in development; and lastly, the wonderful facts of mimicry. finally, the view adopted is the synthesis of many distinct and, at first sight, conflicting conceptions, each of which contains elements of truth, and all of which it appears to be able more or less to harmonize. thus it has been seen that "natural selection" is accepted. it acts and must act, though alone it does not appear capable of fulfilling the task assigned to it by mr. darwin. pangenesis has probably also much truth in it, and has certainly afforded valuable and pregnant suggestions, but unaided and alone it seems inadequate to explain the evolution of the individual organism. those three conceptions of the organic world which may be spoken of as the teleological, the typical, and the transmutationist, have often been regarded as mutually antagonistic and conflicting. the genesis of species as here conceived, however, accepts, locates, and harmonizes all the three. teleology concerns the ends for which organisms were designed. the recognition, therefore, that their formation took place by an evolution not fortuitous, in no way invalidates the acknowledgment of their final causes if on other grounds there are reasons for believing that such final causes exist. conformity to type, or the creation of species according to certain "divine ideas," is in no way interfered with by such a process of evolution as is here advocated. such "divine ideas" must be accepted or declined upon quite other grounds than the mode of their realization, and of their manifestation in the world of sensible phenomena. [page 242] transmutationism (an old name for the evolutionary hypothesis), which was conceived at one time to be the very antithesis to the two preceding conceptions, harmonizes well with them if the evolution be conceived to be orderly and designed. it will in the next chapter be shown to be completely in harmony with conceptions, upon the acceptance of which "final causes" and "divine ideal archetypes" alike depend. thus then, if the cumulative argument put forward in this book is valid, we must admit the insufficiency of natural selection both on account of the residuary phenomena it fails to explain, and on account of certain other phenomena which seem actually to conflict with that theory. we have seen that though the laws of nature are constant, yet some of the conditions which determine specific change may be exceptionally absent at the present epoch of the world's history; also that it is not only possible, but highly probable, that an internal power or tendency is an important if not the main agent in evoking the manifestation of new species on the scene of realized existence, and that in any case, from the facts of homology, innate internal powers to the full as mysterious must anyhow be accepted, whether they act in specific origination or not. besides all this, we have seen that it is probable that the action of this innate power is stimulated, evoked, and determined by external conditions, and also that the same external conditions, in the shape of "natural selection," play an important part in the evolutionary process: and finally, it has been affirmed that the view here advocated, while it is supported by the facts on which darwinism rests, is not open to the objections and difficulties which oppose themselves to the reception of "natural selection," as the exclusive or even as the main agent in the successive and orderly evolution of organic forms in the _genesis of species_. [page 243] * * * * * chapter xii. theology and evolution. prejudiced opinions on the subject.--"creation" sometimes denied from prejudice.---the unknowable.--mr. herbert spencer's objections to theism; to creation.--meanings of term "creation."--confusion from not distinguishing between "primary" and "derivative" creation.--mr. darwin's objections.--bearing of christianity on the theory of evolution.--supposed opposition, the result of a misconception.--theological authority not opposed to evolution.--st. augustin.--st. thomas aquinas.--certain consequences of want of flexibility of mind.--reason and imagination.--the first cause and demonstration.--parallel between christianity and natural theology.--what evolution of species is.--professor agassiz.--innate powers must be recognized.--bearing of evolution on religious belief.--professor huxley.--professor owen.--mr. wallace.--mr. darwin.--_a priori_ conception of divine action.--origin of man.--absolute creation and dogma.--mr. wallace's view.--a supernatural origin for man's body not necessary.--two orders of being in man.--two modes of origin.--harmony of the physical, hyperphysical, and supernatural.--reconciliation of science and religion as regards evolution.--conclusion. the special "darwinian theory" and that of an evolutionary process neither excessively minute nor fortuitous, having now been considered, it is time to turn to the important question, whether both or either of these conceptions may have any bearing, and if any, what, upon christian belief? some readers will consider such an inquiry to be a work of supererogation. seeing clearly themselves the absurdity of prevalent popular views, and the shallowness of popular objections, they may be impatient of any discussion, on the subject. but it is submitted that there are many minds worthy {244} of the highest esteem and of every consideration, which have regarded the subject hitherto almost exclusively from one point of view; that there are some persons who are opposed to the progress (in their own minds or in that of their children or dependents) of physical scientific truth--the natural revelation--through a mistaken estimate of its religious bearings, while there are others who are zealous in its promotion from a precisely similar error. for the sake of both these then the author may perhaps be pardoned for entering slightly on very elementary matters relating to the question, whether evolution or darwinism have any, and if any, what, bearing on theology? there are at least two classes of men who will certainly assert that they have a very important and highly significant bearing upon it. one of these classes consists of persons zealous for religion indeed, but who identify orthodoxy with their own private interpretation of scripture or with narrow opinions in which they have been brought up--opinions doubtless widely spread, but at the same time destitute of any distinct and authoritative sanction on the part of the christian church. the other class is made up of men hostile to religion, and who are glad to make use of any and every argument which they think may possibly be available against it. some individuals within this latter class may not believe in the existence of god, but may yet abstain from publicly avowing this absence of belief, contenting themselves with denials of "creation" and "design," though these denials are really consequences of their attitude of mind respecting the most important and fundamental of all beliefs. without a distinct belief in a personal god it is impossible to have any religion worthy of the name, and no one can at the same time accept the christian religion and deny the dogma of creation. [page 245] "i believe in god," "the creator of heaven and earth," the very first clauses of the apostles' creed, formally commit those who accept them to the assertion of this belief. if, therefore, any theory of physical science really conflicts with such an authoritative statement, its importance to christians is unquestionable. as, however, "creation" forms a part of "revelation," and as "revelation" appeals for its acceptance to "reason" which has to prepare a basis for it by an intelligent acceptance of theism on _purely rational grounds_, it is necessary to start with a few words as to the reasonableness of belief in god, which indeed are less superfluous than some readers may perhaps imagine; "a few words," because this is not the place where the argument can be drawn out, but only one or two hints given in reply to certain modern objections. no better example perhaps can be taken, as a type of these objections, than a passage in mr. herbert spencer's first principles.[246] this author constantly speaks of the "ultimate cause of things" as "the unknowable," a term singularly unfortunate, and as mr. james martineau has pointed out,[247] even self-contradictory: for that entity, the knowledge of {246} the existence of which presses itself ever more and more upon the cultivated intellect, cannot be the unknown, still less _the unknowable_, because we certainly know it, in that we know for certain that it exists. nay more, to predicate incognoscibility of it, is even a certain knowledge of the mode of its existence. mr. h. spencer says:[248] "the consciousness of an inscrutable power manifested to us through all phenomena has been growing ever clearer; and must eventually be freed from its imperfections. the certainty that on the one hand such a power exists, while on the other hand its nature transcends intuition, and is beyond imagination, is the certainty towards which intelligence has from the first been progressing." one would think then that the familiar and accepted word "the inscrutable" (which is in this passage actually employed, and to which no theologian would object) would be an indefinitely better term than "the unknowable." the above extract has, however, such a theistic aspect that some readers may think the opposition here offered superfluous; it may be well, therefore, to quote two other sentences. in another place he observes,[249] "passing over the consideration of credibility, and confining ourselves to that of conceivability, we see that atheism, pantheism, and theism, when rigorously analysed, severally prove to be absolutely unthinkable;" and speaking of "every form of religion," he adds,[250] "the analysis of every possible hypothesis proves, not simply that no hypothesis is sufficient but that no hypothesis is even thinkable." the unknowable is admitted to be a power which cannot be regarded as having sympathy with us, but as one to which no emotion whatever can be ascribed, and we are expressly {247} forbidden "by _duty_," to affirm personality of god as much as to deny it of him. how such a being can be presented as an object on which to exercise religious emotion it is difficult indeed to understand.[251] aspiration, love, devotion to be poured forth upon what we can never know, upon what we can never affirm to know, or care for, us, our thoughts or actions, or to possess the attributes of wisdom and goodness! the worship offered in such a religion must be, as professor huxley says,[252] "for the most part of the silent sort"--silent not only as to the spoken word, but silent as to the mental conception also. it will be difficult to distinguish the follower of this religion from the follower of none, and the man who declines either to assert or to deny the existence of god, is practically in the position of an atheist. for theism enjoins the cultivation of sentiments of love and devotion to god, and the practice of their external expression. atheism forbids both, while the simply non-theist abstains in conformity with the prohibition of the atheist and thus practically sides with him. moreover, since man cannot imagine that of which he has no experience in any way whatever, and since he has experience only of _human_ perfections and of the powers and properties of _inferior_ existences; if he be required to deny human perfections and to abstain from making use of such conceptions, he is thereby necessarily reduced to others of an inferior order. mr. h. spencer says,[253] "those who espouse this {248} alternative position, make the erroneous assumption that the choice is between personality and something lower than personality; whereas the choice is rather between personality and something higher. is it not just possible that there is a mode of being as much transcending intelligence and will, as these transcend mechanical motion?" "it is true we are totally unable to conceive any such higher mode of being. but this is not a reason for questioning its existence; it is rather the reverse." "may we not therefore rightly refrain from assigning to the 'ultimate cause' any attributes whatever, on the ground that such attributes, derived as they must be from our own natures, are not elevations but degradations?" the way however to arrive at the object aimed at (_i.e_. to obtain the best attainable conception of the first cause) is not to refrain from _the only conceptions possible to us_, but to seek the very highest of these, and then declare their utter inadequacy; and this is precisely the course which has been pursued by theologians. it is to be regretted that before writing on this matter mr. spencer did not more thoroughly acquaint himself with the ordinary doctrine on the subject. it is always taught in the church schools of divinity, that nothing, not even _existence_, is to be predicated _univocally_ of "god" and "creatures;" that after exhausting ingenuity to arrive at the loftiest possible conceptions, we must declare them to be _utterly inadequate_; that, after all, they are but accommodations to human infirmity; that they are in a sense objectively false (because of their inadequacy), though subjectively and very practically true. but the difference between this mode of treatment and that adopted by mr. spencer is wide indeed; for the practical result of the mode inculcated by the church is that each one may freely affirm and act upon the highest human conceptions he can attain of the{249} power, wisdom, and goodness of god, his watchful care, his loving providence for every man, at every moment and in every need; for the christian knows that the falseness of his conceptions lies only in their _inadequacy_; he may therefore strengthen and refresh himself, may rejoice and revel in conceptions of the goodness of god, drawn from the tenderest human images of fatherly care and love, or he may chasten and abase himself by consideration of the awful holiness and unapproachable majesty of the divinity derived from analogous sources, knowing that no thought of man can ever be _true enough_, can ever attain the incomprehensible reality, which nevertheless really _is_ all that can be conceived, _plus_ an inconceivable infinity beyond. a good illustration of what is here meant, and of the difference between the theistic position and mr. spencer's, may be supplied by an example he has himself proposed. thus,[254] he imagines an intelligent watch speculating as to its maker, and conceiving of him in terms of watch-being, and figuring him as furnished with springs, escapements, cogged wheels, &c., his motions facilitated by oil--in a word, like himself. it is assumed by mr. spencer that this necessary watch conception would be completely false, and the illustration is made use of to show "the presumption of theologians"--the absurdity and unreasonableness of those men who figure the incomprehensible cause of all phenomena as a being in some way comparable with man. now, putting aside for the moment all other considerations, and accepting the illustration, surely the example demonstrates rather the unreasonableness of the _objector himself_! it is true, indeed, that a man is an organism indefinitely more complex and perfect than any watch; but if the watch could only conceive of its maker in watch terms, or else in terms altogether inferior, the watch would plainly be right in speaking of its maker as a, to it, inconceivably {250} perfect kind of watch, acknowledging at the same time, that this, its conception of him, was _utterly inadequate_, although the best its inferior nature allowed it to form. for if, instead of so conceiving of its maker, it refused to make use of these relative perfections as a makeshift, and so necessarily thought of him as amorphous metal, or mere oil, or by the help of any other inferior conception which a watch might be imagined capable of entertaining, that watch would he wrong indeed. for man can much more properly be compared with, and has much more affinity to, a perfect watch in full activity than to a mere piece of metal, or drop of oil. but the watch is even more in the right still, for its maker, man, virtually _has_ the cogged wheels, springs, escapements, oil, &c., which the watch's conception has been supposed to attribute to him; inasmuch as all these parts must have existed as distinct ideas in the human watchmaker's mind before he could actually construct the clock formed by him. nor is even this all, for, by the hypothesis, the watch _thinks_. it must, therefore, think of its maker as "a thinking being," and in this it is _absolutely and completely right_.[255] either, therefore, the hypothesis is _absurd_ or it actually _demonstrates the very position it was chosen to refute_. unquestionably, then, on the mere ground taken by mr. herbert spencer himself, if we are compelled to think of the first cause either in human terms (but with human imperfections abstracted and human perfections carried to the highest conceivable degree), or, on the other hand, in terms decidedly inferior, such as those are driven to who think of him, but decline to accept as a help the term "personality;" there can be no question but that the first conception is immeasurably nearer the truth than the second. yet the latter is the one put forward and advocated by that author in spite of its unreasonableness, and in spite also of its{251} conflicting with the whole moral nature of man and all his noblest aspirations. again, mr. herbert spencer objects to the conception of god as "first cause," on the ground that "when our symbolic conceptions are such that no cumulative or indirect processes of thought can enable us to ascertain that there are corresponding actualities, nor any predictions be made whose fulfilment can prove this, then they are altogether vicious and illusive, and in no way distinguishable from pure fictions."[256] now, it is quite true that "symbolic conceptions," which are not to be justified either (1) by presentations of sense, or (2) by intuitions, are invalid as representations of real truth. yet the conception of god referred to _is_ justified by our primary intuitions, and we can assure ourselves that it _does_ stand for an actuality by comparing it with (1) our intuitions of free-will and causation, and (2) our intuitions of morality and responsibility. that we _have_ these intuitions is a point on which the author joins issue with mr. spencer, and confidently affirms that they cannot logically be denied without at the same time complete and absolute scepticism resulting from such denial--scepticism wherein vanishes any certainty as to the existence both of mr. spencer and his critic, and by which it is equally impossible to have a thought free from doubt, or to go so far as to affirm the existence of that very doubt or of the doubter who doubts it. it may not be amiss here to protest against the intolerable assumption of a certain school, who are continually talking in lofty terms of "science," but who actually speak of primary religious conceptions as "unscientific," and habitually employ the word "science," when they should limit it by the prefix "physical." this is the more amazing as not a few of this school adopt the idealist philosophy, and affirm that "matter and force" are but names for certain "modes of consciousness." it might be expected of them at least to admit that opinions which repose on primary and fundamental {252} intuitions, are especially and _par excellence_ scientific. such are some of the objections to the christian conception of god. we may now turn to those which are directed against god as the creator, _i.e._ as the absolute originator of the universe, without the employment of any pre-existing means or material. this is again considered by mr. spencer as a thoroughly illegitimate symbolic conception, as much so as the atheistic one--the difficulty as to a _self-existent creator_ being in his opinion equal to that of a _self-existent universe_. to this it may be replied that both are of course equally _unimaginable_, but that it is not a question of facility of conception--not which is easiest to conceive, but which best accounts for, and accords with, psychological facts; namely, with the above-mentioned intuitions. it is contended that _we have_ these primary intuitions, and that with these the conception of a self-existent creator is perfectly harmonious. on the other hand, the notion of a self-existent universe--that there is no real distinction between the finite and the infinite--that the universe and ourselves are one and the same things with the infinite and the self-existent; these assertions, in _addition to_ being unimaginable, _contradict_ our primary intuitions. mr. darwin's objections to "creation" are of quite a different kind, and, before entering upon them, it will be well to endeavour clearly to understand what we mean by "creation," in the various senses in which the term may be used. in the strictest and highest sense "creation" is the absolute origination of anything by god without pre-existing means or material, and is a _supernatural_ act.[257] in the secondary and lower sense, "creation" is the formation of anything by god _derivatively_; that is, that the preceding matter has been created with the potentiality to evolve from it, under suitable conditions, {253} all the various forms it subsequently assumes. and this power having been conferred by god in the first instance, and those laws and powers having been instituted by him, through the action of which the suitable conditions are supplied, he is said in this lower sense to create such various subsequent forms. this is the _natural_ action of god in the physical world, as distinguished from his direct, or, as it may be here called, supernatural action. in yet a third sense, the word "creation" may be more or less improperly applied to the construction of any complex formation or state by a voluntary self-conscious being who makes use of the powers and laws which god has imposed, as when a man is spoken of as the creator of a museum, or of "his own fortune," &c. such action of a created conscious intelligence is purely natural, but more than physical, and may be conveniently spoken of as hyperphysical. we have thus (1) direct or supernatural action; (2) physical action; and (3) hyperphysical action---the two latter both belonging to the order of nature.[258] neither the physical nor the hyperphysical actions, however, exclude the idea of the divine concurrence, and with every consistent theist that idea is necessarily included. dr. asa gray has given expression to this.[259] he says, "agreeing that plants and animals were produced by omnipotent fiat, does not exclude the idea of natural order and what we call secondary causes. the record of the fiat--'let the earth bring forth grass, the herb yielding seed,' &c., 'let the earth bring forth the living creature after his kind'--seems even to imply them," and leads to the conclusion that the various kinds were produced through natural agencies. {254} now, much confusion has arisen from not keeping clearly in view this distinction between _absolute_ creation and _derivative_ creation. with the first, physical science has plainly nothing whatever to do, and is impotent to prove or to refute it. the second is also safe from any attack on the part of physical science, for it is primarily derived from psychical not physical phenomena. the greater part of the apparent force possessed by objectors to creation, like mr. darwin, lies in their treating the assertion of derivative creation as if it was an assertion of absolute creation, or at least of supernatural action. thus, he asks whether some of his opponents believe "that at innumerable periods in the earth's history, certain elemental atoms have been commanded suddenly to flash into living tissues."[260] certain of mr. darwin's objections, however, are not physical, but _metaphysical_, and really attack the dogma of secondary or derivative creation, though to some perhaps they may appear to be directed against absolute creation only. thus he uses, as an illustration, the conception of a man who builds an edifice from fragments of rock at the base of a precipice, by selecting for the construction of the various parts of the building the pieces which are the most suitable owing to the shape they happen to have broken into. afterwards, alluding to this illustration, he says,[261] "the shape of the fragments of stone at the base of our precipice may be called accidental, but this is not strictly correct, for the shape of each depends on a long sequence of events, all obeying natural laws, on the nature of the rock, on the lines of stratification or cleavage, on the form of the mountain which depends on its upheaval and subsequent denudation, and lastly, on the storm and earthquake which threw down the fragments. but in regard to the use to which the fragments may be put, their shape may strictly be said to be{255} accidental. and here we are led to face a great difficulty, in alluding to which i am aware that i am travelling beyond my proper province." "an omniscient creator must have foreseen every consequence which results from the laws imposed by him; but can it be reasonably maintained that the creator intentionally ordered, if we use the words in any ordinary sense, that certain fragments of rock should assume certain shapes, so that the builder might erect his edifice? if the various laws which have determined the shape of each fragment were not predetermined for the builder's sake, can it with any greater probability be maintained that he specially ordained, for the sake of the breeder, each of the innumerable variations in our domestic animals and plants--many of these variations being of no service to man, and not beneficial, far more often injurious, to the creatures themselves? did he ordain that the crop and tail-feathers of the pigeon should vary, in order that the fancier might make his grotesque pouter and fantail breeds? did he cause the frame and mental qualities of the dog to vary, in order that a breed might be formed of indomitable ferocity, with jaws fitted to pin down the bull for man's brutal sport? but, if we give up the principle in one case---if we do not admit that the variations of the primeval dog were intentionally guided, in order that the greyhound, for instance, that perfect image of symmetry and vigour, might be formed,--no shadow of reason can be assigned for the belief that the variations, alike in nature, and the result of the same general laws, which have been the groundwork through natural selection of the formation of the most perfectly adapted animals in the world, man included, were intentionally and specially guided. however much we may wish it, we can hardly follow professor asa gray in his belief that 'variation has been led along certain beneficial lines,' like a stream 'along definite and useful lines of irrigation.'" "if we assume that each particular variation was from the beginning of{256} all time pre-ordained, the plasticity of the organization, which leads to many injurious deviations of structure, as well as that redundant power of reproduction which inevitably leads to a struggle for existence, and, as a consequence, to the natural selection and survival of the fittest, must appear to us superfluous laws of nature. on the other hand, an omnipotent and omniscient creator ordains everything and foresees everything. thus we are brought face to face with a difficulty as insoluble as is that of freewill and predestination." before proceeding to reply to this remarkable passage, it may be well to remind some readers that belief in the existence of god, in his primary creation of the universe, and in his derivative creation of all kinds of being, inorganic and organic, do not repose upon physical phenomena, but, as has been said, on primary intuitions. to deny or ridicule any of these beliefs on physical grounds is to commit the fallacy of _ignoratio elenchi_. it is to commit an absurdity analogous to that of saying a blind child could not recognize his father because he could not _see_ him, forgetting that he could _hear_ and _feel_ him. yet there are some who appear to find it unreasonable and absurd that men should regard phenomena in a light not furnished by or deducible from the very phenomena themselves, although the men so regarding them avow that the light in which they do view them comes from quite another source. it is as if a man, a, coming into b's room and finding there a butterfly, should insist that b had no right to believe that the butterfly had not flown in at the open window, inasmuch as there was nothing about the room or insect to lead to any other belief; while b can well sustain his right so to believe, he having met c, who told him he brought in the chrysalis and, having seen the insect emerge, took away the skin. by a similarly narrow and incomplete view the assertion that human conceptions, such as "the vertebrate idea," &c., are ideas in the mind of god, is sometimes ridiculed; as if the assertors either on the one {257} hand pretended to some prodigious acuteness of mind--a far-reaching genius not possessed by most naturalists--or, on the other hand, as if they detected in the very phenomena furnishing such special conception evidences of divine imaginings. but let the idea of god, according to the highest conceptions of christianity, be once accepted, and then it becomes simply a truism to say that the mind of the deity contains all that is _good_ and _positive_ in the mind of man, _plus_, of course, an absolutely inconceivable infinity beyond. that thus such human conceptions may, nay must, be asserted to be at the same time ideas in the divine mind also, as every real and separate individual that has been, is, or shall be, is present to the same mind. nay, more, that such human conceptions are but faint and obscure adumbrations of corresponding ideas which exist in the mind of god in perfection and fulness.[262] the theist, having arrived at his theistic convictions from quite other sources than a consideration of zoological or botanical phenomena, {258} returns to the consideration of such phenomena and views them in a theistic light without of course asserting or implying that such light has been derived _from them_, or that there is an obligation of reason so to view them on the part of others who refuse to enter upon or to accept those other sources whence have been derived the theistic convictions of the theist. but mr. darwin is not guilty of arguing against metaphysical ideas on physical grounds only, for he employs very distinctly metaphysical ones; namely, his conceptions of the nature and attributes of the first cause. but what conceptions does he offer us? nothing but that low anthropomorphism which, unfortunately, he so often seems to treat as the necessary result of theism. it is again the dummy, helpless and deformed, set up merely for the purpose of being knocked down. it must once more be insisted on, that though man is indeed compelled to conceive of god in human terms, and to speak of him by epithets objectively false, from their hopeless inadequacy, yet nevertheless the christian thinker declares that inadequacy in the strongest manner, and vehemently rejects from his idea of god all terms distinctly implying infirmity or limitation. now, mr. darwin speaks as if all who believe in the almighty were compelled to accept as really applicable to the deity conceptions which affirm limits and imperfections. thus he says: "can it be reasonably maintained that the creator intentionally ordered" "that certain fragments of rock should assume certain shapes, so that the builder might erect his edifice?" why, surely every theist must maintain that in the first foundation of the universe--the primary and absolute creation--god saw and knew every purpose which every atom and particle of matter should ever subserve in all suns and systems, and throughout all coming æons of time. it is almost incredible, but nevertheless it seems necessary to think that the difficulty thus proposed rests on a sort of notion that amidst the boundless profusion of nature there is too much for god to superintend; that the number of objects is too great for an infinite and {259} _omnipresent_ being to attend singly to each and all in their due proportions and needs! in the same way mr. darwin asks whether god can have ordered the race variations referred to in the passage last quoted, for the considerations therein mentioned. to this it may be at once replied that even man often has _several_ distinct intentions and motives for a _single_ action, and the theist has no difficulty in supposing that, out of an infinite number of motives, the motive mentioned in each case may have been an exceedingly subordinate one. the theist, though properly attributing to god what, for want of a better term, he calls "purpose" and "design," yet affirms that the limitations of human purposes and motives are by no means applicable to the divine "purposes." out of many, say a thousand million, reasons for the institution of the laws of the physical universe, some few are to a certain extent conceivable by us; and amongst these the benefits, material and moral, accruing from them to men, and to each individual man in every circumstance of his life, play a certain, perhaps a very subordinate, part.[263] as baden powell observes, "how can we {260} undertake to affirm, amid all the possibilities of things of which we confessedly know so little, that a thousand ends and purposes may not be answered, because we can trace none, or even imagine none, which seem to our short-sighted faculties to be answered in these particular arrangements?"[264] the objection to the bull-dog's ferocity in connexion with "man's brutal sport" opens up the familiar but vast question of the existence of evil, a problem the discussion of which would be out of place here. considering, however, the very great stress which is laid in the present day on the subject of animal suffering by so many amiable and excellent people, one or two remarks on that matter may not be superfluous. to those who accept the belief in god, the soul and moral responsibility; and recognize the full results of that acceptance--to such, physical suffering and moral evil are simply incommensurable. to them the placing of non-moral beings in the same scale with moral agents will be utterly unendurable. but even considering physical pain only, all must admit that this depends greatly on the mental condition of the sufferer. only during consciousness does it exist, and only in the most highly-organized men does it reach its acme. the author has been assured that lower races of men appear less keenly sensitive to physical pain than do more cultivated and refined human beings. thus only in man can there really be any intense degree of suffering, because only in him is there that intellectual recollection of past moments and that anticipation of future ones, which constitute in great part the bitterness of suffering.[265] the momentary pang, the present pain, which beasts endure, though real enough, is yet, doubtless, not to be compared as {261} to its intensity with the suffering which is produced in man through his high prerogative of self-consciousness.[266] as to the "beneficial lines" (of dr. asa gray, before referred to), some of the facts noticed in the preceding chapters seem to point very decidedly in that direction, but all must admit that the actual existing outcome is far more "beneficial" than the reverse. the natural universe has resulted in the development of an unmistakable harmony and beauty, and in a decided preponderance of good and of happiness over their opposites. even if "laws of nature" did appear, on the theistic hypothesis, to be "superfluous" (which it is by no means intended here to admit), it would be nothing less than puerile to prefer rejecting the hypothesis to conceiving that the appearance of superfluity was probably due to human ignorance; and this especially might be expected from naturalists to whom the interdependence of nature and the harmony and utility of obscure phenomena are becoming continually more clear, as, _e.g._, the structure of orchids to their illustrious expositor. having now cleared the ground somewhat, we may turn to the question what bearing christian dogma has upon evolution, and whether christians, as such, need take up any definite attitude concerning it. as has been said, it is plain that physical science and "evolution" _can_ have nothing whatever to do with absolute or primary creation. the rev. baden powell well expresses this, saying: "science demonstrates incessant past changes, and dimly points to yet earlier links in a more vast series of development of material existence; but the idea of a _beginning_, or of _creation_, in the sense of the original operation of the divine volition to constitute nature and matter, is beyond the province of physical {262} philosophy."[267] with secondary or derivative creation, physical science is also incapable of conflict; for the objections drawn by some writers seemingly from physical science, are, as has been already argued, rather metaphysical than physical. derivative creation is not a supernatural act, but is simply the divine action by and through natural laws. to recognize such action in such laws is a religious mode of regarding phenomena, which a consistent theist must necessarily accept, and which an atheistic believer must similarly reject. but this conception, if deemed superfluous by any naturalist, can never be shown to be _false_ by any investigations concerning natural laws, the constant action of which it presupposes. the conflict has arisen through a misunderstanding. some have supposed that by "creation" was necessarily meant either primary, that is, absolute creation, or, at least, some supernatural action; they have therefore opposed the dogma of "creation" in the imagined interest of physical science. others have supposed that by "evolution" was necessarily meant a denial of divine action, a negation of the providence of god. they have therefore combated the theory of "evolution" in the imagined interest of religion. it appears plain then that christian thinkers are perfectly free to accept the general evolution theory. but are there any theological authorities to justify this view of the matter? now, considering how extremely recent are these biological speculations, it might hardly be expected _a priori_ that writers of earlier ages should have given expression to doctrines harmonizing in any degree with such very modern views,[268] nevertheless such most certainly is the case, and {263} it would be easy to give numerous examples. it will be better, however, only to cite one or two authorities of weight. now, perhaps no writer {264} of the earlier christian ages could be quoted whose authority is more generally recognized than that of st. augustin. the same may be said of the mediæval period, for st. thomas aquinas; and, since the movement of luther, suarez may be taken as a writer widely venerated as an authority and one whose orthodoxy has never been questioned. it must be borne in mind that for a considerable time after even the last of these writers no one had disputed the generally received view as to the small age of the world or at least of the kinds of animals and plants inhabiting it. it becomes therefore much more striking if views formed under such a condition of opinion are found to harmonize with modern ideas regarding "creation" and organic life. now st. augustin insists in a very remarkable manner on the merely derivative sense in which god's creation of organic forms is to be understood; that is, that god created them by conferring on the material world the power to evolve them under suitable conditions. he says in his book on genesis:[269] "terrestria animalia, tanquam ex ultimo elemento mundi ultima; nihilominus _potentialiter_, quorum numeros tempus postea visibiliter explicaret." again he says:-"sicut autem in ipso grano invisibiliter erant omnia simul, quæ per tempora in arborem surgerent; ita ipse mundus cogitandus est, cum deus _simul omnia creavit_, habuisse simul omnia quæ in illo et cum illo facta sunt quando factus est dies; non solum coelum cum sole et lunâ et sideribus ... ; sed etiam illa quæ aqua et terra produxit potentialiter atque causaliter, priusquam per temporum moras ita exorirentur, quomodo nobis jam nota sunt in eis operibus, quæ deus usque nunc operatur."[270] "omnium quippe rerum quæ corporaliter visibiliterque nascuntur, {265} occulta quædam semina in istis corporeis mundi hujus elementis latent."[271] and again: "ista quippe originaliter ac primordialiter in quadam textura elementorum cuncta jam creata sunt; sed acceptis opportunitatibus prodeunt."[272] st. thomas aquinas, as was said in the first chapter, quotes with approval the saying of st. augustin that in the first institution of nature we do not look for _miracles_, but for the _laws of nature_: "in prima institutione naturæ non quæritur miraculum, sed quid natura rerum habeat, ut augustinus dicit."[273] again, he quotes with approval st. augustin's assertion that the kinds were created only derivatively, "_potentialiter tantum_."[274] also he says, "in prima autem rerum institutione fuit principium activum verbum dei, quod de materia elementari produxit animalia, vel in actu vel _virtute_, secundum aug. lib. 5 de gen. ad lit. c. 5."[275] speaking of "kinds" (in scholastic phraseology "substantial forms") latent in matter, he says: "quas quidam posuerunt non incipere per actionem naturæ sed prius in materia exstitisse, ponentes latitationem formarum. et hoc accidit eis ex ignorantia materiæ, quia nesciebant distinguere inter potentiam et actum. quia enim formæ præexistunt eas simpliciter præexistere."[276] also cornelius à lapide[277] contends that at least certain animals were not absolutely, but only derivatively created, saying of them, "non fuerunt creata formaliter, sed potentialiter." as to suarez, it will be enough to refer to disp. xv., 2, n. 9, p. 508, t. i. edition _vives_, paris; also nos. 13--15, and many other references{266} to the same effect could easily be given, but these may suffice. it is then evident that ancient and most venerable theological authorities distinctly assert _derivative_ creation, and thus harmonize with all that modern science can possibly require. it may indeed truly be said with roger bacon, "the saints never condemned many an opinion which the moderns think ought to be condemned."[278] the various extracts given show clearly how far "evolution" is from any necessary opposition to the most orthodox theology. the same may be said of spontaneous generation. the most recent form of it, lately advocated by dr. h. charlton bastian,[279] teaches that matter exists in two different forms, the crystalline (or statical) and the colloidal (or dynamical) conditions. it also teaches that colloidal matter, when exposed to certain conditions, presents the phenomena of life, and that it can be formed from crystalline matter, and thus that the _prima materia_ of which these are diverse forms contains potentially all the multitudinous kinds of animal and vegetable existence. this theory moreover harmonizes well with the views here advocated, for just as crystalline matter builds itself, under suitable conditions, along _certain definite lines_, so analogously colloidal matter has _its definite lines and directions_ of development. it is not collected in haphazard, accidental aggregations, but evolves according to its proper laws and special properties. the perfect orthodoxy of these views is unquestionable. nothing is plainer from the venerable writers quoted, as well as from a mass of other {267} authorities, than that "the supernatural" is not to be looked for or expected in the sphere of mere nature. for this statement there is a general _consensus_ of theological authority. the teaching which the author has received is, that god is indeed inscrutable and incomprehensible to us from the infinity of his attributes, so that our minds can, as it were, only take in, in a most fragmentary and indistinct manner (as through a glass darkly), dim conceptions of infinitesimal portions of his inconceivable perfection. in this way the partial glimpses obtained by us in different modes differ from each other; not that god is anything but the most perfect unity, but that apparently conflicting views arise from our inability to apprehend him, except in this imperfect manner, _i.e._ by successive slight approximations along different lines of approach. sir william hamilton has said,[280] "nature conceals god, and man reveals him." it is not, according to the teaching spoken of, exactly thus; but rather that physical nature reveals to us one side, one aspect of the deity, while the moral and religious worlds bring us in contact with another, and at first, to our apprehension, a very different one. the difference and discrepancy, however, which is at first felt, is soon seen to proceed not from the reason but from a want of flexibility in the imagination. this want is far from surprising. not only may a man naturally be expected to be an adept in his own art, but at the same time to show an incapacity for a very different mode of activity.[281] we rarely find an artist who takes much interest in jurisprudence, or {268} a prizefighter who is an acute metaphysician. nay, more than this, a positive distaste may grow up, which, in the intellectual order, may amount to a spontaneous and unreasoning disbelief in that which appears to be in opposition to the more familiar concept, and this at all times. it is often and truly said, "that past ages were pre-eminently credulous as compared with our own, yet the difference is not so much in the amount of the credulity, as in the direction which it takes."[282] dr. newman observes: "any one study, of whatever kind, exclusively pursued, deadens in the mind the interest, nay the perception of any other. thus cicero says, that plato and demosthenes, aristotle and isocrates, might have respectively excelled in each other's province, but that each was absorbed in his own. specimens of this peculiarity occur every day. you can hardly persuade some men to talk about anything but their own pursuit; they refer the whole world to their own centre, and measure all matters by their own rule, like the fisherman in the drama, whose eulogy on his deceased lord was 'he was so fond of fish.'"[283] the same author further says:[284] "when anything, which comes before us, is very unlike what we commonly experience, we consider it on that account untrue; not because it really shocks our reason as improbable, but because it startles our imagination as strange. now, revelation presents to us a perfectly different aspect of the universe from that presented by the sciences. the two informations are like the distinct subjects represented by the lines of the same drawing, which, accordingly as they are read {269} on their concave or convex side, exhibit to us now a group of trees with branches and leaves, and now human faces." ... "while then reason and revelation are consistent in fact, they often are inconsistent in appearance; and this seeming discordance acts most keenly on the imagination, and may suddenly expose a man to the temptation, and even hurry him on to the commission of definite acts of unbelief, in which reason itself really does not come into exercise at all."[285] thus we find in fact just that distinctness between the ideas derived from physical science on the one hand and from religion on the other, which we might _a priori_ expect if there exists that distinctness between the natural and the miraculous which theological authorities lay down. assuming, for argument's sake, the truth of christianity, it evidently has not been the intention of its author to make the evidence for it so plain that its rejection would be the mark of intellectual incapacity. conviction is not forced upon men in the way that the knowledge that the government of england is constitutional, or that paris is the capital of france, is forced upon all who choose to inquire into those subjects. the christian system is one which puts on the strain, as it were, _every_ faculty of man's nature, and the intellect is not (any more than we should _a priori_ expect it to be) exempted from taking part in the probationary trial. a moral element enters into the acceptance of that system. and so with natural religion--with those ideas of the supernatural, viz. god, creation, and morality, which are anterior to revelation and repose upon reason. here again it evidently has not been the intention of the creator to make the evidence of his existence so plain that its non-recognition would be the mark of intellectual incapacity. {270} conviction, as to theism, is not forced upon men as is the conviction of the existence of the sun at noon-day.[286] a moral element enters also here, and the analogy there is in this respect between christianity and theism speaks eloquently of their primary derivation from one common author. thus we might expect that it would be a vain task to seek anywhere in nature for evidence of divine action, such that no one could sanely deny it. god will not allow himself to be caught at the bottom of any man's crucible, or yield himself to the experiments of gross-minded and irreverent inquirers. the natural, like the supernatural, revelation appeals to _the whole_ of man's mental nature and not to the _reason alone_.[287] none, therefore, need feel disappointed that evidence of the direct action of the first cause in merely natural phenomena ever eludes our grasp; for assuredly those same phenomena will ever remain fundamentally inexplicable by physical science alone. there being then nothing in either authority or reason which makes "evolution" repugnant to christianity, is there anything in the christian doctrine of "creation" which is repugnant to the theory of "evolution"? enough has been said as to the distinction between absolute and derivative "creation." it remains to consider the successive "evolution" (darwinian and other) of "specific forms," in a theological light. as to what "evolution" is, we cannot of course hope to explain it completely, but it may be enough to define it as the manifestation to the intellect, by means of sensible impressions, of some ideal entity (power, principle, nature, or activity) which before that manifestation was in{271} a latent, unrealized, and merely "potential" state--a state that is capable of becoming realized, actual, or manifest, the requisite conditions being supplied. "specific forms," kinds or species, are (as was said in the introductory chapter) "peculiar congeries of characters or attributes, innate powers and qualities, and a certain nature realized in individuals." thus, then, the "evolution of specific forms" means the actual manifestation of special powers, or natures, which before were latent, in such a successive manner that there is in some way a genetic relation between posterior manifestations and those which preceded them. on the special darwinian hypothesis the manifestation of these forms is determined simply by the survival of the fittest of many indefinite variations. on the hypothesis here advocated the manifestation is controlled and helped by such survival, but depends on some unknown internal law or laws which determine variation at special times and in special directions. professor agassiz objects to the evolution theory, on the ground that "species, genera, families, &c., exist as thoughts, individuals as facts,"[288] and he offers the dilemma, "if species do not exist at all, as the supporters of the transmutation theory maintain, how can they vary? and if individuals alone exist, how can the differences which may be observed among them prove the variability of species?" but the supporter of "evolution" need only maintain that the several "kinds" become manifested gradually by slight differences among the various individual embodiments of one specific idea. he might reply to the dilemma by saying, species do not exist _as species_ in the sense in which they are said to vary (variation applying only to the concrete embodiments of {272} the specific idea), and the evolution of species is demonstrated not by individuals _as individuals_, but as embodiments of different specific ideas. some persons seem to object to the term "creation" being applied to evolution, because evolution is an "exceedingly slow and gradual process." now even if it were demonstrated that such is really the case, it may be asked, what is "slow and gradual"? the terms are simply relative, and the evolution of a specific form in ten thousand years would be instantaneous to a being whose days were as hundreds of millions of years. there are others again who are inclined absolutely to deny the existence of species altogether, on the ground that their evolution is so gradual that if we could see all the stages it would be impossible to say _when_ the manifestation of the old specific form ceased and that of the new one began. but surely it is no approach to a reason against the existence of a thing that we cannot determine the exact moment of its first manifestation. when watching "dissolving views," who can tell, whilst closely observing the gradual changes, exactly at what moment a new picture, say st. mark's, venice, can be said to have commenced its manifestation, or have begun to dominate a preceding representation of "dotheboys' hall"? that, however, is no reason for denying the complete difference between the two pictures and the ideas they respectively embody. the notion of a special nature, a peculiar innate power and activity--what the scholastics called a "substantial form"--will be distasteful to many. the objection to the notion seems, however, to be a futile one, for it is absolutely impossible to altogether avoid such a conception and such an assumption. if we refuse it to the individuals which embody the species, we must admit it as regards their component parts--nay, even if we accept the hypothesis of pangenesis, we are nevertheless compelled to attribute to each gemmule that peculiar power of reproducing its own nature (its own "substantial form"), with its special activity, and that remarkable {273} power of annexing itself to certain other well-defined gemmules whose nature it is also to plant themselves in a certain definite vicinity. so that in each individual, instead of one such peculiar power and activity dominating and controlling all the parts, you have an infinity of separate powers and activities limited to the several minute component gemmules. it is possible that in some minds, the notion may lurk that such powers are simpler and easier to understand, because the bodies they affect are so minute! this absurdity hardly bears stating. we can easily conceive a being so small, that a gemmule would be to it as large as st. paul's would be to us. admitting then the existence of species, and of their successive evolution, is there anything in these ideas hostile to christian belief? writers such as vogt and buchner will of course contend that there is; but naturalists, generally, assume that god acts in and by the various laws of nature. and this is equivalent to admitting the doctrine of "derivative creation." with very few exceptions, none deny such divine concurrence. even "design" and "purpose" are recognized as quite compatible with evolution, and even with the special "nebular" and darwinian forms of it. professor huxley well says,[289] "it is necessary to remark that there is a wider teleology, which is not touched by the doctrine of evolution, but is actually based upon the fundamental proposition of evolution." ... "the teleological and the mechanical views of nature are not necessarily mutually exclusive; on the contrary, the more purely a mechanist the speculator is, the more firmly does he assume a primordial molecular arrangement, of which all the phenomena of the universe are the consequences; and the more completely thereby is he at the mercy of the teleologist, who can always defy him to disprove that this primordial {274} molecular arrangement was not intended to evolve the phenomena of the universe."[290] professor owen says, that natural evolution, through secondary causes, "by means of slow physical and organic operations through long ages, is not the less clearly recognizable as the act of all adaptive mind, because we have abandoned the old error of supposing it to be the result[291] of a primary, direct, and sudden act of creational construction." ... "the succession of species by continuously operating law, is not necessarily a 'blind operation.' such law, however discerned in the properties and successions of natural objects, intimates, nevertheless, a preconceived progress. organisms may be evolved in orderly succession, stage after stage, towards a foreseen goal, and the broad features of the course may still show the unmistakable impress of divine volition." mr. wallace[292] declares that the opponents of evolution present a less elevated view of the almighty. he says: "why should we suppose the machine too complicated to have been designed by the creator so complete that it would necessarily work out harmonious results? the theory of 'continual interference' is a limitation of the creator's power. it assumes that he could not work by pure law in the organic, as he has done in the inorganic world." thus, then, there is not only no necessary antagonism between the general theory of "evolution" and a divine action, but the compatibility between the two is recognized by naturalists who cannot be suspected of any strong theological bias. {275} the very same may be said as to the special darwinian form of the theory of evolution. it is true mr. darwin writes sometimes as if he thought that his theory militated against even _derivative creation_.[293] this, however, there is no doubt, was not really meant; and indeed, in the passage before quoted and criticised, the possibility of the divine ordination of each variation is spoken of as a tenable view. he says ("origin of species," p. 569), "i see no good reason why the views given in this volume should shock the religious feelings of anyone;" and he speaks of life "having been originally breathed by the creator into a few forms or into one," which is _more_ than the dogma of creation actually requires. we find then that no _in_compatibility is asserted (by any scientific writers worthy of mention) between "evolution" and the co-operation of the divine will; while the same "evolution" has been shown to be thoroughly acceptable to the most orthodox theologians who repudiate the intrusion of the supernatural into the domain of nature. a more complete harmony could scarcely be desired. but if we may never hope to find, in physical nature, evidence of supernatural action, what sort of action might we expect to find there, looking at it from a theistic point of view? surely an action the results of which harmonize with man's reason,[294] which is orderly, which {276} disaccords with the action of blind chance and with the "fortuitous concourse of atoms" of democritus; but at the same time an action which, as to its modes, ever, in parts, and in ultimate analysis, eludes our grasp, and the modes of which are different from those by which we should have attempted to accomplish such ends. now, this is just what we _do_ find. the harmony, the beauty, and the order of the physical universe are the themes of continual panegyrics on the part of naturalists, and mr. darwin, as the duke of argyll remarks,[295] "exhausts every form of words and of illustration by which intention or mental purpose can be described"[296] when speaking of the wonderfully complex adjustments to secure the fertilization of orchids. also, we find co-existing with this harmony a mode of proceeding so different from that of man as (the direct supernatural action eluding us) to form a stumbling-block to many in the way of their recognition of divine action at all: although nothing can be more inconsistent than to speak of the first cause as utterly inscrutable and incomprehensible, and at the same time to expect to find traces of a mode of action exactly similar to our own. it is surely enough if the results harmonize on the whole and preponderatingly with the rational, moral, and æsthetic instincts of man. mr. j. j. murphy[297] has brought strongly forward the evidence of "intelligence" throughout organic nature. he believes "that there is something in organic progress which mere natural selection among spontaneous variations will not account for," and that "this something is that organizing intelligence which guides the action of the inorganic forces, and forms structures which neither natural selection nor any other unintelligent agency could form." {277} this intelligence, however, mr. murphy considers may be unconscious, a conception which it is exceedingly difficult to understand, and which to many minds appears to be little less than a contradiction in terms; the very first condition of an intelligence being that, if it knows anything, it should at least know its own existence. surely the evidence from physical facts agrees well with the overruling, concurrent action of god in the order of nature; which is no miraculous action, but the operation of laws which owe their foundation, institution, and maintenance to an omniscient creator of whose intelligence our own is a feeble adumbration, inasmuch as it is created in the "image and likeness" of its maker. this leads to the final consideration, a difficulty by no means to be passed over in silence, namely the origin of man. to the general theory of evolution, and to the special darwinian form of it, no exception, it has been shown, need be taken on the ground of orthodoxy. but in saying this, it has not been meant to include the soul of man. it is a generally received doctrine that the soul of every individual man is absolutely created in the strict and primary sense of the word, that it is produced by a direct or supernatural[298] act, and, of course, that by such an act the soul of the first man was similarly created. it is therefore important to inquire whether "evolution" conflicts with this doctrine. now the two beliefs are in fact perfectly compatible, and that either on the hypothesis--1. that man's body was created in a manner different in kind from that by which the bodies of other animals were created; or 2. that it was created in a similar manner to theirs. one of the authors of the darwinian theory, indeed, contends that even{278} as regards man's body, an action took place different from that by which brute forms were evolved. mr. wallace[299] considers that "natural selection" alone could not have produced so large a brain in the savage, in possessing which he is furnished with an organ beyond his needs. also that it could not have produced that peculiar distribution of hair, especially the nakedness of the back, which is common to all races of men, nor the peculiar construction of the feet and hands. he says,[300] after speaking of the prehensile foot, common without a single exception to all the apes and lemurs, "it is difficult to see why the prehensile power should have been taken away" by the mere operation of natural selection. "it must certainly have been useful in climbing, and the case of the baboons shows that it is quite compatible with terrestrial locomotion. it may not be compatible with perfectly easy erect locomotion; but, then, how can we conceive that early man, _as an animal_, gained anything by purely erect locomotion? again, the hand of man contains latent capacities and powers which are unused by savages, and must have been even less used by palæolithic man and his still ruder predecessors. it has all the appearance of an organ prepared for the use of civilized man, and one which was required to render civilization possible." again speaking of the "wonderful power, range, flexibility, and sweetness of the musical sounds producible by the human larynx," he adds, "the habits of savages give no indication of how this faculty could have been developed by natural selection; because it is never required or used by them. the singing of savages is a more or less monotonous howling, and the females seldom sing at all. savages certainly never choose their wives for fine voices, but for rude health, and strength and physical beauty. sexual selection could not therefore have developed this wonderful power, which only comes into play among civilized people. it seems as if the organ had been prepared in anticipation of the future {279} progress of man, since it contains latent capacities which are useless to him in his earlier condition. the delicate correlations of structure that give it such marvellous powers, could not therefore have been acquired by means of natural selection." [illustration: fibres of corti.] to this may be added the no less wonderful faculty in the ear of appreciating delicate musical tones, and the harmony of chords. it matters not what part of the organ subserves this function, but it has been supposed that it is ministered to by the fibres _of corti_.[301] now it can hardly be contended that the preservation of any race of men in the struggle for life could have depended on such an extreme delicacy and refinement of the internal ear,[302]--a perfection only fully exercised in the enjoyment and appreciation of the most exquisite musical performances. here, surely, we have an instance of an organ preformed, ready beforehand for such action as could never by itself have been the cause of its development,--the action having only been subsequent, not anterior. the author is not aware what may be the minute structure of the internal ear in the highest apes, but if (as from analogy is probable) it is much as in man, then _a fortiori_ we have an instance of _anticipatory_ development of a most marked and unmistakable kind. and this is not all. there is no {280} reason to suppose that any animal besides man appreciates musical _harmony_. it is certain that no other one _produces_ it. mr. wallace also urges objections drawn from the origin of some of man's mental faculties, such as "the capacity to form ideal conceptions of space and time, of eternity and infinity--the capacity for intense artistic feelings of pleasure, in form, colour and composition--and for those abstract notions of form and number which render geometry and arithmetic possible," also from the origin of the moral sense.[303] the validity of these objections is fully conceded by the author of this book, but he would push it much further, and contend (as has been now repeatedly said), that another law, or other laws, than "natural selection" have determined the evolution of _all_ organic forms, and of inorganic forms also. and it must be contended that mr. wallace, in order to be quite self-consistent, should arrive at the very same conclusion, inasmuch as he is inclined to trace all phenomena to the action of superhuman will. he says:[304] "if therefore we have traced one force, however minute, to an origin in our own will, while we have no knowledge of any other primary cause of force, it does not seem an improbable conclusion that all force may be will-force; and thus, that the whole universe is not merely dependent on, but actually _is_, the will of higher intelligences, or of one supreme intelligence." if there is really evidence, as mr. wallace believes, of the action of an overruling intelligence in the evolution of the "human form divine;" if we may go so far as this, then surely an analogous action may well be traced in the production of the horse, the camel, or the dog, so largely identified with human wants and requirements. and if from other than physical considerations we may believe that such action, though undemonstrable, has been and is; then (reflecting on sensible {281} phenomena the theistic light derived from psychical facts) we may, in the language of mr. wallace, "see indications of that power in facts which, by themselves, would not serve to prove its existence."[305] mr. murphy, as has been said before, finds it necessary to accept the wide-spread action of "intelligence" as the agent by which _all_ organic forms have been called forth from the inorganic. but all science tends to unity, and this tendency makes it reasonable to extend to all physical existences a mode of formation which we may have evidence for in any _one_ of them. it therefore makes it reasonable to extend, if possible, the very same agency which we find operating in the field of biology, also to the inorganic world. if on the grounds brought forward the action of intelligence may be affirmed in the production of man's bodily structure, it becomes probable _a priori_ that it may also be predicated of the formative action by which has been produced the animals which minister to him, and all organic life whatsoever. nay more, it is then congruous to expect analogous action in the development of crystalline and colloidal structures, and in that of all chemical compositions, in geological evolutions, and the formation not only of this earth, but of the solar system and whole sidereal universe. if such really be the direction in which physical science, philosophically considered, points; if intelligence may thus be seen to preside over the evolution of each system of worlds and the unfolding of every blade of grass--this grand result harmonizes indeed with the teachings of faith that god acts and concurs, in the natural order, with those laws of the material universe which were not only instituted by his will, but are sustained by his concurrence; and we are thus enabled to discern in the natural order, however darkly, the divine author of nature--him in whom "we live, and move, and have our being." but if this view is accepted, then it is no longer absolutely {282} necessary to suppose that any action different in kind took place in the production of man's body, from that which took place in the production of the bodies of other animals, and of the whole material universe. of course, if it _can_ be demonstrated that that difference which mr. wallace asserts really exists, it is plain that we then have to do with facts not only harmonizing with religion, but, as it were, preaching and proclaiming it. it is not, however, necessary for christianity that any such view should prevail. man, according to the old scholastic definition, is "a rational animal" (_animal rationale_), and his animality is distinct in nature from his rationality, though inseparably joined, during life, in one common personality. this animal body must have had a different source from that of the spiritual soul which informs it, from the distinctness of the two orders to which those two existences severally belong. scripture seems plainly to indicate this when it says that "god made man from the dust of the earth, and breathed into his nostrils the breath of life." this is a plain and direct statement that man's _body_ was _not_ created in the primary and absolute sense of the word, but was evolved from pre-existing material (symbolized by the term "dust of the earth"), and was therefore only _derivatively created_, i.e. by the operation of secondary laws. his _soul_, on the other hand, was created in quite a different way, not by any pre-existing means, external to god himself, but by the direct action of the almighty, symbolized by the term "breathing:" the very form adopted by christ, when conferring the _supernatural_ powers and graces of the christian dispensation, and a form still daily used in the rites and ceremonies of the church. that the first man should have had this double origin agrees with what we now experience. for supposing each human soul to be directly and immediately created, yet each human body is evolved by the ordinary operation of natural physical laws. [page 283] professor flower in his introductory lecture[306] (p. 20) to his course of hunterian lectures for 1870 well observes: "whatever man's place may be, either _in_ or _out_ of nature, whatever hopes, or fears or feelings about himself or his race he may have, we all of us admit that these are quite uninfluenced by our knowledge of the fact that each individual man comes into the world by the ordinary processes of generation, according to the same laws which apply to the development of all organic beings whatever, that every part of him which can come under the scrutiny of the anatomist or naturalist, has been evolved according to these regular laws from a simple minute ovum, indistinguishable to our senses from that of any of the inferior animals. if this be so--if man is what he is, notwithstanding the corporeal mode of origin of the individual man, so he will assuredly be neither less nor more than man, whatever may be shown regarding the corporeal origin of the whole race, whether this was from the dust of the earth, or by the modification of some pre-existing animal form." man is indeed compound, in him two distinct orders of being impinge and mingle; and with this an origin from two concurrent modes of action is congruous, and might be expected _a priori_. at the same time as the "soul" is "the form of the body," the former might be expected to modify the latter into a structure of harmony and beauty standing alone in the organic world of nature. also that, with the full perfection and beauty of that soul, attained by the concurrent action of "nature" and "grace," a character would be formed like nothing else which is visible in this world, and having a mode of action different, inasmuch as complementary to all inferior modes of action. something of this is evident even to those who approach the subject from the point of view of physical science only. thus mr. wallace observes,[307] that on his view man is to be placed "apart, as not only the head and {284} culminating point of the grand series of organic nature, but as in some degree _a new and distinct order of being_.[308] from those infinitely remote ages when the first rudiments of organic life appeared upon the earth, every plant and every animal has been subject to one great law of physical change. as the earth has gone through its grand cycles of geological, climatal, and organic progress, every form of life has been subject to its irresistible action, and has been continually but imperceptibly moulded into such new shapes as would preserve their harmony with the ever-changing universe. no living thing could escape this law of its being; none (except, perhaps, the simplest and most rudimentary organisms) could remain unchanged and live amid the universal change around it." "at length, however, there came into existence a being in whom that subtle force we term _mind_, became of greater importance than his mere bodily structure. though with a naked and unprotected body, _this_ gave him clothing against the varying inclemencies of the seasons. though unable to compete with the deer in swiftness, or with the wild bull in strength, _this_ gave him weapons with which to capture or overcome both. though less capable than most other animals of living on the herbs and the fruits that unaided nature supplies, this wonderful faculty taught him to govern and direct nature to his own benefit, and make her produce food for him when and where he pleased. from the moment when the first skin was used as a covering; when the first rude spear was formed to assist in the chase; when fire was first used to cook his food; when the first seed was sown or shoot planted, a grand revolution was effected in nature, a revolution which in all the previous ages of the earth's history had had no parallel, for a being had arisen who was no longer necessarily subject to change with the changing universe, a being who was in some degree superior to nature, inasmuch as he knew how to control and regulate her action, and could {285} keep himself in harmony with her, not by a change in body, but by an advance in mind." "on this view of his special attributes, we may admit 'that he is indeed a being apart.' man has not only escaped 'natural selection' himself, but he is actually able to take away some of that power from nature which before his appearance she universally exercised. we can anticipate the time when the earth will produce only cultivated plants and domestic animals; when man's selection shall have supplanted 'natural selection;' and when the ocean will be the only domain in which that power can be exerted." baden powell[309] observes on this subject: "the relation of the animal man to the intellectual, moral, and spiritual man, resembles that of a crystal slumbering in its native quarry to the same crystal mounted in the polarizing apparatus of the philosopher. the difference is not in physical nature, but in investing that nature with a new and higher application. its continuity with the material world remains the same, but a new relation is developed in it, and it claims kindred with ethereal matter and with celestial light." this well expresses the distinction between the merely physical and the hyperphysical natures of man, and the subsumption of the former into the latter which dominates it. the same author in speaking of man's moral and spiritual nature says,[310] "the assertion in its very nature and essence refers wholly to a different order of things, apart from and transcending any material ideas whatsoever." again[311] he adds, "in proportion as man's _moral_ superiority is held to consist in attributes _not_ of a _material_ or corporeal kind or origin, it can signify little how his _physical_ nature may have originated." now physical science, as such, has nothing to do with the soul of man which is hyperphysical. that such an entity exists, that the correlated {286} physical forces go through their protean transformations, have their persistent ebb and flow outside of the world of will and self-conscious moral being, are propositions the proofs of which have no place in this work. this at least may however be confidently affirmed, that no reach of physical science in any coming century will ever approach to a demonstration that countless modes of being, as different from each other as are the force of gravitation and conscious maternal love, may not co-exist. two such modes are made known to us by our natural faculties only: the physical, which includes the first of these examples; the hyperphysical, which embraces the other. for those who accept revelation, a third and a distinct mode of being and of action is also made known, namely, the direct and immediate or, in the sense here given to the term, the supernatural. an analogous relationship runs through and connects all these modes of being and of action. the higher mode in each case employs and makes use of the lower, the action of which it occasionally suspends or alters, as gravity is suspended by electro-magnetic action, or the living energy of an organic being restrains the inter-actions of the chemical affinities belonging to its various constituents. thus conscious will controls and directs the exercise of the vital functions according to desire, and moral consciousness tends to control desire in obedience to higher dictates.[312] the action of living {287} organisms depends upon and subsumes the laws of inorganic matter. similarly the actions of animal life depend upon and subsume the laws of organic matter. in the same way the actions of a self-conscious moral agent, such as man, depend upon and subsume the laws of animal life. when a part or the whole series of these natural actions is altered or suspended by the intervention of action of a still higher order, we have then a "miracle." in this way we find a perfect harmony in the double nature of man, his rationality making use of and subsuming his animality; his soul arising from direct and immediate creation, and his body being formed at first (as now in each separate individual) by derivative or secondary creation, through natural laws. by such secondary creation, _i.e._ by natural laws, for the most part as yet unknown but controlled by "natural selection," all the various kinds of animals and plants have been manifested on this planet. that divine action has concurred and concurs in these laws we know by deductions from our primary intuitions; and physical science, if unable to demonstrate such action, is at least as impotent to disprove it. disjoined from these deductions, the phenomena of the universe present an aspect devoid of all that appeals to the loftiest aspirations of man, that which stimulates his efforts after goodness, and presents consolations for unavoidable shortcomings. conjoined with these same deductions, all the harmony of physical nature and the constancy of its laws are preserved unimpaired, while the reason, the conscience, and the æsthetic instincts are alike gratified. we have thus a true reconciliation of science and religion, in which each gains and neither loses, one being complementary to the other. some apology is due to the reader for certain observations and arguments which have been here advanced, and which have little in the shape of novelty to recommend them. but after all, novelty can hardly be predicated of the views here criticised and opposed. some of these seem almost a {288} return to the "fortuitous concourse of atoms" of democritus, and even the very theory of "natural selection" itself--a "survival of the fittest"--was in part thought out not hundreds but _thousands_ of years ago. opponents of aristotle maintained that by the accidental occurrence of combinations, organisms have been preserved and perpetuated such as final causes, did they exist, would have brought about, disadvantageous combinations or variations being speedily exterminated. "for when the very same combinations happened to be produced which the law of final causes would have called into being, those combinations which proved to be advantageous to the organism were preserved; while those which were not advantageous perished, and still perished like the minotaurs and sphinxes of empedocles."[313] in conclusion, the author ventures to hope that this treatise may not be deemed useless, but have contributed, however slightly, towards clearing the way for peace and conciliation and for a more ready perception, of the harmony which exists between those deductions from our primary intuitions before alluded to, and the teachings of physical science, as far, that is, as concerns the evolution of organic forms--_the genesis of species_. the aim has been to support the doctrine that these species have been evolved by ordinary _natural laws_ (for the most part unknown) controlled by the _subordinate_ action of "natural selection," and at the same time to remind some that there is and can be absolutely nothing in physical science which forbids them to regard those natural laws as acting with the divine concurrence and in obedience to a creative fiat originally imposed on the primeval cosmos, "in the beginning," by its creator, its upholder, and its lord. {289} * * * * * index. a. aard-vark, 174. absolute creation, 252. acanthometræ, 186. acrodont teeth, 148. acts formally moral, 195. acts materially moral, 195. adductor muscles, 79. agassiz, professor, 271. aged, care of, 192. aggregational theory, 163. algoa bay, cat of, 98. allantois, 82. amazons, butterflies of, 85. amazons, cholera in the, 192. american butterflies, 29. american maize, 100. american monkeys, 226. amiurus, 147. amphibia, 109. analogical relations, 157. ancon sheep, 100, 103, 227. andrew murray, mr., 83. angora cats, 175. animal's sufferings, 260. ankle bones, 158. annelids undergoing fission, 169, 211. annulosa, eye of, 76. anoplotherium, 109. anteater, 83. antechinus, 82. antenna, of orchid, 56. anthropomorphism, 258. ape's sexual characters, 49. apostles' creed, 245. appendages of lobster, 161. appendages of normandy pigs, 99. appendages of turkey, 100. appendix, vermiform, 83. appreciation of mr. darwin, 10. apteryx, 7, 70. aqueous humour, 76. aquinas, st. thomas, 17, 263, 265. archegosaurus, 135. archeopteryx, 73. arcturus, 193. argyll, duke of, 14, 276. aristotle, 288. armadillo, extinct kind, 110. arthritis, rheumatic, 183. artiodactyle foot, 109. asa gray, dr., 253, 255, 261. asceticism, 193. ascidians, placental structure, 81. assumptions of mr. darwin, 16. astronomical objections, 136. auditory organ, 74. augustin, st., 17, 263, 264. aurelius, marcus, 206. avian limb, 106. avicularia, 80. axolotl, 165. aye-aye, 107. aylesbury ducks, 234. b. backbone, 135, 162. bacon, roger, 266. baleen, 40. bamboo insect, 33. bandicoot, 67. bartlett, mr. a. d., 126, 234. bartlett, mr. e., 192. basil, st., 17. bastian, dr. h. charlton, 115, 219, 237, 266. bat, wing of, 64. bates, mr., 29, 85, 87. [page 290] bats, 108. beaks, 83. beasts, sufferings of, 260. beauty of shell-fish, 54. bee orchid, 55. bird, wings of, 64. birds compared with reptiles, 70. bird's-head processes, 80. birds of paradise, 90. birth of individual and species, 2. bivalves, 79. black sheep, 122. black-shouldered peacock, 100. bladebone, 70. blood-vessels, 182. blyth, mr., 100, 181. bones of skull, 153. bonnet, m., 217. borwick, mr., 198. "boots" of pigeons, 181. breathing, modified power of, 99. breeding of lions, 234. brill, 37. broccoli, variety of, 100. bryozoa, 81. buchner, dr., 273. budd, dr. w., 183. buffon, 217. bull-dog's instinct, 260. burt, prof. wilder, 180, 184. butterflies, 29. butterflies, amazonian, 85. butterflies, american, 29. butterflies of indian region, 83. butterflies, tails of, 85. butterfly, leaf, 31. c. cacotus, 149. cæcum, 83. calamaries, 77. cambrian deposits, 137. cape ant-eater, 174. care of aged, 192. carinate birds, 70. carnivora, 68. carnivorous dentition, 110. carp fishes, 146. carpal bones, 106, 178. carpenter, dr., 115. carpus, 177, 178. cases of conscience, 201. cassowary, 70. catasetum, 56. causes of spread of darwinism, 10. cebus, 226. celebes, butterflies of, 85. centetes, 148. centipede, 66, 159. cephalopoda, 74. ceroxylus laceratus, 36. cetacea, 42, 83, 105, 108, 174. chances against few individuals, 57. characinidæ, 146. cheirogaleus, 158. chetahs, 234. chickens, mortality of hybrids, 124. chioglossa, 165. chiromys, 107. cholera, 192. choroid, 76. chronic rheumatism, 183. circumcision, 212. clarias, 146. climate, effects of, 98. climbing plants, 107. clock-thinking illustration, 249. cobra, 50. cockle, 79. cod, 39. colloidal matter, 266. conceptions, symbolic, 251. connecticut footsteps, 131. connecting links, supposed, 107. conscience, cases of, 201. conscientious papuan, 197. cope, professor, 71, 130. coracoid, of birds and reptiles, 70. cornea, 77. cornelius à lapide, 265. correlation, laws of, 173. corti, fibres of, 53, 279. coryanthes, 56. costa, m., 88. cranial segments, 172. creation, 245, 252. creator, 15, 252. creed, apostles', 245. crocodile, 43. croll, mr., 137. crustacea, 79, 160. cryptacanthus, 146. crystalline matter, 266. crystals of snow, 186. cuttle-fishes, 74, 75. cuvier, 109. cyprinoids, 146. cytheridea, 79. [page 291] d. dana, professor, 149. darwin, mr. charles, 2, 10, 12, 14-21, 23, 27, 34, 35, 43, 45, 47, 48, 55-57, 59, 65, 88, 94, 98-100, 107, 118-126, 129, 138, 142, 145, 149, 150, 181, 188-190, 196, 208, 209, 214-216, 218, 223, 233, 234, 252, 254, 258, 259, 275, 276. datura tatula, 101. delhi, days at, 98. delpino, signor, 212, 213, 215. democritus, 217, 275, 288. density of air for breathing, 99. dentition, carnivorous, 110. derivation, 238. derivative creation, 252, 282. design, 259. devotion, 193. dibranchiata, 74. difficulties of problem of specific origin, 1. digits, supernumerary, 122, 181. digits, turtle's, 106. dimorphodon, 71. dinornis, 70. dinosauria, 71. diseased pelvis, 182. dissemination of seeds, 65. doris, 170. dotheboys' hall, 272. dragon, the flying, 64, 158. dragon-fly, 77. droughts, 25. duck-billed platypus, 175. dugong, 41, 175. duke of argyll, 14, 276. dyspepsia, 201. e. ear, 74. ear, formation of, 51. early specialization, 111. echinodermata, 44. echinoidea, 44. echinops, 148. echinorhinus, 172. echinus, 43. economy, fuegian political, 192. eczema, 183. edentata, 174. egyptian monuments, 138. elasmobranchs, 140. elbow and knee affections, 183. empedocles, 288. eocene ungulata, 110. eolis, 170. equus, 97. ericulus, 148. ethics, 188. eudes deslongchamps, 99. eurypterida, 141, 171. eutropius, 147. everett, rev. r., 98. evolution requires geometrical increase of time, 139. eye, 76. eye, formation of, 51. eye of trilobites, 135. f. fabre, m., 46. feather-legged breeds, 181. feejeans, 199. fertilization of orchids, 55. "fiat justitia, ruat coelum," 195. fibres of corti, 53, 279. final misery, 194. finger of potto, 105. fish, flying, 64. fishes, fresh-water, 145. fishes, thoracic and jugular, 39, 140. fixity of position of limbs, 39. flat-fishes, 37, 166. flexibility of bodily organization, degrees of, 119. flexibility of mind, 267. flies, horned, 93. flight of spiders, 65. flounder, 37. flower, professor, 163, 232, 283. fly, orchid, 55. flying-dragon, 64, 158. flying fish, 64. foetal teeth of whales, 7. food, effects on pigs, 99. footsteps of connecticut, 131. foraminifera, 186. formally moral acts, 195. formation of eye and ear, 51. forms, substantial, 186, 272. four-gilled cephalopods, 76. fowls, white silk, 122. french theatrical audience, 198. fresh-water fishes, 145. frogs, chilian and european, 149. fuego, terra del, 192. [page 292] g. galago, 158. galaxias, 147. galeus vulgaris, 172. galton, mr. f., 97, 113, 228. gascoyen, mr., 182. gavials, 43. gegenbaur, prof., 176-178. gemmules, 208. generative system, its sensitiveness, 235. genesis of morals, 201. geographical distribution, 144. geographical distribution explained by natural selection, 6. geometrical increments of time, 139. geotria, 147. giraffe, neck of, 24. gizzard-like stomach, 83. glacial epoch, 150. glyptodon, 110. godron, dr., 101. goose, its inflexibility, 119. göppert, mr., 101. gould, mr., 88. grasshopper, great shielded, 89. gray, dr. asa, 253, 255, 261. great ant-eater, 83. great salamander, 172. great shielded grasshopper, 89. greyhounds in mexico, 99. greyhounds, time for evolution of, 138. guinea-fowl, 120. guinea-pig, 126. günther, dr., 145, 146, 172. h. hairless dogs, 174, 175. hamilton, sir wm., 267. harmony, musical, 54, 279. heart in birds and reptiles, 158. hegel, 217. heliconidæ, 29. hell, 194. heptanchus, 172. herbert spencer, mr., 20, 28, 67, 72, 163-166, 168, 170-172, 184, 187, 202, 203, 205, 218, 228, 245, 246, 248, 251. hessian flies, 170. heterobranchus, 146. hewitt, mr., 124, 181. hexanchus, 172. hipparion, 97, 134. homogeny, 158. homology, bilateral or lateral, 156, 164. homology, meaning of term, 7, 156. homology, serial, 159. homology, vertical, 165. homoplasy, 159. honey-suckers, 90. hood of cobra, 50. hook-billed ducks, 100. hooker, dr., 150. horned flies, 93. horny plates, 40, 42. horny stomach, 83. human larynx, 54, 278. humphry, professor, 163. hutton, mr. r. holt, 202, 203. huxley, professor, 67-69, 71, 72, 95, 103, 109, 130, 131, 137, 141, 163, 172, 173, 231, 247, 273. hybrids, mortality of, 124. hydrocyonina, 146. hyperphysical action, 253. hyrax, 179. i. ichthyopsida, 109. ichthyosaurus, 78, 106, 132, 177. ichthyosis, 183. iguanodon, 71. illegitimate symbolic conceptions, 251. illustration by clock-thinking, 249. imaginal disks, 46, 170. implacental mammals, 67, 68. independent origins, 152. indian butterfly, 30. indian region's butterflies, 83. indians and cholera, 192. individual, meaning of word, 2. infirm, care of, 192. influence, local, 83. insect, walking-leaf, 35. insects, walking-stick and bamboo, 33. insectivora, 68. insectivorous mammals, 148. insectivorous teeth, 68. instinct of bull-dog, 260. intermediate forms, 128. intuitions, primary, 251. irregularities in blood-vessels, 182. isaria felina, 115. [page 293] j. japanned peacock, 100. jews, 212. joints of backbone, 157, 162. jugular fishes, 39, 141. julia pastrana, 174. k. kallima inachis, 31. kallima paralekta, 31. kangaroo, 42, 67. kowalewsky, 81. knee and elbow affections, 183. kölliker, professor, 104. l. labyrinthici, 146. labyrinthodon, 104, 134. lamarck, 3. lankester, mr. ray, 152, 158. larynx of kangaroo, 42. larynx of man, 54, 278. lateral homology, 164. laws of correlation, 173. leaf butterfly, 31. legitimate symbolic conceptions, 251. lens, 76. lepidosteus, 172. lepra, 183. lewes, mr. g. h., 94, 212, 214, 216. lewis, st., 206. lewis xv., 206. lewis xvi., 206. limb genesis, 176. limb muscles, 180. limbs, fixity of position of, 39. limbs of lobster, 161. links, supposed connecting, 107. lions, breeding, 234. lions, diseased pelvis, 182. llama, 109. local influences, 83. lobster, 160. long-tailed bird of paradise, 91. lubbock, sir john, 193, 204. lyell sir, charles, on dogs, 99, 106. m. machairodus, 110. macrauchenia, 109. macropodidæ, 69. macroscelides, 68. madagascar, 148, 152. magnificent bird of paradise, 93. maize, american, 100. mammals, 67. mammary gland of kangaroo, 42. mammary gland, origin of, 47. man, origin of, 277. man reveals god, 267. man, voice of, 54. manatee, 41, 175. manchamp breed of sheep, 100. manis, 175. man's larynx, 54. many simultaneous modifications, 57. marcus aurelius, 206. martineau, mr. james, 200, 245. mastacembelus, 145. materially moral acts, 195. matter, crystalline and colloidal, 266. meaning of word "individual," 2. meaning of word "species," 2. mechanical theory of spine, 164. mediterranean oyster, 88, 98. meehan, mr., 88. mexico, dogs in, 99. mill, john stuart, 15, 189, 193, 194. mimicry, 8, 29. miracle, 287. molars, 111. mole, 176. molière, 230. mombas, cats at, 98. monkeys, american, 226. monster proboscis, 123. moral acts, 195. mordacia, 147. murphy, mr. j. j., 52, 53, 76, 103, 114, 115, 137, 185, 221, 276, 281. murray, mr. andrew, 83. mus delicatulus, 82. muscles of limbs, 180. mussel, 79. myrmecophaga, 83. n. nasalis, semnopithecus, 139. nathusius, 99. natural selection, shortly stated, 5. naudin, m. c., 101. nautilus, 76. nebular evolution, 273. neck of giraffe, 24. newman, the rev. dr., 260, 268, 270, 286. [page 294] new zealand crustacea, 149. new zealand fishes, 147. niata cattle, 100. nile fishes, 146. normandy pig, 99. north american fish, 147 nycticebus, 179. o. object of book, 5. objections from astronomy, 136. octopods, 77. offensive remarks of prof. vogt, 13. old, care of the, 192. old fuegian women, 192. omygena exigua, 115. ophiocephalus, 146. optic lobes of pterodactyls, 71. orchids, 92. orchids, bee, &c., 55. organ of hearing, 74. organ of sight, 76. organic polarities, 185. origin of man, 277. orioles, 90. ornithoptera, 84. ornithorhynchus, 175. orthoceratidæ, 170. orycteropus, 174. ostracods, 79. ostrich, 70. otoliths, 74. outlines of butterflies' wings, 86. owen, professor, 74, 102, 123, 217, 238, 274. oyster of mediterranean, 88, 98. oysters, 79. p. paget, mr. j., 182. palæotherium, 109. pallas, 125. pangenesis, 19, 208. pangolin, 175. papilio hospiton, 85. papilio machaon, 85. papilio ulysses, 84. papilionidæ, 83. papuan morals, 197, 198. parthenogenesis, 217. passiflora gracilis, 107. pastrana, julia, 174. pathological polarities, 184. pavo nigripennis, 100. peacock, black shouldered, 100. peacock, inflexibility of, 119. pedicellariæ, 44. pelvis, diseased, 182. pendulous appendages of turkey, 100. perameles, 68. periophthalmus, 146. perissodactyle ungulates, 109. permian, jugular fish, 141. perodicticus, 105, 179. phalangers, 67. phasmidæ, 89. phyllopods, 79. physical actions, 253. "physiological units," 168, 218. pigeons' "boots," 181. placental mammals, 67. placental reproduction, 81. plants, tendrils of, 107. plates of baleen, 40. platypus, 175. pleiades, 193. plesiosaurus, 106, 133, 178. pleurodont dentition, 148. pleuronectidæ, 37, 166. plotosus, 147. poisoning apparatus, 66. poisonous serpents, 50. polarities, organic, 184, 185. political economy, fuegian, 192. polyzoa, 80, 81. pompadour, madame de, 206. poppy, variety of, 101. porcupine, 175. porto santo rabbit, 100, 122. potto, 105, 179. pouched beasts, 67. powell, the rev. baden, 259, 261, 285. premolars, 111. prepotency, 124. primary intuitions, 251. primitive man, 204. problem of origin of kinds, 1. proboscis monkey, 139. proboscis of ungulates, 123. processes, bird's-head, 80. psettus, 146. psoriasis, 183. pterodactyles, compared with birds, 70. pterodactyles, wing of, 64. puccinia, 115. purpose, 259. [page 295] q. quasi-vertebral theory of skull, 172. r. rabbit of porto santo, 100, 122. radial ossicle, 176. rarefied air, effect on dogs, 99. rattlesnake, 49, 50. red bird of paradise, 92. relations, analogical, 157. relations, homological, 156. reptiles compared with birds, 70. retina, 76. retrieving, virtue a kind of, 189, 205. reversion, cases of, 122. rhea, 70. ribs of cetacea and sirenia, 41. ribs of flying-dragon, 64, 158. richardson's figures of pigs, 99. roger bacon, 266. rudimentary structures, 7, 102. s. sabre-toothed tiger, 110. st. augustin, 17, 263-265. st. basil, 17. st. hilaire, m., 179. st. thomas aquinas, 17, 263, 265. salamander, great, 172. salter, mr., 124. salvia officinalis, 213. salvia verticillata, 213. scapula of birds and reptiles, 70. schreber, 13. sclerotic, 76. scorpion, sting of, 66. seals, 83. sea squirts, 81. seeds, dissemination of, 65. seeley, mr., on pterodactyles, 71. segmentation of skull, 172. segmentation of spine, 171. segments, similar, 160. self-existence, 252. semnopithecus, 139. sense, organ of, 51, 69, 74, 76. sensitiveness of generative system, 235. sepia, 77. serpents, poisonous, 50. sexual characters of apes, 49. sexual selection, 48. sharks, 83. shell-fish, beauty of, 54. shells of oysters, 88, 98. shielded grasshopper, 89. silurian strata, 140, 142. simultaneous modifications, 57. sirenia, 42 sir john lubbock, 198, 204. sir william thomson, 136. sitaris, 46. six-shafted bird of paradise, 90. skull bones, 153. skull segments, 172. sloth, windpipe of, 82. smithfield, wife-selling in, 198. snow, crystals of, 186. sole, 37. solenodon, 148. species, meaning of word, 2. spelerpes, 165. spencer, see herbert spencer. spider orchid, 55. spiders, flight of, 65. spine of glyptodon, 110. spine, segmentation of, 172. squalidæ, 38. squilla, 160. sterility of hybrids, 125. stings, 66. straining action of baleen, 41. struthious birds, 70, 151. sturgeon, 171. suarez, 18, 263. substantial forms, 186, 272. sufferings of beasts, 260. supernatural action, 252. supernatural action not to be looked for in nature, 15. supernumerary digits, 122, 181. syllis, 169, 211. symbolic conceptions, 251. symmetrical diseases, 182. syphilitic deposits, 183. t. tadpole's beak, 83. tails of butterflies, 85. tapir, 123, 134. tarsal bones, 159, 198. teeth of cetacea, 83. teeth of insectivora, 68. teeth of kangaroo and macroscelides, 69. teeth of seals, 83. teeth of sharks, 83. [page 296] teleology and evolution compatible, 273. tendrils of climbing plants, 107. tenia echinococcus, 170. teratology, 173. tetragonopterina, 146. thomson, sir william, 136. thoracic fishes, 39. thorax of crustaceans, 79. thylacine, 67. tierra del fuego, 192. tiger, sabre-toothed, 110. time required for evolution, 128. tope, 172. trabeculæ cranii, 172. transitional forms, 128. transmutationism, 242. trevelyan, sir j. peacock, 100. trilobites, 135, 141, 171. tunicaries, 81. turbot, 37. turkey, effects of climate on, 100. turkish dog, 45. two-gilled cephalopods, 76. type, conformity to, 241. u. umbilical vesicle, 82. ungulata, 25, 109. ungulata eocene, 110. units, physiological, 168, 218. unknowable, the, 245. upper silurian strata, 140, 142. urotrichus, 68. v. variability, different degrees of, 119. vermiform appendix, 83. vertebræ of skull, 172. vertebral column, 162, 171. vertebrate limbs, 38, 163. vertical homology, 165. vesicle, umbilical, 82. "vestiges of creation," 3. view here advocated, 5. vitreous humour, 76. vogt, professor, 12, 273. voice of man, 54. voltaire, 230. w. wagner, j. a., 13. wagner, nicholas, 170. walking leaf, 35. walking-stick insect, 33. wallace, mr. alfred, 2, 10, 26, 29, 30, 32, 35, 36, 54, 83, 84, 87, 89, 90, 103, 117, 191, 197, 226, 274, 281-283. weaver fishes, 39. weitbrecht, 179. whale, foetal teeth of, 7. whale, mouth of, 40. whalebone, 40. whales, 78. white silk fowls, 122. wife selling, 198. wild animals, their variability, 120. wilder, professor burt, 180, 184. windpipe, 82. wings of bats, birds, and pterodactyles, 64, 130. wings of birds, origin of, 106. wings of butterflies, outline of, 86. wings of flying-dragon, 64, 158. wings of humming-bird, 157. wings of humming-bird hawk moth, 157. wings of insects, 65. wombat, 83. women, old fuegian, 192. worms undergoing fission, 169, 211. wyman, dr. jeffries, 185. y. york minster, a fuegian, 197. z. zebras, 134. zoological gardens, superintendent of, 126. r. clay, sons, and taylor, printers, london. * * * * * notes [1] in the last edition of the "origin of species" (1869) mr. darwin himself admits that "natural selection" has not been the exclusive means of modification, though he still contends it has been the most important one. [2] see mr. wallace's recent work, entitled "contributions to the theory of natural selection," where, at p. 302, it is very well and shortly stated. [3] "natural selection" is happily so termed by mr. herbert spencer in his "principles of biology." [4] biology is the science of life. it contains zoology, or the science of animals, and botany, or that of plants. [5] for very interesting examples, see mr. wallace's "malay archipelago." [6] see müller's work, "für darwin," lately translated into english by mr. dallas. mr. wallace also predicts the discovery, in madagascar, of a hawk-moth with an enormously long proboscis, and he does this on account of the discovery there of an orchid with a nectary from ten to fourteen inches in length. see _quarterly journal of science_, october 1867, and "natural selection," p. 275. [7] "lectures on man," translated by the anthropological society, 1864, p. 229. [8] ibid. p. 378. [9] see fifth edition, 1869, p. 579. [10] _the rambler_, march 1860, vol. xii. p. 372. [11] "in primâ institutione naturæ non quæritur miraculum, sed quid natura rerum habeat, ut augustinus dicit, lib. ii. sup. gen. ad lit. c. l." (st. thomas, sum. i^æ. lxvii. 4, ad 3.) [12] "hexaem." hom. ix. p. 81. [13] suarez, metaphysica. edition vivés. paris, 1868. vol. i. disputatio xv. § 2. [14] "pangenesis" is the name of the new theory proposed by mr. darwin, in order to account for various obscure physiological facts, such, _e.g._, as the occasional reproduction, by individuals, of parts which they have lost; the appearance in offspring of parental, and sometimes of remote ancestral, characters, &c. it accounts for these phenomena by supposing that every creature possesses countless indefinitely-minute organic atoms, termed "gemmules," which atoms are supposed to be generated in every part of every organ, to be in constant circulation about the body, and to have the power of reproduction. moreover, atoms from every part are supposed to be stored in the generative products. [15] "animals and plants under domestication," vol. ii. p. 192. [16] "animals and plants under domestication," vol. ii. p. 414. [17] "origin of species," 5th edit., 1869, p. 110. [18] ibid. p. 111. [19] ibid. p. 227. [20] the order _ungulata_ contains the hoofed beasts; that is, all oxen, deer, antelopes, sheep, goats, camels, hogs, the hippopotamus, the different kinds of rhinoceros, the tapirs, horses, asses, zebras, quaggas, &c. [21] the elephants of africa and india, with their extinct allies, constitute the order _proboscidea_, and do not belong to the ungulata. [22] see "natural selection," pp. 60-75. [23] "principles of biology," vol. i. p. 122. [24] see "natural selection," chap. iii. p. 45. [25] loc. cit. p. 80. [26] ibid. p. 59. [27] loc. cit. p. 64. [28] "origin of species," 5th edit. p. 104. [29] "animals and plants under domestication," vol. ii. p. 351. [30] loc. cit. pp. 109, 110. [31] heredity is the term used to denote the tendency which there is in offspring to reproduce parental features. [32] loc. cit. p. 64. [33] loc. cit. p. 60. [34] the term "vertebrata" denotes that large group of animals which are characterized by the possession of a spinal column, commonly known as the "backbone." such animals are ourselves, together with all beasts, birds, reptiles, frogs, toads, and efts, and also fishes. [35] it is hardly necessary to observe that these "sea-snakes" have no relation to the often-talked-of "sea-serpent." they are small, venomous reptiles, which abound in the indian seas. [36] "origin of species," 5th edit., 1869, p. 179. [37] "origin of species," 5th edit., p. 532. [38] mr. a. d. bartlett, of the zoological society, informs me that at these periods female apes admit with perfect readiness the access of any males of different species. to be sure this is in confinement; but the fact is, i think, quite conclusive against any such sexual selection in a state of nature as would account for the local coloration referred to. [39] mr. darwin, in the last (fifth) edition of "natural selection," 1869, p. 102, admits that all sexual differences are not to be attributed to the agency of sexual selection, mentioning the wattle of carrier pigeons, tuft of turkey-cock, &c. these characters, however, seem less inexplicable by sexual selection than those given in the text. [40] i am again indebted to the kindness of mr. a. d. bartlett, amongst others. that gentleman informs me that, so far from any mental emotion being produced in rabbits by the presence and movements of snakes, that he has actually seen a male and female rabbit satisfy the sexual instinct in that presence, a rabbit being seized by a snake when _in coitu_. [41] "habit and intelligence," vol. i. p. 319. [42] the reader may consult huxley's "lessons in elementary physiology," p. 204. [43] "natural selection," p. 350. [44] bivalve shell-fish are creatures belonging to the oyster, scallop, and cockle group, _i.e._ to the class lamellibranchiata. [45] the attempt has been made to explain these facts as owing to "manner and symmetry of growth, and to colour being incidental on the chemical nature of the constituents of the shell." but surely beauty depends on some such matters in _all_ cases! [46] it has been suggested in opposition to what is here said, that there is no real resemblance, but that the likeness is "_fanciful!_" the denial, however, of the fact of a resemblance which has struck so many observers, reminds one of the french philosopher's estimate of facts hostile to his theory--"tant pis pour les faits!" [47] fifth edition, p. 236. [48] mr. smith, of the entomological department of the british museum, has kindly informed me that the individuals intermediate in structure are very few in number--not more than five per cent.--compared with the number of distinctly differentiated individuals. besides, in the brazilian kinds these intermediate forms are wanting. [49] by accidental variations mr. darwin does not, of course, mean to imply variations really due to "chance," but to utterly indeterminate antecedents. [50] "origin of species," 5th edition, p. 235. [51] _i.e._ warm-blooded animals which suckle their young, such as apes, bats, hoofed beasts, lions, dogs, bears, weasels, rats, squirrels, armadillos, sloths, whales, porpoises, kangaroos, opossums, &c. [52] "journal of anatomy and physiology" (1868), vol. ii. p. 139. [53] see "ann. and mag. of nat. hist." for august 1870, p. 140. [54] see "proceedings of the royal institution," vol. v. part iv. p. 278: report of a lecture delivered february 7, 1868. also "quarterly journal of the geological society," february 1870: "contributions to the anatomy and taxonomy of the dinosauria." [55] "proceedings of geological society," november 1869, p. 38. [56] the archeopteryx of the oolite has the true carinate shoulder structure. [57] "proceedings of the royal institution," vol. v. p. 279. [58] this remark is made without prejudice to possible affinities in the direction of the ascidians,--an affinity which, if real, would be irrelevant to the question here discussed. [59] "lectures on the comp. anat. of the invertebrate animals," 2nd edit. 1855, p. 619; and todd's "cyclopædia of anatomy," vol. i. p. 554. [60] see "habit and intelligence," vol. i. p. 321. [61] a view recently propounded by kowalewsky. [62] "natural selection," p. 167. [63] "natural selection," p. 173. [64] ibid. p. 177. [65] "malay archipelago," vol. i. p. 439. [66] "natural selection," p. 177. [67] "origin of species," 5th edition, p. 166. [68] vol. ii. p. 280. [69] see "natural selection," p. 64. [70] the italics are not mr. wallace's. [71] "malay archipelago," vol. ii. p. 150; and "natural selection," p. 104. [72] see "malay archipelago," vol. ii. chap. xxxviii. [73] loc. cit. p. 314. [74] _fortnightly review_, new series, vol. iii (april 1868), p. 372. [75] "lay sermons," p. 339. [76] "hereditary genius, an inquiry into its laws," &c. by francis galton, f.r.s. (london: macmillan.) [77] "animals and plants under domestication," vol. i. p. 37. [78] ibid. p. 47. [79] ibid. p. 52. [80] carpenter's "comparative physiology," p. 987, quoted by mr. j. j. murphy, "habit and intelligence," vol. i. p. 171. [81] "animals and plants under domestication," vol. i. p. 72. [82] ibid. p. 76. [83] "animals and plants under domestication," vol. i. p. 71. [84] ibid. p. 114. [85] quoted, ibid. p. 274. [86] ibid. p. 324. [87] ibid. p. 322. [88] ibid. vol. ii. p. 414. [89] proc. zool. soc. of london, april 24, 1860. [90] "animals and plants under domestication," vol. i. p. 291. [91] extracted by j. j. murphy, vol. i. p. 197, from the _quarterly journal of science_, of october 1867, p. 527. [92] "anatomy of vertebrates," vol. iii. p. 795. [93] ibid. p. 807. [94] "animals and plants under domestication," vol. ii. p. 318. [95] "habit and intelligence," vol. i. p. 344. [96] see dec. 2, 1869, vol. i. p. 132. [97] "über die darwin'sche schöpfungstheorie:" ein vortrag, von kölliker; leipzig, 1864. [98] see "lay sermons," p. 342. [99] "anatomy of the lemuroidea." by james murie, m.d., and st. george mivart. trans. zool. soc., march 1866, p. 91. [100] "principles of geology," last edition, vol. i. p. 163. [101] _quarterly journal of science_, april 1866, pp. 257-8. [102] "habit and intelligence," vol. i. p. 178. [103] this animal belongs to the order primates, which includes man, the apes, and the lemurs. the lemurs are the lower kinds of the order, and differ much from the apes. they have their head-quarters in the island of madagascar. the aye-aye is a lemur, but it differs singularly from all its congeners, and still more from all apes. in its dentition it strongly approximates to the rodent (rat, squirrel, and guinea-pig) order, as it has two cutting teeth above, and two below, growing from permanent pulps, and in the adult condition has no canines. [104] _north british review_, new series, vol. vii., march 1867, p. 282. [105] "habit and intelligence," vol. i. p. 75. [106] "habit and intelligence," vol. i. p. 202. [107] "comparative physiology," p. 214, note. [108] see _nature_, june and july 1870, nos. 35, 36, and 37, pp. 170, 193, and 219. [109] "natural selection," p. 293. [110] "animals and plants under domestication," vol. i. pp. 289-295. [111] "origin of species," 5th edition, 1869, p. 45. [112] ibid. p. 13. [113] "animals and plants under domestication," vol. i. p. 115. [114] ibid. vol. i. p. 114. [115] ibid. vol. i. p. 243. [116] ibid. vol. ii. p. 361. [117] ibid. vol. ii. p. 16. [118] "animals and plants under domestication," vol. ii. p. 57. [119] this has been shown by my late friend, mr. h. n. turner, jun., in an excellent paper by him in the "proceedings of the zoological society for 1849," p. 147. the untimely death, through a dissecting wound, of this most promising young naturalist, was a very great loss to zoological science. [120] "animals and plants under domestication," vol. ii. p. 189. [121] "origin of species," 5th edition, 1839, p. 115. [122] ibid. p. 322. [123] ibid. p. 314. [124] "animals and plants under domestication," vol. ii. p. 104. [125] _north british review_, new series, vol. vii., march 1867, p. 317. [126] "origin of species," 5th edition, 1869, p. 212. [127] see also the _popular science review_ for july 1868. [128] a bird with a keeled breast-bone, such as almost all existing birds possess. [129] "anatomy of vertebrates," vol. iii. p. 792. [130] ibid. p. 793. [131] as a tadpole is the _larval form_ of a frog. [132] as professor huxley, with his characteristic candour, fully admitted in his lecture on the dinosauria before referred to. [133] "transactions of the geological society of glasgow," vol. iii. [134] "origin of species," 5th edition, p. 354. [135] see his address to the geological society, on february 19, 1869. [136] see _nature_, vol. i. p. 399, february 17, 1870. [137] ibid. vol. i. p. 454. [138] "habit and intelligence," vol. i. p. 344. [139] "habit and intelligence," vol. i. p. 345. [140] "origin of species," 5th edition, p. 353. [141] "origin of species," 5th edition, p. 381. [142] "origin of species," 5th edition, 1869, p. 463. [143] see his catalogue of acanthopterygian fishes in the british museum, vol. iii. p. 540. [144] proc. zool. soc. 1867, p. 102, and ann. mag. of nat. hist. vol. xx. p. 110. [145] see catalogue, vol. iii. p. 469. [146] ibid. vol. v. p. 311. [147] ibid. p. 345. [148] ibid. p. 13. [149] ibid. p. 21. [150] see catalogue, vol. v. p. 24. [151] ibid. p. 52. [152] ibid. p. 109. [153] ibid. vol. vi. 208. [154] ibid. vol. viii. p. 507. [155] ibid. p. 509. [156] proc. zool. soc. 1868, p. 482 [157] "origin of species," 5th edition, 1869, p. 454. [158] "origin of species," 5th edition, p. 459. [159] see ann. and mag. of nat. hist., july 1870, p. 37. [160] professor huxley's lectures on the elements of comp. anat. p. 184. [161] for an enumeration of the more obvious homological relationships see ann. and mag. of nat. hist. for august 1870, p. 118. [162] see ann. and mag, of nat. hist., july 1870. [163] treatise on the human skeleton, 1858. [164] hunterian lectures for 1864. [165] linnæan transactions, vol. xxv. p. 395, 1866. [166] hunterian lectures for 1870, and journal of anat. for may 1870. [167] see a paper on the "axial skeleton of the urodela," in proc. zool. soc. 1870, p. 266. [168] just as button's superfluous lament over the unfortunate organization of the sloth has been shown, by the increase of our knowledge, to have been uncalled for and absurd, so other supposed instances of non-adaptation will, no doubt, similarly disappear. mr. darwin, in his "origin of species," 5th edition, p. 220, speaks of a woodpecker (_colaptes campestris_) as having an organization quite at variance with its habits, and as never climbing a tree, though possessed of the special arboreal structure of other woodpeckers. it now appears, however, from the observations of mr. w. h. hudson, c.m.z.s., that its habits are in harmony with its structure. see mr. hudson's third letter to the zoological society, published in the proceedings of that society for march 24, 1870, p. 159. [169] dr. cobbold has informed the author that he has never observed a planaria divide spontaneously, and he is sceptical as to that process taking place at all. dr. h. charlton bastian has also stated that, in spite of much observation, he has never seen the process in _vorticella_. [170] professor huxley's hunterian lecture, march 16, 1868. [171] ibid. march 18. [172] "principles of biology," vol. ii. p. 105. [173] "principles of biology," vol. ii. p. 203. [174] quoted by h. stannius in his "handbuch der anatomie der wirbelthiere," zweite auflage, erstes buch, § 7, p. 17. [175] in his last hunterian course of lectures, 1869. [176] "the science of abnormal forms." [177] "animals and plants under domestication," vol. ii. p. 322; and "origin of species," 5th edition, 1869, p. 178. [178] a remarkable woman exhibited in london a few years ago. [179] "animals and plants under domestication," vol. ii. p. 328. [180] "ueber das gliedmaassenskelet der enaliosaurier, jenaischen zeitschrift," bd. v. heft 3, taf. xiii. [181] in his work on the carpus and tarsus. [182] an excellent specimen displaying this resemblance is preserved in the museum of the royal college of surgeons. [183] phil. trans. 1867, p. 353. [184] proc. zool. soc. 1865, p. 255. [185] ibid. p. 351. [186] "hist. générale des anomalies," t. i. p. 228. bruxelles, 1837. [187] nov. comment. petrop. t. ix. p. 269. [188] read on june 2, 1868, before the massachusetts medical society. see vol. ii. no. 3. [189] "animals and plants under domestication," vol. ii. p. 322. [190] "lectures on surgical pathology," 1853, vol. i. p. 18. [191] "lectures on surgical pathology," 1853, vol. i. p. 22. [192] see "medico-chirurgical transactions," vol. xxv. (or vii. of 2nd series), 1842, p. 100, pl. iii. [193] med.-chirurg. trans, vol. xxv. (or vii. of 2nd series), 1842, p. 122. [194] see _boston medical and surgical journal_ for april 5, 1866, vol. lxxiv. p. 189. [195] "principles of biology," vol. i. p. 180. [196] see the "proceedings of the boston society of natural history," vol. xi. june 5, 1867. [197] "habit and intelligence," vol. i. p. 75. [198] ibid. p. 112. [199] ibid. p. 170. [200] "habit and intelligence," vol. i. p. 229. [201] it is hardly necessary to say that the author does not mean that there is, in addition to a real objective crystal, another real, objective separate thing beside it, namely the "force" directing it. all that is meant is that the action of the crystal in crystallizing must be _ideally_ separated from the crystal itself, not that it is _really_ separate. [202] "origin of species," 5th edition, 1869, p. 577. [203] vol. ii. p. 122. [204] "animals and plants under domestication," vol. i p. 295. [205] "natural selection," p. 350. [206] "animals and plants under domestication," vol. ii. [207] see 2nd edition, vol. i. p. 214. [208] page 103. [209] i have not the merit of having noticed this inconsistency; it was pointed out to me by my friend the rev. w. w. roberts. [210] vol. i. p. 215. [211] "malay archipelago," vol. ii. p. 365. [212] "the origin of civilization and the primitive condition of man," p. 261. longmans, 1870. [213] "primitive man," p. 248. [214] "fiji and the fijians," vol. i. p. 183. [215] "essays," second series, vol. ii. p. 13. [216] see no. 117, july 1869, p. 272. [217] _macmillan's magazine_, no. 117, july 1869. [218] "animals and plants under domestication," vol. ii. p. 403. [219] ibid. p. 366. [220] "animals and plants under domestication," vol. ii. p. 402. [221] see _fortnightly review_, new series, vol. iii. april 1868, p. 352. [222] this appeared in the _rivista contemporanea nazionale italiana_, and was translated and given to the english public in _scientific opinion_ for september 29, october 6, and october 13, 1869, pp. 365, 391, and 407. [223] see _scientific opinion_, of october 13, 1869, p. 407. [224] see _scientific opinion_ of september 29, 1869, p. 366. [225] _fortnightly review_, new series, vol. iii. april 1868, p. 508. [226] _scientific opinion_, of october 13, 1869, p. 408. [227] _fortnightly review_, new series, vol. iii. april 1868, p. 509. [228] "histoire naturelle, générale et particulière," tome ii. 1749, p. 327. "ces liqueurs séminales sont toutes deux un extrait de toutes les parties du corps," &c. [229] see _nature_, march 3, 1870, p. 454. mr. wallace says (referring to mr. croll's paper in the _phil. mag._), "as we are now, and have been for 60,000 years, in a period of low eccentricity, _the rate of change of species during that time may be no measure of the rate that has generally obtained in past geological epochs_." [230] "habit and intelligence," vol. i. p. 344. [231] if anyone were to contend that beside the opium there existed a real distinct objective entity, "its soporific virtue," he would be open to ridicule indeed. but the constitution of our minds is such that we cannot but distinguish ideally a thing from its even essential attributes and qualities. the joke is sufficiently amusing, however, regarded as the solemn enunciation of a mere truism. [232] noticed by professor owen in his "archetype," p. 76. recently it has been attempted to discredit darwinism in france by speaking of it as "_de la science mousseuse!_" [233] "lay sermons," p. 342. [234] introductory lecture of february 14, 1870, pp. 24-30, figs. 1-4. (churchill and sons.) [235] see especially "animals and plants under domestication," vol. ii. chap. xviii. [236] "origin of species," 5th edition, pp. 323, 324. [237] "animals and plants under domestication," vol. ii. p. 2. [238] ibid. p. 25. [239] ibid. p. 151. [240] ibid. p. 157. [241] ibid. p. 158. [242] "animals and plants under domestication," vol. i. p. 291. [243] though hardly necessary, it may be well to remark that the views here advocated in no way depend upon the truth of the doctrine of spontaneous generation. [244] vol. iii. p. 808. [245] this is hardly an exact representation of mr. darwin's view. on his theory, if a favourable variation happens to arise (the external circumstances remaining the same), it will yet be preserved. [246] see 2nd edition, p. 113. [247] "essays, philosophical and theological," trübner and co., first series, 1866, p. 190. "every relative disability may be read two ways. a disqualification in the nature of thought for knowing _x_ is, from the other side, a disqualification in the nature of _x_ from being known. to say then that the first cause is wholly removed from our apprehension is not simply a disclaimer of faculty on our part: it is a charge of inability against the first cause too. the dictum about it is this: 'it is a being that may exist out of knowledge, but that is precluded from entering within the sphere of knowledge.' we are told in one breath that this being must be in every sense 'perfect, complete, total--including in itself all power, and transcending all law' (p. 38); and in another that this perfect and omnipotent one is totally incapable of revealing any one of an infinite store of attributes. need we point out the contradictions which this position involves? if you abide by it, you deny the absolute and infinite in the very act of affirming it, for, in debarring the first cause from self-revelation, you impose a limit on its nature. and in the very act of declaring the first cause incognizable, you do not permit it to remain unknown. for that only is unknown, of which you can neither affirm nor deny any predicate; here you deny the power of self-disclosure to the 'absolute,' of which therefore something is known;--viz., that nothing can be known!" [248] loc. cit. p. 108. [249] loc. cit. p. 43. [250] loc. cit. p. 46. [251] mr. j. martineau, in his "essays," vol. i. p. 211, observes, "mr. spencer's conditions of pious worship are hard to satisfy; there must be between the divine and human no communion of thought, relations of conscience, or approach of affection." ... "but you cannot constitute a religion out of mystery alone, any more than out of knowledge alone; nor can you measure the relation of doctrines to humility and piety by the mere amount of conscious darkness which they leave. all worship, being directed to what is _above_ us and transcends our comprehension, stands in presence of a mystery. but not all that stands before a mystery is worship." [252] "lay sermons," p. 20. [253] loc. cit. p. 109. [254] loc. cit. p. 111. [255] in this criticism on mr. herbert spencer, the author finds he has been anticipated by mr. james martineau. (see "essays," vol. i. p. 208.) [256] loc. cit. p. 29. [257] the author means by this, that it is _directly_ and _immediately_ the act of god, the word "supernatural" being used in a sense convenient for the purposes of this work, and not in its ordinary theological sense. [258] the phrase "order of nature" is not here used in its theological sense as distinguished from the "order of grace," but as a term, here convenient, to denote actions not due to direct and immediate divine intervention. [259] "a free examination of darwin's treatise," p. 29, reprinted from the _atlantic monthly_ for july, august, and october, 1860. [260] "origin of species," 5th edition, p. 571. [261] "animals and plants under domestication," vol. ii. p. 431. [262] the rev. baden powell says, "all sciences approach perfection as they approach to a unity of first principles,--in all cases recurring to or tending towards certain high elementary conceptions which are the representatives of the unity of the great archetypal ideas according to which the whole system is arranged. inductive conceptions, very partially and imperfectly realized and apprehended by human intellect, are the exponents in our minds of these great principles in nature." "all science is but the partial reflexion in the _reason of man_, of the great all-pervading _reason of the universe_. and thus the _unity_ of science is the reflexion of the _unity_ of nature, and of the _unity_ of that supreme reason and intelligence which pervades and rules over nature, and from whence all reason and all science is derived." (unity of worlds, essay i., § ii.; unity of sciences, pp. 79 and 81.) also he quotes from oersted's "soul in nature" (pp. 12, 16, 18, 87, 92, and 377). "if the laws of reason did not exist in nature, we should vainly attempt to force them upon her: if the laws of nature did not exist in our reason, we should not be able to comprehend them." ... "we find an agreement between our reason and works which our reason did not produce." ... "all existence is a dominion of reason." "the laws of nature are laws of reason, and altogether form an endless unity of reason; ... one and the same throughout the universe." [263] in the same way mr. lewes, in criticising the duke of argyll's "reign of law" (_fortnightly review_, july 1867, p. 100), asks whether we should consider that man wise who spilt a gallon of wine in order to fill a wineglass? but, because we should not do so, it by no means follows that we can argue from such an action to the action of god in the visible universe. for the man's object, in the case supposed, is simply to fill the wine-glass, and the wine spilt is so much loss. with god it may be entirely different in both respects. all these objections are fully met by the principle thus laid down by st. thomas aquinas: "quod si aliqua causa particularis deficiat a suo effectu, hoc est propter aliquam causam particularem impediantem quæ continetur sub ordine causæ universalis. unde effectus ordinem causæ universalis nullo modo potest exire." ... "sicut indigestio contingit præter ordinem virtutis nutritivæ ex aliquo impedimento, puta ex grossitie cibi, quam necesse est reducere in aliam causam, et sic usque ad causam primam universalem. cum igitur deus sit prima causa universalis non unius generi tantum, sed universaliter totius entis, impossibile est quod aliquid contingat præter ordinem divinæ gubernationis; sed ex hoc ipso quod aliquid ex unâ parte videtur exire ab ordine divinæ providentiæ, quo consideratur secundam aliquam particularem causam, necesse est quod in eundem ordinem relabatur secundum aliam causam."--_sum. theol_. p. i. q. 19, a. 6, and q. 103, a. 7. [264] "unity of worlds," essay ii., § ii., p. 260. [265] see the exceedingly good passage on this subject by the rev. dr. newman, in his "discourses for mixed congregations," 1850, p. 345. [266] see mr. g. h. lewes's "sea-side studies," for some excellent remarks, beginning at p. 329, as to the small susceptibility of certain animals to pain. [267] "philosophy of creation," essay iii., § iv., p. 480. [268] it seems almost strange that modern english thought should so long hold aloof from familiar communion with christian writers of other ages and countries. it is rarely indeed that acquaintance is shown with such authors, though a bright example to the contrary was set by sir william hamilton. sir charles lyell (in his "principles of geology," 7th edition, p. 35) speaks with approval of the early italian geologists. of vallisneri he says, "i return with pleasure to the geologists of italy who preceded, as has been already shown, the naturalists of other countries in their investigations into the ancient history of the earth, and who still maintained a decided pre-eminence. they refuted and ridiculed the physico-theological systems of burnet, whiston, and woodward; while vallisneri, in his comments on the woodwardian theory, remarked how much the interests of religion, as well as of those of sound philosophy, had suffered by perpetually mixing up the sacred writings with questions of physical science." again, he quotes the carmelite friar generelli, who, illustrating moro before the academy of cremona in 1749, strongly opposed those who would introduce the supernatural into the domain of nature. "i hold in utter abomination, most learned academicians! those systems which are built with their foundations in the air, and cannot be propped up without a miracle, and i undertake, with the assistance of moro, to explain to you how these marine monsters were transported into the mountains by natural causes." sir charles lyell notices with exemplary impartiality the spirit of intolerance on both sides. how in france, buffon, on the one hand, was influenced by the theological faculty of the sorbonne to recant his theory of the earth, and how voltaire, on the other, allowed his prejudices to get the better, if not of his judgment, certainly of his expression of it. thinking that fossil remains of shells, &c., were evidence in favour of orthodox views, voltaire, sir charles lyell (principles, p. 56) tells us, "endeavoured to inculcate scepticism as to the real nature of such shells, and to recall from contempt the exploded dogma of the sixteenth century, that they were sports of nature. he also pretended that vegetable impressions were not those of real plants." ... "he would sometimes, in defiance of all consistency, shift his ground when addressing the vulgar; and, admitting the true nature of the shells collected in the alps and other places, pretend that they were eastern species, which had fallen from the hats of pilgrims coming from syria. the numerous essays written by him on geological subjects were all calculated to strengthen prejudices, partly because he was ignorant of the real state of the science, and partly from his bad faith." as to the harmony between many early church writers of great authority and modern views as regards certain matters of geology, see "geology and revelation," by the rev. gerald molloy, d.d., london, 1870. [269] "de genesi ad litt.," lib. v., cap. v., no. 14 in ben. edition, voi. iii. p. 186. [270] lib. cit., cap. xxii., no. 44. [271] lib. cit., "de trinitate," lib. iii., cap. viii, no. 14. [272] lib. cit., cap. ix., no. 16. [273] st. thomas, summa, i., quest. 67, art. 4, ad 3. [274] primæ partis, vol. ii., quest. 74, art. 2. [275] lib. cit., quest. 71, art. 1. [276] lib. cit., quest. 45, art. 8. [277] _vide_ in genesim comment, cap. i. [278] roger bacon, opus tertium, c. ix. p. 27, quoted in the _rambler_ for 1859, vol. xii. p. 375. [279] see _nature_, june and july, 1870. those who, like professors huxley and tyndall, do not accept his conclusions, none the less agree with him in principle, though they limit the evolution of the organic world from the inorganic to a very remote period of the world's history. (see professor huxley's address to the british association at liverpool, 1870, p. 17.) [280] "lectures on metaphysics and logic," vol. i. lecture ii., p. 40. [281] in the same way that an undue cultivation of any one kind of knowledge is prejudicial to philosophy. mr. james martineau well observes, "nothing is more common than to see maxims, which are unexceptionable as the assumptions of particular sciences, coerced into the service of a universal philosophy, and so turned into instruments of mischief and distortion. that "we can know nothing but phenomena,"--that "causation is simply constant priority,"--that "men are governed invariably by their interests," are examples of rules allowable as dominant hypotheses in physics or political economy, but exercising a desolating tyranny when thrust on to the throne of universal empire. he who seizes upon these and similar maxims, and carries them in triumph on his banner, may boast of his escape from the uncertainties of metaphysics, but is himself all the while the unconscious victim of their very vulgarest deception." ("essays," second series, _a plea for philosophical studies_, p. 421.) [282] lecky's "history of rationalism," vol. i. p. 73. [283] "lectures on university subjects," by j. h. newman, d.d., p. 322. [284] loc. cit. p. 324. [285] thus professor tyndall, in the _pall mall gazette_ of june 15, 1868, speaking of physical science, observes, "the _logical feebleness_ of science is not sufficiently borne in mind. it keeps down the weed of superstition, not by logic, but by slowly rendering the mental soil unfit for its cultivation." [286] by this it is not, of course, meant to deny that the existence of god can be demonstrated so as to demand the assent of the intellect taken, so to speak, by itself. [287] see some excellent remarks in the rev. dr. newman's parochial sermons--the new edition (1869), vol. i. p. 211. [288] _american journal of science_, july 1860, p. 143, quoted in dr. asa gray's pamphlet, p. 47. [289] see _the academy_ for october 1869, no. 1, p. 13. [290] professor huxley goes on to say that the mechanist may, in turn, demand of the teleologist how the latter knows it was so intended. to this it may be replied he knows it as a necessary truth of reason deduced from his own primary intuitions, which intuitions cannot be questioned without _absolute_ scepticism. [291] the professor doubtless means the _direct_ and _immediate_ result. (see trans. zool. soc. vol. v. p. 90.) [292] "natural selection," p. 280. [293] dr. asa gray, _e.g._, has thus understood mr. darwin. the doctor says in his pamphlet, p. 38, "mr. darwin uses expressions which imply that the natural forms which surround us, because they have a history or natural sequence, could have been only generally, but not particularly designed,--a view at once superficial and contradictory; whereas his true line should be, that his hypothesis concerns the _order_ and not the _cause_, the _how_ and not the _why_ of the phenomena, and so leaves the question of design just where it was before." [294] "all science is but the partial reflexion in the _reason of man_, of the great all-pervading _reason of the universe_. and the _unity_ of science is the reflexion of the _unity_ of nature and of the _unity_ of that supreme reason and intelligence which pervades and rules over nature, and from whence all reason and all science is derived." (rev. baden powell, "unity of the sciences," essay i. § ii. p. 81.) [295] "the reign of law," p. 40. [296] though mr. darwin's epithets denoting design are metaphorical, his admiration of the result is unequivocal, nay, enthusiastic! [297] see "habit and intelligence," vol. i. p. 348. [298] the term, as before said, not being used in its ordinary theological sense, but to denote an immediate divine action as distinguished from god's action through the powers conferred on the physical universe. [299] see "natural selection," pp. 332 to 360. [300] loc. cit., p. 349. [301] see professor huxley's "lessons in elementary physiology," p. 218. [302] it may be objected, perhaps, that excessive delicacy of the ear might have been produced by having to guard against the approach of enemies, some savages being remarkable for their keenness of hearing at great distances. but the perceptions of _intensity_ and _quality_ of sound are very different. some persons who have an extremely acute ear for delicate sounds, and who are fond of music, have yet an incapacity for detecting whether an instrument is slightly out of tune. [303] loc. cit., pp. 351, 352. [304] loc. cit., p. 368. [305] loc. cit., p. 350. [306] published by john churchill. [307] natural selection, p. 324. [308] the italics are not mr. wallace's. [309] "unity of worlds," essay ii. § ii. p. 247. [310] ibid. essay i. § ii. p. 76. [311] ibid. essay iii. § iv. p. 466. [312] a good exposition of how an inferior action has to yield to one higher is given by dr. newman in his "lectures on university subjects," p. 372. "what is true in one science, is dictated to us indeed according to that science, but not according to another science, or in another department. "what is certain in the military art, has force in the military art, but not in statesmanship; and if statesmanship be a higher department of action than war, and enjoins the contrary, it has no force on our reception and obedience at all. and so what is true in medical science, might in all cases be carried out, _were_ man a mere animal or brute without a soul; but since he is a rational, responsible being, a thing may be ever so true in medicine, yet may be unlawful in fact, in consequence of the _higher_ law of morals and religion coming to some different conclusion." [313] quoted from the _rambler_ of march 1860, p. 364: [greek: "hopou men oun hapanta sunebê, hôsper kain ei heneka tou egineto, tauta men esôthê apo tou automatou sustanta epitêdeiôs hosa de mê houtôs apôleto kai apollutai, kathapeo empedoklês legei ta bougenê kai androprôra.]"--arist. _phys._ ii. c. 8. generously made available by the internet archive/canadian libraries) the foundations of the origin of species cambridge university press london: fetter lane, e.c. c. f. clay, manager {illustration} edinburgh: 100, princes street also london: h. k. lewis, 136, gower street, w.c. berlin: a. asher and co. leipzig: f. a. brockhaus new york: g. p. putnam's sons bombay and calcutta: macmillan and co., ltd. _all rights reserved_ {illustration: charles darwin from a photograph by maull & fox in 1854} the foundations of the origin of species two essays written in 1842 and 1844 by charles darwin edited by his son francis darwin honorary fellow of christ's college cambridge: at the university press 1909 astronomers might formerly have said that god ordered each planet to move in its particular destiny. in same manner god orders each animal created with certain form in certain country. but how much more simple and sublime power,--let attraction act according to certain law, such are inevitable consequences,--let animal(s) be created, then by the fixed laws of generation, such will be their successors. from darwin's _note book_, 1837, p. 101. to the master and fellows of christ's college, this book is dedicated by the editor in token of respect and gratitude contents essay of 1842 pages introduction xi part i § i. on variation under domestication, and on the principles of selection 1 § ii. on variation in a state of nature and on the natural means of selection 4 § iii. on variation in instincts and other mental attributes 17 part ii §§ iv. and v. on the evidence from geology. (the reasons for combining the two sections are given in the introduction) 22 § vi. geographical distribution 29 § vii. affinities and classification 35 § viii. unity of type in the great classes 38 § ix. abortive organs 45 § x. recapitulation and conclusion 48 essay of 1844 part i chapter i 57-80 on the variation of organic beings under domestication; and on the principles of selection. variation on the hereditary tendency causes of variation on selection crossing breeds whether our domestic races have descended from one or more wild stocks limits to variation in degree and kind in what consists domestication--summary chapter ii 81-111 on the variation of organic beings in a wild state; on the natural means of selection; and on the comparison of domestic races and true species. variation natural means of selection differences between "races" and "species":-first, in their trueness or variability difference between "races" and "species" in fertility when crossed causes of sterility in hybrids infertility from causes distinct from hybridisation points of resemblance between "races" and "species" external characters of hybrids and mongrels summary limits of variation chapter iii 112-132 on the variation of instincts and other mental attributes under domestication and in a state of nature; on the difficulties in this subject; and on analogous difficulties with respect to corporeal structures. variation of mental attributes under domestication hereditary habits compared with instincts variation in the mental attributes of wild animals principles of selection applicable to instincts difficulties in the acquirement of complex instincts by selection difficulties in the acquirement by selection of complex corporeal structures part ii on the evidence favourable and opposed to the view that species are naturally formed races, descended from common stocks. chapter iv 133-143 on the number of intermediate forms required on the theory of common descent; and on their absence in a fossil state chapter v 144-150 gradual appearance and disappearance of species. gradual appearance of species extinction of species chapter vi on the geographical distribution of organic beings in past and present times. section first 151-174 distribution of the inhabitants in the different continents relation of range in genera and species distribution of the inhabitants in the same continent insular faunas alpine floras cause of the similarity in the floras of some distant mountains whether the same species has been created more than once on the number of species, and of the classes to which they belong in different regions second section 174-182 geographical distribution of extinct organisms changes in geographical distribution summary on the distribution of living and extinct organic beings section third 183-197 an attempt to explain the foregoing laws of geographical distribution, on the theory of allied species having a common descent improbability of finding fossil forms intermediate between existing species chapter vii 198-213 on the nature of the affinities and classification of organic beings. gradual appearance and disappearance of groups what is the natural system? on the kind of relation between distinct groups classification of races or varieties classification of races and species similar origin of genera and families chapter viii 214-230 unity of type in the great classes; and morphological structures. unity of type morphology embryology attempt to explain the facts of embryology on the graduated complexity in each great class modification by selection of the forms of immature animals importance of embryology in classification order in time in which the great classes have first appeared chapter ix 231-238 abortive or rudimentary organs. the abortive organs of naturalists the abortive organs of physiologists abortion from gradual disuse chapter x 239-255 recapitulation and conclusion. recapitulation why do we wish to reject the theory of common descent? conclusion index 257 portrait _frontispiece_ facsimile _to face_ p. 50 introduction we know from the contents of charles darwin's note book of 1837 that he was at that time a convinced evolutionist{1}. nor can there be any doubt that, when he started on board the _beagle_, such opinions as he had were on the side of immutability. when therefore did the current of his thoughts begin to set in the direction of evolution? {1} see the extracts in _life and letters of charles darwin_, ii. p. 5. we have first to consider the factors that made for such a change. on his departure in 1831, henslow gave him vol. i. of lyell's _principles_, then just published, with the warning that he was not to believe what he read{2}. but believe he did, and it is certain (as huxley has forcibly pointed out{3}) that the doctrine of uniformitarianism when applied to biology leads of necessity to evolution. if the extermination of a species is no more catastrophic than the natural death of an individual, why should the birth of a species be any more miraculous than the birth of an individual? it is quite clear that this thought was vividly present to darwin when he was writing out his early thoughts in the 1837 note book{4}:-"propagation explains why modern animals same type as extinct, which is law almost proved. they die, without they change, like golden pippins; it is a _generation of species_ like generation _of individuals_." "if _species_ generate other _species_ their race is not utterly cut off." {2} the second volume,--especially important in regard to evolution,--reached him in the autumn of 1832, as prof. judd has pointed out in his most interesting paper in _darwin and modern science_. cambridge, 1909. {3} obituary notice of c. darwin, _proc. r. soc._ vol. 44. reprinted in huxley's _collected essays_. see also _life and letters of c. darwin_, ii. p. 179. {4} see the extracts in the _life and letters_, ii. p. 5. these quotations show that he was struggling to see in the origin of species a process just as scientifically comprehensible as the birth of individuals. they show, i think, that he recognised the two things not merely as similar but as identical. it is impossible to know how soon the ferment of uniformitarianism began to work, but it is fair to suspect that in 1832 he had already begun to see that mutability was the logical conclusion of lyell's doctrine, though this was not acknowledged by lyell himself. there were however other factors of change. in his autobiography{5} he wrote:--"during the voyage of the _beagle_ i had been deeply impressed by discovering in the pampean formation great fossil animals covered with armour like that on the existing armadillos; secondly, by the manner in which closely allied animals replace one another in proceeding southward over the continent; and thirdly, by the south american character of most of the productions of the galapagos archipelago, and more especially by the manner in which they differ slightly on each island of the group; none of the islands appearing to be very ancient in a geological sense. it was evident that such facts as these, as well as many others, could only be explained on the supposition that species gradually become modified; and the subject haunted me." {5} _life and letters_, i. p. 82. again we have to ask: how soon did any of these influences produce an effect on darwin's mind? different answers have been attempted. huxley{6} held that these facts could not have produced their essential effect until the voyage had come to an end, and the "relations of the existing with the extinct species and of the species of the different geographical areas with one another were determined with some exactness." he does not therefore allow that any appreciable advance towards evolution was made during the actual voyage of the _beagle_. {6} _obituary notice_, _loc. cit._ professor judd{7} takes a very different view. he holds that november 1832 may be given with some confidence as the "date at which darwin commenced that long series of observations and reasonings which eventually culminated in the preparation of the _origin of species_." {7} _darwin and modern science._ though i think these words suggest a more direct and continuous march than really existed between fossil-collecting in 1832 and writing the _origin of species_ in 1859, yet i hold that it was during the voyage that darwin's mind began to be turned in the direction of evolution, and i am therefore in essential agreement with prof. judd, although i lay more stress than he does on the latter part of the voyage. let us for a moment confine our attention to the passage, above quoted, from the autobiography and to what is said in the introduction to the _origin_, ed. i., viz. "when on board h.m.s. 'beagle,' as naturalist, i was much struck with certain facts in the distribution of the inhabitants of south america, and in the geological relations of the present to the past inhabitants of that continent." these words, occurring where they do, can only mean one thing,--namely that the facts suggested an evolutionary interpretation. and this being so it must be true that his thoughts _began to flow in the direction of descent_ at this early date. i am inclined to think that the "new light which was rising in his mind{8}" had not yet attained any effective degree of steadiness or brightness. i think so because in his pocket book under the date 1837 he wrote, "in july opened first note-book on 'transmutation of species.' had been greatly struck _from about month of previous march_{9} on character of south american fossils, and species on galapagos archipelago. these facts origin (_especially latter_), of all my views." but he did not visit the galapagos till 1835 and i therefore find it hard to believe that his evolutionary views attained any strength or permanence until at any rate quite late in the voyage. the galapagos facts are strongly against huxley's view, for darwin's attention was "thoroughly aroused{10}" by comparing the birds shot by himself and by others on board. the case must have struck him at once,--without waiting for accurate determinations,--as a microcosm of evolution. {8} huxley, _obituary_, p. xi. {9} in this citation the italics are mine. {10} _journal of researches_, ed. 1860, p. 394. it is also to be noted, in regard to the remains of extinct animals, that, in the above quotation from his pocket book, he speaks of march 1837 as the time at which he began to be "greatly struck on character of south american fossils," which suggests at least that the impression made in 1832 required reinforcement before a really powerful effect was produced. we may therefore conclude, i think, that the evolutionary current in my father's thoughts had continued to increase in force from 1832 onwards, being especially reinforced at the galapagos in 1835 and again in 1837 when he was overhauling the results, mental and material, of his travels. and that when the above record in the pocket book was made he unconsciously minimised the earlier beginnings of his theorisings, and laid more stress on the recent thoughts which were naturally more vivid to him. in his letter{11} to otto zacharias (1877) he wrote, "on my return home in the autumn of 1836, i immediately began to prepare my journal for publication, and then saw how many facts indicated the common descent of species." this again is evidence in favour of the view that the later growths of his theory were the essentially important parts of its development. {11} f. darwin's _life of charles darwin_ (in one volume), 1892, p. 166. in the same letter to zacharias he says, "when i was on board the _beagle_ i believed in the permanence of species, but as far as i can remember vague doubts occasionally flitted across my mind." unless prof. judd and i are altogether wrong in believing that late or early in the voyage (it matters little which) a definite approach was made to the evolutionary standpoint, we must suppose that in 40 years such advance had shrunk in his recollection to the dimensions of "vague doubts." the letter to zacharias shows i think some forgetting of the past where the author says, "but i did not become convinced that species were mutable until, i think, two or three years had elapsed." it is impossible to reconcile this with the contents of the evolutionary note book of 1837. i have no doubt that in his retrospect he felt that he had not been "convinced that species were mutable" until he had gained a clear conception of the mechanism of natural selection, _i.e._ in 1838-9. but even on this last date there is some room, not for doubt, but for surprise. the passage in the autobiography{12} is quite clear, namely that in october 1838 he read malthus's _essay on the principle of population_ and "being well prepared to appreciate the struggle for existence ..., it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. the result of this would be the formation of new species. here then i had at last got a theory by which to work." {12} _life and letters_, i. p. 83. it is surprising that malthus should have been needed to give him the clue, when in the note book of 1837 there should occur--however obscurely expressed--the following forecast{13} of the importance of the survival of the fittest. "with respect to extinction, we can easily see that a variety of the ostrich (petise{14}), may not be well adapted, and thus perish out; or on the other hand, like orpheus{15}, being favourable, many might be produced. this requires the principle that the permanent variations produced by confined breeding and changing circumstances are continued and produce according to the adaptation of such circumstances, and therefore that death of species is a consequence (contrary to what would appear in america) of non-adaptation of circumstances." {13} _life and letters_, ii. p. 8. {14} avestruz petise, _i.e. rhea darwini_. {15} a bird. i can hardly doubt, that with his knowledge of the interdependence of organisms and the tyranny of conditions, his experience would have crystallized out into "a theory by which to work" even without the aid of malthus. in my father's autobiography{16} he writes, "in june 1842 i first allowed myself the satisfaction of writing a very brief abstract of my theory in pencil in 35 pages; and this was enlarged during the summer of 1844 into one of 230 pages{17}, which i had fairly copied out and still possess." these two essays, of 1842 and 1844, are now printed under the title _the foundations of the origin of species_. {16} _life and letters_, i. p. 84. {17} it contains as a fact 231 pp. it is a strongly bound folio, interleaved with blank pages, as though for notes and additions. his own ms. from which it was copied contains 189 pp. it will be noted that in the above passage he does not mention the ms. of 1842 as being in existence, and when i was at work on _life and letters_ i had not seen it. it only came to light after my mother's death in 1896 when the house at down was vacated. the ms. was hidden in a cupboard under the stairs which was not used for papers of any value, but rather as an overflow for matter which he did not wish to destroy. the statement in the autobiography that the ms. was written in 1842 agrees with an entry in my fathers diary:-"1842. may 18th went to maer. june 15th to shrewsbury, and on 18th to capel curig.... during my stay at maer and shrewsbury (five years after commencement) wrote pencil sketch of my species theory." again in a letter to lyell (june 18, 1858) he speaks of his "ms. sketch written out in 1842{18}." in the _origin of species_, ed. i. p. 1, he speaks of beginning his speculations in 1837 and of allowing himself to draw up some "short notes" after "five years' work," _i.e._ in 1842. so far there seems no doubt as to 1842 being the date of the first sketch; but there is evidence in favour of an earlier date{19}. thus across the table of contents of the bound copy of the 1844 ms. is written in my father's hand "this was sketched in 1839." again in a letter to mr wallace{20} (jan. 25, 1859) he speaks of his own contributions to the linnean paper{21} of july 1, 1858, as "written in 1839, now just twenty years ago." this statement as it stands is undoubtedly incorrect, since the extracts are from the ms. of 1844, about the date of which no doubt exists; but even if it could be supposed to refer to the 1842 essay, it must, i think, be rejected. i can only account for his mistake by the supposition that my father had in mind the date (1839) at which the framework of his theory was laid down. it is worth noting that in his autobiography (p. 88) he speaks of the time "about 1839, when the theory was clearly conceived." however this may be there can be no doubt that 1842 is the correct date. since the publication of _life and letters_ i have gained fresh evidence on this head. a small packet containing 13 pp. of ms. came to light in 1896. on the outside is written "first pencil sketch of species theory. written at maer and shrewsbury during may and june 1842." it is not however written in pencil, and it consists of a single chapter on _the principles of variation in domestic organisms_. a single unnumbered page is written in pencil, and is headed "maer, may 1842, useless"; it also bears the words "this page was thought of as introduction." it consists of the briefest sketch of the geological evidence for evolution, together with words intended as headings for discussion,--such as "affinity,--unity of type,--foetal state,--abortive organs." {18} _life and letters_, ii. p. 116. {19} _life and letters_, ii. p. 10. {20} _life and letters_, ii. p. 146. {21} _j. linn. soc. zool._ iii. p. 45. the back of this "useless" page is of some interest, although it does not bear on the question of date,--the matter immediately before us. it seems to be an outline of the essay or sketch of 1842, consisting of the titles of the three chapters of which it was to have consisted. "i. the principles of var. in domestic organisms. "ii. the possible and probable application of these same principles to wild animals and consequently the possible and probable production of wild races, analogous to the domestic ones of plants and animals. "iii. the reasons for and against believing that such races have really been produced, forming what are called species." it will be seen that chapter iii as originally designed corresponds to part ii (p. 22) of the essay of 1842, which is (p. 7) defined by the author as discussing "whether the characters and relations of animated things are such as favour the idea of wild species being races descended from a common stock." again at p. 23 the author asks "what then is the evidence in favour of it (the theory of descent) and what the evidence against it." the generalised section of his essay having been originally chapter iii{22} accounts for the curious error which occurs in pp. 18 and 22 where the second part of the essay is called part iii. {22} it is evident that _parts_ and _chapters_ were to some extent interchangeable in the author's mind, for p. 1 (of the ms. we have been discussing) is headed in ink chapter i, and afterwards altered in pencil to part i. the division of the essay into two parts is maintained in the enlarged essay of 1844, in which he writes: "the second part of this work is devoted to the general consideration of how far the general economy of nature justifies or opposes the belief that related species and genera are descended from common stocks." the _origin of species_ however is not so divided. we may now return to the question of the date of the essay. i have found additional evidence in favour of 1842 in a sentence written on the back of the table of contents of the 1844 ms.--not the copied version but the original in my father's writing: "this was written and enlarged from a sketch in 37 pages{23} in pencil (the latter written in summer of 1842 at maer and shrewsbury) in beginning of 1844, and finished it <_sic_> in july; and finally corrected the copy by mr fletcher in the last week in september." on the whole it is impossible to doubt that 1842 is the date of the earlier of the two essays. {23} on p. 23 of the ms. of the _foundations_ is a reference to the "back of p. 21 bis": this suggests that additional pages had been interpolated in the ms. and that it may once have had 37 in place of 35 pp. the sketch of 1842 is written on bad paper with a soft pencil, and is in many parts extremely difficult to read, many of the words ending in mere scrawls and being illegible without context. it is evidently written rapidly, and is in his most elliptical style, the articles being frequently omitted, and the sentences being loosely composed and often illogical in structure. there is much erasure and correction, apparently made at the moment of writing, and the ms. does not give the impression of having been re-read with any care. the whole is more like hasty memoranda of what was clear to himself, than material for the convincing of others. many of the pages are covered with writing on the back, an instance of his parsimony in the matter of paper{24}. this matter consists partly of passages marked for insertion in the text, and these can generally (though by no means always) be placed where he intended. but he also used the back of one page for a preliminary sketch to be rewritten on a clean sheet. these parts of the work have been printed as footnotes, so as to allow what was written on the front of the pages to form a continuous text. a certain amount of repetition is unavoidable, but much of what is written on the backs of the pages is of too much interest to be omitted. some of the matter here given in footnotes may, moreover, have been intended as the final text and not as the preliminary sketch. {24} _life and letters_, i. p. 153. when a word cannot be deciphered, it is replaced by:--, the angular brackets being, as already explained, a symbol for an insertion by the editor. more commonly, however, the context makes the interpretation of a word reasonably sure although the word is not strictly legible. such words are followed by an inserted mark of interrogation >. lastly, words inserted by the editor, of which the appropriateness is doubtful, are printed thus . two kinds of erasure occur in the ms. of 1842. one by vertical lines which seem to have been made when the 35 pp. ms. was being expanded into that of 1844, and merely imply that such a page is done with: and secondly the ordinary erasures by horizontal lines. i have not been quite consistent in regard to these: i began with the intention of printing (in square brackets) all such erasures. but i ultimately found that the confusion introduced into the already obscure sentences was greater than any possible gain; and many such erasures are altogether omitted. in the same way i have occasionally omitted hopelessly obscure and incomprehensible fragments, which if printed would only have burthened the text with a string of s and queried words. nor have i printed the whole of what is written on the backs of the pages, where it seemed to me that nothing but unnecessary repetition would have been the result. in the matter of punctuation i have given myself a free hand. i may no doubt have misinterpreted the author's meaning in so doing, but without such punctuation, the number of repellantly crabbed sentences would have been even greater than at present. in dealing with the essay of 1844, i have corrected some obvious slips without indicating such alterations, because the ms. being legible, there is no danger of changing the author's meaning. the sections into which the essay of 1842 is divided are in the original merely indicated by a gap in the ms. or by a line drawn across the page. no titles are given except in the case of § viii.; and § ii. is the only section which has a number in the original. i might equally well have made sections of what are now subsections, _e.g. natural selection_ p. 7, or _extermination_ p. 28. but since the present sketch is the germ of the essay of 1844, it seemed best to preserve the identity between the two works, by using such of the author's divisions as correspond to the chapters of the enlarged version of 1844. the geological discussion with which part ii begins corresponds to two chapters (iv and v) of the 1844 essay. i have therefore described it as §§ iv. and v., although i cannot make sure of its having originally consisted of two sections. with this exception the ten sections of the essay of 1842 correspond to the ten chapters of that of 1844. the _origin of species_ differs from the sketch of 1842 in not being divided into two parts. but the two volumes resemble each other in general structure. both begin with a statement of what may be called the mechanism of evolution,--variation and selection: in both the argument proceeds from the study of domestic organisms to that of animals and plants in a state of nature. this is followed in both by a discussion of the _difficulties on theory_ and this by a section _instinct_ which in both cases is treated as a special case of difficulty. if i had to divide the _origin_ (first edition) into two parts without any knowledge of earlier ms., i should, i think, make part ii begin with ch. vi, _difficulties on theory_. a possible reason why this part of the argument is given in part i of the essay of 1842 may be found in the essay of 1844, where it is clear that the chapter on instinct is placed in part i because the author thought it of importance to show that heredity and variation occur in mental attributes. the whole question is perhaps an instance of the sort of difficulty which made the author give up the division of his argument into two parts when he wrote the _origin_. as matters stand §§ iv. and v. of the 1842 essay correspond to the geological chapters, ix and x, in the _origin_. from this point onwards the material is grouped in the same order in both works: geographical distribution; affinities and classification; unity of type and morphology; abortive or rudimentary organs; recapitulation and conclusion. in enlarging the essay of 1842 into that of 1844, the author retained the sections of the sketch as chapters in the completer presentment. it follows that what has been said of the relation of the earlier essay to the _origin_ is generally true of the 1844 essay. in the latter, however, the geological discussion is, clearly instead of obscurely, divided into two chapters, which correspond roughly with chapters ix and x of the _origin_. but part of the contents of chapter x (_origin_) occurs in chapter vi (1844) on geographical distribution. the treatment of distribution is particularly full and interesting in the 1844 essay, but the arrangement of the material, especially the introduction of § iii. p. 183, leads to some repetition which is avoided in the _origin_. it should be noted that hybridism, which has a separate chapter (viii) in the _origin_, is treated in chapter ii of the essay. finally that chapter xiii (_origin_) corresponds to chapters vii, viii and ix of the work of 1844. the fact that in 1842, seventeen years before the publication of the _origin_, my father should have been able to write out so full an outline of his future work, is very remarkable. in his autobiography{25} he writes of the 1844 essay, "but at that time i overlooked one problem of great importance.... this problem is the tendency in organic beings descended from the same stock to diverge in character as they become modified." the absence of the principle of divergence is of course also a characteristic of the sketch of 1842. but at p. 37, the author is not far from this point of view. the passage referred to is: "if any species, _a_, in changing gets an advantage and that advantage ... is inherited, _a_ will be the progenitor of several genera or even families in the hard struggle of nature. _a_ will go on beating out other forms, it might come that _a_ would people earth,--we may now not have one descendant on our globe of the one or several original creations{26}." but if the descendants of _a_ have peopled the earth by beating out other forms, they must have diverged in occupying the innumerable diverse modes of life from which they expelled their predecessors. what i wrote{27} on this subject in 1887 is i think true: "descent with modification implies divergence, and we become so habituated to a belief in descent, and therefore in divergence, that we do not notice the absence of proof that divergence is in itself an advantage." {25} _life and letters_, i. p. 84. {26} in the footnotes to the essay of 1844 attention is called to similar passages. {27} _life and letters_, ii. p. 15. the fact that there is no set discussion on the principle of divergence in the 1844 essay, makes it clear why the joint paper read before the linnean society on july 1, 1858, included a letter{28} to asa gray, as well as an extract{29} from the essay of 1844. it is clearly because the letter to gray includes a discussion on divergence, and was thus, probably, the only document, including this subject, which could be appropriately made use of. it shows once more how great was the importance attached by its author to the principle of divergence. {28} the passage is given in the _life and letters_, ii. p. 124. {29} the extract consists of the section on _natural means of selection_, p. 87. i have spoken of the hurried and condensed manner in which the sketch of 1842 is written; the style of the later essay (1844) is more finished. it has, however, the air of an uncorrected ms. rather than of a book which has gone through the ordeal of proof sheets. it has not all the force and conciseness of the _origin_, but it has a certain freshness which gives it a character of its own. it must be remembered that the _origin_ was an abstract or condensation of a much bigger book, whereas the essay of 1844 was an expansion of the sketch of 1842. it is not therefore surprising that in the _origin_ there is occasionally evident a chafing against the author's self-imposed limitation. whereas in the 1844 essay there is an air of freedom, as if the author were letting himself go, rather than applying the curb. this quality of freshness and the fact that some questions were more fully discussed in 1844 than in 1859, makes the earlier work good reading even to those who are familiar with the _origin_. the writing of this essay "during the summer of 1844," as stated in the autobiography{30}, and "from memory," as darwin says elsewhere{31}, was a remarkable achievement, and possibly renders more conceivable the still greater feat of the writing of the _origin_ between july 1858 and september 1859. {30} _life and letters_, i. p. 84. {31} _life and letters_, ii. p. 18. it is an interesting subject for speculation: what influence on the world the essay of 1844 would have exercised, had it been published in place of the origin. the author evidently thought of its publication in its present state as an undesirable expedient, as appears clearly from the following extracts from the _life and letters_, vol. ii. pp. 16--18: _c. darwin to mrs darwin._ down, _july 5, 1844_. "... i have just finished my sketch of my species theory. if, as i believe, my theory in time be accepted even by one competent judge, it will be a considerable step in science. "i therefore write this in case of my sudden death, as my most solemn and last request, which i am sure you will consider the same as if legally entered in my will, that you will devote £400 to its publication, and further will yourself, or through hensleigh{32}, take trouble in promoting it. i wish that my sketch be given to some competent person, with this sum to induce him to take trouble in its improvement and enlargement. i give to him all my books on natural history, which are either scored or have references at the end to the pages, begging him carefully to look over and consider such passages as actually bearing, or by possibility bearing, on this subject. i wish you to make a list of all such books as some temptation to an editor. i also request that you will hand over him all those scraps roughly divided into eight or ten brown paper portfolios. the scraps, with copied quotations from various works, are those which may aid my editor. i also request that you, or some amanuensis, will aid in deciphering any of the scraps which the editor may think possibly of use. i leave to the editor's judgment whether to interpolate these facts in the text, or as notes, or under appendices. as the looking over the references and scraps will be a long labour, and as the _correcting_ and enlarging and altering my sketch will also take considerable time, i leave this sum of £400 as some remuneration, and any profits from the work. i consider that for this the editor is bound to get the sketch published either at a publisher's or his own risk. many of the scraps in the portfolios contain mere rude suggestions and early views, now useless, and many of the facts will probably turn out as having no bearing on my theory. {32} mrs darwin's brother. "with respect to editors, mr lyell would be the best if he would undertake it; i believe he would find the work pleasant, and he would learn some facts new to him. as the editor must be a geologist as well as a naturalist, the next best editor would be professor forbes of london. the next best (and quite best in many respects) would be professor henslow. dr hooker would be _very_ good. the next, mr strickland{33}. if none of these would undertake it, i would request you to consult with mr lyell, or some other capable man, for some editor, a geologist and naturalist. should one other hundred pounds make the difference of procuring a good editor, i request earnestly that you will raise £500. {33} after mr strickland's name comes the following sentence, which has been erased, but remains legible. "professor owen would be very good; but i presume he would not undertake such a work." "my remaining collections in natural history may be given to any one or any museum where would be accepted...." "lyell, especially with the aid of hooker (and of any good zoological aid), would be best of all. without an editor will pledge himself to give up time to it, it would be of no use paying such a sum. "if there should be any difficulty in getting an editor who would go thoroughly into the subject, and think of the bearing of the passages marked in the books and copied out of scraps of paper, then let my sketch be published as it is, stating that it was done several years ago{34}, and from memory without consulting any works, and with no intention of publication in its present form." {34} the words "several years ago, and" seem to have been added at a later date. the idea that the sketch of 1844 might remain, in the event of his death, as the only record of his work, seems to have been long in his mind, for in august, 1854, when he had finished with the cirripedes, and was thinking of beginning his "species work," he added on the back of the above letter, "hooker by far best man to edit my species volume. august 1854." i have called attention in footnotes to many points in which the _origin_ agrees with the _foundations_. one of the most interesting is the final sentence, practically the same in the essays of 1842 and 1844, and almost identical with the concluding words of the _origin_. i have elsewhere pointed out{35} that the ancestry of this eloquent passage may be traced one stage further back,--to the note book of 1837. i have given this sentence as an appropriate motto for the _foundations_ in its character of a study of general laws. it will be remembered that a corresponding motto from whewell's _bridgewater treatise_ is printed opposite the title-page of the _origin of species_. {35} _life and letters_, ii. p. 9. mr huxley who, about the year 1887, read the essay of 1844, remarked that "much more weight is attached to the influence of external conditions in producing variation and to the inheritance of acquired habits than in the _origin_." in the _foundations_ the effect of conditions is frequently mentioned, and darwin seems to have had constantly in mind the need of referring each variation to a cause. but i gain the impression that the slighter prominence given to this view in the _origin_ was not due to change of opinion, but rather because he had gradually come to take this view for granted; so that in the scheme of that book, it was overshadowed by considerations which then seemed to him more pressing. with regard to the inheritance of acquired characters i am not inclined to agree with huxley. it is certain that the _foundations_ contains strong recognition of the importance of germinal variation, that is of external conditions acting indirectly through the "reproductive functions." he evidently considered this as more important than the inheritance of habit or other acquired peculiarities. another point of interest is the weight he attached in 1842-4 to "sports" or what are now called "mutations." this is i think more prominent in the _foundations_ than in the first edition of the _origin_, and certainly than in the fifth and sixth editions. among other interesting points may be mentioned the "good effects of crossing" being "possibly analogous to good effects of change in condition,"--a principle which he upheld on experimental grounds in his _cross and self-fertilisation_ in 1876. in conclusion, i desire to express my thanks to mr wallace for a footnote he was good enough to supply: and to professor bateson, sir w. thiselton-dyer, dr gadow, professor judd, dr marr, col. prain and dr stapf for information on various points. i am also indebted to mr rutherford, of the university library, for his careful copy of the manuscript of 1842. cambridge, _june 9, 1909._ explanation of signs, &c. [] means that the words so enclosed are erased in the original ms. <> indicates an insertion by the editor. _origin_, ed. vi. refers to the popular edition. part i. § i. an individual organism placed under new conditions [often] sometimes varies in a small degree and in very trifling respects such as stature, fatness, sometimes colour, health, habits in animals and probably disposition. also habits of life develope certain parts. disuse atrophies. [most of these slight variations tend to become hereditary.] when the individual is multiplied for long periods by buds the variation is yet small, though greater and occasionally a single bud or individual departs widely from its type (example){36} and continues steadily to propagate, by buds, such new kind. {36} evidently a memorandum that an example should be given. when the organism is bred for several generations under new or varying conditions, the variation is greater in amount and endless in kind [especially{37} holds good when individuals have long been exposed to new conditions]. the nature of the external conditions tends to effect some definite change in all or greater part of offspring,--little food, small size--certain foods harmless &c. &c. organs affected and diseases--extent unknown. a certain degree of variation (müller's twins){38} seems inevitable effect of process of reproduction. but more important is that simple > generation, especially under new conditions [when no crossing] infinite variation and not direct effect of external conditions, but only in as much as it affects the reproductive functions{39}. there seems to be no part (_beau ideal_ of liver){40} of body, internal or external, or mind or habits, or instincts which does not vary in some small degree and [often] some > to a great amount. {37} the importance of exposure to new conditions for several generations is insisted on in the _origin_, ed. i. p. 7, also p. 131. in the latter passage the author guards himself against the assumption that variations are "due to chance," and speaks of "our ignorance of the cause of each particular variation." these statements are not always remembered by his critics. {38} cf. _origin_, ed. i. p. 10, vi. p. 9, "young of the same litter, sometimes differ considerably from each other, though both the young and the parents, as müller has remarked, have apparently been exposed to exactly the same conditions of life." {39} this is paralleled by the conclusion in the _origin_, ed. i. p. 8, that "the most frequent cause of variability may be attributed to the male and female reproductive elements having been affected prior to the act of conception." {40} the meaning seems to be that there must be some variability in the liver otherwise anatomists would not speak of the 'beau ideal' of that organ. [all such] variations [being congenital] or those very slowly acquired of all kinds [decidedly evince a tendency to become hereditary], when not so become simple variety, when it does a race. each{41} parent transmits its peculiarities, therefore if varieties allowed freely to cross, except by the _chance_ of two characterized by same peculiarity happening to marry, such varieties will be constantly demolished{42}. all bisexual animals must cross, hermaphrodite plants do cross, it seems very possible that hermaphrodite animals do cross,--conclusion strengthened: ill effects of breeding in and in, good effects of crossing possibly analogous to good effects of change in condition >{43}. {41} the position of the following passage is uncertain. "if individuals of two widely different varieties be allowed to cross, a third race will be formed--a most fertile source of the variation in domesticated animals. if freely allowed, the characters of pure parents will be lost, number of races thus but differences > besides the . but if varieties differing in very slight respects be allowed to cross, such small variation will be destroyed, at least to our senses,--a variation [clearly] just to be distinguished by long legs will have offspring not to be so distinguished. free crossing great agent in producing uniformity in any breed. introduce tendency to revert to parent form." {42} the swamping effect of intercrossing is referred to in the _origin_, ed. i. p. 103, vi. p. 126. {43} a discussion on the intercrossing of hermaphrodites in relation to knight's views occurs in the _origin_, ed. i. p. 96, vi. p. 119. the parallelism between crossing and changed conditions is briefly given in the _origin_, ed. i. p. 267, vi. p. 391, and was finally investigated in _the effects of cross and self-fertilisation in the vegetable kingdom_, 1876. therefore if in any country or district all animals of one species be allowed freely to cross, any small tendency in them to vary will be constantly counteracted. secondly reversion to parent form--analogue of _vis medicatrix_{44}. but if man selects, then new races rapidly formed,--of late years systematically followed,--in most ancient times often practically followed{45}. by such selection make race-horse, dray-horse--one cow good for tallow, another for eating &c.--one plant's good lay in leaves another in fruit &c. &c.: the same plant to supply his wants at different times of year. by former means animals become adapted, as a direct effect to a cause, to external conditions, as size of body to amount of food. by this latter means they may also be so adapted, but further they may be adapted to ends and pursuits, which by no possibility can affect growth, as existence of tallow-chandler cannot tend to make fat. in such selected races, if not removed to new conditions, and preserved from all cross, after several generations become very true, like each other and not varying. but man{46} selects only > what is useful and curious--has bad judgment, is capricious,--grudges to destroy those that do not come up to his pattern,--has no [knowledge] power of selecting according to internal variations,--can hardly keep his conditions uniform,--[cannot] does not select those best adapted to the conditions under which form > lives, but those most useful to him. this might all be otherwise. {44} there is an article on the _vis medicatrix_ in brougham's _dissertations_, 1839, a copy of which is in the author's library. {45} this is the classification of selection into methodical and unconscious given in the _origin_, ed. i. p. 33, vi. p. 38. {46} this passage, and a similar discussion on the power of the creator (p. 6), correspond to the comparison between the selective capacities of man and nature, in the _origin_, ed. i. p. 83, vi. p. 102. § ii. let us see how far above principles of variation apply to wild animals. wild animals vary exceedingly little--yet they are known as individuals{47}. british plants, in many genera number quite uncertain of varieties and species: in shells chiefly external conditions{48}. primrose and cowslip. wild animals from different [countries can be recognized]. specific character gives some organs as varying. variations analogous in kind, but less in degree with domesticated animals--chiefly external and less important parts. {47} i.e. they are individually distinguishable. {48} see _origin_, ed. i. p. 133, vi. p. 165. our experience would lead us to expect that any and every one of these organisms would vary if taken away > and placed under new conditions. geology proclaims a constant round of change, bringing into play, by every possible > change of climate and the death of pre-existing inhabitants, endless variations of new conditions. these > generally very slow, doubtful though how far the slowness > would produce tendency to vary. but geolog show change in configuration which, together with the accidents of air and water and the means of transportal which every being possesses, must occasionally bring, rather suddenly, organism to new conditions and > expose it for several generations. hence > we should expect every now and then a wild form to vary{49}; possibly this may be cause of some species varying more than others. {49} when the author wrote this sketch he seems not to have been so fully convinced of the general occurrence of variation in nature as he afterwards became. the above passage in the text possibly suggests that at this time he laid more stress on _sports_ or _mutations_ than was afterwards the case. according to nature of new conditions, so we might expect all or majority of organisms born under them to vary in some definite way. further we might expect that the mould in which they are cast would likewise vary in some small degree. but is there any means of selecting those offspring which vary in the same manner, crossing them and keeping their offspring separate and thus producing selected races: otherwise as the wild animals freely cross, so must such small heterogeneous varieties be constantly counter-balanced and lost, and a uniformity of character [kept up] preserved. the former variation as the direct and necessary effects of causes, which we can see can act on them, as size of body from amount of food, effect of certain kinds of food on certain parts of bodies &c. &c.; such new varieties may then become adapted to those external [natural] agencies which act on them. but can varieties be produced adapted to end, which cannot possibly influence their structure and which it is absurd to look as effects of chance. can varieties like some vars of domesticated animals, like almost all wild species be produced adapted by exquisite means to prey on one animal or to escape from another,--or rather, as it puts out of question effects of intelligence and habits, can a plant become adapted to animals, as a plant which cannot be impregnated without agency of insect; or hooked seeds depending on animal's existence: woolly animals cannot have any direct effect on seeds of plant. this point which all theories about climate adapting woodpecker{50} to crawl > up trees, miseltoe, . but if every part of a plant or animal was to vary , and if a being infinitely more sagacious than man (not an omniscient creator) during thousands and thousands of years were to select all the variations which tended towards certain ends ([or were to produce causes > which tended to the same end]), for instance, if he foresaw a canine animal would be better off, owing to the country producing more hares, if he were longer legged and keener sight,--greyhound produced{51}. if he saw that aquatic skinned toes. if for some unknown cause he found it would advantage a plant, which > like most plants is occasionally visited by bees &c.: if that plant's seed were occasionally eaten by birds and were then carried on to rotten trees, he might select trees with fruit more agreeable to such birds as perched, to ensure their being carried to trees; if he perceived those birds more often dropped the seeds, he might well have selected a bird who would rotten trees or [gradually select plants which had proved to live on less and less rotten trees]. who, seeing how plants vary in garden, what blind foolish man has done{52} in a few years, will deny an all-seeing being in thousands of years could effect (if the creator chose to do so), either by his own direct foresight or by intermediate means,--which will represent > the creator of this universe. seems usual means. be it remembered i have nothing to say about life and mind and _all_ forms descending from one common type{53}. i speak of the variation of the existing great divisions of the organised kingdom, how far i would go, hereafter to be seen. {50} the author may possibly have taken the case of the woodpecker from buffon, _histoire nat. des oiseaux_, t. vii. p. 3, 1780, where however it is treated from a different point of view. he uses it more than once, see for instance _origin_, ed. i. pp. 3, 60, 184, vi. pp. 3, 76, 220. the passage in the text corresponds with a discussion on the woodpecker and the mistletoe in _origin_, ed. i. p. 3, vi. p. 3. {51} this illustration occurs in the _origin_, ed. i. pp. 90, 91, vi. pp. 110, 111. {52} see _origin_, ed. i. p. 83, vi. p. 102, where the word _creator_ is replaced by _nature_. {53} note in the original. "good place to introduce, saying reasons hereafter to be given, how far i extend theory, say to all mammalia--reasons growing weaker and weaker." before considering whether be any natural means of selection, and secondly (which forms the 2nd part of this sketch) the far more important point whether the characters and relations of animated are such as favour the idea of wild species being races > descended from a common stock, as the varieties of potato or dahlia or cattle having so descended, let us consider probable character of [selected races] wild varieties. _natural selection._ de candolle's war of nature,--seeing contented face of nature,--may be well at first doubted; we see it on borders of perpetual cold{54}. but considering the enormous geometrical power of increase in every organism and as > every country, in ordinary cases must be stocked to full extent, reflection will show that this is the case. malthus on man,--in animals no moral [check] restraint >--they breed in time of year when provision most abundant, or season most favourable, every country has its seasons,--calculate robins,--oscillating from years of destruction{55}. if proof were wanted let any singular change of climate here >, how astoundingly some tribes > increase, also introduced animals{56}, the pressure is always ready,--capacity of alpine plants to endure other climates,--think of endless seeds scattered abroad,--forests regaining their percentage{57},--a thousand wedges{58} are being forced into the oeconomy of nature. this requires much reflection; study malthus and calculate rates of increase and remember the resistance,--only periodical. {54} see _origin_, ed. i. pp. 62, 63, vi. p. 77, where similar reference is made to de candolle; for malthus see _origin_, p. 5. {55} this may possibly refer to the amount of destruction going on. see _origin_, ed. i. p. 68, vi. p. 84, where there is an estimate of a later date as to death-rate of birds in winter. "calculate robins" probably refers to a calculation of the rate of increase of birds under favourable conditions. {56} in the _origin_, ed. i. pp. 64, 65, vi. p. 80, he instances cattle and horses and certain plants in s. america and american species of plants in india, and further on, as unexpected effects of changed conditions, the enclosure of a heath, and the relation between the fertilisation of clover and the presence of cats (_origin_, ed. i. p. 74, vi. p. 91). {57} _origin_, ed. i. p. 74, vi. p. 91. "it has been observed that the trees now growing on ... ancient indian mounds ... display the same beautiful diversity and proportion of kinds as in the surrounding virgin forests." {58} the simile of the wedge occurs in the _origin_, ed. i. p. 67; it is deleted in darwin's copy of the first edition: it does not occur in ed. vi. the unavoidable effect of this that many of every species are destroyed either in egg or [young or mature (the former state the more common)]. in the course of a thousand generations infinitesimally small differences must inevitably tell{59}; when unusually cold winter, or hot or dry summer comes, then out of the whole body of individuals of any species, if there be the smallest differences in their structure, habits, instincts [senses], health &c, will on an average tell; as conditions change a rather larger proportion will be preserved: so if the chief check to increase falls on seeds or eggs, so will, in the course of 1000 generations or ten thousand, those seeds (like one with down to fly{60}) which fly furthest and get scattered most ultimately rear most plants, and such small differences tend to be hereditary like shades of expression in human countenance. so if one parent > fish deposits its egg in infinitesimally different circumstances, as in rather shallower or deeper water &c., it will then > tell. {59} in a rough summary at the close of the essay, occur the words:--"every creature lives by a struggle, smallest grain in balance must tell." {60} cf. _origin_, ed. i. p. 77, vi. p. 94. let hares{61} increase very slowly from change of climate affecting peculiar plants, and some other rabbit decrease in same proportion [let this unsettle organisation of], a canine animal, who formerly derived its chief sustenance by springing on rabbits or running them by scent, must decrease too and might thus readily become exterminated. but if its form varied very slightly, the long legged fleet ones, during a thousand years being selected, and the less fleet rigidly destroyed must, if no law of nature be opposed to it, alter forms. {61} this is a repetition of what is given at p. 6. remember how soon bakewell on the same principle altered cattle and western, sheep,--carefully avoiding a cross (pigeons) with any breed. we cannot suppose that one plant tends to vary in fruit and another in flower, and another in flower and foliage,--some have been selected for both fruit and flower: that one animal varies in its covering and another not,--another in its milk. take any organism and ask what is it useful for and on that point it will be found to vary,--cabbages in their leaf,--corn in size quality of grain, both in times of year,--kidney beans for young pod and cotton for envelope of seeds &c. &c.: dogs in intellect, courage, fleetness and smell >: pigeons in peculiarities approaching to monsters. this requires consideration,--should be introduced in first chapter if it holds, i believe it does. it is hypothetical at best{62}. {62} compare _origin_, ed. i. p. 41, vi. p. 47. "i have seen it gravely remarked, that it was most fortunate that the strawberry began to vary just when gardeners began to attend closely to this plant. no doubt the strawberry had always varied since it was cultivated, but the slight varieties had been neglected." nature's variation far less, but such selection far more rigid and scrutinising. man's races not [even so well] only not better adapted to conditions than other races, but often not > one race adapted to its conditions, as man keeps and propagates some alpine plants in garden. nature lets animal live, till on actual proof it is found less able to do the required work to serve the desired end, man judges solely by his eye, and knows not whether nerves, muscles, arteries, are developed in proportion to the change of external form. besides selection by death, in bisexual animals the selection in time of fullest vigour, namely struggle of males; even in animals which pair there seems a surplus > and a battle, possibly as in man more males produced than females, struggle of war or charms{63}. hence that male which at that time is in fullest vigour, or best armed with arms or ornaments of its species, will gain in hundreds of generations some small advantage and transmit such characters to its offspring. so in female rearing its young, the most vigorous and skilful and industrious, instincts best developed, will rear more young, probably possessing her good qualities, and a greater number will thus prepared for the struggle of nature. compared to man using a male alone of good breed. this latter section only of limited application, applies to variation of [specific] sexual characters. introduce here contrast with lamarck,--absurdity of habit, or chance?? or external conditions, making a woodpecker adapted to tree{64}. {63} here we have the two types of sexual selection discussed in the _origin_, ed. i. pp. 88 et seq., vi. pp. 108 et seq. {64} it is not obvious why the author objects to "chance" or "external conditions making a woodpecker." he allows that variation is ultimately referable to conditions and that the nature of the connexion is unknown, i.e. that the result is fortuitous. it is not clear in the original to how much of the passage the two ? refer. before considering difficulties of theory of selection let us consider character of the races produced, as now explained, by nature. conditions have varied slowly and the organisms best adapted in their whole course of life to the changed conditions have always been selected,--man selects small dog and afterwards gives it profusion of food,--selects a long-backed and short-legged breed and gives it no particular exercise to suit this function &c. &c. in ordinary cases nature has not allowed her race to be contaminated with a cross of another race, and agriculturists know how difficult they find always to prevent this,--effect would be trueness. this character and sterility when crossed, and generally a greater amount of difference, are two main features, which distinguish domestic races from species. [sterility not universal admitted by all{65}. _gladiolus_, _crinum_, _calceolaria_{66} must be species if there be such a thing. races of dogs and oxen: but certainly very general; indeed a gradation of sterility most perfect{67} very general. some nearest species will not cross (crocus, some heath >), some genera cross readily (fowls{68} and grouse, peacock &c.). hybrids no ways monstrous quite perfect except secretions{69} hence even the mule has bred,--character of sterility, especially a few years ago > thought very much more universal than it now is, has been thought the distinguishing character; indeed it is obvious if all forms freely crossed, nature would be a chaos. but the very gradation of the character, even if it always existed in some degree which it does not, renders it impossible as marks > those > suppose distinct as species{70}]. will analogy throw any light on the fact of the supposed races of nature being sterile, though none of the domestic ones are? mr herbert koelreuter have shown external differences will not guide one in knowing whether hybrids will be fertile or not, but the chief circumstance is constitutional differences{71}, such as being adapted to different climate or soil, differences which [must] probably affect the whole body of the organism and not any one part. now wild animals, taken out of their natural conditions, seldom breed. i do not refer to shows or to zoological societies where many animals unite, but breed, and others will never unite, but to wild animals caught and kept _quite tame_ left loose and well fed about houses and living many years. hybrids produced almost as readily as pure breds. st hilaire great distinction of tame and domestic,--elephants,--ferrets{72}. reproductive organs not subject to disease in zoological garden. dissection and microscope show that hybrid is in exactly same condition as another animal in the intervals of breeding season, or those animals which taken wild and _not bred_ in domesticity, remain without breeding their whole lives. it should be observed that so far from domesticity being unfavourable in itself makes more fertile: [when animal is domesticated and breeds, productive power increased from more food and selection of fertile races]. as far as animals go might be thought effect on their mind and a special case. {65} the meaning is "that sterility is not universal is admitted by all." {66} see _var. under dom._, ed. 2, i. p. 388, where the garden forms of _gladiolus_ and _calceolaria_ are said to be derived from crosses between distinct species. herbert's hybrid _crinums_ are discussed in the _origin_, ed. i. p. 250, vi. p. 370. it is well known that the author believed in a multiple origin of domestic dogs. {67} the argument from gradation in sterility is given in the _origin_, ed. i. pp. 248, 255, vi. pp. 368, 375. in the _origin_, i have not come across the cases mentioned, viz. crocus, heath, or grouse and fowl or peacock. for sterility between closely allied species, see _origin_, ed. i. p. 257, vi. p. 377. in the present essay the author does not distinguish between fertility between species and the fertility of the hybrid offspring, a point on which he insists in the _origin_, ed. i. p. 245, vi. p. 365. {68} ackermann (_ber. d. vereins f. naturkunde zu kassel_, 1898, p. 23) quotes from gloger that a cross has been effected between a domestic hen and a _tetrao tetrix_; the offspring died when three days old. {69} no doubt the sexual cells are meant. i do not know on what evidence it is stated that the mule has bred. {70} the sentence is all but illegible. i think that the author refers to forms usually ranked as varieties having been marked as species when it was found that they were sterile together. see the case of the red and blue _anagallis_ given from gärtner in the _origin_, ed. i. p. 247, vi. p. 368. {71} in the _origin_, ed. i. p. 258, where the author speaks of constitutional differences in this connexion, he specifies that they are confined to the reproductive system. {72} the sensitiveness of the reproductive system to changed conditions is insisted on in the _origin_, ed. i. p. 8, vi. p. 10. the ferret is mentioned, as being prolific in captivity, in _var. under dom._, ed. 2, ii. p. 90. but turning to plants we find same class of facts. i do not refer to seeds not ripening, perhaps the commonest cause, but to plants not setting, which either is owing to some imperfection of ovule or pollen. lindley says sterility is the [curse] bane of all propagators,--linnæus about alpine plants. american bog plants,--pollen in exactly same state as in hybrids,--same in geraniums. persian and chinese{73} lilac will not seed in italy and england. probably double plants and all fruits owe their developed parts primarily > to sterility and extra food thus > applied{74}. there is here gradation sterility and then parts, like diseases, are transmitted hereditarily. we cannot assign any cause why the pontic azalea produces plenty of pollen and not american{75}, why common lilac seeds and not persian, we see no difference in healthiness. we know not on what circumstances these facts depend, why ferret breeds, and cheetah{76}, elephant and pig in india will not. {73} lindley's remark is quoted in the _origin_, ed. i. p. 9. linnæus' remark is to the effect that alpine plants tend to be sterile under cultivation (see _var. under dom._, ed. 2, ii. p. 147). in the same place the author speaks of peat-loving plants being sterile in our gardens,--no doubt the american bog-plants referred to above. on the following page (p. 148) the sterility of the lilac (_syringa persica_ and _chinensis_) is referred to. {74} the author probably means that the increase in the petals is due to a greater food supply being available for them owing to sterility. see the discussion in _var. under dom._, ed. 2, ii. p. 151. it must be noted that doubleness of the flower may exist without noticeable sterility. {75} i have not come across this case in the author's works. {76} for the somewhat doubtful case of the cheetah (_felis jubata_) see _var. under dom._, ed. 2, ii. p. 133. i do not know to what fact "pig in india" refers. now in crossing it is certain every peculiarity in form and constitution is transmitted: an alpine plant transmits its alpine tendency to its offspring, an american plant its american-bog constitution, and animals, those peculiarities, on which{77} when placed out of their natural conditions they are incapable of breeding; and moreover they transmit every part of their constitution, their respiration, their pulse, their instinct, which are all suddenly modified, can it be wondered at that they are incapable of breeding? i think it may be truly said it would be more wonderful if they did. but it may be asked why have not the recognised varieties, supposed to have been produced through the means of man, [not refused to breed] have all bred{78}. variation depends on change of condition and selection{79}, as far as man's systematic or unsystematic selection gone; he takes external form, has little power from ignorance over internal invisible constitutional differences. races which have long been domesticated, and have much varied, are precisely those which were capable of bearing great changes, whose constitutions were adapted to a diversity of climates. nature changes slowly and by degrees. according to many authors probably breeds of dogs are another case of modified species freely crossing. there is no variety which has been adapted to peculiar soil or situation for a thousand years and another rigorously adapted to another, till such can be produced, the question is not tried{80}. man in past ages, could transport into different climates, animals and plants which would freely propagate in such new climates. nature could effect, with selection, such changes slowly, so that precisely those animals which are adapted to submit to great changes have given rise to diverse races,--and indeed great doubt on this head{81}. {77} this sentence should run "on which depends their incapacity to breed in unnatural conditions." {78} this sentence ends in confusion: it should clearly close with the words "refused to breed" in place of the bracket and the present concluding phrase. {79} the author doubtless refers to the change produced by the _summation_ of variation by means of selection. {80} the meaning of this sentence is made clear by a passage in the ms. of 1844:--"until man selects two varieties from the same stock, adapted to two climates or to other different external conditions, and confines each rigidly for one or several thousand years to such conditions, always selecting the individuals best adapted to them, he cannot be said to have even commenced the experiment." that is, the attempt to produce mutually sterile domestic breeds. {81} this passage is to some extent a repetition of a previous one and may have been intended to replace an earlier sentence. i have thought it best to give both. in the _origin_, ed. i. p. 141, vi. p. 176, the author gives his opinion that the power of resisting diverse conditions, seen in man and his domestic animals, is an example "of a very common flexibility of constitution." before leaving this subject well to observe that it was shown that a certain amount of variation is consequent on mere act of reproduction, both by buds and sexually,--is vastly increased when parents exposed for some generations to new conditions{82}, and we now find that many animals when exposed for first time to very new conditions, are incapable of breeding as hybrids. it [probably] bears also on supposed fact of crossed animals when not infertile, as in mongrels, tending to vary much, as likewise seems to be the case, when true hybrids possess just sufficient fertility to propagate with the parent breeds and _inter se_ for some generations. this is koelreuter's belief. these facts throw light on each other and support the truth of each other, we see throughout a connection between the reproductive faculties and exposure to changed conditions of life whether by crossing or exposure of the individuals{83}. {82} in the _origin_, ed. i. chs. i. and v., the author does not admit reproduction, apart from environment, as being a cause of variation. with regard to the cumulative effect of new conditions there are many passages in the _origin_, ed. i. e.g. pp. 7, 12, vi. pp. 8, 14. {83} as already pointed out, this is the important principle investigated in the author's _cross and self-fertilisation_. professor bateson has suggested to me that the experiments should be repeated with gametically pure individuals. _difficulties on theory of selection_{84}. it may be objected such perfect organs as eye and ear, could never be formed, in latter less difficulty as gradations more perfect; at first appears monstrous and to end appears difficulty. but think of gradation, even now manifest, (tibia and fibula). everyone will allow if every fossil preserved, gradation infinitely more perfect; for possibility of selection a perfect > gradation is required. different groups of structure, slight gradation in each group,--every analogy renders it probable that intermediate forms have existed. be it remembered what strange metamorphoses; part of eye, not directly connected with vision, might come to be [thus used] gradually worked in for this end,--swimming bladder by gradation of structure is admitted to belong to the ear system,--rattlesnake. [woodpecker best adapted to climb.] in some cases gradation not possible,--as vertebræ,--actually vary in domestic animals,--less difficult if growth followed. looking to whole animals, a bat formed not for flight{85}. suppose we had flying fish{86} and not one of our now called flying fish preserved, who would have guessed intermediate habits. woodpeckers and tree-frogs both live in countries where no trees{87}. {84} in the _origin_ a chapter is given up to "difficulties on theory": the discussion in the present essay seems slight even when it is remembered how small a space is here available. for _tibia_ &c. see p. 48. {85} this may be interpreted "the general structure of a bat is the same as that of non-flying mammals." {86} that is truly winged fish. {87} the terrestrial woodpecker of s. america formed the subject of a paper by darwin, _proc. zool. soc._, 1870. see _life and letters_, vol. iii. p. 153. the gradations by which each individual organ has arrived at its present state, and each individual animal with its aggregate of organs has arrived, probably never could be known, and all present great difficulties. i merely wish to show that the proposition is not so monstrous as it at first appears, and that if good reason can be advanced for believing the species have descended from common parents, the difficulty of imagining intermediate forms of structure not sufficient to make one at once reject the theory. § iii. the mental powers of different animals in wild and tame state [present still greater difficulties] require a separate section. be it remembered i have nothing to do with origin of memory, attention, and the different faculties of the mind{88}, but merely with their differences in each of the great divisions of nature. disposition, courage, pertinacity >, suspicion, restlessness, ill-temper, sagacity and reverse unquestionably vary in animals and are inherited (cuba wildness dogs, rabbits, fear against particular object as man galapagos{89}). habits purely corporeal, breeding season &c., time of going to rest &c., vary and are hereditary, like the analogous habits of plants which vary and are inherited. habits of body, as manner of movement d^o. and d^o. habits, as pointing and setting on certain occasions d^o. taste for hunting certain objects and manner of doing so,--sheep-dog. these are shown clearly by crossing and their analogy with true instinct thus shown,--retriever. do not know objects for which they do it. lord brougham's definition{90}. origin partly habit, but the amount necessarily unknown, partly selection. young pointers pointing stones and sheep--tumbling pigeons--sheep{91} going back to place where born. instinct aided by reason, as in the taylor-bird{92}. taught by parents, cows choosing food, birds singing. instincts vary in wild state (birds get wilder) often lost{93}; more perfect,--nest without roof. these facts [only clear way] show how incomprehensibly brain has power of transmitting intellectual operations. {88} the same proviso occurs in the _origin_, ed. i. p. 207, vi. p. 319. {89} the tameness of the birds in the galapagos is described in the _journal of researches_ (1860), p. 398. dogs and rabbits are probably mentioned as cases in which the hereditary fear of man has been lost. in the 1844 ms. the author states that the cuban feral dog shows great natural wildness, even when caught quite young. {90} in the _origin_, ed. i. p. 207, vi. p. 319, he refuses to define instinct. for lord brougham's definition see his _dissertations on subjects of science etc._, 1839, p. 27. {91} see james hogg (the ettrick shepherd), works, 1865, _tales and sketches_, p. 403. {92} this refers to the tailor-bird making use of manufactured thread supplied to it, instead of thread twisted by itself. {93} _often lost_ applies to _instinct_: _birds get wilder_ is printed in a parenthesis because it was apparently added as an after-thought. _nest without roof_ refers to the water-ousel omitting to vault its nest when building in a protected situation. faculties{94} distinct from true instincts,--finding [way]. it must i think be admitted that habits whether congenital or acquired by practice [sometimes] often become inherited{95}; instincts, influence, equally with structure, the preservation of animals; therefore selection must, with changing conditions tend to modify the inherited habits of animals. if this be admitted it will be found _possible_ that many of the strangest instincts may be thus acquired. i may observe, without attempting definition, that an inherited habit or trick (trick because may be born) fulfils closely what we mean by instinct. a habit is often performed unconsciously, the strangest habits become associated, d^o. tricks, going in certain spots &c. &c., even against will, is excited by external agencies, and looks not to the end,--a person playing a pianoforte. if such a habit were transmitted it would make a marvellous instinct. let us consider some of the most difficult cases of instincts, whether they could be _possibly_ acquired. i do not say _probably_, for that belongs to our 3rd part{96}, i beg this may be remembered, nor do i mean to attempt to show exact method. i want only to show that whole theory ought not at once to be rejected on this score. {94} in the ms. of 1844 is an interesting discussion on _faculty_ as distinct from _instinct_. {95} at this date and for long afterwards the inheritance of acquired characters was assumed to occur. {96} part ii. is here intended: see the introduction. every instinct must, by my theory, have been acquired gradually by slight changes of former instinct, each change being useful to its then species. shamming death struck me at first as remarkable objection. i found none really sham death{97}, and that there is gradation; now no one doubts that those insects which do it either more or less, do it for some good, if then any species was led to do it more, and then > escaped &c. &c. {97} the meaning is that the attitude assumed in _shamming_ is not accurately like that of death. take migratory instincts, faculty distinct from instinct, animals have notion of time,--like savages. ordinary finding way by memory, but how does savage find way across country,--as incomprehensible to us, as animal to them,--geological changes,--fishes in river,--case of sheep in spain{98}. architectural instincts,--a manufacturer's employee in making single articles extraordinary skill,--often said seem to make it almost , child born with such a notion of playing{99},--we can fancy tailoring acquired in same perfection,--mixture of reason,--water-ouzel,--taylor-bird,--gradation of simple nest to most complicated. {98} this refers to the _transandantes_ sheep mentioned in the ms. of 1844, as having acquired a migratory instinct. {99} in the _origin_, ed. i. p. 209, vi. p. 321, mozart's pseudo-instinctive skill in piano-playing is mentioned. see _phil. trans._, 1770, p. 54. bees again, distinction of faculty,--how they make a hexagon,--waterhouse's theory{100},--the impulse to use whatever faculty they possess,--the taylor-bird has the faculty of sewing with beak, instinct impels him to do it. {100} in the discussion on bees' cells, _origin_, ed. i. p. 225, vi. p. 343, the author acknowledges that his theory originated in waterhouse's observations. last case of parent feeding young with different food (take case of galapagos birds, gradation from hawfinch to sylvia) selection and habit might lead old birds to vary taste > and form, leaving their instinct of feeding their young with same food{101},--or i see no difficulty in parents being forced or induced to vary the food brought, and selection adapting the young ones to it, and thus by degree any amount of diversity might be arrived at. although we can never hope to see the course revealed by which different instincts have been acquired, for we have only present animals (not well known) to judge of the course of gradation, yet once grant the principle of habits, whether congenital or acquired by experience, being inherited and i can see no limit to the [amount of variation] extraordinariness > of the habits thus acquired. {101} the hawfinch-and _sylvia-_types are figured in the _journal of researches_, p. 379. the discussion of change of form in relation to change of instinct is not clear, and i find it impossible to suggest a paraphrase. _summing up this division._ if variation be admitted to occur occasionally in some wild animals, and how can we doubt it, when we see [all] thousands organisms, for whatever use taken by man, do vary. if we admit such variations tend to be hereditary, and how can we doubt it when we resemblances of features and character,--disease and monstrosities inherited and endless races produced (1200 cabbages). if we admit selection is steadily at work, and who will doubt it, when he considers amount of food on an average fixed and reproductive powers act in geometrical ratio. if we admit that external conditions vary, as all geology proclaims, they have done and are now doing,--then, if no law of nature be opposed, there must occasionally be formed races, [slightly] differing from the parent races. so then any such law{102}, none is known, but in all works it is assumed, in > flat contradiction to all known facts, that the amount of possible variation is soon acquired. are not all the most varied species, the oldest domesticated: who think that horses or corn could be produced? take dahlia and potato, who will pretend in 5000 years{103} : perfectly adapted to conditions and then again brought into varying conditions. think what has been done in few last years, look at pigeons, and cattle. with the amount of food man can produce he may have arrived at limit of fatness or size, or thickness of wool >, but these are the most trivial points, but even in these i conclude it is impossible to say we know the limit of variation. and therefore with the [adapting] selecting power of nature, infinitely wise compared to those of man, that it is impossible to say we know the limit of races, which would be true kind; if of different constitutions would probably be infertile one with another, and which might be adapted in the most singular and admirable manner, according to their wants, to external nature and to other surrounding organisms,--such races would be species. but is there any evidence species been thus produced, this is a question wholly independent of all previous points, and which on examination of the kingdom of nature ought to answer one way or another. {102} i should interpret this obscure sentence as follows, "no such opposing law is known, but in all works on the subject a law is (in flat contradiction to all known facts) assumed to limit the possible amount of variation." in the _origin_, the author never limits the power of variation, as far as i know. {103} in _var. under dom._ ed. 2, ii. p. 263, the _dahlia_ is described as showing sensitiveness to conditions in 1841. all the varieties of the _dahlia_ are said to have arisen since 1804 (_ibid._ i. p. 393). part ii{104}. {104} in the original ms. the heading is: part iii.; but part ii. is clearly intended; for details see the introduction. i have not been able to discover where § iv. ends and § v. begins. §§ iv. & v. i may premise, that according to the view ordinarily received, the myriads of organisms peopling this world have been created by so many distinct acts of creation. as we know nothing of the will of a creator,--we can see no reason why there should exist any relation between the organisms thus created; or again, they might be created according to any scheme. but it would be marvellous if this scheme should be the same as would result from the descent of groups of organisms from [certain] the same parents, according to the circumstances, just attempted to be developed. with equal probability did old cosmogonists say fossils were created, as we now see them, with a false resemblance to living beings{105}; what would the astronomer say to the doctrine that the planets moved according to the law of gravitation, but from the creator having willed each separate planet to move in its particular orbit? i believe such a proposition (if we remove all prejudices) would be as legitimate as to admit that certain groups of living and extinct organisms, in their distribution, in their structure and in their relations one to another and to external conditions, agreed with the theory and showed signs of common descent, and yet were created distinct. as long as it was thought impossible that organisms should vary, or should anyhow become adapted to other organisms in a complicated manner, and yet be separated from them by an impassable barrier of sterility{106}, it was justifiable, even with some appearance in favour of a common descent, to admit distinct creation according to the will of an omniscient creator; or, for it is the same thing, to say with whewell that the beginnings of all things surpass the comprehension of man. in the former sections i have endeavoured to show that such variation or specification is not impossible, nay, in many points of view is absolutely probable. what then is the evidence in favour of it and what the evidence against it. with our imperfect knowledge of past ages [surely there will be some] it would be strange if the imperfection did not create some unfavourable evidence. {105} this passage corresponds roughly to the conclusion of the _origin_, see ed. i. p. 482, vi. p. 661. {106} a similar passage occurs in the conclusion of the _origin_, ed. i. p. 481, vi. p. 659. give sketch of the past,--beginning with facts appearing hostile under present knowledge,--then proceed to geograph. distribution,--order of appearance,--affinities,--morphology &c., &c. our theory requires a very gradual introduction of new forms{107}, and extermination of the old (to which we shall revert). the extermination of old may sometimes be rapid, but never the introduction. in the groups descended from common parent, our theory requires a perfect gradation not differing more than breed of cattle, or potatoes, or cabbages in forms. i do not mean that a graduated series of animals must have existed, intermediate between horse, mouse, tapir{108}, elephant [or fowl and peacock], but that these must have had a common parent, and between horse and this > parent &c., &c., but the common parent may possibly have differed more from either than the two do now from each other. now what evidence of this is there? so perfect gradation in some departments, that some naturalists have thought that in some large divisions, if all existing forms were collected, a near approach to perfect gradation would be made. but such a notion is preposterous with respect to all, but evidently so with mammals. other naturalists have thought this would be so if all the specimens entombed in the strata were collected{109}. i conceive there is no probability whatever of this; nevertheless it is certain all the numerous fossil forms fall in, as buckland remarks, _not_ present classes, families and genera, they fall between them: so is it with new discoveries of existing forms. most ancient fossils, that is most separated space of time, are most apt to fall between the classes--(but organisms from those countries most separated by space also fall between the classes <_e.g._> ornithorhyncus?). as far as geological discoveries they tend towards such gradation{110}. illustrate it with net. toxodon,--tibia and fibula,--dog and otter,--but so utterly improbable is , in _ex. gr._ pachydermata, to compose series as perfect as cattle, that if, as many geologists seem to infer, each separate formation presents even an approach to a consecutive history, my theory must be given up. even if it were consecutive, it would only collect series of one district in our present state of knowledge; but what probability is there that any one formation during the _immense_ period which has elapsed during each period will _generally_ present a consecutive history. [compare number living at one period to fossils preserved--look at enormous periods of time.] {107} see _origin_, ed. i. p. 312, vi. p. 453. {108} see _origin_, ed. i. pp. 280, 281, vi. p. 414. the author uses his experience of pigeons for examples for what he means by _intermediate_; the instance of the horse and tapir also occurs. {109} the absence of intermediate forms between living organisms (and also as regards fossils) is discussed in the _origin_, ed. i. pp. 279, 280, vi. p. 413. in the above discussion there is no evidence that the author felt this difficulty so strongly as it is expressed in the _origin_, ed. i. p. 299,--as perhaps "the most obvious and gravest objection that can be urged against my theory." but in a rough summary written on the back of the penultimate page of the ms. he refers to the geological evidence:--"evidence, as far as it does go, is favourable, exceedingly incomplete,--greatest difficulty on this theory. i am convinced not insuperable." buckland's remarks are given in the _origin_, ed. i. p. 329, vi. p. 471. {110} that the evidence of geology, as far as it goes, is favourable to the theory of descent is claimed in the _origin_, ed. i. pp. 343-345, vi. pp. 490-492. for the reference to _net_ in the following sentence, see note 1, p. 48, {note 161} of this essay. referring only to marine animals, which are obviously most likely to be preserved, they must live where > sediment (of a kind favourable for preservation, not sand and pebble){111} is depositing quickly and over large area and must be thickly capped, littoral deposits: for otherwise denudation ,--they must live in a shallow space which sediment will tend to fill up,--as movement is progress if soon brought > up > subject to denudation,--[if] as during subsidence favourable, accords with facts of european deposits{112}, but subsidence apt to destroy agents which produce sediment{113}. {111} see _origin_, ed. i. p. 288, vi. p. 422. "the remains that do become embedded, if in sand and gravel, will, when the beds are upraised, generally be dissolved by the percolation of rain-water." {112} the position of the following is not clear:--"think of immense differences in nature of european deposits,--without interposing new causes,--think of time required by present slow changes, to cause, on very same area, such diverse deposits, iron-sand, chalk, sand, coral, clay!" {113} the paragraph which ends here is difficult to interpret. in spite of obscurity it is easy to recognize the general resemblance to the discussion on the importance of subsidence given in the _origin_, ed. i. pp. 290 et seq., vi. pp. 422 et seq. i believe safely inferred groups of marine > fossils only preserved for future ages where sediment goes on long continuous and with rapid but not too rapid deposition in area of subsidence. in how few places in any one region like europe will > these contingencies be going on? hence > in past ages mere [gaps] pages preserved{114}. lyell's doctrine carried to extreme,--we shall understand difficulty if it be asked:--what chance of series of gradation between cattle by at age as far back as miocene{115}? we know then cattle existed. compare number of living,--immense duration of each period,--fewness of fossils. {114} see note 3, p. 27. {115} compare _origin_, ed. i. p. 298, vi. p. 437. "we shall, perhaps, best perceive the improbability of our being enabled to connect species by numerous, fine, intermediate, fossil links, by asking ourselves whether, for instance, geologists at some future period will be able to prove that our different breeds of cattle, sheep, horses, and dogs have descended from a single stock or from several aboriginal stocks." this only refers to consecutiveness of history of organisms of each formation. the foregoing argument will show firstly, that formations are distinct merely from want of fossils , and secondly, that each formation is full of gaps, has been advanced to account for _fewness_ of _preserved_ organisms compared to what have lived on the world. the very same argument explains why in older formations the organisms appear to come on and disappear suddenly,--but in [later] tertiary not quite suddenly{116}, in later tertiary gradually,--becoming rare and disappearing,--some have disappeared within man's time. it is obvious that our theory requires gradual and nearly uniform introduction, possibly more sudden extermination,--subsidence of continent of australia &c., &c. {116} the sudden appearance of groups of allied species in the lowest known fossiliferous strata is discussed in the _origin_, ed. i. p. 306, vi. p. 446. the gradual appearance in the later strata occurs in the _origin_, ed. i. p. 312, vi. p. 453. our theory requires that the first form which existed of each of the great divisions would present points intermediate between existing ones, but immensely different. most geologists believe silurian{117} fossils are those which first existed in the whole world, not those which have chanced to be the oldest not destroyed,--or the first which existed in profoundly deep seas in progress of conversion from sea to land: if they are first they we> give up. not so hutton or lyell: if first reptile{118} of red sandstone > really was first which existed: if pachyderm{119} of paris was first which existed: fish of devonian: dragon fly of lias: for we cannot suppose them the progenitors: they agree too closely with existing divisions. but geologists consider europe as > a passage from sea to island > to continent (except wealden, see lyell). these animals therefore, i consider then mere introduction > from continents long since submerged. {117} compare _origin_, ed. i. p. 307, vi. p. 448. {118} i have interpreted as _sandstone_ a scrawl which i first read as _sea_; i have done so at the suggestion of professor judd, who points out that "footprints in the red sandstone were known at that time, and geologists were not then particular to distinguish between amphibians and reptiles." {119} this refers to cuvier's discovery of _palæotherium_ &c. at montmartre. finally, if views of some geologists be correct, my theory must be given up. [lyell's views, as far as they go, are in _favour_, but they go so little in favour, and so much more is required, that it may viewed as objection.] if geology present us with mere pages in chapters, towards end of history, formed by tearing out bundles of leaves, and each page illustrating merely a small portion of the organisms of that time, the facts accord perfectly with my theory{120}. {120} this simile is more fully given in the _origin_, ed. i. p. 310, vi. p. 452. "for my part, following out lyell's metaphor, i look at the natural geological record, as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. of this volume, only here and there a short chapter has been preserved; and of each page, only here and there a few lines. each word of the slowly-changing language, in which the history is supposed to be written, being more or less different in the interrupted succession of chapters, may represent the apparently abruptly changed forms of life, entombed in our consecutive, but widely separated formations." professor judd has been good enough to point out to me, that darwin's metaphor is founded on the comparison of geology to history in ch. i. of the _principles of geology_, ed. i. 1830, vol. i. pp. 1-4. professor judd has also called my attention to another passage,--_principles_, ed. i. 1833, vol. iii. p. 33, when lyell imagines an historian examining "two buried cities at the foot of vesuvius, immediately superimposed upon each other." the historian would discover that the inhabitants of the lower town were greeks while those of the upper one were italians. but he would be wrong in supposing that there had been a sudden change from the greek to the italian language in campania. i think it is clear that darwin's metaphor is partly taken from this passage. see for instance (in the above passage from the _origin_) such phrases as "history ... written in a changing dialect"--"apparently abruptly changed forms of life." the passage within [] in the above paragraph:--"lyell's views as far as they go &c.," no doubt refers, as professor judd points out, to lyell not going so far as darwin on the question of the imperfection of the geological record. _extermination._ we have seen that in later periods the organisms have disappeared by degrees and [perhaps] probably by degrees in earlier, and i have said our theory requires it. as many naturalists seem to think extermination a most mysterious circumstance{121} and call in astonishing agencies, it is well to recall what we have shown concerning the struggle of nature. an exterminating agency is at work with every organism: we scarcely see it: if robins would increase to thousands in ten years how severe must the process be. how imperceptible a small increase: fossils become rare: possibly sudden extermination as australia, but as present means very slow and many means of escape, i shall doubt very sudden exterminations. who can explain why some species abound more,--why does marsh titmouse, or ring-ouzel, now little change,--why is one sea-slug rare and another common on our coasts,--why one species of rhinoceros more than another,--why is tiger of india so rare? curious and general sources of error, the place of an organism is instantly filled up. {121} on rarity and extinction see _origin_, ed. i. pp. 109, 319, vi. pp. 133, 461. we know state of earth has changed, and as earthquakes and tides go on, the state must change,--many geologists believe a slow gradual cooling. now let us see in accordance with principles of [variation] specification explained in sect. ii. how species would probably be introduced and how such results accord with what is known. the first fact geology proclaims is immense number of extinct forms, and new appearances. tertiary strata leads to belief, that forms gradually become rare and disappear and are gradually supplied by others. we see some forms now becoming rare and disappearing, we know of no sudden creation: in older periods the forms _appear_ to come in suddenly, scene shifts: but even here devonian, permian &c. [keep on supplying new links in chain]--genera and higher forms come on and disappear, in same way leaving a species on one or more stages below that in which the form abounded. § vi. let us consider the absolute state of distribution of organisms of earth's face. referring chiefly, but not exclusively (from difficulty of transport, fewness, and the distinct characteristics of groups) to mammalia; and first considering the three or four main [regions] divisions; north america, europe, asia, including greater part of e. indian archipelago and africa are intimately allied. africa most distinct, especially most southern parts. and the arctic regions, which unite n. america, asia and europe, only separated (if we travel one way by behring's st.) by a narrow strait, is most intimately allied, indeed forms but one restricted group. next comes s. america,--then australia, madagascar (and some small islands which stand very remote from the land). looking at these main divisions separately, the organisms vary according to changes in condition{122} of different parts. but besides this, barriers of every kind seem to separate regions in a greater degree than proportionally to the difference of climates on each side. thus great chains of mountains, spaces of sea between islands and continents, even great rivers and deserts. in fact the amount difference in the organisms bears a certain, but not invariable relation to the amount of physical difficulties to transit{123}. {122} in the _origin_, ed. i. p. 346, vi. p. 493, the author begins his discussion on geographical distribution by minimising the effect of physical conditions. he lays great stress on the effect of _barriers_, as in the present essay. {123} note in the original, "would it be more striking if we took animals, take rhinoceros, and study their habitats?" there are some curious exceptions, namely, similarity of fauna of mountains of europe and n. america and lapland. other cases just reverse, mountains of eastern s. america, altai >, s. india >{124}: mountain summits of islands often eminently peculiar. fauna generally of some islands, even when close, very dissimilar, in others very similar. [i am here led to observe one or more centres of creation{125}.] {124} note by mr a. r. wallace. "the want of similarity referred to, is, between the mountains of brazil and guiana and those of the andes. also those of the indian peninsula as compared with the himalayas. in both cases there is continuous intervening land. "the islands referred to were, no doubt, the galapagos for dissimilarity from s. america; our own islands as compared with europe, and perhaps java, for similarity with continental asia." {125} the arguments against multiple centres of creation are given in the _origin_, ed. i. p. 352, vi. p. 499. the simple geologist can explain many of the foregoing cases of distribution. subsidence of a continent in which free means of dispersal, would drive the lowland plants up to the mountains, now converted into islands, and the semi-alpine plants would take place of alpine, and alpine be destroyed, if mountains originally were not of great height. so we may see, during gradual changes{126} of climate on a continent, the propagation of species would vary and adapt themselves to small changes causing much extermination{127}. the mountains of europe were quite lately covered with ice, and the lowlands probably partaking of the arctic climate and fauna. then as climate changed, arctic fauna would take place of ice, and an inundation of plants from different temperate countries seize the lowlands, leaving islands of arctic forms. but if this had happened on an island, whence could the new forms have come,--here the geologist calls in creationists. if island formed, the geologist will suggest many of the forms might have been borne from nearest land, but if peculiar, he calls in creationist,--as such island rises in height &c., he still more calls in creation. the creationist tells one, on a spot the american spirit of creation makes _orpheus_ and _tyrannus_ and american doves, and in accordance with past and extinct forms, but no persistent relation between areas and distribution, geologico-geograph.-distribution. {126} in the _origin_, ed. i. p. 366, vi. p. 516, the author does not give his views on the distribution of alpine plants as original but refers to edward forbes' work (_geolog. survey memoirs_, 1846). in his autobiography, darwin refers to this. "i was forestalled" he says, "in only one important point, which my vanity has always made me regret." (_life and letters_, i. p. 88.) {127} discuss one or more centres of creation: allude strongly to facilities of dispersal and amount of geological change: allude to mountain-summits afterwards to be referred to. the distribution varies, as everyone knows, according to adaptation, explain going from n. to s. how we come to fresh groups of species in the same general region, but besides this we find difference, according to greatness of barriers, in greater proportion than can be well accounted for by adaptation. this very striking when we think of cattle of pampas, plants > &c. &c. then go into discussion; this holds with 3 or 4 main divisions as well as the endless minor ones in each of these 4 great ones: in these i chiefly refer to mammalia &c. &c. the similarity of type, but not in species, in same continent has been much less insisted on than the dissimilarity of different great regions generically: it is more striking. galapagos islands, tristan d'acunha, _volcanic_ islands covered with craters we know lately did not support any organisms. how unlike these islands in nature to neighbouring lands. these facts perhaps more striking than almost any others. [geology apt to affect geography therefore we ought to expect to find the above.] geological-geographical distribution. in looking to past times we find australia equally distinct. s. america was distinct, though with more forms in common. n. america its nearest neighbour more in common,--in some respects more, in some less allied to europe. europe we find > equally european. for europe is now part of asia though not . africa unknown,--examples, elephant, rhinoceros, hippopotamus, hyaena. as geology destroys geography we cannot be surprised in going far back we find marsupials and edentata in europe: but geology destroys geography. now according to analogy of domesticated animals let us see what would result. let us take case of farmer on pampas, where everything approaches nearer to state of nature. he works on organisms having strong tendency to vary: and he knows only way to make a distinct breed is to select and separate. it would be useless to separate the best bulls and pair with best cows if their offspring run loose and bred with the other herds, and tendency to reversion not counteracted; he would endeavour therefore to get his cows on islands and then commence his work of selection. if several farmers in different _rincons_{128} were to set to work, especially if with different objects, several breeds would soon be produced. so would it be with horticulturist and so history of every plant shows; the number of varieties{129} increase in proportion to care bestowed on their selection and, with crossing plants, separation. now, according to this analogy, change of external conditions, and isolation either by chance landing a form on an island, or subsidence dividing a continent, or great chain of mountains, and the number of individuals not being numerous will best favour variation and selection{130}. no doubt change could be effected in same country without any barrier by long continued selection on one species: even in case of a plant not capable of crossing would easier get possession and solely occupy an island{131}. now we can at once see that two parts of a continent isolated, new species thus generated in them, would have closest affinities, like cattle in counties of england: if barrier afterwards destroyed one species might destroy the other or both keep their ground. so if island formed near continent, let it be ever so different, that continent would supply inhabitants, and new species (like the old) would be allied with that continent. an island generally very different soil and climate, and number and order of inhabitants supplied by chance, no point so favourable for generation of new species{132},--especially the mountains, hence, so it is. as isolated mountains formed in a plain country (if such happens) is an island. as other islands formed, the old species would spread and thus extend and the fauna of distant island might ultimately meet and a continent formed between them. no one doubts continents formed by repeated elevations and depressions{133}. in looking backwards, but not so far that all geographical boundaries are destroyed, we can thus at once see why existing forms are related to the extinct in the same manner as existing ones are in some part of existing continent. by chance we might even have one or two absolute parent fossils. {128} _rincon_ in spanish means a _nook_ or _corner_, it is here probably used to mean a small farm. {129} the following is written across the page: "no one would expect a set of similar varieties to be produced in the different countries, so species different." {130} the parent of an organism, we may generally suppose to be in less favourable condition than the selected offspring and therefore generally in fewer numbers. (this is not borne out by horticulture, mere hypothesis; as an organism in favourable conditions might by selection be adapted to still more favourable conditions.) barrier would further act in preventing species formed in one part migrating to another part. {131} number of species not related to capabilities of the country: furthermore not always those best adapted, perhaps explained by creationists by changes and progress. although creationists can, by help of geology, explain much, how can he explain the marked relation of past and present in same area, the varying relation in other cases, between past and present, the relation of different parts of same great area. if island, to adjoining continent, if quite different, on mountain summits,--the number of individuals not being related to capabilities, or how &c.--our theory, i believe, can throw much light and all facts accord. {132} see _origin_, ed. i. p. 390, vi. p. 543. {133} on oscillation see _origin_, ed. i. p. 291, vi. p. 426. the detection of transitional forms would be rendered more difficult on rising point of land. the distribution therefore in the above enumerated points, even the trivial ones, which on any other can be viewed as so many ultimate facts, all follow a simple manner on the theory of the occurrence of species by and being adapted by selection to , conjoined with their power of dispersal, and the steady geographico-geological changes which are now in progress and which undoubtedly have taken place. ought to state the opinion of the immutability of species and the creation by so many separate acts of will of the creator{134}. {134} effect of climate on stationary island and on continent, but continent once island. moreover repeated oscillations fresh diffusion when non-united, then isolation, when rising again immigration prevented, new habitats formed, new species, when united free immigration, hence uniform characters. hence more forms the island. mountain summits. why not true species. first let us recall in part i, conditions of variation: change of conditions during several generations, and if frequently altered so much better [perhaps excess of food]. secondly, continued selection [while in wild state]. thirdly, isolation in all or nearly all,--as well to recall advantages of. [in continent, if we look to terrestrial animal, long continued change might go on, which would only cause change in numerical number proportions>: if continued long enough might ultimately affect all, though to most continents chance of immigration. some few of whole body of species must be long affected and entire selection working same way. but here isolation absent, without barrier, cut off such . we can see advantage of isolation. but let us take case of island thrown up by volcanic agency at some distances, here we should have occasional visitants, only in few numbers and exposed to new conditions and more important,--a quite new grouping of organic beings, which would open out new sources of subsistence, or control > old ones. the number would be few, can old have the very best opportunity. moreover as the island continued changing,--continued slow changes, river, marshes, lakes, mountains &c. &c., new races as successively formed and a fresh occasional visitant. if island formed continent, some species would emerge and immigrate. everyone admits continents. we can see why galapagos and c. verde differ ], depressed and raised. we can see from this repeated action and the time required for a continent, why many more forms than in new zealand no mammals or other classes . we can at once see how it comes when there has been an old channel of migration,--cordilleras; we can see why indian asiatic flora,--[why species] having a wide range gives better chance of some arriving at new points and being selected, and adapted to new ends. i need hardly remark no necessity for change. finally, as continent (most extinction > during formation of continent) is formed after repeated elevation and depression, and interchange of species we might foretell much extinction, and that the survivor would belong to same type, as the extinct, in same manner as different part of same continent, which were once separated by space as they are by time . as all mammals have descended from one stock, we ought to expect that every continent has been at some time connected, hence obliteration of present ranges. i do not mean that the fossil mammifers found in s. america are the lineal successors of the present forms of s. america: for it is highly improbable that more than one or two cases (who will say how many races after plata bones) should be found. i believe this from numbers, who have lived,--mere > chance of fewness. moreover in every case from very existence of genera and species only few at one time will leave progeny, under form of new species, to distant ages; and the more distant the ages the fewer the progenitors. an observation may be here appended, bad chance of preservation on rising island, the nurseries of new species, appeal to experience . this observation may be extended, that in all cases, subsiding land must be, in early stages, less favourable to formation of new species; but it will isolate them, and then if land recommences rising how favourable. as preoccupation is bar to diffusion to species, so would it be to a selected variety. but it would not be if that variety was better fitted to some not fully occupied station; so during elevation or the formation of new stations, is scene for new species. but during elevation not favourable to preservation of fossil (except in caverns >); when subsidence highly favourable in early stages to preservation of fossils; when subsidence, less sediment. so that our strata, as general rule will be the tomb of old species (not undergoing any change) when rising land the nursery. but if there be vestige will generally be preserved to future ages, the new ones will not be entombed till fresh subsidence supervenes. in this long gap we shall have no record: so that wonderful if we should get transitional forms. i do not mean every stage, for we cannot expect that, as before shown, until geologists will be prepared to say that although under unnaturally favourable condition we can trace in future ages short-horn and herefordshire . {note 115} § vii. looking now to the affinities of organisms, without relation to their distribution, and taking all fossil and recent, we see the degrees of relationship are of different degrees and arbitrary,--sub-genera,--genera,--sub-families, families, orders and classes and kingdoms. the kind of classification which everyone feels is most correct is called the natural system, but no can define this. if we say with whewell undefined instinct of the importance of organs{135}, we have no means in lower animals of saying which is most important, and yet everyone feels that some one system alone deserves to be called natural. the true relationship of organisms is brought before one by considering relations of analogy, an otter-like animal amongst mammalia and an otter amongst marsupials. in such cases external resemblance and habit of life and _the final end of whole organization_ very strong, yet no relation{136}. naturalists cannot avoid these terms of relation and affinity though they use them metaphorically. if used in simple earnestness the natural system ought to be a genealogical ; and our knowledge of the points which are most easily affected in transmission are those which we least value in considering the natural system, and practically when we find they do vary we regard them of less value{137}. in classifying varieties the same language is used and the same kind of division: here also (in pine-apple){138} we talk of the natural classification, overlooking similarity of the fruits, because whole plant differs. the origin of sub-genera, genera, &c., &c., is not difficult on notion of genealogical succession, and accords with what we know of similar gradations of affinity in domesticated organisms. in the same region the organic beings are related to each other and the external conditions in many physical respects are allied{139} and their differences of same kind, and therefore when a new species has been selected and has obtained a place in the economy of nature, we may suppose that generally it will tend to extend its range during geographical changes, and thus, becoming isolated and exposed to new conditions, will slightly alter and its structure by selection become slightly remodified, thus we should get species of a sub-genus and genus,--as varieties of merino-sheep,--varieties of british and indian cattle. fresh species might go on forming and others become extinct and all might become extinct, and then we should have extinct genus; a case formerly mentioned, of which numerous cases occur in palæontology. but more often the same advantages which caused the new species to spread and become modified into several species would favour some of the species being preserved: and if two of the species, considerably different, each gave rise to group of new species, you would have two genera; the same thing will go on. we may look at case in other way, looking to future. according to mere chance every existing species may generate another, but if any species, a, in changing gets an advantage and that advantage (whatever it may be, intellect, &c., &c., or some particular structure or constitution) is inherited{140}, a will be the progenitor of several genera or even families in the hard struggle of nature. a will go on beating out other forms, it might come that a would people earth,--we may now not have one descendant on our globe of the one or several original creations{141}. external conditions air, earth, water being same{142} on globe, and the communication not being perfect, organisms of widely different descent might become adapted to the same end and then we should have cases of analogy{143}, [they might even tend to become numerically representative]. from this often happening each of the great divisions of nature would have their representative eminently adapted to earth, to {144}, to water, and to these in and then these great divisions would show numerical relations in their classification. {135} after "organs" is inserted, apparently as an afterthought:--"no, and instance metamorphosis, afterwards explicable." {136} for analogical resemblances see _origin_, ed. i. p. 427, vi. p. 582. {137} "practically when naturalists are at work, they do not trouble themselves about the physiological value of the characters.... if they find a character nearly uniform, ... they use it as one of high value," _origin_, ed. i. p. 417, vi. p. 573. {138} "we are cautioned ... not to class two varieties of the pine-apple together, merely because their fruit, though the most important part, happens to be nearly identical," _origin_, ed. i. p. 423, vi. p. 579. {139} the whole of this passage is obscure, but the text is quite clear, except for one illegible word. {140} "just as it is not likely every present breed of fancy birds and cattle will propagate, only some of the best." {141} this suggests that the author was not far from the principle of divergence on which he afterwards laid so much stress. see _origin_, ed. i. p. 111, vi. p. 134, also _life and letters_, i. p. 84. {142} that is to say the same conditions occurring in different parts of the globe. {143} the position of the following is uncertain, "greyhound and racehorse have an analogy to each other." the same comparison occurs in the _origin_, ed. i. p. 427, vi. p. 583. {144} _air_ is evidently intended; in the ms. _water_ is written twice. § viii. unity [or similarity] of type in the great classes. nothing more wonderful in nat. hist. than looking at the vast number of organisms, recent and fossil, exposed to the most diverse conditions, living in the most distant climes, and at immensely remote periods, fitted to wholely different ends, yet to find large groups united by a similar type of structure. when we for instance see bat, horse, porpoise-fin, hand, all built on same structure{145}, having bones{146} with same name, we see there is some deep bond of union between them{147}, to illustrate this is the foundation and objects > what is called the natural system; and which is foundation of distinction > of true and adaptive characters{148}. now this wonderful fact of hand, hoof, wing, paddle and claw being the same, is at once explicable on the principle of some parent-forms, which might either be or walking animals, becoming through infinite number of small selections adapted to various conditions. we know that proportion, size, shape of bones and their accompanying soft parts vary, and hence constant selection would alter, to almost any purpose > the framework of an organism, but yet would leave a general, even closest similarity in it. {145} written between the lines occurs:--"extend to birds and other classes." {146} written between the lines occurs:--"many bones merely represented." {147} in the _origin_, ed. i. p. 434, vi. p. 595, the term _morphology_ is taken as including _unity of type_. the paddle of the porpoise and the wing of the bat are there used as instances of morphological resemblance. {148} the sentence is difficult to decipher. [we know the number of similar parts, as vertebræ and ribs can vary, hence this also we might expect.] also the changes carried on to a certain point, doubtless type will be lost, and this is case with plesiosaurus{149}. the unity of type in past and present ages of certain great divisions thus undoubtedly receives the simplest explanation. {149} in the _origin_, ed. i. p. 436, vi. p. 598, the author speaks of the "general pattern" being obscured in the paddles of "extinct gigantic sea-lizards." there is another class of allied and almost identical facts, admitted by the soberest physiologists, [from the study of a certain set of organs in a group of organisms] and refers referring> to a unity of type of different organs in the same individual, denominated the science of "morphology." the this> discovered by beautiful and regular series, and in the case of plants from monstrous changes, that certain organs in an individual are other organs metamorphosed. thus every botanist considers petals, nectaries, stamens, pistils, germen as metamorphosed leaf. they thus explain, in the most lucid manner, the position and number of all parts of the flower, and the curious conversion under cultivation of one part into another. the complicated double set of jaws and palpi of crustaceans{150}, and all insects are considered as metamorphosed and to see the series is to admit this phraseology. the skulls of the vertebrates are undoubtedly composed of three metamorphosed vertebræ; thus we can understand the strange form of the separate bones which compose the casket holding man's brain. these{151} facts differ but slightly from those of last section, if with wing, paddle, hand and hoof, some common structure was yet visible, or could be made out by a series of occasional monstrous conversions, and if traces could be discovered of whole having once existed as walking or swimming instruments, these organs would be said to be metamorphosed, as it is they are only said to exhibit a common type. {150} see _origin_, ed. i. p. 437, vi. p. 599. {151} the following passage seems to have been meant to precede the sentence beginning "these facts":--"it is evident, that when in each individual species, organs are metamorph. a unity of type extends." this distinction is not drawn by physiologists, and is only implied by some by their general manner of writing. these facts, though affecting every organic being on the face of the globe, which has existed, or does exist, can only be viewed by the creationist as ultimate and inexplicable facts. but this unity of type through the individuals of a group, and this metamorphosis of the same organ into other organs, adapted to diverse use, necessarily follows on the theory of descent{152}. for let us take case of vertebrata, which if{153} they descended from one parent and by this theory all the vertebrata have been altered by slow degrees, such as we see in domestic animals. we know that proportions alter, and even that occasionally numbers of vertebræ alter, that parts become soldered, that parts are lost, as tail and toes, but we know here we can see that possibly a walking organ might > be converted into swimming or into a gliding organ and so on to a flying organ. but such gradual changes would not alter the unity of type in their descendants, as parts lost and soldered and vertebræ. but we can see that if this carried to extreme, unity lost,--plesiosaurus. here we have seen the same organ is formed > different purposes : and if, in several orders of vertebrata, we could trace origin spinous processes and monstrosities &c. we should say, instead of there existing a unity of type, morphology{154}, as we do when we trace the head as being the vertebræ metamorphosed. be it observed that naturalists, as they use terms of affinity without attaching real meaning, here also they are obliged to use metamorphosis, without meaning that any parent of crustacean was really an animal with as many legs as crustacean has jaws. the theory of descent at once explains these wonderful facts. {152} this is, i believe, the first place in which the author uses the words "theory of descent." {153} the sentence should probably run, "let us take the case of the vertebrata: if we assume them to be descended from one parent, then by this theory they have been altered &c." {154} that is "we should call it a morphological fact." now few of the physiologists who use this language really suppose that the parent of insect with the metamorphosed jaw, was an insect with [more] so many legs, or that the parent of flowering plants, originally had no stamens, or pistils or petals, but some other means of propagation,--and so in other cases. now according to our theory during the infinite number of changes, we might expect that an organ used for a purpose might be used for a different one by his descendant, as must have been the case by our theory with the bat, porpoise, horse, &c., which are descended from one parent. and if it so chanced that traces of the former use and structure of the part should be retained, which is manifestly possible if not probable, then we should have the organs, on which morphology is founded and which instead of being metaphorical becomes plain and utterly unintelligible becomes simple matter of fact{155}. {155} in the _origin_, ed. i. p. 438, vi. p. 602, the author, referring to the expressions used by naturalists in regard to morphology and metamorphosis, says "on my view these terms may be used literally." <_embryology._> this general unity of type in great groups of organisms (including of course these morphological cases) displays itself in a most striking manner in the stages through which the foetus passes{156}. in early stage, the wing of bat, hoof, hand, paddle are not to be distinguished. at a still earlier there is no difference between fish, bird, &c. &c. and mammal. it is not that they cannot be distinguished, but the arteries{157} . it is not true that one passes through the form of a lower group, though no doubt fish more nearly related to foetal state{158}. {156} see _origin_, ed. i. p. 439, vi. p. 605. {157} in the _origin_, ed. i. p. 440, vi. p. 606, the author argues that the "loop-like course of the arteries" in the vertebrate embryo has no direct relation to the conditions of existence. {158} the following passages are written across the page:--"they pass through the same phases, but some, generally called the higher groups, are further metamorphosed. ? degradation and complication? no tendency to perfection. ? justly argued against lamarck?" this similarity at the earliest stage is remarkably shown in the course of the arteries which become greatly altered, as foetus advances in life and assumes the widely different course and number which characterize full-grown fish and mammals. how wonderful that in egg, in water or air, or in womb of mother, artery{159} should run in same course. {159} an almost identical passage occurs in the _origin_, ed. i. p. 440, vi. p. 606. light can be thrown on this by our theory. the structure of each organism is chiefly adapted to the sustension of its life, when full-grown, when it has to feed itself and propagate{160}. the structure of a kitten is quite in secondary degree adapted to its habits, whilst fed by its mother's milk and prey. hence variation in the structure of the full-grown species will _chiefly_ determine the preservation of a species now become ill-suited to its habitat, or rather with a better place opened to it in the economy of nature. it would not matter to the full-grown cat whether in its young state it was more or less eminently feline, so that it become so when full-grown. no doubt most variation, (not depending on habits of life of individual) depends on early change{161} and we must suspect that at whatever time of life the alteration of foetus is effected, it tends to appear at same period. when we a tendency to particular disease in old age transmitted by the male, we know some effect is produced during conception, on the simple cell of ovule, which will not produce its effect till half a century afterwards and that effect is not visible{162}. so we see in grey-hound, bull-dog, in race-horse and cart-horse, which have been selected for their form in full-life, there is much less (?) difference in the few first days after birth{163}, than when full-grown: so in cattle, we see it clearly in cases of cattle, which differ obviously in shape and length of horns. if man were during 10,000 years to be able to select, far more diverse animals from horse or cow, i should expect there would be far less differences in the very young and foetal state: and this, i think, throws light on above marvellous fact. in larvæ, which have long life selection, perhaps, does much,--in the pupa not so much{164} there is no object gained in varying form &c. of foetus (beyond certain adaptations to mother's womb) and therefore selection will not further act on it, than in giving to its changing tissues a tendency to certain parts afterwards to assume certain forms. {160} the following: "deaths of brothers old by same peculiar disease" which is written between the lines seems to have been a memorandum which is expanded a few lines lower. i believe the case of the brothers came from dr r. w. darwin. {161} see the discussion to this effect in the _origin_, ed. i. pp. 443-4, vi. p. 610. the author there makes the distinction between a cause affecting the germ-cell and the reaction occurring at a late period of life. {162} possibly the sentence was meant to end "is not visible till then." {163} see _origin_, ed. i. pp. 444-5, vi. p. 611. the query appended to _much less_ is justified, since measurement was necessary to prove that the greyhound and bulldog puppies had not nearly acquired "their full amount of proportional difference." {164} i think light can be thrown on these facts. from the following peculiarities being hereditary, [we know that some change in the germinal vesicle is effected, which will only betray itself years after] diseases--man, goitre, gout, baldness, fatness, size, [longevity time of reproduction, shape of horns, case of old brothers dying of same disease]. and we know that the germinal vesicle must have been affected, though no effect is apparent or can be apparent till years afterwards,--no more apparent than when these peculiarities appear by the exposure of the full-grown individual. so that when we see a variety in cattle, even if the variety be due to act of reproduction, we cannot feel sure at what period this change became apparent. it may have been effected during early age of free life foetal existence, as monsters show. from arguments before used, and crossing, we may generally suspect in germ; but i repeat it does not follow, that the change should be apparent till life fully developed; any more than fatness depending on heredity should be apparent during early childhood, still less during foetal existence. in case of horns of cattle, which when inherited must depend on germinal vesicle, obviously no effect till cattle full-grown. practically it would appear that the [hereditary] peculiarities characterising our domestic races, therefore resulting from vesicle, do not appear with their full characters in very early states; thus though two breeds of cows have calves different, they are not so different,--grey-hound and bull-dog. and this is what is be expected, for man is indifferent to characters of young animals and hence would select those full-grown animals which possessed the desirable characteristics. so that from mere chance we might expect that some of the characters would be such only as became fully apparent in mature life. furthermore we may suspect it to be a law, that at whatever time a new character appears, whether from vesicle, or effects of external conditions, it would appear at corresponding time . thus diseases appearing in old age produce children with d^o.,--early maturity,--longevity,--old men, brothers, of same disease--young children of d^o. i said men do not select for quality of young,--calf with big bullocks. silk-worms, peculiarities which, appear in caterpillar state or cocoon state, are transmitted to corresponding states. the effect of this would be that if some peculiarity was born in a young animal, but never exercised, it might be inherited in young animal; but if exercised that part of structure would be increased and would be inherited in corresponding time of life after such training. i have said that man selects in full-life, so would it be in nature. in struggle of existence, it matters nothing to a feline animal, whether kitten eminently feline, as long as it sucks. therefore natural selection would act equally well on character which was fully only in full age. selection could tend to alter no character in foetus, (except relation to mother) it would alter less in young state (putting on one side larva condition) but alter every part in full-grown condition. look to a foetus and its parent, and again after ages foetus and its descendant; the parent more variable > than foetus, which explains all.] thus there is no power to change the course of the arteries, as long as they nourish the foetus; it is the selection of slight changes which supervene at any time during of life. the less differences of foetus,--this has obvious meaning on this view: otherwise how strange that a [monkey] horse, a man, a bat should at one time of life have arteries, running in a manner, which is only intelligibly useful in a fish! the natural system being on theory genealogical, we can at once see, why foetus, retaining traces of the ancestral form, is of the highest value in classification. § ix. there is another grand class of facts relating to what are called abortive organs. these consist of organs which the same reasoning power that shows us how beautifully these organs in some cases are adapted to certain end, declares in other cases are absolutely useless. thus teeth in rhinoceros{165}, whale, narwhal,--bone on tibia, muscles which do not move,--little bone of wing of apteryx,--bone representing extremities in some snake,--little wings within > soldered cover of beetles,--men and bulls, mammæ: filaments without anthers in plants, mere scales representing petals in others, in feather-hyacinth whole flower. almost infinitely numerous. no one can reflect on these without astonishment, can anything be clearer than that wings are to fly and teeth , and yet we find these organs perfect in every detail in situations where they cannot possibly be of their normal use{166}. {165} some of these examples occur in _origin_, ed. i. pp. 450-51, vi. pp. 619-20. {166} the two following sentences are written, one down the margin, the other across the page. "abortive organs eminently useful in classification. embryonic state of organs. rudiments of organs." the term abortive organ has been thus applied to above structure (as _invariable_ as all other parts{167}) from their absolute similarity to monstrous cases, where from _accident_, certain organs are not developed; as infant without arms or fingers with mere stump representing them: teeth represented by mere points of ossification: headless children with mere button,--viscera represented by small amorphous masses, &c.,--the tail by mere stump,--a solid horn by minute hanging one{168}. there is a tendency in all these cases, when life is preserved, for such structures to become hereditary. we see it in tailless dogs and cats. in plants we see this strikingly,--in thyme, in _linum flavum_,--stamen in _geranium pyrenaicum_{169}. nectaries abort into petals in columbine <_aquilegia_>, produced from some accident and then become hereditary, in some cases only when propagated by buds, in other cases by seed. these cases have been produced suddenly by accident in early growth, but it is part of law of growth that when any organ is not used it tends to diminish (duck's wing{170}?) muscles of dog's ears, rabbits, muscles wither, arteries grow up. when eye born defective, optic nerve (tuco tuco) is atrophied. as every part whether useful or not (diseases, double flowers) tends to be transmitted to offspring, the origin of abortive organs whether produced at the birth or slowly acquired is easily understood in domestic races of organisms: [a struggle between the atrophy and hereditariness. abortive organs in domestic races.] there will always be a struggle between atrophy of an organ rendered useless, and hereditariness{171}. because we can understand the origin of abortive organs in certain cases, it would be wrong to conclude absolutely that all must have had same origin, but the strongest analogy is in favour of it. and we can by our theory, for during infinite changes some organ, we might have anticipated, would have become useless. readily explain the fact, so astounding on any other view, namely that organs possibly useless have been formed often with the same exquisite care as when of vital importance. {167} i imagine the meaning to be that abortive organs are specific characters in contrast to monstrosities. {168} minute hanging horns are mentioned in the _origin_, ed. i. p. 454, vi. p. 625, as occurring in hornless breeds of cattle. {169} _linum flavum_ is dimorphic: thyme gynodiæcious. it is not clear what point is referred to under _geranium pyrenaicum_. {170} the author's work on duck's wings &c. is in _var. under dom._, ed. 2, i. p. 299. {171} the words _vis medicatrix_ are inserted after "useless," apparently as a memorandum. our theory, i may remark would permit an organ become abortive with respect to its primary use, to be turned to any other purpose, (as the buds in a cauliflower) thus we can see no difficulty in bones of male marsupials being used as fulcrum of muscles, or style of marygold{172},--indeed in one point of view, the heads of [vertebrated] animal may be said to be abortive vertebræ turned into other use: legs of some crustacea abortive jaws, &c., &c. de candolle's analogy of table covered with dishes{173}. {172} in the male florets of certain compositæ the style functions merely as a piston for forcing out the pollen. {173} if abortive organs are a trace preserved by hereditary tendency, of organ in ancestor of use, we can at once see why important in natural classification, also why more plain in young animal because, as in last section, the selection has altered the old animal most. i repeat, these wondrous facts, of parts created for no use in past and present time, all can by my theory receive simple explanation; or they receive none and we must be content with some such empty metaphor, as that of de candolle, who compares creation to a well covered table, and says abortive organs may be compared to the dishes (some should be empty) placed symmetrically! degradation and complication see lamarck: no tendency to perfection: if room, [even] high organism would have greater power in beating lower one, thought > to be selected for a degraded end. § x. recapitulation and conclusion. let us recapitulate the whole > these latter sections by taking case of the three species of rhinoceros, which inhabit java, sumatra, and mainland of malacca or india. we find these three close neighbours, occupants of distinct but neighbouring districts, as a group having a different aspect from the rhinoceros of africa, though some of these latter inhabit very similar countries, but others most diverse stations. we find them intimately related [scarcely > differences more than some breeds of cattle] in structure to the rhinoceros, which for immense periods have inhabited this one, out of three main zoological divisions of the world. yet some of these ancient animals were fitted to very different stations: we find all three of the generic character of the rhinoceros, which form a [piece of net]{174} set of links in the broken chain representing the pachydermata, as the chain likewise forms a portion in other and longer chains. we see this wonderfully in dissecting the coarse leg of all three and finding nearly the same bones as in bat's wings or man's hand, but we see the clear mark in solid tibia of the fusion into it of the fibula. in all three we find their heads composed of three altered vertebræ, short neck, same bones as giraffe. in the upper jaws of all three we find small teeth like rabbit's. in dissecting them in foetal state we find at a not very early stage their form exactly alike the most different animals, and even with arteries running as in a fish: and this similarity holds when the young one is produced in womb, pond, egg or spawn. now these three undoubted species scarcely differ more than breeds of cattle, are probably subject to many the same contagious diseases; if domesticated these forms would vary, and they might possibly breed together, and fuse into something{175} different their aboriginal forms; might be selected to serve different ends. {174} the author doubtless meant that the complex relationships between organisms can be roughly represented by a net in which the knots stand for species. {175} between the lines occurs:--"one > form be lost." now the creationist believes these three rhinoceroses were created{176} with their deceptive appearance of true, not relationship; as well can i believe the planets revolve in their present courses not from one law of gravity but from distinct volition of creator. {176} the original sentence is here broken up by the insertion of:--"out of the dust of java, sumatra, these > allied to past and present age and , with the stamp of inutility in some of their organs and conversion in others." if real species, sterile one with another, differently adapted, now inhabiting different countries, with different structures and instincts, are admitted to have common descent, we can only legitimately stop where our facts stop. look how far in some case a chain of species will lead us. may we not jump (considering how much extermination, and how imperfect geological records) from one sub-genus to another sub-genus. can genera restrain us; many of the same arguments, which made us give up species, inexorably demand genera and families and orders to fall, and classes tottering. we ought to stop only when clear unity of type, independent of use and adaptation, ceases. be it remembered no naturalist pretends to give test from external characters of species; in many genera the distinction is quite arbitrary{177}. but there remains one other way of comparing species with races; it is to compare the effects of crossing them. would it not be wonderful, if the union of two organisms, produced by two separate acts of creation, blended their characters together when crossed according to the same rules, as two races which have undoubtedly descended from same parent stock; yet this can be shown to be the case. for sterility, though a usual >, is not an invariable concomitant, it varies much in degree and has been shown to be probably dependent on causes closely analogous with those which make domesticated organisms sterile. independent of sterility there is no difference between mongrels and hybrids, as can be shown in a long series of facts. it is strikingly seen in cases of instincts, when the minds of the two species or races become blended together{178}. in both cases if the half-breed be crossed with either parent for a few generations, all traces of the one parent form is lost (as kölreuter in two tobacco species almost sterile together), so that the creationist in the case of a species, must believe that one act of creation is absorbed into another! {177} between the lines occur the words:--"species vary according to same general laws as varieties; they cross according to same laws." {178} "a cross with a bull-dog has affected for many generations the courage and obstinacy of greyhounds," _origin_, ed. i. p. 214, vi. p. 327. {illustration: facsimile of the original manuscript of the paragraph on p. 50.} conclusion. such are my reasons for believing that specific forms are not immutable. the affinity of different groups, the unity of types of structure, the representative forms through which foetus passes, the metamorphosis of organs, the abortion of others cease to be metaphorical expressions and become intelligible facts. we no longer look on animal as a savage does at a ship{179}, or other great work of art, as a thing wholly beyond comprehension, but we feel far more interest in examining it. how interesting is every instinct, when we speculate on their origin as an hereditary or congenital habit or produced by the selection of individuals differing slightly from their parents. we must look at every complicated mechanism and instinct, as the summary of a long history, of{180} useful contrivances, much like a work of art. how interesting does the distribution of all animals become, as throwing light on ancient geography. [we see some seas bridged over.] geology loses in its glory from the imperfection of its archives{181}, but how does it gain in the immensity of the periods of its formations and of the gaps separating these formations. there is much grandeur in looking at the existing animals either as the lineal descendants of the forms buried under thousand feet of matter, or as the coheirs of some still more ancient ancestor. it accords with what we know of the law impressed on matter by the creator, that the creation and extinction of forms, like the birth and death of individuals should be the effect of secondary [laws] means{182}. it is derogatory that the creator of countless systems of worlds should have created each of the myriads of creeping parasites and [slimy] worms which have swarmed each day of life on land and water [this] one globe. we cease being astonished, however much we may deplore, that a group of animals should have been directly created to lay their eggs in bowels and flesh of other,--that some organisms should delight in cruelty,--that animals should be led away by false instincts,--that annually there should be an incalculable waste of eggs and pollen. from death, famine, rapine, and the concealed war of nature we can see that the highest good, which we can conceive, the creation of the higher animals has directly come. doubtless it at first transcends our humble powers, to conceive laws capable of creating individual organisms, each characterised by the most exquisite workmanship and widely-extended adaptations. it accords better with [our modesty] the lowness of our faculties to suppose each must require the fiat of a creator, but in the same proportion the existence of such laws should exalt our notion of the power of the omniscient creator{183}. there is a simple grandeur in the view of life with its powers of growth, assimilation and reproduction, being originally breathed into matter under one or a few forms, and that whilst this our planet has gone circling on according to fixed laws, and land and water, in a cycle of change, have gone on replacing each other, that from so simple an origin, through the process of gradual selection of infinitesimal changes, endless forms most beautiful and most wonderful have been evolved{184}. {179} the simile of the savage and the ship occurs in the _origin_, ed. i. p. 485, vi. p. 665. {180} in the _origin_, ed. i. p. 486, vi. p. 665, the author speaks of the "summing up of many contrivances": i have therefore introduced the above words which make the passage clearer. in the _origin_ the comparison is with "a great mechanical invention,"--not with a work of art. {181} see a similar passage in the _origin_, ed. i. p. 487, vi. p. 667. {182} see the _origin_, ed. i. p. 488, vi. p. 668. {183} the following discussion, together with some memoranda are on the last page of the ms. "the supposed creative spirit does not create either number or kind which from analogy adapted to site (viz. new zealand): it does not keep them all permanently adapted to any country,--it works on spots or areas of creation,--it is not persistent for great periods,--it creates forms of same groups in same regions, with no physical similarity,--it creates, on islands or mountain summits, species allied to the neighbouring ones, and not allied to alpine nature as shown in other mountain summits--even different on different island of similarly constituted archipelago, not created on two points: never mammifers created on small isolated island; nor number of organisms adapted to locality: its power seems influenced or related to the range of other species wholly distinct of the same genus,--it does not equally effect, in amount of difference, all the groups of the same class." {184} this passage is the ancestor of the concluding words in the first edition of the _origin of species_ which have remained substantially unchanged throughout subsequent editions, "there is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved." in the 2nd edition "by the creator" is introduced after "originally breathed." n.b.--there ought somewhere to be a discussion from lyell to show that external conditions do vary, or a note to lyell's works . besides other difficulties in ii. part, non-acclimatisation of plants. difficulty when asked _how_ did white and negro become altered from common intermediate stock: no facts. we do not know that species are immutable, on the contrary. what arguments against this theory, except our not perceiving every step, like the erosion of valleys{185}. {185} compare the _origin_, ed. i. p. 481, vi. p. 659, "the difficulty is the same as that felt by so many geologists, when lyell first insisted that long lines of inland cliffs had been formed, and great valleys excavated, by the slow action of the coast-waves." the essay of 1844 part i chapter i on the variation of organic beings under domestication; and on the principles of selection the most favourable conditions for variation seem to be when organic beings are bred for many generations under domestication{186}: one may infer this from the simple fact of the vast number of races and breeds of almost every plant and animal, which has long been domesticated. under certain conditions organic beings even during their individual lives become slightly altered from their usual form, size, or other characters: and many of the peculiarities thus acquired are transmitted to their offspring. thus in animals, the size and vigour of body, fatness, period of maturity, habits of body or consensual movements, habits of mind and temper, are modified or acquired during the life of the individual{187}, and become inherited. there is reason to believe that when long exercise has given to certain muscles great development, or disuse has lessened them, that such development is also inherited. food and climate will occasionally produce changes in the colour and texture of the external coverings of animals; and certain unknown conditions affect the horns of cattle in parts of abyssinia; but whether these peculiarities, thus acquired during individual lives, have been inherited, i do not know. it appears certain that malconformation and lameness in horses, produced by too much work on hard roads,--that affections of the eyes in this animal probably caused by bad ventilation,--that tendencies towards many diseases in man, such as gout, caused by the course of life and ultimately producing changes of structure, and that many other diseases produced by unknown agencies, such as goitre, and the idiotcy resulting from it, all become hereditary. {186} the cumulative effect of domestication is insisted on in the _origin_, see _e.g. origin_, ed. i. p. 7, vi. p. 8. {187} this type of variation passes into what he describes as the direct effect of conditions. since they are due to causes acting during the adult life of the organism they might be called individual variations, but he uses this term for congenital variations, _e.g._ the differences discoverable in plants raised from seeds of the same pod _(origin_, ed. i. p. 45, vi. p. 53). it is very doubtful whether the flowers and leaf-buds, annually produced from the same bulb, root, or tree, can properly be considered as parts of the same individual, though in some respects they certainly seem to be so. if they are parts of an individual, plants also are subject to considerable changes during their _individual_ lives. most florist-flowers if neglected degenerate, that is, they lose some of their characters; so common is this, that trueness is often stated, as greatly enhancing the value of a variety{188}: tulips break their colours only after some years' culture; some plants become double and others single, by neglect or care: these characters can be transmitted by cuttings or grafts, and in some cases by true or seminal propagation. occasionally a single bud on a plant assumes at once a new and widely different character: thus it is certain that nectarines have been produced on peach trees and moss roses on provence roses; white currants on red currant bushes; flowers of a different colour from that of the stock, in chrysanthemums, dahlias, sweet-williams, azaleas, &c., &c.; variegated leaf-buds on many trees, and other similar cases. these new characters appearing in single buds, can, like those lesser changes affecting the whole plant, be multiplied not only by cuttings and such means, but often likewise by true seminal generation. {188} : case of orchis,--most remarkable as not long cultivated by seminal propagation. case of varieties which soon acquire, like _ægilops_ and carrot (and maize) _a certain general character_ and then go on varying. the changes thus appearing during the lives of individual animals and plants are extremely rare compared with those which are congenital or which appear soon after birth. slight differences thus arising are infinitely numerous: the proportions and form of every part of the frame, inside and outside, appear to vary in very slight degrees: anatomists dispute what is the "beau ideal" of the bones, the liver and kidneys, like painters do of the proportions of the face: the proverbial expression that no two animals or plants are born absolutely alike, is much truer when applied to those under domestication, than to those in a state of nature{189}. besides these slight differences, single individuals are occasionally born considerably unlike in certain parts or in their whole structure to their parents: these are called by horticulturists and breeders "sports"; and are not uncommon except when very strongly marked. such sports are known in some cases to have been parents of some of our domestic races; and such probably have been the parents of many other races, especially of those which in some senses may be called hereditary monsters; for instance where there is an additional limb, or where all the limbs are stunted (as in the ancon sheep), or where a part is wanting, as in rumpless fowls and tailless dogs or cats{190}. the effects of external conditions on the size, colour and form, which can rarely and obscurely be detected during one individual life, become apparent after several generations: the slight differences, often hardly describable, which characterize the stock of different countries, and even of districts in the same country, seem to be due to such continued action. {189} here, as in the ms. of 1842, the author is inclined to minimise the variation occurring in nature. {190} this is more strongly stated than in the _origin_, ed. i. p. 30. _on the hereditary tendency._ a volume might be filled with facts showing what a strong tendency there is to inheritance, in almost every case of the most trifling, as well as of the most remarkable congenital peculiarities{191}. the term congenital peculiarity, i may remark, is a loose expression and can only mean a peculiarity apparent when the part affected is nearly or fully developed: in the second part, i shall have to discuss at what period of the embryonic life connatal peculiarities probably first appear; and i shall then be able to show from some evidence, that at whatever period of life a new peculiarity first appears, it tends hereditarily to appear at a corresponding period{192}. numerous though slight changes, slowly supervening in animals during mature life (often, though by no means always, taking the form of disease), are, as stated in the first paragraphs, very often hereditary. in plants, again, the buds which assume a different character from their stock likewise tend to transmit their new peculiarities. there is not sufficient reason to believe that either mutilations{193} or changes of form produced by mechanical pressure, even if continued for hundreds of generations, or that any changes of structure quickly produced by disease, are inherited; it would appear as if the tissue of the part affected must slowly and freely grow into the new form, in order to be inheritable. there is a very great difference in the hereditary tendency of different peculiarities, and of the same peculiarity, in different individuals and species; thus twenty thousand seeds of the weeping ash have been sown and not one come up true;--out of seventeen seeds of the weeping yew, nearly all came up true. the ill-formed and almost monstrous "niata" cattle of s. america and ancon sheep, both when bred together and when crossed with other breeds, seem to transmit their peculiarities to their offspring as truly as the ordinary breeds. i can throw no light on these differences in the power of hereditary transmission. breeders believe, and apparently with good cause, that a peculiarity generally becomes more firmly implanted after having passed through several generations; that is if one offspring out of twenty inherits a peculiarity from its parents, then its descendants will tend to transmit this peculiarity to a larger proportion than one in twenty; and so on in succeeding generations. i have said nothing about mental peculiarities being inheritable for i reserve this subject for a separate chapter. {191} see _origin_, ed. i. p. 13. {192} _origin_, ed. i. p. 86, vi. p. 105. {193} it is interesting to find that though the author, like his contemporaries, believed in the inheritance of acquired characters, he excluded the case of mutilation. _causes of variation._ attention must here be drawn to an important distinction in the first origin or appearance of varieties: when we see an animal highly kept producing offspring with an hereditary tendency to early maturity and fatness; when we see the wild-duck and australian dog always becoming, when bred for one or a few generations in confinement, mottled in their colours; when we see people living in certain districts or circumstances becoming subject to an hereditary taint to certain organic diseases, as consumption or plica polonica,--we naturally attribute such changes to the direct effect of known or unknown agencies acting for one or more generations on the parents. it is probable that a multitude of peculiarities may be thus directly caused by unknown external agencies. but in breeds, characterized by an extra limb or claw, as in certain fowls and dogs; by an extra joint in the vertebræ; by the loss of a part, as the tail; by the substitution of a tuft of feathers for a comb in certain poultry; and in a multitude of other cases, we can hardly attribute these peculiarities directly to external influences, but indirectly to the laws of embryonic growth and of reproduction. when we see a multitude of varieties (as has often been the case, where a cross has been carefully guarded against) produced from seeds matured in the very same capsule{194}, with the male and female principle nourished from the same roots and necessarily exposed to the same external influences; we cannot believe that the endless slight differences between seedling varieties thus produced, can be the effect of any corresponding difference in their exposure. we are led (as müller has remarked) to the same conclusion, when we see in the same litter, produced by the same act of conception, animals considerably different. {194} this corresponds to _origin_, ed. i. p. 10, vi. p. 9. as variation to the degree here alluded to has been observed only in organic beings under domestication, and in plants amongst those most highly and long cultivated, we must attribute, in such cases, the varieties (although the difference between each variety cannot possibly be attributed to any corresponding difference of exposure in the parents) to the indirect effects of domestication on the action of the reproductive system{195}. it would appear as if the reproductive powers failed in their ordinary function of producing new organic beings closely like their parents; and as if the entire organization of the embryo, under domestication, became in a slight degree plastic{196}. we shall hereafter have occasion to show, that in organic beings, a considerable change from the natural conditions of life, affects, independently of their general state of health, in another and remarkable manner the reproductive system. i may add, judging from the vast number of new varieties of plants which have been produced in the same districts and under nearly the same routine of culture, that probably the indirect effects of domestication in making the organization plastic, is a much more efficient source of variation than any direct effect which external causes may have on the colour, texture, or form of each part. in the few instances in which, as in the dahlia{197}, the course of variation has been recorded, it appears that domestication produces little effect for several generations in rendering the organization plastic; but afterwards, as if by an accumulated effect, the original character of the species suddenly gives way or breaks. {195} _origin_, ed. i. p. 8, vi. p. 10. {196} for _plasticity_ see _origin_, ed. i. pp. 12, 132. {197} _var. under dom._, ed. ii. i. p. 393. _on selection._ we have hitherto only referred to the first appearance in individuals of new peculiarities; but to make a race or breed, something more is generally{198} requisite than such peculiarities (except in the case of the peculiarities being the direct effect of constantly surrounding conditions) should be inheritable,--namely the principle of selection, implying separation. even in the rare instances of sports, with the hereditary tendency very strongly implanted, crossing must be prevented with other breeds, or if not prevented the best characterized of the half-bred offspring must be carefully selected. where the external conditions are constantly tending to give some character, a race possessing this character will be formed with far greater ease by selecting and breeding together the individuals most affected. in the case of the endless slight variations produced by the indirect effects of domestication on the action of the reproductive system, selection is indispensable to form races; and when carefully applied, wonderfully numerous and diverse races can be formed. selection, though so simple in theory, is and has been important to a degree which can hardly be overrated. it requires extreme skill, the results of long practice, in detecting the slightest difference in the forms of animals, and it implies some distinct object in view; with these requisites and patience, the breeder has simply to watch for every the smallest approach to the desired end, to select such individuals and pair them with the most suitable forms, and so continue with succeeding generations. in most cases careful selection and the prevention of accidental crosses will be necessary for several generations, for in new breeds there is a strong tendency to vary and especially to revert to ancestral forms: but in every succeeding generation less care will be requisite for the breed will become truer; until ultimately only an occasional individual will require to be separated or destroyed. horticulturalists in raising seeds regularly practise this, and call it "roguing," or destroying the "rogues" or false varieties. there is another and less efficient means of selection amongst animals: namely repeatedly procuring males with some desirable qualities, and allowing them and their offspring to breed freely together; and this in the course of time will affect the whole lot. these principles of selection have been _methodically_ followed for scarcely a century; but their high importance is shown by the practical results, and is admitted in the writings of the most celebrated agriculturalists and horticulturalists;--i need only name anderson, marshall, bakewell, coke, western, sebright and knight. {198} selection is here used in the sense of isolation, rather than as implying the summation of small differences. professor henslow in his _heredity of acquired characters in plants_, 1908, p. 2, quotes from darwin's _var. under dom._, ed. i. ii. p. 271, a passage in which the author, speaking of the direct action of conditions, says:--"a new sub-variety would thus be produced without the aid of selection." darwin certainly did not mean to imply that such varieties are freed from the action of natural selection, but merely that a new form may appear without _summation_ of new characters. professor henslow is apparently unaware that the above passage is omitted in the second edition of _var. under dom._, ii. p. 260. even in well-established breeds the individuals of which to an unpractised eye would appear absolutely similar, which would give, it might have been thought, no scope to selection, the whole appearance of the animal has been changed in a few years (as in the case of lord western's sheep), so that practised agriculturalists could scarcely credit that a change had not been effected by a cross with other breeds. breeders both of plants and animals frequently give their means of selection greater scope, by crossing different breeds and selecting the offspring; but we shall have to recur to this subject again. the external conditions will doubtless influence and modify the results of the most careful selection; it has been found impossible to prevent certain breeds of cattle from degenerating on mountain pastures; it would probably be impossible to keep the plumage of the wild-duck in the domesticated race; in certain soils, no care has been sufficient to raise cauliflower seed true to its character; and so in many other cases. but with patience it is wonderful what man has effected. he has selected and therefore in one sense made one breed of horses to race and another to pull; he has made sheep with fleeces good for carpets and other sheep good for broadcloth; he has, in the same sense, made one dog to find game and give him notice when found, and another dog to fetch him the game when killed; he has made by selection the fat to lie mixed with the meat in one breed and in another to accumulate in the bowels for the tallow-chandler{199}; he has made the legs of one breed of pigeons long, and the beak of another so short, that it can hardly feed itself; he has previously determined how the feathers on a bird's body shall be coloured, and how the petals of many flowers shall be streaked or fringed, and has given prizes for complete success;--by selection, he has made the leaves of one variety and the flower-buds of another variety of the cabbage good to eat, at different seasons of the year; and thus has he acted on endless varieties. i do not wish to affirm that the long-and short-wooled sheep, or that the pointer and retriever, or that the cabbage and cauliflower have certainly descended from one and the same aboriginal wild stock; if they have not so descended, though it lessens what man has effected, a large result must be left unquestioned. {199} see the essay of 1842, p. 3. in saying as i have done that man makes a breed, let it not be confounded with saying that man makes the individuals, which are given by nature with certain desirable qualities; man only adds together and makes a permanent gift of nature's bounties. in several cases, indeed, for instance in the "ancon" sheep, valuable from not getting over fences, and in the turnspit dog, man has probably only prevented crossing; but in many cases we positively know that he has gone on selecting, and taking advantage of successive small variations. selection{200} has been _methodically_ followed, as i have said, for barely a century; but it cannot be doubted that occasionally it has been practised from the remotest ages, in those animals completely under the dominion of man. in the earliest chapters of the bible there are rules given for influencing the colours of breeds, and black and white sheep are spoken of as separated. in the time of pliny the barbarians of europe and asia endeavoured by cross-breeding with a wild stock to improve the races of their dogs and horses. the savages of guyana now do so with their dogs: such care shows at least that the characters of individual animals were attended to. in the rudest times of english history, there were laws to prevent the exportation of fine animals of established breeds, and in the case of horses, in henry viii's time, laws for the destruction of all horses under a certain size. in one of the oldest numbers of the _phil. transactions_, there are rules for selecting and improving the breeds of sheep. sir h. bunbury, in 1660, has given rules for selecting the finest seedling plants, with as much precision as the best recent horticulturalist could. even in the most savage and rude nations, in the wars and famines which so frequently occur, the most useful of their animals would be preserved: the value set upon animals by savages is shown by the inhabitants of tierra del fuego devouring their old women before their dogs, which as they asserted are useful in otter-hunting{201}: who can doubt but that in every case of famine and war, the best otter-hunters would be preserved, and therefore in fact selected for breeding. as the offspring so obviously take after their parents, and as we have seen that savages take pains in crossing their dogs and horses with wild stocks, we may even conclude as probable that they would sometimes pair the most useful of their animals and keep their offspring separate. as different races of men require and admire different qualities in their domesticated animals, each would thus slowly, though unconsciously, be selecting a different breed. as pallas has remarked, who can doubt but that the ancient russian would esteem and endeavour to preserve those sheep in his flocks which had the thickest coats. this kind of insensible selection by which new breeds are not selected and kept separate, but a peculiar character is slowly given to the whole mass of the breed, by often saving the life of animals with certain characteristics, we may feel nearly sure, from what we see has been done by the more direct method of separate selection within the last 50 years in england, would in the course of some thousand years produce a marked effect. {200} see _origin_, ed. i. p. 33, vi. p. 38. the evidence is given in the present essay rather more fully than in the _origin_. {201} _journal of researches_, ed. 1860, p. 214. "doggies catch otters, old women no." _crossing breeds._ when once two or more races are formed, or if more than one race, or species fertile _inter se_, originally existed in a wild state, their crossing becomes a most copious source of new races{202}. when two well-marked races are crossed the offspring in the first generation take more or less after either parent or are quite intermediate between them, or rarely assume characters in some degree new. in the second and several succeeding generations, the offspring are generally found to vary exceedingly, one compared with another, and many revert nearly to their ancestral forms. this greater variability in succeeding generations seems analogous to the breaking or variability of organic beings after having been bred for some generations under domestication{203}. so marked is this variability in cross-bred descendants, that pallas and some other naturalists have supposed that all variation is due to an original cross; but i conceive that the history of the potato, dahlia, scotch rose, the guinea-pig, and of many trees in this country, where only one species of the genus exists, clearly shows that a species may vary where there can have been no crossing. owing to this variability and tendency to reversion in cross-bred beings, much careful selection is requisite to make intermediate or new permanent races: nevertheless crossing has been a most powerful engine, especially with plants, where means of propagation exist by which the cross-bred varieties can be secured without incurring the risk of fresh variation from seminal propagation: with animals the most skilful agriculturalists now greatly prefer careful selection from a well-established breed, rather than from uncertain cross-bred stocks. {202} the effects of crossing is much more strongly stated here than in the _origin_. see ed. i. p. 20, vi. p. 23, where indeed the opposite point of view is given. his change of opinion may be due to his work on pigeons. the whole of the discussion on crossing corresponds to chapter viii of the _origin_, ed. i. rather than to anything in the earlier part of the book. {203} the parallelism between the effects of a cross and the effects of conditions is given from a different point of view in the _origin_, ed. i. p. 266, vi. p. 391. see the experimental evidence for this important principle in the author's work on _cross and self-fertilisation_. professor bateson has suggested that the experiments should be repeated with gametically pure plants. although intermediate and new races may be formed by the mingling of others, yet if the two races are allowed to mingle quite freely, so that none of either parent race remain pure, then, especially if the parent races are not widely different, they will slowly blend together, and the two races will be destroyed, and one mongrel race left in its place. this will of course happen in a shorter time, if one of the parent races exists in greater number than the other. we see the effect of this mingling, in the manner in which the aboriginal breeds of dogs and pigs in the oceanic islands and the many breeds of our domestic animals introduced into s. america, have all been lost and absorbed in a mongrel race. it is probably owing to the freedom of crossing, that, in uncivilised countries, where inclosures do not exist, we seldom meet with more than one race of a species: it is only in enclosed countries, where the inhabitants do not migrate, and have conveniences for separating the several kinds of domestic animals, that we meet with a multitude of races. even in civilised countries, want of care for a few years has been found to destroy the good results of far longer periods of selection and separation. this power of crossing will affect the races of all _terrestrial_ animals; for all terrestrial animals require for their reproduction the union of two individuals. amongst plants, races will not cross and blend together with so much freedom as in terrestrial animals; but this crossing takes place through various curious contrivances to a surprising extent. in fact such contrivances exist in so very many hermaphrodite flowers by which an occasional cross may take place, that i cannot avoid suspecting (with mr knight) that the reproductive action requires, at _intervals_, the concurrence of distinct individuals{204}. most breeders of plants and animals are firmly convinced that benefit is derived from an occasional cross, not with another race, but with another family of the same race; and that, on the other hand, injurious consequences follow from long-continued close interbreeding in the same family. of marine animals, many more, than was till lately believed, have their sexes on separate individuals; and where they are hermaphrodite, there seems very generally to be means through the water of one individual occasionally impregnating another: if individual animals can singly propagate themselves for perpetuity, it is unaccountable that no terrestrial animal, where the means of observation are more obvious, should be in this predicament of singly perpetuating its kind. i conclude, then, that races of most animals and plants, when unconfined in the same country, would tend to blend together. {204} the so-called knight-darwin law is often misunderstood. see goebel in _darwin and modern science_, 1909, p. 419; also f. darwin, _nature_, oct. 27, 1898. _whether our domestic races have descended from one or more wild stocks._ several naturalists, of whom pallas{205} regarding animals, and humboldt regarding certain plants, were the first, believe that the breeds of many of our domestic animals such as of the horse, pig, dog, sheep, pigeon, and poultry, and of our plants have descended from more than one aboriginal form. they leave it doubtful, whether such forms are to be considered wild races, or true species, whose offspring are fertile when crossed _inter se_. the main arguments for this view consist, firstly, of the great difference between such breeds, as the race-and cart-horse, or the greyhound and bull-dog, and of our ignorance of the steps or stages through which these could have passed from a common parent; and secondly that in the most ancient historical periods, breeds resembling some of those at present most different, existed in different countries. the wolves of n. america and of siberia are thought to be different species; and it has been remarked that the dogs belonging to the savages in these two countries resemble the wolves of the same country; and therefore that they have probably descended from two different wild stocks. in the same manner, these naturalists believe that the horse of arabia and of europe have probably descended from two wild stocks both apparently now extinct. i do not think the assumed fertility of these wild stocks any very great difficulty on this view; for although in animals the offspring of most cross-bred species are infertile, it is not always remembered that the experiment is very seldom fairly tried, except when two near species _both_ breed freely (which does not readily happen, as we shall hereafter see) when under the dominion of man. moreover in the case of the china{206} and common goose, the canary and siskin, the hybrids breed freely; in other cases the offspring from hybrids crossed with either pure parent are fertile, as is practically taken advantage of with the yak and cow; as far as the analogy of plants serves, it is impossible to deny that some species are quite fertile _inter se_; but to this subject we shall recur. {205} pallas' theory is discussed in the _origin_, ed. i. pp. 253, 254, vi. p. 374. {206} see darwin's paper on the fertility of hybrids from the common and chinese goose in _nature_, jan. 1, 1880. on the other hand, the upholders of the view that the several breeds of dogs, horses, &c., &c., have descended each from one stock, may aver that their view removes all _difficulty about fertility_, and that the main argument from the high antiquity of different breeds, somewhat similar to the present breeds, is worth little without knowing the date of the domestication of such animals, which is far from being the case. they may also with more weight aver that, knowing that organic beings under domestication do vary in some degree, the argument from the great difference between certain breeds is worth nothing, without we know the limits of variation during a long course of time, which is far from the case. they may argue that almost every county in england, and in many districts of other countries, for instance in india, there are slightly different breeds of the domestic animals; and that it is opposed to all that we know of the distribution of wild animals to suppose that these have descended from so many different wild races or species: if so, they may argue, is it not probable that countries quite separate and exposed to different climates would have breeds not slightly, but considerably, different? taking the most favourable case, on both sides, namely that of the dog; they might urge that such breeds as the bull-dog and turnspit have been reared by man, from the ascertained fact that strictly analogous breeds (namely the niata ox and ancon sheep) in other quadrupeds have thus originated. again they may say, seeing what training and careful selection has effected for the greyhound, and seeing how absolutely unfit the italian greyhound is to maintain itself in a state of nature, is it not probable that at least all greyhounds,--from the rough deerhound, the smooth persian, the common english, to the italian,--have descended from one stock{207}? if so, is it so improbable that the deerhound and long-legged shepherd dog have so descended? if we admit this, and give up the bull-dog, we can hardly dispute the probable common descent of the other breeds. {207} _origin_, ed. i. p. 19, vi. p. 22. the evidence is so conjectural and balanced on both sides that at present i conceive that no one can decide: for my own part, i lean to the probability of most of our domestic animals having descended from more than one wild stock; though from the arguments last advanced and from reflecting on the slow though inevitable effect of different races of mankind, under different circumstances, saving the lives of and therefore selecting the individuals most useful to them, i cannot doubt but that one class of naturalists have much overrated the probable number of the aboriginal wild stocks. as far as we admit the difference of our races due to the differences of their original stocks, so much must we give up of the amount of variation produced under domestication. but this appears to me unimportant, for we certainly know in some few cases, for instance in the dahlia, and potato, and rabbit, that a great number of varieties have proceeded from one stock; and, in many of our domestic races, we know that man, by slowly selecting and by taking advantage of sudden sports, has considerably modified old races and produced new ones. whether we consider our races as the descendants of one or several wild stocks, we are in far the greater number of cases equally ignorant what these stocks were. _limits to variation in degree and kind._ man's power in making races deends, in the first instance, on the stock on which he works being variable; but his labours are modified and limited, as we have seen, by the direct effects of the external conditions,--by the deficient or imperfect hereditariness of new peculiarities,--and by the tendency to continual variation and especially to reversion to ancestral forms. if the stock is not variable under domestication, of course he can do nothing; and it appears that species differ considerably in this tendency to variation, in the same way as even sub-varieties from the same variety differ greatly in this respect, and transmit to their offspring this difference in tendency. whether the absence of a tendency to vary is an unalterable quality in certain species, or depends on some deficient condition of the particular state of domestication to which they are exposed, there is no evidence. when the organization is rendered variable, or plastic, as i have expressed it, under domestication, different parts of the frame vary more or less in different species: thus in the breeds of cattle it has been remarked that the horns are the most constant or least variable character, for these often remain constant, whilst the colour, size, proportions of the body, tendency to fatten &c., vary; in sheep, i believe, the horns are much more variable. as a general rule the less important parts of the organization seem to vary most, but i think there is sufficient evidence that every part occasionally varies in a slight degree. even when man has the primary requisite variability he is necessarily checked by the health and life of the stock he is working on: thus he has already made pigeons with such small beaks that they can hardly eat and will not rear their own young; he has made families of sheep with so strong a tendency to early maturity and to fatten, that in certain pastures they cannot live from their extreme liability to inflammation; he has made (_i.e._ selected) sub-varieties of plants with a tendency to such early growth that they are frequently killed by the spring frosts; he has made a breed of cows having calves with such large hinder quarters that they are born with great difficulty, often to the death of their mothers{208}; the breeders were compelled to remedy this by the selection of a breeding stock with smaller hinder quarters; in such a case, however, it is possible by long patience and great loss, a remedy might have been found in selecting cows capable of giving birth to calves with large hinder quarters, for in human kind there no doubt hereditary bad and good confinements. besides the limits already specified, there can be little doubt that the variation of different parts of the frame are connected together by many laws{209}: thus the two sides of the body, in health and disease, seem almost always to vary together: it has been asserted by breeders that if the head is much elongated, the bones of the extremities will likewise be so; in seedling-apples large leaves and fruit generally go together, and serve the horticulturalist as some guide in his selection; we can here see the reason, as the fruit is only a metamorphosed leaf. in animals the teeth and hair seem connected, for the hairless chinese dog is almost toothless. breeders believe that one part of the frame or function being increased causes other parts to decrease: they dislike great horns and great bones as so much flesh lost; in hornless breeds of cattle certain bones of the head become more developed: it is said that fat accumulating in one part checks its accumulation in another, and likewise checks the action of the udder. the whole organization is so connected that it is probable there are many conditions determining the variation of each part, and causing other parts to vary with it; and man in making new races must be limited and ruled by all such laws. {208} _var. under dom._, ed. ii. vol. ii. p. 211. {209} this discussion corresponds to the _origin_, ed. i. pp. 11 and 143, vi. pp. 13 and 177. _in what consists domestication._ in this chapter we have treated of variation under domestication, and it now remains to consider in what does this power of domestication consist{210}, a subject of considerable difficulty. observing that organic beings of almost every class, in all climates, countries, and times, have varied when long bred under domestication, we must conclude that the influence is of some very general nature{211}. mr knight alone, as far as i know, has tried to define it; he believes it consists of an excess of food, together with transport to a more genial climate, or protection from its severities. i think we cannot admit this latter proposition, for we know how many vegetable products, aborigines of this country, here vary, when cultivated without any protection from the weather; and some of our variable trees, as apricots, peaches, have undoubtedly been derived from a more genial climate. there appears to be much more truth in the doctrine of excess of food being the cause, though i much doubt whether this is the sole cause, although it may well be requisite for the kind of variation desired by man, namely increase of size and vigour. no doubt horticulturalists, when they wish to raise new seedlings, often pluck off all the flower-buds, except a few, or remove the whole during one season, so that a great stock of nutriment may be thrown into the flowers which are to seed. when plants are transported from high-lands, forests, marshes, heaths, into our gardens and greenhouses, there must be a considerable change of food, but it would be hard to prove that there was in every case an excess of the kind proper to the plant. if it be an excess of food, compared with that which the being obtained in its natural state{212}, the effects continue for an improbably long time; during how many ages has wheat been cultivated, and cattle and sheep reclaimed, and we cannot suppose their _amount_ of food has gone on increasing, nevertheless these are amongst the most variable of our domestic productions. it has been remarked (marshall) that some of the most highly kept breeds of sheep and cattle are truer or less variable than the straggling animals of the poor, which subsist on commons, and pick up a bare subsistence{213}. in the case of forest-trees raised in nurseries, which vary more than the same trees do in their aboriginal forests, the cause would seem simply to lie in their not having to struggle against other trees and weeds, which in their natural state doubtless would limit the conditions of their existence. it appears to me that the power of domestication resolves itself into the accumulated effects of a change of all or some of the natural conditions of the life of the species, often associated with excess of food. these conditions moreover, i may add, can seldom remain, owing to the mutability of the affairs, habits, migrations, and knowledge of man, for very long periods the same. i am the more inclined to come to this conclusion from finding, as we shall hereafter show, that changes of the natural conditions of existence seem peculiarly to affect the action of the reproductive system{214}. as we see that hybrids and mongrels, after the first generation, are apt to vary much, we may at least conclude that variability does not altogether depend on excess of food. {210} see _origin_, ed. i. p. 7, vi. p. 7. {211} "isidore g. st hilaire insists that breeding in captivity essential element. schleiden on alkalies. what is it in domestication which causes variation?" {212} "it appears that slight changes of condition good for health; that more change affects the generative system, so that variation results in the offspring; that still more change checks or destroys fertility not of the offspring." compare the _origin_, ed. i. p. 9, vi. p. 11. what the meaning of "not of the offspring" may be is not clear. {213} in the _origin_, ed. i. p. 41, vi. p. 46 the question is differently treated; it is pointed out that a large stock of individuals gives a better chance of available variations occurring. darwin quotes from marshall that sheep in small lots can never be improved. this comes from marshall's _review of the reports to the board of agriculture_, 1808, p. 406. in this essay the name marshall occurs in the margin. probably this refers to _loc. cit._ p. 200, where unshepherded sheep in many parts of england are said to be similar owing to mixed breeding not being avoided. {214} see _origin_, ed. i. p. 8, vi. p. 8. after these views, it may be asked how it comes that certain animals and plants, which have been domesticated for a considerable length of time, and transported from very different conditions of existence, have not varied much, or scarcely at all; for instance, the ass, peacock, guinea-fowl, asparagus, jerusalem artichoke{215}. i have already said that probably different species, like different sub-varieties, possess different degrees of tendency to vary; but i am inclined to attribute in these cases the want of numerous races less to want of variability than to selection not having been practised on them. no one will take the pains to select without some corresponding object, either of use or amusement; the individuals raised must be tolerably numerous, and not so precious, but that he may freely destroy those not answering to his wishes. if guinea-fowls or peacocks{216} became "fancy" birds, i cannot doubt that after some generations several breeds would be raised. asses have not been worked on from mere neglect; but they differ in _some_ degree in different countries. the insensible selection, due to different races of mankind preserving those individuals most useful to them in their different circumstances, will apply only to the oldest and most widely domesticated animals. in the case of plants, we must put entirely out of the case those exclusively (or almost so) propagated by cuttings, layers or tubers, such as the jerusalem artichoke and laurel; and if we put on one side plants of little ornament or use, and those which are used at so early a period of their growth that no especial characters signify, as asparagus{217} and seakale, i can think of none long cultivated which have not varied. in no case ought we to expect to find as much variation in a race when it alone has been formed, as when several have been formed, for their crossing and recrossing will greatly increase their variability. {215} see _origin_, ed. i. p. 42, vi. p. 48. {216} there are white peacocks. {217} there are varieties of asparagus. _summary of first chapter._ to sum up this chapter. races are made under domestication: 1st, by the direct effects of the external conditions to which the species is exposed: 2nd, by the indirect effects of the exposure to new conditions, often aided by excess of food, rendering the organization plastic, and by man's selecting and separately breeding certain individuals, or introducing to his stock selected males, or often preserving with care the life of the individuals best adapted to his purposes: 3rd, by crossing and recrossing races already made, and selecting their offspring. after some generations man may relax his care in selection: for the tendency to vary and to revert to ancestral forms will decrease, so that he will have only occasionally to remove or destroy one of the yearly offspring which departs from its type. ultimately, with a large stock, the effects of free crossing would keep, even without this care, his breed true. by these means man can produce infinitely numerous races, curiously adapted to ends, both most important and most frivolous; at the same time that the effects of the surrounding conditions, the laws of inheritance, of growth, and of variation, will modify and limit his labours. chapter ii on the variation of organic beings in a wild state; on the natural means of selection; and on the comparison of domestic races and true species having treated of variation under domestication, we now come to it in a _state of nature_. most organic beings in a state of nature vary exceedingly little{218}: i put out of the case variations (as stunted plants &c., and sea-shells in brackish water{219}) which are directly the effect of external agencies and which we do not _know are in the breed_{220}, or are _hereditary_. the amount of hereditary variation is very difficult to ascertain, because naturalists (partly from the want of knowledge, and partly from the inherent difficulty of the subject) do not all agree whether certain forms are species or races{221}. some strongly marked races of plants, comparable with the decided sports of horticulturalists, undoubtedly exist in a state of nature, as is actually known by experiment, for instance in the primrose and cowslip{222}, in two so-called species of dandelion, in two of foxglove{223}, and i believe in some pines. lamarck has observed that, as long as we confine our attention to one limited country, there is seldom much difficulty in deciding what forms to call species and what varieties; and that it is when collections flow in from all parts of the world that naturalists often feel at a loss to decide the limit of variation. undoubtedly so it is, yet amongst british plants (and i may add land shells), which are probably better known than any in the world, the best naturalists differ very greatly in the relative proportions of what they call species and what varieties. in many genera of insects, and shells, and plants, it seems almost hopeless to establish which are which. in the higher classes there are less doubts; though we find considerable difficulty in ascertaining what deserve to be called species amongst foxes and wolves, and in some birds, for instance in the case of the white barn-owl. when specimens are brought from different parts of the world, how often do naturalists dispute this same question, as i found with respect to the birds brought from the galapagos islands. yarrell has remarked that the individuals of the same undoubted species of birds, from europe and n. america, usually present slight, indefinable though perceptible differences. the recognition indeed of one animal by another of its kind seems to imply some difference. the disposition of wild animals undoubtedly differs. the variation, such as it is, chiefly affects the same parts in wild organisms as in domestic breeds; for instance, the size, colour, and the external and less important parts. in many species the variability of certain organs or qualities is even stated as one of the specific characters: thus, in plants, colour, size, hairiness, the number of the stamens and pistils, and even their presence, the form of the leaves; the size and form of the mandibles of the males of some insects; the length and curvature of the beak in some birds (as in opetiorynchus) are variable characters in some species and quite fixed in others. i do not perceive that any just distinction can be drawn between this recognised variability of certain parts in many species and the more general variability of the whole frame in domestic races. {218} in chapter ii of the first edition of the _origin_ darwin insists rather on the presence of variability in a state of nature; see, for instance, p. 45, ed. vi. p. 53, "i am convinced that the most experienced naturalist would be surprised at the number of the cases of variability ... which he could collect on good authority, as i have collected, during a course of years." {219} see _origin_, ed. i. p. 44, vi. p. 52. {220} here discuss _what is a species_, sterility can most rarely be told when crossed.--descent from common stock. {221} give only rule: chain of intermediate forms, and _analogy_; this important. every naturalist at first when he gets hold of new variable type is _quite puzzled_ to know what to think species and what variations. {222} the author had not at this time the knowledge of the meaning of dimorphism. {223} compare feathered heads in very different birds with spines in echidna and hedgehog. plants under very different climate not varying. digitalis shows jumps > in variation, like laburnum and orchis case--in fact hostile cases. variability of sexual characters alike in domestic and wild. although the amount of variation be exceedingly small in most organic beings in a state of nature, and probably quite wanting (as far as our senses serve) in the majority of cases; yet considering how many animals and plants, taken by mankind from different quarters of the world for the most diverse purposes, have varied under domestication in every country and in every age, i think we may safely conclude that all organic beings with few exceptions, if capable of being domesticated and bred for long periods, would vary. domestication seems to resolve itself into a change from the natural conditions of the species [generally perhaps including an increase of food]; if this be so, organisms in a state of nature must _occasionally_, in the course of ages, be exposed to analogous influences; for geology clearly shows that many places must, in the course of time, become exposed to the widest range of climatic and other influences; and if such places be isolated, so that new and better adapted organic beings cannot freely emigrate, the old inhabitants will be exposed to new influences, probably far more varied, than man applies under the form of domestication. although every species no doubt will soon breed up to the full number which the country will support, yet it is easy to conceive that, on an average, some species may receive an increase of food; for the times of dearth may be short, yet enough to kill, and recurrent only at long intervals. all such changes of conditions from geological causes would be exceedingly slow; what effect the slowness might have we are ignorant; under domestication it appears that the effects of change of conditions accumulate, and then break out. whatever might be the result of these slow geological changes, we may feel sure, from the means of dissemination common in a lesser or greater degree to every organism taken conjointly with the changes of geology, which are steadily (and sometimes suddenly, as when an isthmus at last separates) in progress, that occasionally organisms must suddenly be introduced into new regions, where, if the conditions of existence are not so foreign as to cause its extermination, it will often be propagated under circumstances still more closely analogous to those of domestication; and therefore we expect will evince a tendency to vary. it appears to me quite _inexplicable_ if this has never happened; but it can happen very rarely. let us then suppose that an organism by some chance (which might be hardly repeated in 1000 years) arrives at a modern volcanic island in process of formation and not fully stocked with the most appropriate organisms; the new organism might readily gain a footing, although the external conditions were considerably different from its native ones. the effect of this we might expect would influence in some small degree the size, colour, nature of covering &c., and from inexplicable influences even special parts and organs of the body. but we might further (and is far more important) expect that the reproductive system would be affected, as under domesticity, and the structure of the offspring rendered in some degree plastic. hence almost every part of the body would tend to vary from the typical form in slight degrees, and in no determinate way, and therefore _without selection_ the free crossing of these small variations (together with the tendency to reversion to the original form) would constantly be counteracting this unsettling effect of the extraneous conditions on the reproductive system. such, i conceive, would be the unimportant result without selection. and here i must observe that the foregoing remarks are equally applicable to that small and admitted amount of variation which has been observed in some organisms in a state of nature; as well as to the above hypothetical variation consequent on changes of condition. let us now suppose a being{224} with penetration sufficient to perceive differences in the outer and innermost organization quite imperceptible to man, and with forethought extending over future centuries to watch with unerring care and select for any object the offspring of an organism produced under the foregoing circumstances; i can see no conceivable reason why he could not form a new race (or several were he to separate the stock of the original organism and work on several islands) adapted to new ends. as we assume his discrimination, and his forethought, and his steadiness of object, to be incomparably greater that those qualities in man, so we may suppose the beauty and complications of the adaptations of the new races and their differences from the original stock to be greater than in the domestic races produced by man's agency: the ground-work of his labours we may aid by supposing that the external conditions of the volcanic island, from its continued emergence and the occasional introduction of new immigrants, vary; and thus to act on the reproductive system of the organism, on which he is at work, and so keep its organization somewhat plastic. with time enough, such a being might rationally (without some unknown law opposed him) aim at almost any result. {224} a corresponding passage occurs in _origin_, ed. i. p. 83, vi. p. 101, where however nature takes the place of the selecting being. for instance, let this imaginary being wish, from seeing a plant growing on the decaying matter in a forest and choked by other plants, to give it power of growing on the rotten stems of trees, he would commence selecting every seedling whose berries were in the smallest degree more attractive to tree-frequenting birds, so as to cause a proper dissemination of the seeds, and at the same time he would select those plants which had in the slightest degree more and more power of drawing nutriment from rotten wood; and he would destroy all other seedlings with less of this power. he might thus, in the course of century after century, hope to make the plant by degrees grow on rotten wood, even high up on trees, wherever birds dropped the non-digested seeds. he might then, if the organization of the plant was plastic, attempt by continued selection of chance seedlings to make it grow on less and less rotten wood, till it would grow on sound wood{225}. supposing again, during these changes the plant failed to seed quite freely from non-impregnation, he might begin selecting seedlings with a little sweeter differently tasted honey or pollen, to tempt insects to visit the flowers regularly: having effected this, he might wish, if it profited the plant, to render abortive the stamens and pistils in different flowers, which he could do by continued selection. by such steps he might aim at making a plant as wonderfully related to other organic beings as is the mistletoe, whose existence absolutely depends on certain insects for impregnation, certain birds for transportal, and certain trees for growth. furthermore, if the insect which had been induced regularly to visit this hypothetical plant profited much by it, our same being might wish by selection to modify by gradual selection the insect's structure, so as to facilitate its obtaining the honey or pollen: in this manner he might adapt the insect (always presupposing its organization to be in some degree plastic) to the flower, and the impregnation of the flower to the insect; as is the case with many bees and many plants. {225} the mistletoe is used as an illustration in _origin_, ed. i. p. 3, vi. p. 3, but with less detail. seeing what blind capricious man has actually effected by selection during the few last years, and what in a ruder state he has probably effected without any systematic plan during the last few thousand years, he will be a bold person who will positively put limits to what the supposed being could effect during whole geological periods. in accordance with the plan by which this universe seems governed by the creator, let us consider whether there exists any _secondary_ means in the economy of nature by which the process of selection could go on adapting, nicely and wonderfully, organisms, if in ever so small a degree plastic, to diverse ends. i believe such secondary means do exist{226}. {226} the selection, in cases where adult lives only few hours as ephemera, must fall on larva--curious speculation of the effect changes in it would bring in parent. _natural means of selection{227}._ {227} this section forms part of the joint paper by darwin and wallace read before the linnean society on july 1, 1858. de candolle, in an eloquent passage, has declared that all nature is at war, one organism with another, or with external nature. seeing the contented face of nature, this may at first be well doubted; but reflection will inevitably prove it is too true. the war, however, is not constant, but only recurrent in a slight degree at short periods and more severely at occasional more distant periods; and hence its effects are easily overlooked. it is the doctrine of malthus applied in most cases with ten-fold force. as in every climate there are seasons for each of its inhabitants of greater and less abundance, so all annually breed; and the moral restraint, which in some small degree checks the increase of mankind, is entirely lost. even slow-breeding mankind has doubled in 25 years{228}, and if he could increase his food with greater ease, he would double in less time. but for animals, without artificial means, _on an average_ the amount of food for each species must be constant; whereas the increase of all organisms tends to be geometrical, and in a vast majority of cases at an enormous ratio. suppose in a certain spot there are eight pairs of [robins] birds, and that _only_ four pairs of them annually (including double hatches) rear only four young; and that these go on rearing their young at the same rate: then at the end of seven years (a short life, excluding violent deaths, for any birds) there will be 2048 robins, instead of the original sixteen; as this increase is quite impossible, so we must conclude either that robins do not rear nearly half their young or that the average life of a robin when reared is from accident not nearly seven years. both checks probably concur. the same kind of calculation applied to all vegetables and animals produces results either more or less striking, but in scarcely a single instance less striking than in man{229}. {228} occurs in _origin_, ed. i. p. 64, vi. p. 79. {229} corresponds approximately with _origin_, ed. i. pp. 64-65, vi. p. 80. many practical illustrations of this rapid tendency to increase are on record, namely during peculiar seasons, in the extraordinary increase of certain animals, for instance during the years 1826 to 1828, in la plata, when from drought, some millions of cattle perished, the whole country _swarmed_ with innumerable mice: now i think it cannot be doubted that during the breeding season all the mice (with the exception of a few males or females in excess) ordinarily pair; and therefore that this astounding increase during three years must be attributed to a greater than usual number surviving the first year, and then breeding, and so on, till the third year, when their numbers were brought down to their usual limits on the return of wet weather. where man has introduced plants and animals into a new country favourable to them, there are many accounts in how surprisingly few years the whole country has become stocked with them. this increase would necessarily stop as soon as the country was fully stocked; and yet we have every reason to believe from what is known of wild animals that _all_ would pair in the spring. in the majority of cases it is most difficult to imagine where the check falls, generally no doubt on the seeds, eggs, and young; but when we remember how impossible even in mankind (so much better known than any other animal) it is to infer from repeated casual observations what the average of life is, or to discover how different the percentage of deaths to the births in different countries, we ought to feel no legitimate surprise at not seeing where the check falls in animals and plants. it should always be remembered that in most cases the checks are yearly recurrent in a small regular degree, and in an extreme degree during occasionally unusually cold, hot, dry, or wet years, according to the constitution of the being in question. lighten any check in the smallest degree, and the geometrical power of increase in every organism will instantly increase the average numbers of the favoured species. nature may be compared to a surface, on which rest ten thousand sharp wedges touching each other and driven inwards by incessant blows{230}. fully to realise these views much reflection is requisite; malthus on man should be studied; and all such cases as those of the mice in la plata, of the cattle and horses when first turned out in s. america, of the robins by our calculation, &c., should be well considered: reflect on the enormous multiplying power _inherent and annually in action_ in all animals; reflect on the countless seeds scattered by a hundred ingenious contrivances, year after year, over the whole face of the land; and yet we have every reason to suppose that the average percentage of every one of the inhabitants of a country will _ordinarily_ remain constant. finally, let it be borne in mind that this average number of individuals (the external conditions remaining the same) in each country is kept up by recurrent struggles against other species or against external nature (as on the borders of the arctic regions{231}, where the cold checks life); and that ordinarily each individual of each species holds its place, either by its own struggle and capacity of acquiring nourishment in some period (from the egg upwards) of its life, or by the struggle of its parents (in short lived organisms, when the main check occurs at long intervals) against and compared with other individuals of the _same_ or _different_ species. {230} this simile occurs in _origin_, ed. i. p. 67, not in the later editions. {231} in case like mistletoe, it may be asked why not more species, no other species interferes; answer almost sufficient, same causes which check the multiplication of individuals. but let the external conditions of a country change; if in a small degree, the relative proportions of the inhabitants will in most cases simply be slightly changed; but let the number of inhabitants be small, as in an island{232}, and free access to it from other countries be circumscribed; and let the change of condition continue progressing (forming new stations); in such case the original inhabitants must cease to be so perfectly adapted to the changed conditions as they originally were. it has been shown that probably such changes of external conditions would, from acting on the reproductive system, cause the organization of the beings most affected to become, as under domestication, plastic. now can it be doubted from the struggle each individual (or its parents) has to obtain subsistence that any minute variation in structure, habits, or instincts, adapting that individual better to the new conditions, would tell upon its vigour and health? in the struggle it would have a better _chance_ of surviving, and those of its offspring which inherited the variation, let it be ever so slight, would have a better _chance_ to survive. yearly more are bred than can survive; the smallest grain in the balance, in the long run, must tell on which death shall fall, and which shall survive{233}. let this work of selection, on the one hand, and death on the other, go on for a thousand generations; who would pretend to affirm that it would produce no effect, when we remember what in a few years bakewell effected in cattle and western in sheep, by this identical principle of selection. {232} see _origin_, ed. i. pp. 104, 292, vi. pp. 127, 429. {233} recognition of the importance of minute differences in the struggle occurs in the essay of 1842, p. 8 note 3.{note 59} to give an imaginary example, from changes in progress on an island, let the organization{234} of a canine animal become slightly plastic, which animal preyed chiefly on rabbits, but sometimes on hares; let these same changes cause the number of rabbits very slowly to decrease and the number of hares to increase; the effect of this would be that the fox or dog would be driven to try to catch more hares, and his numbers would tend to decrease; his organization, however, being slightly plastic, those individuals with the lightest forms, longest limbs, and best eye-sight (though perhaps with less cunning or scent) would be slightly favoured, let the difference be ever so small, and would tend to live longer and to survive during that time of the year when food was shortest; they would also rear more young, which young would tend to inherit these slight peculiarities. the less fleet ones would be rigidly destroyed. i can see no more reason to doubt but that these causes in a thousand generations would produce a marked effect, and adapt the form of the fox to catching hares instead of rabbits, than that greyhounds can be improved by selection and careful breeding. so would it be with plants under similar circumstances; if the number of individuals of a species with plumed seeds could be increased by greater powers of dissemination within its own area (that is if the check to increase fell chiefly on the seeds), those seeds which were provided with ever so little more down, or with a plume placed so as to be slightly more acted on by the winds, would in the long run tend to be most disseminated; and hence a greater number of seeds thus formed would germinate, and would tend to produce plants inheriting this slightly better adapted down. {234} see _origin_, ed. i. p. 90, vi. p. 110. besides this natural means of selection, by which those individuals are preserved, whether in their egg or seed or in their mature state, which are best adapted to the place they fill in nature, there is a second agency at work in most bisexual animals tending to produce the same effect, namely the struggle of the males for the females. these struggles are generally decided by the law of battle; but in the case of birds, apparently, by the charms of their song{235}, by their beauty or their power of courtship, as in the dancing rock-thrush of guiana. even in the animals which pair there seems to be an excess of males which would aid in causing a struggle: in the polygamous animals{236}, however, as in deer, oxen, poultry, we might expect there would be severest struggle: is it not in the polygamous animals that the males are best formed for mutual war? the most vigorous males, implying perfect adaptation, must generally gain the victory in their several contests. this kind of selection, however, is less rigorous than the other; it does not require the death of the less successful, but gives to them fewer descendants. this struggle falls, moreover, at a time of year when food is generally abundant, and perhaps the effect chiefly produced would be the alteration of sexual characters, and the selection of individual forms, no way related to their power of obtaining food, or of defending themselves from their natural enemies, but of fighting one with another. this natural struggle amongst the males may be compared in effect, but in a less degree, to that produced by those agriculturalists who pay less attention to the careful selection of all the young animals which they breed and more to the occasional use of a choice male{237}. {235} these two forms of sexual selection are given in _origin_, ed. i. p. 87, vi. p. 107. the guiana rock-thrush is given as an example of bloodless competition. {236} seals? pennant about battles of seals. {237} in the linnean paper of july 1, 1858 the final word is _mate_: but the context shows that it should be _male_; it is moreover clearly so written in the ms. _differences between "races" and "species":--first, in their trueness or variability._ races{238} produced by these natural means of selection{239} we may expect would differ in some respects from those produced by man. man selects chiefly by the eye, and is not able to perceive the course of every vessel and nerve, or the form of the bones, or whether the internal structure corresponds to the outside shape. he{240} is unable to select shades of constitutional differences, and by the protection he affords and his endeavours to keep his property alive, in whatever country he lives, he checks, as much as lies in his power, the selecting action of nature, which will, however, go on to a lesser degree with all living things, even if their length of life is not determined by their own powers of endurance. he has bad judgment, is capricious, he does not, or his successors do not, wish to select for the same exact end for hundreds of generations. he cannot always suit the selected form to the properest conditions; nor does he keep those conditions uniform: he selects that which is useful to him, not that best adapted to those conditions in which each variety is placed by him: he selects a small dog, but feeds it highly; he selects a long-backed dog, but does not exercise it in any peculiar manner, at least not during every generation. he seldom allows the most vigorous males to struggle for themselves and propagate, but picks out such as he possesses, or such as he prefers, and not necessarily those best adapted to the existing conditions. every agriculturalist and breeder knows how difficult it is to prevent an occasional cross with another breed. he often grudges to destroy an individual which departs considerably from the required type. he often begins his selection by a form or sport considerably departing from the parent form. very differently does the natural law of selection act; the varieties selected differ only slightly from the parent forms{241}; the conditions are constant for long periods and change slowly; rarely can there be a cross; the selection is rigid and unfailing, and continued through many generations; a selection can _never be made_ without the form be _better_ adapted to the conditions than the parent form; the selecting power goes on without caprice, and steadily for thousands of years adapting the form to these conditions. the selecting power is not deceived by external appearances, it tries the being during its whole life; and if less well > adapted than its _congeners_, without fail it is destroyed; every part of its structure is thus scrutinised and proved good towards the place in nature which it occupies. {238} in the _origin_ the author would here have used the word _variety_. {239} the whole of p. 94 and 15 lines of p. 95 are, in the ms., marked through in pencil with vertical lines, beginning at "races produced, &c." and ending with "to these conditions." {240} see _origin_, ed. i. p. 83, vi. p. 102. {241} in the present essay there is some evidence that the author attributed more to _sports_ than was afterwards the case: but the above passage points the other way. it must always be remembered that many of the minute differences, now considered small mutations, are the small variations on which darwin conceived selection to act. we have every reason to believe that in proportion to the number of generations that a domestic race is kept free from crosses, and to the care employed in continued steady selection with one end in view, and to the care in not placing the variety in conditions unsuited to it; in such proportion does the new race become "true" or subject to little variation{242}. how incomparably "truer" then would a race produced by the above rigid, steady, natural means of selection, excellently trained and perfectly adapted to its conditions, free from stains of blood or crosses, and continued during thousands of years, be compared with one produced by the feeble, capricious, misdirected and ill-adapted selection of man. those races of domestic animals produced by savages, partly by the inevitable conditions of their life, and partly unintentionally by their greater care of the individuals most valuable to them, would probably approach closest to the character of a species; and i believe this is the case. now the characteristic mark of a species, next, if not equal in importance to its sterility when crossed with another species, and indeed almost the only other character (without we beg the question and affirm the essence of a species, is its not having descended from a parent common to any other form), is the similarity of the individuals composing the species, or in the language of agriculturalists their "trueness." {242} see _var. under dom._, ed. ii. vol. ii. p. 230. _difference between "races" and "species" in fertility when crossed._ the sterility of species, or of their offspring, when crossed has, however, received more attention than the uniformity in character of the individuals composing the species. it is exceedingly natural that such sterility{243} should have been long thought the certain characteristic of species. for it is obvious that if the allied different forms which we meet with in the same country could cross together, instead of finding a number of distinct species, we should have a confused and blending series. the fact however of a perfect gradation in the degree of sterility between species, and the circumstance of some species most closely allied (for instance many species of crocus and european heaths) refusing to breed together, whereas other species, widely different, and even belonging to distinct genera, as the fowl and the peacock, pheasant and grouse{244}, azalea and rhododendron, thuja and juniperus, breeding together ought to have caused a doubt whether the sterility did not depend on other causes, distinct from a law, coincident with their creation. i may here remark that the fact whether one species will or will not breed with another is far less important than the sterility of the offspring when produced; for even some domestic races differ so greatly in size (as the great stag-greyhound and lap-dog, or cart-horse and burmese ponies) that union is nearly impossible; and what is less generally known is, that in plants kölreuter has shown by hundreds of experiments that the pollen of one species will fecundate the germen of another species, whereas the pollen of this latter will never act on the germen of the former; so that the simple fact of mutual impregnation certainly has no relation whatever to the distinctness in creation of the two forms. when two species are attempted to be crossed which are so distantly allied that offspring are never produced, it has been observed in some cases that the pollen commences its proper action by exserting its tube, and the germen commences swelling, though soon afterwards it decays. in the next stage in the series, hybrid offspring are produced though only rarely and few in number, and these are absolutely sterile: then we have hybrid offspring more numerous, and occasionally, though very rarely, breeding with either parent, as is the case with the common mule. again, other hybrids, though infertile _inter se_, will breed _quite_ freely with either parent, or with a third species, and will yield offspring generally infertile, but sometimes fertile; and these latter again will breed with either parent, or with a third or fourth species: thus kölreuter blended together many forms. lastly it is now admitted by those botanists who have longest contended against the admission, that in certain families the hybrid offspring of many of the species are sometimes perfectly fertile in the first generation when bred together: indeed in some few cases mr herbert{245} found that the hybrids were decidedly more fertile than either of their pure parents. there is no way to escape from the admission that the hybrids from some species of plants are fertile, except by declaring that no form shall be considered as a species, if it produces with another species fertile offspring: but this is begging the question{246}. it has often been stated that different species of animals have a sexual repugnance towards each other; i can find no evidence of this; it appears as if they merely did not excite each others passions. i do not believe that in this respect there is any essential distinction between animals and plants; and in the latter there cannot be a feeling of repugnance. {243} if domestic animals are descended from several species and _become_ fertile _inter se_, then one can see they gain fertility by becoming adapted to new conditions and certainly domestic animals can withstand changes of climate without loss of fertility in an astonishing manner. {244} see suchetet, _l'hybridité dans la nature_, bruxelles, 1888, p. 67. in _var. under dom._, ed. ii. vol. ii. hybrids between the fowl and the pheasant are mentioned. i can give no information on the other cases. {245} _origin_, ed. i. p. 250, vi. p. 370. {246} this was the position of gärtner and of kölreuter: see _origin_, ed. i. pp. 246-7, vi. pp. 367-8. _causes of sterility in hybrids._ the difference in nature between species which causes the greater or lesser degree of sterility in their offspring appears, according to herbert and kölreuter, to be connected much less with external form, size, or structure, than with constitutional peculiarities; by which is meant their adaptation to different climates, food and situation, &c.: these peculiarities of constitution probably affect the entire frame, and no one part in particular{247}. {247} yet this seems introductory to the case of the heaths and crocuses above mentioned. from the foregoing facts i think we must admit that there exists a perfect gradation in fertility between species which when crossed are quite fertile (as in rhododendron, calceolaria, &c.), and indeed in an extraordinary degree fertile (as in crinum), and those species which never produce offspring, but which by certain effects (as the exsertion of the pollen-tube) evince their alliance. hence, i conceive, we must give up sterility, although undoubtedly in a lesser or greater degree of very frequent occurrence, as an unfailing mark by which _species_ can be distinguished from _races_, _i.e._ from those forms which have descended from a common stock. _infertility from causes distinct from hybridisation._ let us see whether there are any analogous facts which will throw any light on this subject, and will tend to explain why the offspring of certain species, when crossed, should be sterile, and not others, without requiring a distinct law connected with their creation to that effect. great numbers, probably a large majority of animals when caught by man and removed from their natural conditions, although taken very young, rendered quite tame, living to a good old age, and apparently quite healthy, seem incapable under these circumstances of breeding{248}. i do not refer to animals kept in menageries, such as at the zoological gardens, many of which, however, appear healthy and live long and unite but do not produce; but to animals caught and left partly at liberty in their native country. rengger{249} enumerates several caught young and rendered tame, which he kept in paraguay, and which would not breed: the hunting leopard or cheetah and elephant offer other instances; as do bears in europe, and the 25 species of hawks, belonging to different genera, thousands of which have been kept for hawking and have lived for long periods in perfect vigour. when the expense and trouble of procuring a succession of young animals in a wild state be borne in mind, one may feel sure that no trouble has been spared in endeavours to make them breed. so clearly marked is this difference in different kinds of animals, when captured by man, that st hilaire makes two great classes of animals useful to man:--the _tame_, which will not breed, and the _domestic_ which will breed in domestication. from certain singular facts we might have supposed that the non-breeding of animals was owing to some perversion of instinct. but we meet with exactly the same class of facts in plants: i do not refer to the large number of cases where the climate does not permit the seed or fruit to ripen, but where the flowers do not "set," owing to some imperfection of the ovule or pollen. the latter, which alone can be distinctly examined, is often manifestly imperfect, as any one with a microscope can observe by comparing the pollen of the persian and chinese lilacs{250} with the common lilac; the two former species (i may add) are equally sterile in italy as in this country. many of the american bog plants here produce little or no pollen, whilst the indian species of the same genera freely produce it. lindley observes that sterility is the bane of the horticulturist{251}: linnæus has remarked on the sterility of nearly all alpine flowers when cultivated in a lowland district{252}. perhaps the immense class of double flowers chiefly owe their structure to an excess of food acting on parts rendered slightly sterile and less capable of performing their true function, and therefore liable to be rendered monstrous, which monstrosity, like any other disease, is inherited and rendered common. so far from domestication being in itself unfavourable to fertility, it is well known that when an organism is once capable of submission to such conditions fertility is increased{253} beyond the natural limit. according to agriculturists, slight changes of conditions, that is of food or habitation, and likewise crosses with races slightly different, increase the vigour and probably the fertility of their offspring. it would appear also that even a great change of condition, for instance, transportal from temperate countries to india, in many cases does not in the least affect fertility, although it does health and length of life and the period of maturity. when sterility is induced by domestication it is of the same kind, and varies in degree, exactly as with hybrids: for be it remembered that the most sterile hybrid is no way monstrous; its organs are perfect, but they do not act, and minute microscopical investigations show that they are in the same state as those of pure species in the intervals of the breeding season. the defective pollen in the cases above alluded to precisely resembles that of hybrids. the occasional breeding of hybrids, as of the common mule, may be aptly compared to the most rare but occasional reproduction of elephants in captivity. the cause of many exotic geraniums producing (although in vigorous health) imperfect pollen seems to be connected with the period when water is given them{254}; but in the far greater majority of cases we cannot form any conjecture on what exact cause the sterility of organisms taken from their natural conditions depends. why, for instance, the cheetah will not breed whilst the common cat and ferret (the latter generally kept shut up in a small box) do,--why the elephant will not whilst the pig will abundantly--why the partridge and grouse in their own country will not, whilst several species of pheasants, the guinea-fowl from the deserts of africa and the peacock from the jungles of india, will. we must, however, feel convinced that it depends on some constitutional peculiarities in these beings not suited to their new condition; though not necessarily causing an ill state of health. ought we then to wonder much that those hybrids which have been produced by the crossing of species with different constitutional tendencies (which tendencies we know to be eminently inheritable) should be sterile: it does not seem improbable that the cross from an alpine and lowland plant should have its constitutional powers deranged, in nearly the same manner as when the parent alpine plant is brought into a lowland district. analogy, however, is a deceitful guide, and it would be rash to affirm, although it may appear probable, that the sterility of hybrids is due to the constitutional peculiarities of one parent being disturbed by being blended with those of the other parent in exactly the same manner as it is caused in some organic beings when placed by man out of their natural conditions{255}. although this would be rash, it would, i think, be still rasher, seeing that sterility is no more incidental to _all_ cross-bred productions than it is to all organic beings when captured by man, to assert that the sterility of certain hybrids proved a distinct creation of their parents. {248} animals seem more often made sterile by being taken out of their native condition than plants, and so are more sterile when crossed. we have one broad fact that sterility in hybrids is not closely related to external difference, and these are what man alone gets by selection. {249} see _var. under dom._, ed. ii. vol. ii. p. 132; for the case of the cheetah see _loc cit._ p. 133. {250} _var. under dom._, ed. ii. vol. ii. p. 148. {251} quoted in the _origin_, ed. i. p. 9. {252} see _var. under dom._, ed. ii. vol. ii. p. 147. {253} _var. under dom._, ed. ii. vol. ii. p. 89. {254} see _var. under dom._, ed. ii. vol. ii. p. 147. {255} _origin_, ed. i. p. 267, vi. p. 392. this is the principle experimentally investigated in the author's _cross-and self-fertilisation_. but it may be objected{256} (however little the sterility of certain hybrids is connected with the distinct creations of species), how comes it, if species are only races produced by natural selection, that when crossed they so frequently produce sterile offspring, whereas in the offspring of those races confessedly produced by the arts of man there is no one instance of sterility. there is not much difficulty in this, for the races produced by the natural means above explained will be slowly but steadily selected; will be adapted to various and diverse conditions, and to these conditions they will be rigidly confined for immense periods of time; hence we may suppose that they would acquire different constitutional peculiarities adapted to the stations they occupy; and on the constitutional differences between species their sterility, according to the best authorities, depends. on the other hand man selects by external appearance{257}; from his ignorance, and from not having any test at least comparable in delicacy to the natural struggle for food, continued at intervals through the life of each individual, he cannot eliminate fine shades of constitution, dependent on invisible differences in the fluids or solids of the body; again, from the value which he attaches to each individual, he asserts his utmost power in contravening the natural tendency of the most vigorous to survive. man, moreover, especially in the earlier ages, cannot have kept his conditions of life constant, and in later ages his stock pure. until man selects two varieties from the same stock, adapted to two climates or to other different external conditions, and confines each rigidly for one or several thousand years to such conditions, always selecting the individuals best adapted to them, he cannot be said to have even commenced the experiment. moreover, the organic beings which man has longest had under domestication have been those which were of the greatest use to him, and one chief element of their usefulness, especially in the earlier ages, must have been their capacity to undergo sudden transportals into various climates, and at the same time to retain their fertility, which in itself implies that in such respects their constitutional peculiarities were not closely limited. if the opinion already mentioned be correct, that most of the domestic animals in their present state have descended from the fertile commixture of wild races or species, we have indeed little reason now to expect infertility between any cross of stock thus descended. {256} _origin_, ed. i. p. 268, vi. p. 398. {257} mere difference of structure no guide to what will or will not cross. first step gained by races keeping apart. it is worthy of remark, that as many organic beings, when taken by man out of their natural conditions, have their reproductive system affected as to be incapable of propagation, so, we saw in the first chapter, that although organic beings when taken by man do propagate freely, their offspring after some generations vary or sport to a degree which can only be explained by their reproductive system being some way affected. again, when species cross, their offspring are generally sterile; but it was found by kölreuter that when hybrids are capable of breeding with either parent, or with other species, that their offspring are subject after some generations to excessive variation{258}. agriculturists, also, affirm that the offspring from mongrels, after the first generation, vary much. hence we see that both sterility and variation in the succeeding generations are consequent both on the removal of individual species from their natural states and on species crossing. the connection between these facts may be accidental, but they certainly appear to elucidate and support each other,--on the principle of the reproductive system of all organic beings being eminently sensitive to any disturbance, whether from removal or commixture, in their constitutional relations to the conditions to which they are exposed. {258} _origin_, ed. i. p. 272, vi. p. 404. _points of resemblance between "races" and "species{259}."_ {259} this section seems not to correspond closely with any in the _origin_, ed. i.; in some points it resembles pp. 15, 16, also the section on analogous variation in distinct species, _origin_, ed. i. p. 159, vi. p. 194. races and reputed species agree in some respects, although differing from causes which, we have seen, we can in some degree understand, in the fertility and "trueness" of their offspring. in the first place, there is no clear sign by which to distinguish races from species, as is evident from the great difficulty experienced by naturalists in attempting to discriminate them. as far as external characters are concerned, many of the races which are descended from the same stock differ far more than true species of the same genus; look at the willow-wrens, some of which skilful ornithologists can hardly distinguish from each other except by their nests; look at the wild swans, and compare the distinct species of these genera with the races of domestic ducks, poultry, and pigeons; and so again with plants, compare the cabbages, almonds, peaches and nectarines, &c. with the species of many genera. st hilaire has even remarked that there is a greater difference in size between races, as in dogs (for he believes all have descended from one stock), than between the species of any one genus; nor is this surprising, considering that amount of food and consequently of growth is the element of change over which man has most power. i may refer to a former statement, that breeders believe the growth of one part or strong action of one function causes a decrease in other parts; for this seems in some degree analogous to the law of "organic compensation{260}," which many naturalists believe holds good. to give an instance of this law of compensation,--those species of carnivora which have the canine teeth greatly developed have certain molar teeth deficient; or again, in that division of the crustaceans in which the tail is much developed, the thorax is little so, and the converse. the points of difference between different races is often strikingly analogous to that between species of the same genus: trifling spots or marks of colour{261} (as the bars on pigeons' wings) are often preserved in races of plants and animals, precisely in the same manner as similar trifling characters often pervade all the species of a genus, and even of a family. flowers in varying their colours often become veined and spotted and the leaves become divided like true species: it is known that the varieties of the same plant never have red, blue and yellow flowers, though the hyacinth makes a very near approach to an exception{262}; and different species of the same genus seldom, though sometimes they have flowers of these three colours. dun-coloured horses having a dark stripe down their backs, and certain domestic asses having transverse bars on their legs, afford striking examples of a variation analogous in character to the distinctive marks of other species of the same genus. {260} the law of compensation is discussed in the _origin_, ed. i. p. 147, vi. p. 182. {261} boitard and corbié on outer edging red in tail of bird,--so bars on wing, white or black or brown, or white edged with black or : analogous to marks running through genera but with different colours. tail coloured in pigeons. {262} oxalis and gentian. _external characters of hybrids and mongrels._ there is, however, as it appears to me, a more important method of comparison between species and races, namely the character of the offspring{263} when species are crossed and when races are crossed: i believe, in no one respect, except in sterility, is there any difference. it would, i think, be a marvellous fact, if species have been formed by distinct acts of creation, that they should act upon each other in uniting, like races descended from a common stock. in the first place, by repeated crossing one species can absorb and wholly obliterate the characters of another, or of several other species, in the same manner as one race will absorb by crossing another race. marvellous, that one act of creation should absorb another or even several acts of creation! the offspring of species, that is hybrids, and the offspring of races, that is mongrels, resemble each other in being either intermediate in character (as is most frequent in hybrids) or in resembling sometimes closely one and sometimes the other parent; in both the offspring produced by the same act of conception sometimes differ in their degree of resemblance; both hybrids and mongrels sometimes retain a certain part or organ very like that of either parent, both, as we have seen, become in succeeding generations variable; and this tendency to vary can be transmitted by both; in both for many generations there is a strong tendency to reversion to their ancestral form. in the case of a hybrid laburnum and of a supposed mongrel vine different parts of the same plants took after each of their two parents. in the hybrids from some species, and in the mongrel of some races, the offspring differ according as which of the two species, or of the two races, is the father (as in the common mule and hinny) and which the mother. some races will breed together, which differ so greatly in size, that the dam often perishes in labour; so it is with some species when crossed; when the dam of one species has borne offspring to the male of another species, her succeeding offspring are sometimes stained (as in lord morton's mare by the quagga, wonderful as the fact{264} is) by this first cross; so agriculturists positively affirm is the case when a pig or sheep of one breed has produced offspring by the sire of another breed. {263} this section corresponds roughly to that on _hybrids and mongrels compared independently of their fertility_, _origin_, ed. i. p. 272, vi. p. 403. the discussion on gärtner's views, given in the _origin_, is here wanting. the brief mention of prepotency is common to them both. {264} see _animals and plants_, ed. ii. vol. i. p. 435. the phenomenon of _telegony_, supposed to be established by this and similar cases, is now generally discredited in consequence of ewart's experiments. _summary of second chapter_{265}. {265} the section on p. 109 is an appendix to the summary. let us sum up this second chapter. if slight variations do occur in organic beings in a state of nature; if changes of condition from geological causes do produce in the course of ages effects analogous to those of domestication on any, however few, organisms; and how can we doubt it,--from what is actually known, and from what may be presumed, since thousands of organisms taken by man for sundry uses, and placed in new conditions, have varied. if such variations tend to be hereditary; and how can we doubt it,--when we see shades of expression, peculiar manners, monstrosities of the strangest kinds, diseases, and a multitude of other peculiarities, which characterise and form, being inherited, the endless races (there are 1200 kinds of cabbages{266}) of our domestic plants and animals. if we admit that every organism maintains its place by an almost periodically recurrent struggle; and how can we doubt it,--when we know that all beings tend to increase in a geometrical ratio (as is instantly seen when the conditions become for a time more favourable); whereas on an average the amount of food must remain constant, if so, there will be a natural means of selection, tending to preserve those individuals with any slight deviations of structure more favourable to the then existing conditions, and tending to destroy any with deviations of an opposite nature. if the above propositions be correct, and there be no law of nature limiting the possible amount of variation, new races of beings will,--perhaps only rarely, and only in some few districts,--be formed. {266} i do not know the authority for this statement. _limits of variation._ that a limit to variation does exist in nature is assumed by most authors, though i am unable to discover a single fact on which this belief is grounded{267}. one of the commonest statements is that plants do not become acclimatised; and i have even observed that kinds not raised by seed, but propagated by cuttings, &c., are instanced. a good instance has, however, been advanced in the case of kidney beans, which it is believed are now as tender as when first introduced. even if we overlook the frequent introduction of seed from warmer countries, let me observe that as long as the seeds are gathered promiscuously from the bed, without continual observation and _careful_ selection of those plants which have stood the climate best during their whole growth, the experiment of acclimatisation has hardly been begun. are not all those plants and animals, of which we have the greatest number of races, the oldest domesticated? considering the quite recent progress{268} of systematic agriculture and horticulture, is it not opposed to every fact, that we have exhausted the capacity of variation in our cattle and in our corn,--even if we have done so in some trivial points, as their fatness or kind of wool? will any one say, that if horticulture continues to flourish during the next few centuries, that we shall not have numerous new kinds of the potato and dahlia? but take two varieties of each of these plants, and adapt them to certain fixed conditions and prevent any cross for 5000 years, and then again vary their conditions; try many climates and situations; and who{269} will predict the number and degrees of difference which might arise from these stocks? i repeat that we know nothing of any limit to the possible amount of variation, and therefore to the number and differences of the races, which might be produced by the natural means of selection, so infinitely more efficient than the agency of man. races thus produced would probably be very "true"; and if from having been adapted to different conditions of existence, they possessed different constitutions, if suddenly removed to some new station, they would perhaps be sterile and their offspring would perhaps be infertile. such races would be undistinguishable from species. but is there any evidence that the species, which surround us on all sides, have been thus produced? this is a question which an examination of the economy of nature we might expect would answer either in the affirmative or negative{270}. {267} in the _origin_ no limit is placed to variation as far as i know. {268} history of pigeons shows increase of peculiarities during last years. {269} compare an obscure passage in the essay of 1842, p. 14. {270} certainly ought to be here introduced, viz., difficulty in forming such organ, as eye, by selection. chapter iii on the variation of instincts and other mental attributes under domestication and in state of nature; on the difficulties in this subject; and on analogous difficulties with respect to corporeal structures _variation of mental attributes under domestication._ i have as yet only alluded to the mental qualities which differ greatly in different species. let me here premise that, as will be seen in the second part, there is no evidence and consequently no attempt to show that _all_ existing organisms have descended from any one common parent-stock, but that only those have so descended which, in the language of naturalists, are clearly related to each other. hence the facts and reasoning advanced in this chapter do not apply to the first origin of the senses{271}, or of the chief mental attributes, such as of memory, attention, reasoning, &c., &c., by which most or all of the great related groups are characterised, any more than they apply to the first origin of life, or growth, or the power of reproduction. the application of such facts as i have collected is merely to the differences of the primary mental qualities and of the instincts in the species{272} of the several great groups. in domestic animals every observer has remarked in how great a degree, in the individuals of the same species, the dispositions, namely courage, pertinacity, suspicion, restlessness, confidence, temper, pugnaciousness, affection, care of their young, sagacity, &c., &c., vary. it would require a most able metaphysician to explain how many primary qualities of the mind must be changed to cause these diversities of complex dispositions. from these dispositions being inherited, of which the testimony is unanimous, families and breeds arise, varying in these respects. i may instance the good and ill temper of different stocks of bees and of horses,--the pugnacity and courage of game fowls,--the pertinacity of certain dogs, as bull-dogs, and the sagacity of others,--for restlessness and suspicion compare a wild rabbit reared with the greatest care from its earliest age with the extreme tameness of the domestic breed of the same animal. the offspring of the domestic dogs which have run wild in cuba{273}, though caught quite young, are most difficult to tame, probably nearly as much so as the original parent-stock from which the domestic dog descended. the habitual "_periods_" of different families of the same species differ, for instance, in the time of year of reproduction, and the period of life when the capacity is acquired, and the hour of roosting (in malay fowls), &c., &c. these periodical habits are perhaps essentially corporeal, and may be compared to nearly similar habits in plants, which are known to vary extremely. consensual movements (as called by müller) vary and are inherited,--such as the cantering and ambling paces in horses, the tumbling of pigeons, and perhaps the handwriting, which is sometimes so similar between father and sons, may be ranked in this class. _manners_, and even tricks which perhaps are only _peculiar_ manners, according to w. hunter and my father, are distinctly inherited in cases where children have lost their parent in early infancy. the inheritance of expression, which often reveals the finest shades of character, is familiar to everyone. {271} a similar proviso occurs in the chapter on instinct in _origin_, ed. i. p. 207, vi. p. 319. {272} the discussion occurs later in chapter vii of the _origin_, ed. i. than in the present essay, where moreover it is fuller in some respects. {273} in the margin occurs the name of poeppig. in _var. under dom._, ed. ii. vol. i. p. 28, the reference to poeppig on the cuban dogs contains no mention of the wildness of their offspring. again the tastes and pleasures of different breeds vary, thus the shepherd-dog delights in chasing the sheep, but has no wish to kill them,--the terrier (see knight) delights in killing vermin, and the spaniel in finding game. but it is impossible to separate their mental peculiarities in the way i have done: the tumbling of pigeons, which i have instanced as a consensual movement, might be called a trick and is associated with a taste for flying in a close flock at a great height. certain breeds of fowls have a taste for roosting in trees. the different actions of pointers and setters might have been adduced in the same class, as might the peculiar _manner_ of hunting of the spaniel. even in the same breed of dogs, namely in fox-hounds, it is the fixed opinion of those best able to judge that the different pups are born with different tendencies; some are best to find their fox in the cover; some are apt to run straggling, some are best to make casts and to recover the lost scent, &c.; and that these peculiarities undoubtedly are transmitted to their progeny. or again the tendency to point might be adduced as a distinct habit which has become inherited,--as might the tendency of a true sheep dog (as i have been assured is the case) to run round the flock instead of directly at them, as is the case with other young dogs when attempted to be taught. the "transandantes" sheep{274} in spain, which for some centuries have been yearly taken a journey of several hundred miles from one province to another, know when the time comes, and show the greatest restlessness (like migratory birds in confinement), and are prevented with difficulty from starting by themselves, which they sometimes do, and find their own way. there is a case on good evidence{275} of a sheep which, when she lambed, would return across a mountainous country to her own birth-place, although at other times of year not of a rambling disposition. her lambs inherited this same disposition, and would go to produce their young on the farm whence their parent came; and so troublesome was this habit that the whole family was destroyed. {274} several authors. {275} in the margin "hogg" occurs as authority for this fact. for the reference, see p. 17, note 4. these facts must lead to the conviction, justly wonderful as it is, that almost infinitely numerous shades of disposition, of tastes, of peculiar movements, and even of individual actions, can be modified or acquired by one individual and transmitted to its offspring. one is forced to admit that mental phenomena (no doubt through their intimate connection with the brain) can be inherited, like infinitely numerous and fine differences of corporeal structure. in the same manner as peculiarities of corporeal structure slowly acquired or lost during mature life (especially cognisant > in disease), as well as congenital peculiarities, are transmitted; so it appears to be with the mind. the inherited paces in the horse have no doubt been acquired by compulsion during the lives of the parents: and temper and tameness may be modified in a breed by the treatment which the individuals receive. knowing that a pig has been taught to point, one would suppose that this quality in pointer-dogs was the simple result of habit, but some facts, with respect to the occasional appearance of a similar quality in other dogs, would make one suspect that it originally appeared in a less perfect degree, "_by chance_," that is from a congenital tendency{276} in the parent of the breed of pointers. one cannot believe that the tumbling, and high flight in a compact body, of one breed of pigeons has been taught; and in the case of the slight differences in the manner of hunting in young fox-hounds, they are doubtless congenital. the inheritance of the foregoing and similar mental phenomena ought perhaps to create less surprise, from the reflection that in no case do individual acts of reasoning, or movements, or other phenomena connected with consciousness, appear to be transmitted. an action, even a very complicated one, when from long practice it is performed unconsciously without any effort (and indeed in the case of many peculiarities of manners opposed to the will) is said, according to a common expression, to be performed "instinctively." those cases of languages, and of songs, learnt in early childhood and _quite_ forgotten, being _perfectly_ repeated during the unconsciousness of illness, appear to me only a few degrees less wonderful than if they had been transmitted to a second generation{277}. {276} in the _origin_, ed. i., he speaks more decidedly against the belief that instincts are hereditary habits, see for instance pp. 209, 214, ed. vi. pp. 321, 327. he allows, however, something to habit (p. 216). {277} a suggestion of hering's and s. butler's views on memory and inheritance. it is not, however, implied that darwin was inclined to accept these opinions. _hereditary habits compared with instincts._ the chief characteristics of true instincts appear to be their invariability and non-improvement during the mature age of the individual animal: the absence of knowledge of the end, for which the action is performed, being associated, however, sometimes with a degree of reason; being subject to mistakes and being associated with certain states of the body or times of the year or day. in most of these respects there is a resemblance in the above detailed cases of the mental qualities acquired or modified during domestication. no doubt the instincts of wild animals are more uniform than those habits or qualities modified or recently acquired under domestication, in the same manner and from the same causes that the corporeal structure in this state is less uniform than in beings in their natural conditions. i have seen a young pointer point as fixedly, the first day it was taken out, as any old dog; magendie says this was the case with a retriever which he himself reared: the tumbling of pigeons is not probably improved by age: we have seen that in the case above given that the young sheep inherited the migratory tendency to their particular birth-place the first time they lambed. this last fact offers an instance of a domestic instinct being associated with a state of body; as do the "transandantes" sheep with a time of year. ordinarily the acquired instincts of domestic animals seem to require a certain degree of education (as generally in pointers and retrievers) to be perfectly developed: perhaps this holds good amongst wild animals in rather a greater degree than is generally supposed; for instance, in the singing of birds, and in the knowledge of proper herbs in ruminants. it seems pretty clear that bees transmit knowledge from generation to generation. lord brougham{278} insists strongly on ignorance of the end proposed being eminently characteristic of true instincts; and this appears to me to apply to many acquired hereditary habits; for instance, in the case of the young pointer alluded to before, which pointed so steadfastly the first day that we were obliged several times to carry him away{279}. this puppy not only pointed at sheep, at large white stones, and at every little bird, but likewise "backed" the other pointers: this young dog must have been as unconscious for what end he was pointing, namely to facilitate his master's killing game to eat, as is a butterfly which lays her eggs on a cabbage, that her caterpillars would eat the leaves. so a horse that ambles instinctively, manifestly is ignorant that he performs that peculiar pace for the ease of man; and if man had never existed, he would never have ambled. the young pointer pointing at white stones appears to be as much a mistake of its acquired instinct, as in the case of flesh-flies laying their eggs on certain flowers instead of putrifying meat. however true the ignorance of the end may generally be, one sees that instincts are associated with some degree of reason; for instance, in the case of the tailor-bird, who spins threads with which to make her nest will use artificial threads when she can procure them{280}; so it has been known that an old pointer has broken his point and gone round a hedge to drive out a bird towards his master{281}. {278} lord brougham's _dissertations on subjects of science_, etc., 1839, p. 27. {279} this case is more briefly given in the _origin_, ed. i. p. 213, vi. p. 326. the simile of the butterfly occurs there also. {280} "a little dose, as pierre huber expresses it, of judgment or reason, often comes into play." _origin_, ed. i. p. 208, vi. p. 320. {281} in the margin is written "retriever killing one bird." this refers to the cases given in the _descent of man_, 2nd ed. (in 1 vol.) p. 78, of a retriever being puzzled how to deal with a wounded and a dead bird, killed the former and carried both at once. this was the only known instance of her wilfully injuring game. there is one other quite distinct method by which the instincts or habits acquired under domestication may be compared with those given by nature, by a test of a fundamental kind; i mean the comparison of the mental powers of mongrels and hybrids. now the instincts, or habits, tastes, and dispositions of one _breed_ of animals, when crossed with another breed, for instance a shepherd-dog with a harrier, are blended and appear in the same curiously mixed degree, both in the first and succeeding generations, exactly as happens when one _species_ is crossed with another{282}. this would hardly be the case if there was any fundamental difference between the domestic and natural instinct{283}; if the former were, to use a metaphorical expression, merely superficial. {282} see _origin_, ed. i. p. 214, vi. p. 327. {283} give some definition of instinct, or at least give chief attributes. the term instinct is often used in sense which implies no more than that the animal does the action in question. faculties and instincts may i think be imperfectly separated. the mole has the faculty of scratching burrows, and the instinct to apply it. the bird of passage has the faculty of finding its way and the instinct to put it in action at certain periods. it can hardly be said to have the faculty of knowing the time, for it can possess no means, without indeed it be some consciousness of passing sensations. think over all habitual actions and see whether faculties and instincts can be separated. we have faculty of waking in the night, if an instinct prompted us to do something at certain hour of night or day. savages finding their way. wrangel's account--probably a faculty inexplicable by the possessor. there are besides faculties "_means_," as conversion of larvæ into neuters and queens. i think all this generally implied, anyhow useful. _variation in the mental attributes of wild animals._ with respect to the variation{284} of the mental powers of animals in a wild state, we know that there is a considerable difference in the disposition of different individuals of the same species, as is recognised by all those who have had the charge of animals in a menagerie. with respect to the wildness of animals, that is fear directed particularly against man, which appears to be as true an instinct as the dread of a young mouse of a cat, we have excellent evidence that it is slowly acquired and becomes hereditary. it is also certain that, in a natural state, individuals of the same species lose or do not practice their migratory instincts--as woodcocks in madeira. with respect to any variation in the more complicated instincts, it is obviously most difficult to detect, even more so than in the case of corporeal structure, of which it has been admitted the variation is exceedingly small, and perhaps scarcely any in the majority of species at any one period. yet, to take one excellent case of instinct, namely the nests of birds, those who have paid most attention to the subject maintain that not only certain individuals species> seem to be able to build very imperfectly, but that a difference in skill may not unfrequently be detected between individuals{285}. certain birds, moreover, adapt their nests to circumstances; the water-ouzel makes no vault when she builds under cover of a rock--the sparrow builds very differently when its nest is in a tree or in a hole, and the golden-crested wren sometimes suspends its nest below and sometimes places it _on_ the branches of trees. {284} a short discussion of a similar kind occurs in the _origin_, ed. i. p. 211, vi. p. 324. {285} this sentence agrees with the ms., but is clearly in need of correction. _principles of selection applicable to instincts._ as the instincts of a species are fully as important to its preservation and multiplication as its corporeal structure, it is evident that if there be the slightest congenital differences in the instincts and habits, or if certain individuals during their lives are induced or compelled to vary their habits, and if such differences are in the smallest degree more favourable, under slightly modified external conditions, to their preservation, such individuals must in the long run have a better _chance_ of being preserved and of multiplying{286}. if this be admitted, a series of small changes may, as in the case of corporeal structure, work great changes in the mental powers, habits and instincts of any species. {286} this corresponds to _origin_, ed. i. p. 212, vi. p. 325. _difficulties in the acquirement of complex instincts by selection._ every one will at first be inclined to explain (as i did for a long time) that many of the more complicated and wonderful instincts could not be acquired in the manner here supposed{287}. the second part of this work is devoted to the general consideration of how far the general economy of nature justifies or opposes the belief that related species and genera are descended from common stocks; but we may here consider whether the instincts of animals offer such a _primâ facie_ case of impossibility of gradual acquirement, as to justify the rejection of any such theory, however strongly it may be supported by other facts. i beg to repeat that i wish here to consider not the _probability_ but the _possibility_ of complicated instincts having been acquired by the slow and long-continued selection of very slight (either congenital or produced by habit) modifications of foregoing simpler instincts; each modification being as useful and necessary, to the species practising it, as the most complicated kind. {287} this discussion is interesting in differing from the corresponding section of the _origin_, ed. i. p. 216, vi. p. 330, to the end of the chapter. in the present essay the subjects dealt with are nest-making instincts, including the egg-hatching habit of the australian bush-turkey. the power of "shamming death." "faculty" in relation to instinct. the instinct of lapse of time, and of direction. bees' cells very briefly given. birds feeding their young on food differing from their own natural food. in the _origin_, ed. i., the cases discussed are the instinct of laying eggs in other birds' nests; the slave-making instinct in ants; the construction of the bee's comb, very fully discussed. first, to take the case of birds'-nests; of existing species (almost infinitely few in comparison with the multitude which must have existed, since the period of the new red sandstone of n. america, of whose habits we must always remain ignorant) a tolerably perfect series could be made from eggs laid on the bare ground, to others with a few sticks just laid round them, to a simple nest like the wood-pigeons, to others more and more complicated: now if, as is asserted, there occasionally exist slight differences in the building powers of an individual, and if, which is at least probable, that such differences would tend to be inherited, then we can see that it is at least _possible_ that the nidificatory instincts may have been acquired by the gradual selection, during thousands and thousands of generations, of the eggs and young of those individuals, whose nests were in some degree better adapted to the preservation of their young, under the then existing conditions. one of the most surprising instincts on record is that of the australian bush-turkey, whose eggs are hatched by the heat generated from a huge pile of fermenting materials, which it heaps together; but here the habits of an allied species show how this instinct _might possibly_ have been acquired. this second species inhabits a tropical district, where the heat of the sun is sufficient to hatch its eggs; this bird, burying its eggs, apparently for concealment, under a lesser heap of rubbish, but of a dry nature, so as not to ferment. now suppose this bird to range slowly into a climate which was cooler, and where leaves were more abundant, in that case, those individuals, which chanced to have their collecting instinct strongest developed, would make a somewhat larger pile, and the eggs, aided during some colder season, under the slightly cooler climate by the heat of incipient fermentation, would in the long run be more freely hatched and would probably produce young ones with the same more highly developed collecting tendencies; of these again, those with the best developed powers would again tend to rear most young. thus this strange instinct might _possibly_ be acquired, every individual bird being as ignorant of the laws of fermentation, and the consequent development of heat, as we know they must be. secondly, to take the case of animals feigning death (as it is commonly expressed) to escape danger. in the case of insects, a perfect series can be shown, from some insects, which momentarily stand still, to others which for a second slightly contract their legs, to others which will remain immovably drawn together for a quarter of an hour, and may be torn asunder or roasted at a slow fire, without evincing the smallest sign of sensation. no one will doubt that the length of time, during which each remains immovable, is well adapted to escape the dangers to which it is most exposed, and few will deny the _possibility_ of the change from one degree to another, by the means and at the rate already explained. thinking it, however, wonderful (though not impossible) that the attitude of death should have been acquired by methods which imply no imitation, i compared several species, when feigning, as is said, death, with others of the same species really dead, and their attitudes were in no one case the same. thirdly, in considering many instincts it is useful to _endeavour_ to separate the faculty{288} by which they perform it, and the mental power which urges to the performance, which is more properly called an instinct. we have an instinct to eat, we have jaws &c. to give us the faculty to do so. these faculties are often unknown to us: bats, with their eyes destroyed, can avoid strings suspended across a room, we know not at present by what faculty they do this. thus also, with migratory birds, it is a wonderful instinct which urges them at certain times of the year to direct their course in certain directions, but it is a faculty by which they know the time and find their way. with respect to time{289}, man without seeing the sun can judge to a certain extent of the hour, as must those cattle which come down from the inland mountains to feed on sea-weed left bare at the changing hour of low-water{290}. a hawk (d'orbigny) seems certainly to have acquired a knowledge of a period of every 21 days. in the cases already given of the sheep which travelled to their birth-place to cast their lambs, and the sheep in spain which know their time of march{291}, we may conjecture that the tendency to move is associated, we may then call it instinctively, with some corporeal sensations. with respect to direction we can easily conceive how a tendency to travel in a certain course may possibly have been acquired, although we must remain ignorant how birds are able to preserve any direction whatever in a dark night over the wide ocean. i may observe that the power of some savage races of mankind to find their way, although perhaps wholly different from the faculty of birds, is nearly as unintelligible to us. bellinghausen, a skilful navigator, describes with the utmost wonder the manner in which some esquimaux guided him to a certain point, by a course never straight, through newly formed hummocks of ice, on a thick foggy day, when he with a compass found it impossible, from having no landmarks, and from their course being so extremely crooked, to preserve any sort of uniform direction: so it is with australian savages in thick forests. in north and south america many birds slowly travel northward and southward, urged on by the food they find, as the seasons change; let them continue to do this, till, as in the case of the sheep in spain, it has become an urgent instinctive desire, and they will gradually accelerate their journey. they would cross narrow rivers, and if these were converted by subsidence into narrow estuaries, and gradually during centuries to arms of the sea, still we may suppose their restless desire of travelling onwards would impel them to cross such an arm, even if it had become of great width beyond their span of vision. how they are able to preserve a course in any direction, i have said, is a faculty unknown to us. to give another illustration of the means by which i conceive it _possible_ that the direction of migrations have been determined. elk and reindeer in n. america annually cross, as if they could marvellously smell or see at the distance of a hundred miles, a wide tract of absolute desert, to arrive at certain islands where there is a scanty supply of food; the changes of temperature, which geology proclaims, render it probable that this desert tract formerly supported some vegetation, and thus these quadrupeds might have been annually led on, till they reached the more fertile spots, and so acquired, like the sheep of spain, their migratory powers. {288} the distinction between _faculty_ and _instinct_ corresponds in some degree to that between perception of a stimulus and a specific reaction. i imagine that the author would have said that the sensitiveness to light possessed by a plant is _faculty_, while _instinct_ decides whether the plant curves to or from the source of illumination. {289} at the time when corn was pitched in the market instead of sold by sample, the geese in the town fields of newcastle used to know market day and come in to pick up the corn spilt. {290} macculloch and others. {291} i can find no reference to the _transandantes_ sheep in darwin's published work. he was possibly led to doubt the accuracy of the statement on which he relied. for the case of the sheep returning to their birth-place see p. 17, note 4.{note 91} fourthly, with respect to the combs of the hive-bee{292}; here again we must look to some faculty or means by which they make their hexagonal cells, without indeed we view these instincts as mere machines. at present such a faculty is quite unknown: mr waterhouse supposes that several bees are led by their instinct to excavate a mass of wax to a certain thinness, and that the result of this is that hexagons necessarily remain. whether this or some other theory be true, some such means they must possess. they abound, however, with true instincts, which are the most wonderful that are known. if we examine the little that is known concerning the habits of other species of bees, we find much simpler instincts: the humble bee merely fills rude balls of wax with honey and aggregates them together with little order in a rough nest of grass. if we knew the instinct of all the bees, which ever had existed, it is not improbable that we should have instincts of every degree of complexity, from actions as simple as a bird making a nest, and rearing her young, to the wonderful architecture and government of the hive-bee; at least such is _possible_, which is all that i am here considering. {292} _origin_, ed. i. p. 224, vi. p. 342. finally, i will briefly consider under the same point of view one other class of instincts, which have often been advanced as truly wonderful, namely parents bringing food to their young which they themselves neither like nor partake of{293};--for instance, the common sparrow, a granivorous bird, feeding its young with caterpillars. we might of course look into the case still earlier, and seek how an instinct in the parent, of feeding its young at all, was first derived; but it is useless to waste time in conjectures on a series of gradations from the young feeding themselves and being slightly and occasionally assisted in their search, to their entire food being brought to them. with respect to the parent bringing a different kind of food from its own kind, we may suppose either that the remote stock, whence the sparrow and other congenerous birds have descended, was insectivorous, and that its own habits and structure have been changed, whilst its ancient instincts with respect to its young have remained unchanged; or we may suppose that the parents have been induced to vary slightly the food of their young, by a slight scarcity of the proper kind (or by the instincts of some individuals not being so truly developed), and in this case those young which were most capable of surviving were necessarily most often preserved, and would themselves in time become parents, and would be similarly compelled to alter their food for their young. in the case of those animals, the young of which feed themselves, changes in their instincts for food, and in their structure, might be selected from slight variations, just as in mature animals. again, where the food of the young depends on where the mother places her eggs, as in the case of the caterpillars of the cabbage-butterfly, we may suppose that the parent stock of the species deposited her eggs sometimes on one kind and sometimes on another of congenerous plants (as some species now do), and if the cabbage suited the caterpillars better than any other plant, the caterpillars of those butterflies, which had chosen the cabbage, would be most plentifully reared, and would produce butterflies more apt to lay their eggs on the cabbage than on the other congenerous plants. {293} this is an expansion of an obscure passage in the essay of 1842, p. 19. however vague and unphilosophical these conjectures may appear, they serve, i think, to show that one's first impulse utterly to reject any theory whatever, implying a gradual acquirement of these instincts, which for ages have excited man's admiration, may at least be delayed. once grant that dispositions, tastes, actions or habits can be slightly modified, either by slight congenital differences (we must suppose in the brain) or by the force of external circumstances, and that such slight modifications can be rendered inheritable,--a proposition which no one can reject,--and it will be difficult to put any limit to the complexity and wonder of the tastes and habits which may _possibly_ be thus acquired. _difficulties in the acquirement by selection of complex corporeal structures._ after the past discussion it will perhaps be convenient here to consider whether any particular corporeal organs, or the entire structure of any animals, are so wonderful as to justify the rejection _primâ facie_ of our theory{294}. in the case of the eye, as with the more complicated instincts, no doubt one's first impulse is to utterly reject every such theory. but if the eye from its most complicated form can be shown to graduate into an exceedingly simple state,--if selection can produce the smallest change, and if such a series exists, then it is clear (for in this work we have nothing to do with the first origin of organs in their simplest forms{295}) that it may _possibly_ have been acquired by gradual selection of slight, but in each case, useful deviations{296}. every naturalist, when he meets with any new and singular organ, always expects to find, and looks for, other and simpler modifications of it in other beings. in the case of the eye, we have a multitude of different forms, more or less simple, not graduating into each other, but separated by sudden gaps or intervals; but we must recollect how incomparably greater would the multitude of visual structures be if we had the eyes of every fossil which ever existed. we shall discuss the probable vast proportion of the extinct to the recent in the succeeding part. notwithstanding the large series of existing forms, it is most difficult even to conjecture by what intermediate stages very many simple organs could possibly have graduated into complex ones: but it should be here borne in mind, that a part having originally a wholly different function, may on the theory of gradual selection be slowly worked into quite another use; the gradations of forms, from which naturalists believe in the hypothetical metamorphosis of part of the ear into the swimming bladder in fishes{297}, and in insects of legs into jaws, show the manner in which this is possible. as under domestication, modifications of structure take place, without any continued selection, which man finds very useful, or valuable for curiosity (as the hooked calyx of the teazle, or the ruff round some pigeons' necks), so in a state of nature some small modifications, apparently beautifully adapted to certain ends, may perhaps be produced from the accidents of the reproductive system, and be at once propagated without long-continued selection of small deviations towards that structure{298}. in conjecturing by what stages any complicated organ in a species may have arrived at its present state, although we may look to the analogous organs in other existing species, we should do this merely to aid and guide our imaginations; for to know the real stages we must look only through one line of species, to one ancient stock, from which the species in question has descended. in considering the eye of a quadruped, for instance, though we may look at the eye of a molluscous animal or of an insect, as a proof how simple an organ will serve some of the ends of vision; and at the eye of a fish as a nearer guide of the manner of simplification; we must remember that it is a mere chance (assuming for a moment the truth of our theory) if any existing organic being has preserved any one organ, in exactly the same condition, as it existed in the ancient species at remote geological periods. {294} the difficulties discussed in the _origin_, ed. i. p. 171, vi. p. 207, are the rarity of transitional varieties, the origin of the tail of the giraffe; the otter-like polecat (_mustela vison_); the flying habit of the bat; the penguin and the logger-headed duck; flying fish; the whale-like habit of the bear; the woodpecker; diving petrels; the eye; the swimming bladder; cirripedes; neuter insects; electric organs. of these, the polecat, the bat, the woodpecker, the eye, the swimming bladder are discussed in the present essay, and in addition some botanical problems. {295} in the _origin_, ed. vi. p. 275, the author replies to mivart's criticisms (_genesis of species_, 1871), referring especially to that writer's objection "that natural selection is incompetent to account for the incipient stages of useful structures." {296} "and that each eye throughout the animal kingdom is not only most useful, but _perfect_ for its possessor." {297} _origin_, ed. i. p. 190, vi. p. 230. {298} this is one of the most definite statements in the present essay of the possible importance of _sports_ or what would now be called _mutations_. as is well known the author afterwards doubted whether species could arise in this way. see _origin_, ed. v. p. 103, vi. p. 110, also _life and letters_, vol. iii. p. 107. the nature or condition of certain structures has been thought by some naturalists to be of no use to the possessor{299}, but to have been formed wholly for the good of other species; thus certain fruit and seeds have been thought to have been made nutritious for certain animals--numbers of insects, especially in their larval state, to exist for the same end--certain fish to be bright coloured to aid certain birds of prey in catching them, &c. now could this be proved (which i am far from admitting) the theory of natural selection would be quite overthrown; for it is evident that selection depending on the advantage over others of one individual with some slight deviation would never produce a structure or quality profitable only to another species. no doubt one being takes advantage of qualities in another, and may even cause its extermination; but this is far from proving that this quality was produced for such an end. it may be advantageous to a plant to have its seeds attractive to animals, if one out of a hundred or a thousand escapes being digested, and thus aids dissemination: the bright colours of a fish may be of some advantage to it, or more probably may result from exposure to certain conditions in favourable haunts for food, _notwithstanding_ it becomes subject to be caught more easily by certain birds. {299} see _origin_, ed. i. p. 210, vi. p. 322, where the question is discussed for the case of instincts with a proviso that the same argument applies to structure. it is briefly stated in its general bearing in _origin_, ed. i. p. 87, vi. p. 106. if instead of looking, as above, at certain individual organs, in order to speculate on the stages by which their parts have been matured and selected, we consider an individual animal, we meet with the same or greater difficulty, but which, i believe, as in the case of single organs, rests entirely on our ignorance. it may be asked by what intermediate forms could, for instance, a bat possibly have passed; but the same question might have been asked with respect to the seal, if we had not been familiar with the otter and other semi-aquatic carnivorous quadrupeds. but in the case of the bat, who can say what might have been the habits of some parent form with less developed wings, when we now have insectivorous opossums and herbivorous squirrels fitted for merely gliding through the air{300}. one species of bat is at present partly aquatic in its habits{301}. woodpeckers and tree-frogs are especially adapted, as their names express, for climbing trees; yet we have species of both inhabiting the open plains of la plata, where a tree does not exist{302}. i might argue from this circumstance that a structure eminently fitted for climbing trees might descend from forms inhabiting a country where a tree did not exist. notwithstanding these and a multitude of other well-known facts, it has been maintained by several authors that one species, for instance of the carnivorous order, could not pass into another, for instance into an otter, because in its transitional state its habits would not be adapted to any proper conditions of life; but the jaguar{303} is a thoroughly terrestrial quadruped in its structure, yet it takes freely to the water and catches many fish; will it be said that it is _impossible_ that the conditions of its country might become such that the jaguar should be driven to feed more on fish than they now do; and in that case is it impossible, is it not probable, that any the slightest deviation in its instincts, its form of body, in the width of its feet, and in the extension of the skin (which already unites the base of its toes) would give such individuals a better _chance_ of surviving and propagating young with similar, barely perceptible (though thoroughly exercised), deviations{304}? who will say what could thus be effected in the course of ten thousand generations? who can answer the same question with respect to instincts? if no one can, the _possibility_ (for we are not in this chapter considering the _probability_) of simple organs or organic beings being modified by natural selection and the effects of external agencies into complicated ones ought not to be absolutely rejected. {300} no one will dispute that the gliding is most useful, probably necessary for the species in question. {301} is this the galeopithecus? i forget. <_galeopithecus_ "or the flying lemur" is mentioned in the corresponding discussion in the _origin_, ed. i. p. 181, vi. p. 217, as formerly placed among the bats. i do not know why it is described as partly aquatic in its habits.> {302} in the _origin_, ed. vi. p. 221, the author modified the statement that it _never_ climbs trees; he also inserted a sentence quoting mr hudson to the effect that in other districts this woodpecker climbs trees and bores holes. see mr darwin's paper, _zoolog. soc. proc._, 1870, and _life and letters_, iii. p. 153. {303} note by the late alfred newton. richardson in _fauna boreali-americana_, i. p. 49. {304} see richardson a far better case of a polecat animal <_mustela vison_>, which half-year is aquatic. part ii{305} on the evidence favourable and opposed to the view that species are naturally formed races, descended from common stocks {305} in the _origin_ the division of the work into parts i and ii is omitted. in the ms. the chapters of part ii are numbered afresh, the present being ch. i of pt. ii. i have thought it best to call it ch. iv and there is evidence that darwin had some thought of doing the same. it corresponds to ch. ix of _origin_, ed. i., ch. x in ed. vi. chapter iv on the number of intermediate forms required on the theory of common descent; and on their absence in a fossil state i must here premise that, according to the view ordinarily received, the myriads of organisms, which have during past and present times peopled this world, have been created by so many distinct acts of creation. it is impossible to reason concerning the will of the creator, and therefore, according to this view, we can see no cause why or why not the individual organism should have been created on any fixed scheme. that all the organisms of this world have been produced on a scheme is certain from their general affinities; and if this scheme can be shown to be the same with that which would result from allied organic beings descending from common stocks, it becomes highly improbable that they have been separately created by individual acts of the will of a creator. for as well might it be said that, although the planets move in courses conformably to the law of gravity, yet we ought to attribute the course of each planet to the individual act of the will of the creator{306}. it is in every case more conformable with what we know of the government of this earth, that the creator should have imposed only general laws. as long as no method was known by which races could become exquisitely adapted to various ends, whilst the existence of species was thought to be proved by the sterility{307} of their offspring, it was allowable to attribute each organism to an individual act of creation. but in the two former chapters it has (i think) been shown that the production, under existing conditions, of exquisitely adapted species, is at least _possible_. is there then any direct evidence in favour or against this view? i believe that the geographical distribution of organic beings in past and present times, the kind of affinity linking them together, their so-called "metamorphic" and "abortive" organs, appear in favour of this view. on the other hand, the imperfect evidence of the continuousness of the organic series, which, we shall immediately see, is required on our theory, is against it; and is the most weighty objection{308}. the evidence, however, even on this point, as far as it goes, is favourable; and considering the imperfection of our knowledge, especially with respect to past ages, it would be surprising if evidence drawn from such sources were not also imperfect. {306} in the essay of 1842 the author uses astronomy in the same manner as an illustration. in the _origin_ this does not occur; the reference to the action of secondary causes is more general, _e.g._ ed. i. p. 488, vi. p. 668. {307} it is interesting to find the argument from sterility given so prominent a place. in a corresponding passage in the _origin_, ed. i. p. 480, vi. p. 659, it is more summarily treated. the author gives, as the chief bar to the acceptance of evolution, the fact that "we are always slow in admitting any great change of which we do not see the intermediate steps"; and goes on to quote lyell on geological action. it will be remembered that the question of sterility remained a difficulty for huxley. {308} similar statements occur in the essay of 1842, p. 24, note 1, and in the _origin_, ed. i. p. 299. as i suppose that species have been formed in an analogous manner with the varieties of the domesticated animals and plants, so must there have existed intermediate forms between all the species of the same group, not differing more than recognised varieties differ. it must not be supposed necessary that there should have existed forms exactly intermediate in character between any two species of a genus, or even between any two varieties of a species; but it is necessary that there should have existed every intermediate form between the one species or variety of the common parent, and likewise between the second species or variety, and this same common parent. thus it does not necessarily follow that there ever has existed series of intermediate sub-varieties (differing no more than the occasional seedlings from the same seed-capsule,) between broccoli and common red cabbage; but it is certain that there has existed, between broccoli and the wild parent cabbage, a series of such intermediate seedlings, and again between red cabbage and the wild parent cabbage: so that the broccoli and red cabbage are linked together, but not _necessarily_ by directly intermediate forms{309}. it is of course possible that there _may_ have been directly intermediate forms, for the broccoli may have long since descended from a common red cabbage, and this from the wild cabbage. so on my theory, it must have been with species of the same genus. still more must the supposition be avoided that there has necessarily ever existed (though one _may_ have descended from other) directly intermediate forms between any two genera or families--for instance between the genus _sus_ and the tapir{310}; although it is necessary that intermediate forms (not differing more than the varieties of our domestic animals) should have existed between sus and some unknown parent form, and tapir with this same parent form. the latter may have differed more from sus and tapir than these two genera now differ from each other. in this sense, according to our theory, there has been a gradual passage (the steps not being wider apart than our domestic varieties) between the species of the same genus, between genera of the same family, and between families of the same order, and so on, as far as facts, hereafter to be given, lead us; and the number of forms which must have at former periods existed, thus to make good this passage between different species, genera, and families, must have been almost infinitely great. {309} in the _origin_, ed. i. p. 280, vi. p. 414 he uses his newly-acquired knowledge of pigeons to illustrate this point. {310} compare the _origin_, ed. i. p. 281, vi. p. 414. what evidence{311} is there of a number of intermediate forms having existed, making a passage in the above sense, between the species of the same groups? some naturalists have supposed that if every fossil which now lies entombed, together with all existing species, were collected together, a perfect series in every great class would be formed. considering the enormous number of species requisite to effect this, especially in the above sense of the forms not being _directly_ intermediate between the existing species and genera, but only intermediate by being linked through a common but often widely different ancestor, i think this supposition highly improbable. i am however far from underrating the probable number of fossilised species: no one who has attended to the wonderful progress of palæontology during the last few years will doubt that we as yet have found only an exceedingly small fraction of the species buried in the crust of the earth. although the almost infinitely numerous intermediate forms in no one class may have been preserved, it does not follow that they have not existed. the fossils which have been discovered, it is important to remark, do tend, the little way they go, to make good the series; for as observed by buckland they all fall into or between existing groups{312}. moreover, those that fall between our existing groups, fall in, according to the manner required by our theory, for they do not directly connect two existing species of different groups, but they connect the groups themselves: thus the pachydermata and ruminantia are now separated by several characters, the pachydermata{313} have both a tibia and fibula, whilst ruminantia have only a tibia; now the fossil macrauchenia has a leg bone exactly intermediate in this respect, and likewise has some other intermediate characters. but the macrauchenia does not connect any one species of pachydermata with some one other of ruminantia but it shows that these two groups have at one time been less widely divided. so have fish and reptiles been at one time more closely connected in some points than they now are. generally in those groups in which there has been most change, the more ancient the fossil, if not identical with recent, the more often it falls between existing groups, or into small existing groups which now lie between other large existing groups. cases like the foregoing, of which there are many, form steps, though few and far between, in a series of the kind required by my theory. {311} _origin_, ed. i. p. 301, vi. p. 440. {312} _origin_, ed. i. p. 329, vi. p. 471. {313} the structure of the pachyderm leg was a favourite with the author. it is discussed in the essay of 1842, p. 48. in the present essay the following sentence in the margin appears to refer to pachyderms and ruminants: "there can be no doubt, if we banish all fossils, existing groups stand more separate." the following occurs between the lines "the earliest forms would be such as others could radiate from." as i have admitted the high improbability, that if every fossil were disinterred, they would compose in each of the divisions of nature a perfect series of the kind required; consequently i freely admit, that if those geologists are in the right who consider the lowest known formation as contemporaneous with the first appearances of life{314}; or the several formations as at all closely consecutive; or any one formation as containing a nearly perfect record of the organisms which existed during the whole period of its deposition in that quarter of the globe;--if such propositions are to be accepted, my theory must be abandoned. {314} _origin_, ed. i. p. 307, vi. p. 448. if the palæozoic system is really contemporaneous with the first appearance of life, my theory must be abandoned, both inasmuch as it limits _from shortness of time_ the total number of forms which can have existed on this world, and because the organisms, as fish, mollusca{315} and star-fish found in its lower beds, cannot be considered as the parent forms of all the successive species in these classes. but no one has yet overturned the arguments of hutton and lyell, that the lowest formations known to us are only those which have escaped being metamorphosed ; if we argued from some considerable districts, we might have supposed that even the cretaceous system was that in which life first appeared. from the number of distant points, however, in which the silurian system has been found to be the lowest, and not always metamorphosed, there are some objections to hutton's and lyell's view; but we must not forget that the now existing land forms only 1/5 part of the superficies of the globe, and that this fraction is only imperfectly known. with respect to the fewness of the organisms found in the silurian and other palæozoic formations, there is less difficulty, inasmuch as (besides their gradual obliteration) we can expect formations of this vast antiquity to escape entire denudation, only when they have been accumulated over a wide area, and have been subsequently protected by vast superimposed deposits: now this could generally only hold good with deposits accumulating in a wide and deep ocean, and therefore unfavourable to the presence of many living things. a mere narrow and not very thick strip of matter, deposited along a coast where organisms most abound, would have no chance of escaping denudation and being preserved to the present time from such immensely distant ages{316}. {315} the parent-forms of mollusca would probably differ greatly from all recent,--it is not directly that any one division of mollusca would descend from first time unaltered, whilst others had become metamorphosed from it. {316} _origin_, ed. i. p. 291, vi. p. 426. if the several known formations are at all nearly consecutive in time, and preserve a fair record of the organisms which have existed, my theory must be abandoned. but when we consider the great changes in mineralogical nature and texture between successive formations, what vast and entire changes in the geography of the surrounding countries must generally have been effected, thus wholly to have changed the nature of the deposits on the same area. what time such changes must have required! moreover how often has it not been found, that between two conformable and apparently immediately successive deposits a vast pile of water-worn matter is interpolated in an adjoining district. we have no means of conjecturing in many cases how long a period{317} has elapsed between successive formations, for the species are often wholly different: as remarked by lyell, in some cases probably as long a period has elapsed between two formations as the whole tertiary system, itself broken by wide gaps. {317} reflect on coming in of the chalk, extending from iceland to the crimea. consult the writings of any one who has particularly attended to any one stage in the tertiary system (and indeed of every system) and see how deeply impressed he is with the time required for its accumulation{318}. reflect on the years elapsed in many cases, since the latest beds containing only living species have been formed;--see what jordan smith says of the 20,000 years since the last bed, which is above the boulder formation in scotland, has been upraised; or of the far longer period since the recent beds of sweden have been upraised 400 feet, what an enormous period the boulder formation must have required, and yet how insignificant are the records (although there has been plenty of elevation to bring up submarine deposits) of the shells, which we know existed at that time. think, then, over the entire length of the tertiary epoch, and think over the probable length of the intervals, separating the secondary deposits. of these deposits, moreover, those consisting of sand and pebbles have seldom been favourable, either to the embedment or to the preservation of fossils{319}. {318} _origin_, ed. i. p. 282, vi. p. 416. {319} _origin_, ed. i. pp. 288, 300, vi. pp. 422, 438. nor can it be admitted as probable that any one secondary formation contains a fair record even of those organisms which are most easily preserved, namely hard marine bodies. in how many cases have we not certain evidence that between the deposition of apparently closely consecutive beds, the lower one existed for an unknown time as land, covered with trees. some of the secondary formations which contain most marine remains appear to have been formed in a wide and not deep sea, and therefore only those marine animals which live in such situations would be preserved{320}. in all cases, on indented rocky coasts, or any other coast, where sediment is not accumulating, although often highly favourable to marine animals, none can be embedded: where pure sand and pebbles are accumulating few or none will be preserved. i may here instance the great western line of the s. american coast{321}, tenanted by many peculiar animals, of which none probably will be preserved to a distant epoch. from these causes, and especially from such deposits as are formed along a line of coast, steep above and below water, being necessarily of little width, and therefore more likely to be subsequently denuded and worn away, we can see why it is improbable that our secondary deposits contain a fair record of the marine fauna of any one period. the east indian archipelago offers an area, as large as most of our secondary deposits, in which there are wide and shallow seas, teeming with marine animals, and in which sediment is accumulating; now supposing that all the hard marine animals, or rather those having hard parts to preserve, were preserved to a future age, excepting those which lived on rocky shores where no sediment or only sand and gravel were accumulating, and excepting those embedded along the steeper coasts, where only a narrow fringe of sediment was accumulating, supposing all this, how poor a notion would a person at a future age have of the marine fauna of the present day. lyell{322} has compared the geological series to a work of which only the few latter but not consecutive chapters have been preserved; and out of which, it may be added, very many leaves have been torn, the remaining ones only illustrating a scanty portion of the fauna of each period. on this view, the records of anteceding ages confirm my theory; on any other they destroy it. {320} neither highest or lowest fish (_i.e._ myxina > or lepidosiren) could be preserved in intelligible condition in fossils. {321} _origin_, ed. i. p. 290, vi. p. 425. {322} see _origin_, ed. i. p. 310, vi. p. 452 for lyell's metaphor. i am indebted to prof. judd for pointing out that darwin's version of the metaphor is founded on the first edition of lyell's _principles_, vol. i. and vol. iii.; see the essay of 1842, p. 27. finally, if we narrow the question into, why do we not find in some instances every intermediate form between any two species? the answer may well be that the average duration of each specific form (as we have good reason to believe) is immense in years, and that the transition could, according to my theory, be effected only by numberless small gradations; and therefore that we should require for this end a most perfect record, which the foregoing reasoning teaches us not to expect. it might be thought that in a vertical section of great thickness in the same formation some of the species ought to be found to vary in the upper and lower parts{323}, but it may be doubted whether any formation has gone on accumulating without any break for a period as long as the duration of a species; and if it had done so, we should require a series of specimens from every part. how rare must be the chance of sediment accumulating for some 20 or 30 thousand years on the same spot{324}, with the bottom subsiding, so that a proper depth might be preserved for any one species to continue living: what an amount of subsidence would be thus required, and this subsidence must not destroy the source whence the sediment continued to be derived. in the case of terrestrial animals, what chance is there when the present time is become a pleistocene formation (at an earlier period than this, sufficient elevation to expose marine beds could not be expected), what chance is there that future geologists will make out the innumerable transitional sub-varieties, through which the short-horned and long-horned cattle (so different in shape of body) have been derived from the same parent stock{325}? yet this transition has been effected in _the same country_, and in a far _shorter time_, than would be probable in a wild state, both contingencies highly favourable for the future hypothetical geologists being enabled to trace the variation. {323} see _more letters_, vol. i. pp. 344-7, for darwin's interest in the celebrated observations of hilgendorf and hyatt. {324} this corresponds partly to _origin_, ed. i. p. 294, vi. p. 431. {325} _origin_, ed. i. p. 299, vi. p. 437. chapter v gradual appearance and disappearance of species{326} {326} this chapter corresponds to ch. x of _origin_, ed. i., vi. ch. xi, "on the geological succession of organic beings." in the tertiary system, in the last uplifted beds, we find all the species recent and living in the immediate vicinity; in rather older beds we find only recent species, but some not living in the immediate vicinity{327}; we then find beds with two or three or a few more extinct or very rare species; then considerably more extinct species, but with gaps in the regular increase; and finally we have beds with only two or three or not one living species. most geologists believe that the gaps in the percentage, that is the sudden increments, in the number of the extinct species in the stages of the tertiary system are due to the imperfection of the geological record. hence we are led to believe that the species in the tertiary system have been gradually introduced; and from analogy to carry on the same view to the secondary formations. in these latter, however, entire groups of species generally come in abruptly; but this would naturally result, if, as argued in the foregoing chapter, these secondary deposits are separated by wide epochs. moreover it is important to observe that, with our increase of knowledge, the gaps between the older formations become fewer and smaller; geologists of a few years standing remember how beautifully has the devonian system{328} come in between the carboniferous and silurian formations. i need hardly observe that the slow and gradual appearance of new forms follows from our theory, for to form a new species, an old one must not only be plastic in its organization, becoming so probably from changes in the conditions of its existence, but a place in the natural economy of the district must [be made,] come to exist, for the selection of some new modification of its structure, better fitted to the surrounding conditions than are the other individuals of the same or other species{329}. {327} _origin_, ed. i. p. 312, vi. p. 453. {328} in the margin the author has written "lonsdale." this refers to w. lonsdale's paper "notes on the age of the limestone of south devonshire," _geolog. soc. trans._, series 2, vol. v. 1840, p. 721. according to mr h. b. woodward (_history of the geological society of london_, 1907, p. 107) "lonsdale's 'important and original suggestion of the existence of an intermediary type of palæozoic fossils, since called devonian,' led to a change which was then 'the greatest ever made at one time in the classification of our english formations'." mr woodward's quotations are from murchison and buckland. {329} better begin with this. if species really, after catastrophes, created in showers over world, my theory false. in the tertiary system the same facts, which make us admit as probable that new species have slowly appeared, lead to the admission that old ones have slowly disappeared, not several together, but one after another; and by analogy one is induced to extend this belief to the secondary and palæozoic epochs. in some cases, as the subsidence of a flat country, or the breaking or the joining of an isthmus, and the sudden inroad of many new and destructive species, extinction might be locally sudden. the view entertained by many geologists, that each fauna of each secondary epoch has been suddenly destroyed over the whole world, so that no succession could be left for the production of new forms, is subversive of my theory, but i see no grounds whatever to admit such a view. on the contrary, the law, which has been made out, with reference to distinct epochs, by independent observers, namely, that the wider the geographical range of a species the longer is its duration in time, seems entirely opposed to any universal extermination{330}. the fact of species of mammiferous animals and fish being renewed at a quicker rate than mollusca, though both aquatic; and of these the terrestrial genera being renewed quicker than the marine; and the marine mollusca being again renewed quicker than the infusorial animalcula, all seem to show that the extinction and renewal of species does not depend on general catastrophes, but on the particular relations of the several classes to the conditions to which they are exposed{331}. {330} opposite to this passage the author has written "d'archiac, forbes, lyell." {331} this passage, for which the author gives as authorities the names of lyell, forbes and ehrenberg, corresponds in part to the discussion beginning on p. 313 of _origin_, ed. i., vi. p. 454. some authors seem to consider the fact of a few species having survived{332} amidst a number of extinct forms (as is the case with a tortoise and a crocodile out of the vast number of extinct sub-himalayan fossils) as strongly opposed to the view of species being mutable. no doubt this would be the case, if it were presupposed with lamarck that there was some inherent tendency to change and development in all species, for which supposition i see no evidence. as we see some species at present adapted to a wide range of conditions, so we may suppose that such species would survive unchanged and unexterminated for a long time; time generally being from geological causes a correlative of changing conditions. how at present one species becomes adapted to a wide range, and another species to a restricted range of conditions, is of difficult explanation. {332} the author gives falconer as his authority: see _origin_, ed. i. p. 313, vi. p. 454. _extinction of species._ the extinction of the larger quadrupeds, of which we imagine we better know the conditions of existence, has been thought little less wonderful than the appearance of new species; and has, i think, chiefly led to the belief of universal catastrophes. when considering the wonderful disappearance within a late period, whilst recent shells were living, of the numerous great and small mammifers of s. america, one is strongly induced to join with the catastrophists. i believe, however, that very erroneous views are held on this subject. as far as is historically known, the disappearance of species from any one country has been slow--the species becoming rarer and rarer, locally extinct, and finally lost{333}. it may be objected that this has been effected by man's direct agency, or by his indirect agency in altering the state of the country; in this latter case, however, it would be difficult to draw any just distinction between his agency and natural agencies. but we now know in the later tertiary deposits, that shells become rarer and rarer in the successive beds, and finally disappear: it has happened, also, that shells common in a fossil state, and thought to have been extinct, have been found to be still living species, but very _rare_ ones{334}. if the rule is that organisms become extinct by becoming rarer and rarer, we ought not to view their extinction, even in the case of the larger quadrupeds, as anything wonderful and out of the common course of events. for no naturalist thinks it wonderful that one species of a genus should be rare and another abundant, notwithstanding he be quite incapable of explaining the causes of the comparative rareness{335}. why is one species of willow-wren or hawk or woodpecker common in england, and another extremely rare: why at the cape of good hope is one species of rhinoceros or antelope far more abundant than other species? why again is the same species much more abundant in one district of a country than in another district? no doubt there are in each case good causes: but they are unknown and unperceived by us. may we not then safely infer that as certain causes are acting _unperceived_ around us, and are making one species to be common and another exceedingly rare, that they might equally well cause the final extinction of some species without being perceived by us? we should always bear in mind that there is a recurrent struggle for life in every organism, and that in every country a destroying agency is always counteracting the geometrical tendency to increase in every species; and yet without our being able to tell with certainty at what period of life, or at what period of the year, the destruction falls the heaviest. ought we then to expect to trace the steps by which this destroying power, always at work and scarcely perceived by us, becomes increased, and yet if it continues to increase ever so slowly (without the fertility of the species in question be likewise increased) the average number of the individuals of that species must decrease, and become finally lost. i may give a single instance of a check causing local extermination which might long have escaped discovery{336}; the horse, though swarming in a wild state in la plata, and likewise under apparently the most unfavourable conditions in the scorched and alternately flooded plains of caraccas, will not in a wild state extend beyond a certain degree of latitude into the intermediate country of paraguay; this is owing to a certain fly depositing its eggs on the navels of the foals: as, however, man with a _little_ care can rear horses in a tame state _abundantly_ in paraguay, the problem of its extinction is probably complicated by the greater exposure of the wild horse to occasional famine from the droughts, to the attacks of the jaguar and other such evils. in the falkland islands the check to the _increase_ of the wild horse is said to be loss of the sucking foals{337}, from the stallions compelling the mares to travel across bogs and rocks in search of food: if the pasture on these islands decreased a little, the horse, perhaps, would cease to exist in a wild state, not from the absolute want of food, but from the impatience of the stallions urging the mares to travel whilst the foals were too young. {333} this corresponds approximately to _origin_, ed. i. p. 317, vi. p. 458. {334} the case of _trigonia_, a great secondary genus of shells surviving in a single species in the australian seas, is given as an example in the _origin_, ed. i. p. 321, vi. p. 463. {335} this point, on which the author laid much stress, is discussed in the _origin_, ed. i. p. 319, vi. p. 461. {336} _origin_, ed. i. p. 72, vi. p. 89. {337} this case does not occur in the _origin_, ed. from our more intimate acquaintance with domestic animals, we cannot conceive their extinction without some glaring agency; we forget that they would undoubtedly in a state of nature (where other animals are ready to fill up their place) be acted on in some part of their lives by a destroying agency, keeping their numbers on an average constant. if the common ox was known only as a wild s. african species, we should feel no surprise at hearing that it was a very rare species; and this rarity would be a stage towards its extinction. even in man, so infinitely better known than any other inhabitant of this world, how impossible it has been found, without statistical calculations, to judge of the proportions of births and deaths, of the duration of life, and of the increase and decrease of population; and still less of the causes of such changes: and yet, as has so often been repeated, decrease in numbers or rarity seems to be the high-road to extinction. to marvel at the extermination of a species appears to me to be the same thing as to know that illness is the road to death,--to look at illness as an ordinary event, nevertheless to conclude, when the sick man dies, that his death has been caused by some unknown and violent agency{338}. {338} an almost identical sentence occurs in the _origin_, ed. i. p. 320, vi. p. 462. in a future part of this work we shall show that, as a general rule, groups of allied species{339} gradually appear and disappear, one after the other, on the face of the earth, like the individuals of the same species: and we shall then endeavour to show the probable cause of this remarkable fact. {339} _origin_, ed. i. p. 316, vi. p. 457. chapter vi on the geographical distribution of organic beings in past and present times for convenience sake i shall divide this chapter into three sections{340}. in the first place i shall endeavour to state the laws of the distribution of existing beings, as far as our present object is concerned; in the second, that of extinct; and in the third section i shall consider how far these laws accord with the theory of allied species having a common descent. {340} chapters xi and xii in the _origin_, ed. i., vi. chs. xii and xiii ("on geographical distribution") show signs of having been originally one, in the fact that one summary serves for both. the geological element is not separately treated there, nor is there a separate section on "how far these laws accord with the theory, &c." in the ms. the author has here written in the margin "if same species appear at two spot at once, fatal to my theory." see _origin_, ed. i. p. 352, vi. p. 499 section first. _distribution of the inhabitants in the different continents._ in the following discussion i shall chiefly refer to terrestrial mammifers, inasmuch as they are better known; their differences in different countries, strongly marked; and especially as the necessary means of their transport are more evident, and confusion, from the accidental conveyance by man of a species from one district to another district, is less likely to arise. it is known that all mammifers (as well as all other organisms) are united in one great system; but that the different species, genera, or families of the same order inhabit different quarters of the globe. if we divide the land{341} into two divisions, according to the amount of difference, and disregarding the numbers of the terrestrial mammifers inhabiting them, we shall have first australia including new guinea; and secondly the rest of the world: if we make a three-fold division, we shall have australia, s. america, and the rest of the world; i must observe that north america is in some respects neutral land, from possessing some s. american forms, but i believe it is more closely allied (as it certainly is in its birds, plants and shells) with europe. if our division had been four-fold, we should have had australia, s. america, madagascar (though inhabited by few mammifers) and the remaining land: if five-fold, africa, especially the southern eastern parts, would have to be separated from the remainder of the world. these differences in the mammiferous inhabitants of the several main divisions of the globe cannot, it is well known, be explained by corresponding differences in their conditions{342}; how similar are parts of tropical america and africa; and accordingly we find some _analogous_ resemblances,--thus both have monkeys, both large feline animals, both large lepidoptera, and large dung-feeding beetles; both have palms and epiphytes; and yet the essential difference between their productions is as great as between those of the arid plains of the cape of good hope and the grass-covered savannahs of la plata{343}. consider the distribution of the marsupialia, which are eminently characteristic of australia, and in a lesser degree of s. america; when we reflect that animals of this division, feeding both on animal and vegetable matter, frequent the dry open or wooded plains and mountains of australia, the humid impenetrable forests of new guinea and brazil; the dry rocky mountains of chile, and the grassy plains of banda oriental, we must look to some other cause, than the nature of the country, for their absence in africa and other quarters of the world. {341} this division of the land into regions does not occur in the _origin_, ed. i. {342} _origin_, ed. i. p. 346, vi. p. 493. {343} opposite this passage is written "_not botanically_," in sir j. d. hooker's hand. the word _palms_ is underlined three times and followed by three exclamation marks. an explanatory note is added in the margin "singular paucity of palms and epiphytes in trop. africa compared with trop. america and ind. or." <=east indies>. furthermore it may be observed that _all_ the organisms inhabiting any country are not perfectly adapted to it{344}; i mean by not being perfectly adapted, only that some few other organisms can generally be found better adapted to the country than some of the aborigines. we must admit this when we consider the enormous number of horses and cattle which have run wild during the three last centuries in the uninhabited parts of st domingo, cuba, and s. america; for these animals must have supplanted some aboriginal ones. i might also adduce the same fact in australia, but perhaps it will be objected that 30 or 40 years has not been a sufficient period to test this power of struggling and overcoming the aborigines. we know the european mouse is driving before it that of new zealand, like the norway rat has driven before it the old english species in england. scarcely an island can be named, where casually introduced plants have not supplanted some of the native species: in la plata the cardoon covers square leagues of country on which some s. american plants must once have grown: the commonest weed over the whole of india is an introduced mexican poppy. the geologist who knows that slow changes are in progress, replacing land and water, will easily perceive that even if all the organisms of any country had originally been the best adapted to it, this could hardly continue so during succeeding ages without either extermination, or changes, first in the relative proportional numbers of the inhabitants of the country, and finally in their constitutions and structure. {344} this partly corresponds to _origin_, ed. i. p. 337, vi. p. 483. inspection of a map of the world at once shows that the five divisions, separated according to the greatest amount of difference in the mammifers inhabiting them, are likewise those most widely separated from each other by barriers{345} which mammifers cannot pass: thus australia is separated from new guinea and some small adjoining islets only by a narrow and shallow strait; whereas new guinea and its adjoining islets are cut off from the other east indian islands by deep water. these latter islands, i may remark, which fall into the great asiatic group, are separated from each other and the continent only by shallow water; and where this is the case we may suppose, from geological oscillations of level, that generally there has been recent union. south america, including the southern part of mexico, is cut off from north america by the west indies, and the great table-land of mexico, except by a mere fringe of tropical forests along the coast: it is owing, perhaps, to this fringe that n. america possesses some s. american forms. madagascar is entirely isolated. africa is also to a great extent isolated, although it approaches, by many promontories and by lines of shallower sea, to europe and asia: southern africa, which is the most distinct in its mammiferous inhabitants, is separated from the northern portion by the great sahara desert and the table-land of abyssinia. that the distribution of organisms is related to barriers, stopping their progress, we clearly see by comparing the distribution of marine and terrestrial productions. the marine animals being different on the two sides of land tenanted by the same terrestrial animals, thus the shells are wholly different on the opposite sides of the temperate parts of south america{346}, as they are (?) in the red sea and the mediterranean. we can at once perceive that the destruction of a barrier would permit two geographical groups of organisms to fuse and blend into one. but the original cause of groups being different on opposite sides of a barrier can only be understood on the hypothesis of each organism having been created or produced on one spot or area, and afterwards migrating as widely as its means of transport and subsistence permitted it. {345} on the general importance of barriers, see _origin_, ed. i. p. 347, vi. p. 494. {346} _origin_, ed. i. p. 348, vi. p. 495. _relation of range in genera and species._ it is generally{347} found, that where a genus or group ranges over nearly the entire world, many of the species composing the group have wide ranges: on the other hand, where a group is restricted to any one country, the species composing it generally have restricted ranges in that country{348}. thus among mammifers the feline and canine genera are widely distributed, and many of the individual species have enormous ranges [the genus mus i believe, however, is a strong exception to the rule]. mr gould informs me that the rule holds with birds, as in the owl genus, which is mundane, and many of the species range widely. the rule holds also with land and fresh-water mollusca, with butterflies and very generally with plants. as instances of the converse rule, i may give that division of the monkeys which is confined to s. america, and amongst plants, the cacti, confined to the same continent, the species of both of which have generally narrow ranges. on the ordinary theory of the separate creation of each species, the cause of these relations is not obvious; we can see no reason, because many allied species have been created in the several main divisions of the world, that several of these species should have wide ranges; and on the other hand, that species of the same group should have narrow ranges if all have been created in one main division of the world. as the result of such and probably many other unknown relations, it is found that, even in the same great classes of beings, the different divisions of the world are characterised by either merely different species, or genera, or even families: thus in cats, mice, foxes, s. america differs from asia and africa only in species; in her pigs, camels and monkeys the difference is generic or greater. again, whilst southern africa and australia differ more widely in their mammalia than do africa and s. america, they are more closely (though indeed very distantly) allied in their plants. {347} the same laws seem to govern distribution of species and genera, and individuals in time and space. {348} _origin_, ed. i. p. 404, vi. p. 559. _distribution of the inhabitants in the same continent._ if we now look at the distribution of the organisms in any one of the above main divisions of the world, we shall find it split up into many regions, with all or nearly all their species distinct, but yet partaking of one common character. this similarity of type in the subdivisions of a great region is equally well-known with the dissimilarity of the inhabitants of the several great regions; but it has been less often insisted on, though more worthy of remark. thus for instance, if in africa or s. america, we go from south to north{349}, or from lowland to upland, or from a humid to a dryer part, we find wholly different species of those genera or groups which characterise the continent over which we are passing. in these subdivisions we may clearly observe, as in the main divisions of the world, that sub-barriers divide different groups of species, although the opposite sides of such sub-barriers may possess nearly the same climate, and may be in other respects nearly similar: thus it is on the opposite sides of the cordillera of chile, and in a lesser degree on the opposite sides of the rocky mountains. deserts, arms of the sea, and even rivers form the barriers; mere preoccupied space seems sufficient in several cases: thus eastern and western australia, in the same latitude, with very similar climate and soils, have scarcely a plant, and few animals or birds, in common, although all belong to the peculiar genera characterising australia. it is in short impossible to explain the differences in the inhabitants, either of the main divisions of the world, or of these sub-divisions, by the differences in their physical conditions, and by the adaptation of their inhabitants. some other cause must intervene. {349} _origin_, ed. i. p. 349, vi. p. 496. we can see that the destruction of sub-barriers would cause (as before remarked in the case of the main divisions) two sub-divisions to blend into one; and we can only suppose that the original difference in the species, on the opposite sides of sub-barriers, is due to the creation or production of species in distinct areas, from which they have wandered till arrested by such sub-barriers. although thus far is pretty clear, it may be asked, why, when species in the same main division of the world were produced on opposite sides of a sub-barrier, both when exposed to similar conditions and when exposed to widely different influences (as on alpine and lowland tracts, as on arid and humid soils, as in cold and hot climates), have they invariably been formed on a similar type, and that type confined to this one division of the world? why when an ostrich{350} was produced in the southern parts of america, was it formed on the american type, instead of on the african or on australian types? why when hare-like and rabbit-like animals were formed to live on the savannahs of la plata, were they produced on the peculiar rodent type of s. america, instead of on the true{351} hare-type of north america, asia and africa? why when borrowing rodents, and camel-like animals were formed to tenant the cordillera, were they formed on the same type{352} with their representatives on the plains? why were the mice, and many birds of different species on the opposite sides of the cordillera, but exposed to a very similar climate and soil, created on the same peculiar s. american type? why were the plants in eastern and western australia, though wholly different as species, formed on the same peculiar australian types? the generality of the rule, in so many places and under such different circumstances, makes it highly remarkable and seems to demand some explanation. {350} the case of the ostrich (_rhea_) occurs in the _origin_, ed. i. p. 349, vi. p. 496. {351} there is a hare in s. america,--so bad example. {352} see _origin_, ed. i. p. 349, vi. p. 497. _insular faunas._ if we now look to the character of the inhabitants of small islands{353}, we shall find that those situated close to other land have a similar fauna with that land{354}, whilst those at a considerable distance from other land often possess an almost entirely peculiar fauna. the galapagos archipelago{355} is a remarkable instance of this latter fact; here almost every bird, its one mammifer, its reptiles, land and sea shells, and even fish, are almost all peculiar and distinct species, not found in any other quarter of the world: so are the majority of its plants. but although situated at the distance of between 500 and 600 miles from the s. american coast, it is impossible to even glance at a large part of its fauna, especially at the birds, without at once seeing that they belong to the american type{356}. hence, in fact, groups of islands thus circumstanced form merely small but well-defined sub-divisions of the larger geographical divisions. but the fact is in such cases far more striking: for taking the galapagos archipelago as an instance; in the first place we must feel convinced, seeing that every island is wholly volcanic and bristles with craters, that in a geological sense the whole is of recent origin comparatively with a continent; and as the species are nearly all peculiar, we must conclude that they have in the same sense recently been produced on this very spot; and although in the nature of the soil, and in a lesser degree in the climate, there is a wide difference with the nearer part of the s. american coast, we see that the inhabitants have been formed on the same closely allied type. on the other hand, these islands, as far as their physical conditions are concerned, resemble closely the cape de verde volcanic group, and yet how wholly unlike are the productions of these two archipelagoes. the cape de verde{357} group, to which may be added the canary islands, are allied in their inhabitants (of which many are peculiar species) to the coast of africa and southern europe, in precisely the same manner as the galapagos archipelago is allied to america. we here clearly see that mere geographical proximity affects, more than any relation of adaptation, the character of species. how many islands in the pacific exist far more like in their physical conditions to juan fernandez than this island is to the coast of chile, distant 300 miles; why then, except from mere proximity, should this island alone be tenanted by two very peculiar species of humming-birds--that form of birds which is so exclusively american? innumerable other similar cases might be adduced. {353} for the general problem of oceanic islands, see _origin_, ed. i. p. 388, vi. p. 541. {354} this is an illustration of the general theory of barriers (_origin_, ed. i. p. 347, vi. p. 494). at i. p. 391, vi. p. 544 the question is discussed from the point of view of means of transport. between the lines, above the words "with that land," the author wrote "cause, formerly joined, no one doubts after lyell." {355} _origin_, ed. i. p. 390, vi. p. 543. {356} see _origin_, ed. i. p. 397, vi. p. 552. {357} the cape de verde and galapagos archipelagoes are compared in the _origin_, ed. i. p. 398, vi. p. 553. see also _journal of researches_, 1860, p. 393. the galapagos archipelago offers another, even more remarkable, example of the class of facts we are here considering. most of its genera are, as we have said, american, many of them are mundane, or found everywhere, and some are quite or nearly confined to this archipelago. the islands are of absolutely similar composition, and exposed to the same climate; most of them are in sight of each other; and yet several of the islands are inhabited, each by peculiar species (or in some cases perhaps only varieties) of some of the genera characterising the archipelago. so that the small group of the galapagos islands typifies, and follows exactly the same laws in the distribution of its inhabitants, as a great continent. how wonderful it is that two or three closely similar but distinct species of a mocking-thrush{358} should have been produced on three neighbouring and absolutely similar islands; and that these three species of mocking-thrush should be closely related to the other species inhabiting wholly different climates and different districts of america, and only in america. no similar case so striking as this of the galapagos archipelago has hitherto been observed; and this difference of the productions in the different islands may perhaps be partly explained by the depth of the sea between them (showing that they could not have been united within recent geological periods), and by the currents of the sea sweeping _straight_ between them,--and by storms of wind being rare, through which means seeds and birds could be blown, or drifted, from one island to another. there are however some similar facts: it is said that the different, though neighbouring islands of the east indian archipelago are inhabited by some different species of the same genera; and at the sandwich group some of the islands have each their peculiar species of the same genera of plants. {358} in the _origin_, ed. i. p. 390, a strong point is made of birds which immigrated "with facility and in a body" not having been modified. thus the author accounts for the small percentage of peculiar "marine birds." islands standing quite isolated within the intra-tropical oceans have generally very peculiar floras, related, though feebly (as in the case of st helena{359} where almost every species is distinct), with the nearest continent: tristan d'acunha is feebly related, i believe, in its plants, both to africa and s. america, not by having species in common, but by the genera to which they belong{360}. the floras of the numerous scattered islands of the pacific are related to each other and to all the surrounding continents; but it has been said, that they have more of an indo-asiatic than american character{361}. this is somewhat remarkable, as america is nearer to all the eastern islands, and lies in the direction of the trade-wind and prevailing currents; on the other hand, all the heaviest gales come from the asiatic side. but even with the aid of these gales, it is not obvious on the ordinary theory of creation how the possibility of migration (without we suppose, with extreme improbability, that each species with an indo-asiatic character has actually travelled from the asiatic shores, where such species do not now exist) explains this asiatic character in the plants of the pacific. this is no more obvious than that (as before remarked) there should exist a relation between the creation of closely allied species in several regions of the world, and the fact of many such species having wide ranges; and on the other hand, of allied species confined to one region of the world having in that region narrow ranges. {359} "the affinities of the st helena flora are strongly south african." hooker's _lecture on insular floras_ in the _gardeners' chronicle_, jan. 1867. {360} it is impossible to make out the precise form which the author intended to give to this sentence, but the meaning is clear. {361} this is no doubt true, the flora of the sandwich group however has marked american affinities. _alpine floras._ we will now turn to the floras of mountain-summits which are well known to differ from the floras of the neighbouring lowlands. in certain characters, such as dwarfness of stature, hairiness, &c., the species from the most distant mountains frequently resemble each other,--a kind of analogy like that for instance of the succulency of most desert plants. besides this analogy, alpine plants present some eminently curious facts in their distribution. in some cases the summits of mountains, although immensely distant from each other, are clothed by the same identical species{362} which are likewise the same with those growing on the likewise very distant arctic shores. in other cases, although few or none of the species may be actually identical, they are closely related; whilst the plants of the lowland districts surrounding the two mountains in question will be wholly dissimilar. as mountain-summits, as far as their plants are concerned, are islands rising out of an ocean of land in which the alpine species cannot live, nor across which is there any known means of transport, this fact appears directly opposed to the conclusion which we have come to from considering the general distribution of organisms both on continents and on islands--namely, that the degree of relationship between the inhabitants of two points depends on the completeness and nature of the barriers between those points{363}. i believe, however, this anomalous case admits, as we shall presently see, of some explanation. we might have expected that the flora of a mountain summit would have presented the same relation to the flora of the surrounding lowland country, which any isolated part of a continent does to the whole, or an island does to the mainland, from which it is separated by a rather wide space of sea. this in fact is the case with the plants clothing the summits of _some_ mountains, which mountains it may be observed are particularly isolated; for instance, all the species are peculiar, but they belong to the forms characteristic of the surrounding continent, on the mountains of caraccas, of van dieman's land and of the cape of good hope{364}. on some other mountains, for instance tierra del fuego and in brazil, some of the plants though distinct species are s. american forms; whilst others are allied to or are identical with the alpine species of europe. in islands of which the lowland flora is distinct but allied to that of the nearest continent, the alpine plants are sometimes (or perhaps mostly) eminently peculiar and distinct{365}; this is the case on teneriffe, and in a lesser degree even on some of the mediterranean islands. {362} see _origin_, ed. i. p. 365, vi. p. 515. the present discussion was written before the publication of forbes' celebrated paper on the same subject; see _life and letters_, vol. i. p. 88. {363} the apparent breakdown of the doctrine of barriers is slightly touched on in the _origin_, ed. i. p. 365, vi. p. 515. {364} in the _origin_, ed. i. p. 375, vi. p. 526, the author points out that on the mountains at the cape of good hope "some few representative european forms are found, which have not been discovered in the inter-tropical parts of africa." {365} see hooker's _lecture on insular floras_ in the _gardeners' chronicle_, jan. 1867. if all alpine floras had been characterised like that of the mountain of caraccas, or of van dieman's land, &c., whatever explanation is possible of the general laws of geographical distribution would have applied to them. but the apparently anomalous case just given, namely of the mountains of europe, of some mountains in the united states (dr boott) and of the summits of the himalaya (royle), having many identical species in common conjointly with the arctic regions, and many species, though not identical, closely allied, require a separate explanation. the fact likewise of several of the species on the mountains of tierra del fuego (and in a lesser degree on the mountains of brazil) not belonging to american forms, but to those of europe, though so immensely remote, requires also a separate explanation. _cause of the similarity in the floras of some distant mountains._ now we may with confidence affirm, from the number of the then floating icebergs and low descent of the glaciers, that within a period so near that species of shells have remained the same, the whole of central europe and of north america (and perhaps of eastern asia) possessed a very cold climate; and therefore it is probable that the floras of these districts were the same as the present arctic one,--as is known to have been to some degree the case with then existing sea-shells, and those now living on the arctic shores. at this period the mountains must have been covered with ice of which we have evidence in the surfaces polished and scored by glaciers. what then would be the natural and almost inevitable effects of the gradual change into the present more temperate climate{366}? the ice and snow would disappear from the mountains, and as new plants from the more temperate regions of the south migrated northward, replacing the arctic plants, these latter would crawl{367} up the now uncovered mountains, and likewise be driven northward to the present arctic shores. if the arctic flora of that period was a nearly uniform one, as the present one is, then we should have the same plants on these mountain-summits and on the present arctic shores. on this view the arctic flora of that period must have been a widely extended one, more so than even the present one; but considering how similar the physical conditions must always be of land bordering on perpetual frost, this does not appear a great difficulty; and may we not venture to suppose that the almost infinitely numerous icebergs, charged with great masses of rocks, soil and _brushwood_{368} and often driven high up on distant beaches, might have been the means of widely distributing the seeds of the same species? {366} in the margin the author has written "(forbes)." this may have been inserted at a date later than 1844, or it may refer to a work by forbes earlier than his alpine paper. {367} see _origin_, ed. i. p. 367, vi. p. 517. {368} perhaps vitality checked by cold and so prevented germinating. i will only hazard one other observation, namely that during the change from an extremely cold climate to a more temperate one the conditions, both on lowland and mountain, would be singularly favourable for the diffusion of any existing plants, which could live on land, just freed from the rigour of eternal winter; for it would possess no inhabitants; and we cannot doubt that _preoccupation_{369} is the chief bar to the diffusion of plants. for amongst many other facts, how otherwise can we explain the circumstance that the plants on the opposite, though similarly constituted sides of a wide river in eastern europe (as i was informed by humboldt) should be widely different; across which river birds, swimming quadrupeds and the wind must often transport seeds; we can only suppose that plants already occupying the soil and freely seeding check the germination of occasionally transported seeds. {369} a note by the author gives "many authors" apparently as authority for this statement. at about the same period when icebergs were transporting boulders in n. america as far as 36° south, where the cotton tree now grows in south america, in latitude 42° (where the land is now clothed with forests having an almost tropical aspect with the trees bearing epiphytes and intertwined with canes), the same ice action was going on; is it not then in some degree probable that at this period the whole tropical parts of the two americas possessed{370} (as falconer asserts that india did) a more temperate climate? in this case the alpine plants of the long chain of the cordillera would have descended much lower and there would have been a broad high-road{371} connecting those parts of north and south america which were then frigid. as the present climate supervened, the plants occupying the districts which now are become in both hemispheres temperate and even semi-tropical must have been driven to the arctic and antarctic{372} regions; and only a few of the loftiest points of the cordillera can have retained their former connecting flora. the transverse chain of chiquitos might perhaps in a similar manner during the ice-action period have served as a connecting road (though a broken one) for alpine plants to become dispersed from the cordillera to the highlands of brazil. it may be observed that some (though not strong) reasons can be assigned for believing that at about this same period the two americas were not so thoroughly divided as they now are by the west indies and tableland of mexico. i will only further remark that the present most singularly close similarity in the vegetation of the lowlands of kerguelen's land{373} and of tierra del fuego (hooker), though so far apart, may perhaps be explained by the dissemination of seeds during this same cold period, by means of icebergs, as before alluded to{374}. {370} opposite to this passage, in the margin, the author has written:--"too hypothetical." {371} the cordillera is described as supplying a great line of invasion in the _origin_, ed. i. p. 378. {372} this is an approximation to the author's views on trans-tropical migration (_origin_, ed. i. pp. 376-8). see thiselton-dyer's interesting discussion in _darwin and modern science_, p. 304. {373} see hooker's _lecture on insular floras_ in the _gardeners' chronicle_, jan. 1867. {374} similarity of flora of coral islands easily explained. finally, i think we may safely grant from the foregoing facts and reasoning that the anomalous similarity in the vegetation of certain very distant mountain-summits is not in truth opposed to the conclusion of the intimate relation subsisting between proximity in space (in accordance with the means of transport in each class) and the degree of affinity of the inhabitants of any two countries. in the case of several quite isolated mountains, we have seen that the general law holds good. _whether the same species has been created more than once._ as the fact of the same species of plants having been found on mountain-summits immensely remote has been one chief cause of the belief of some species having been contemporaneously produced or created at two different points{375}, i will here briefly discuss this subject. on the ordinary theory of creation, we can see no reason why on two similar mountain-summits two similar species may not have been created; but the opposite view, independently of its simplicity, has been generally received from the analogy of the general distribution of all organisms, in which (as shown in this chapter) we almost always find that great and continuous barriers separate distinct series; and we are naturally led to suppose that the two series have been separately created. when taking a more limited view we see a river, with a quite similar country on both sides, with one side well stocked with a certain animal and on the other side not one (as is the case with the bizcacha{376} on the opposite sides of the plata), we are at once led to conclude that the bizcacha was produced on some one point or area on the western side of the river. considering our ignorance of the many strange chances of diffusion by birds (which occasionally wander to immense distances) and quadrupeds swallowing seeds and ova (as in the case of the flying water-beetle which disgorged the eggs of a fish), and of whirlwinds carrying seeds and animals into strong upper currents (as in the case of volcanic ashes and showers of hay, grain and fish{377}), and of the possibility of species having survived for short periods at intermediate spots and afterwards becoming extinct there{378}; and considering our knowledge of the great changes which _have_ taken place from subsidence and elevation in the surface of the earth, and of our ignorance of the greater changes which _may have_ taken place, we ought to be very slow in admitting the probability of double creations. in the case of plants on mountain-summits, i think i have shown how almost necessarily they would, under the past conditions of the northern hemisphere, be as similar as are the plants on the present arctic shores; and this ought to teach us a lesson of caution. {375} on centres of creation see _origin_, ed. i. p. 352, vi. p. 499. {376} in the _journal of researches_, ed. 1860, p. 124, the distribution of the bizcacha is described as limited by the river uruguay. the case is not i think given in the _origin_. {377} in the _origin_, ed. i. a special section (p. 356, vi. p. 504) is devoted to _means of dispersal_. the much greater prominence given to this subject in the _origin_ is partly accounted for by the author's experiments being of later date, _i.e._ 1855 (_life and letters_, vol. ii. p. 53). the carriage of fish by whirlwinds is given in the _origin_, ed. i. p. 384, vi. p. 536. {378} the case of islands serving as halting places is given in the _origin_, ed. i. p. 357, vi. p. 505. but here the evidence of this having occurred is supposed to be lost by the subsidence of the islands, not merely by the extinction of the species. but the strongest argument against double creations may be drawn from considering the case of mammifers{379} in which, from their nature and from the size of their offspring, the means of distribution are more in view. there are no cases where the same species is found in _very remote_ localities, except where there is a continuous belt of land: the arctic region perhaps offers the strongest exception, and here we know that animals are transported on icebergs{380}. the cases of lesser difficulty may all receive a more or less simple explanation; i will give only one instance; the nutria{381}, i believe, on the eastern coast of s. america live exclusively in fresh-water rivers, and i was much surprised how they could have got into rivulets, widely apart, on the coast of patagonia; but on the opposite coast i found these quadrupeds living exclusively in the sea, and hence their migration along the patagonian coast is not surprising. there is no case of the same mammifer being found on an island far from the coast, and on the mainland, as happens with plants{382}. on the idea of double creations it would be strange if the same species of several plants should have been created in australia and europe; and no one instance of the same species of mammifer having been created, or aboriginally existing, in two as nearly remote and equally isolated points. it is more philosophical, in such cases, as that of some plants being found in australia and europe, to admit that we are ignorant of the means of transport. i will allude only to one other case, namely, that of the mydas{383}, an alpine animal, found only on the distant peaks of the mountains of java: who will pretend to deny that during the ice period of the northern and southern hemispheres, and when india is believed to have been colder, the climate might not have permitted this animal to haunt a lower country, and thus to have passed along the ridges from summit to summit? mr lyell has further observed that, _as in space, so in time_, there is no reason to believe that after the extinction of a species, the self-same form has ever reappeared{384}. i think, then, we may, notwithstanding the many cases of difficulty, conclude with some confidence that every species has been created or produced on a single point or area. {379} "we find no inexplicable cases of the same mammal inhabiting distant points of the world." _origin_, ed. i. p. 352, vi. p. 500. see also _origin_, ed. i. p. 393, vi. p. 547. {380} many authors. {381} _nutria_ is the spanish for otter, and is now a synonym for _lutra_. the otter on the atlantic coast is distinguished by minute differences from the pacific species. both forms are said to take to the sea. in fact the case presents no especial difficulties. {382} in _origin_, ed. i. p. 394, vi. p. 548, bats are mentioned as an explicable exception to this statement. {383} this reference is doubtless to _mydaus_, a badger-like animal from the mountains of java and sumatra (wallace, _geographical distribution_, ii. p. 199). the instance does not occur in the _origin_ but the author remarks (_origin_, ed. i. p. 376, vi. p. 527) that cases, strictly analogous to the distribution of plants, occur among terrestrial mammals. {384} see _origin_, ed. i. p. 313, vi. p. 454. _on the number of species, and of the classes to which they belong in different regions._ the last fact in geographical distribution, which, as far as i can see, in any way concerns the origin of species, relates to the absolute number and nature of the organic beings inhabiting different tracts of land. although every species is admirably adapted (but not necessarily better adapted than every other species, as we have seen in the great increase of introduced species) to the country and station it frequents; yet it has been shown that the entire difference between the species in distant countries cannot possibly be explained by the difference of the physical conditions of these countries. in the same manner, i believe, neither the number of the species, nor the nature of the great classes to which they belong, can possibly in all cases be explained by the conditions of their country. new zealand{385}, a linear island stretching over about 700 miles of latitude, with forests, marshes, plains and mountains reaching to the limits of eternal snow, has far more diversified habitats than an equal area at the cape of good hope; and yet, i believe, at the cape of good hope there are, of phanerogamic plants, from five to ten times the number of species as in all new zealand. why on the theory of absolute creations should this large and diversified island only have from 400 to 500 (? dieffenbach) phanerogamic plants? and why should the cape of good hope, characterised by the uniformity of its scenery, swarm with more species of plants than probably any other quarter of the world? why on the ordinary theory should the galapagos islands abound with terrestrial reptiles? and why should many equal-sized islands in the pacific be without a single one{386} or with only one or two species? why should the great island of new zealand be without one mammiferous quadruped except the mouse, and that was probably introduced with the aborigines? why should not one island (it can be shown, i think, that the mammifers of mauritius and st iago have all been introduced) in the open ocean possess a mammiferous quadruped? let it not be said that quadrupeds cannot live in islands, for we know that cattle, horses and pigs during a long period have run wild in the west indian and falkland islands; pigs at st helena; goats at tahiti; asses in the canary islands; dogs in cuba; cats at ascension; rabbits at madeira and the falklands; monkeys at st iago and the mauritius; even elephants during a long time in one of the very small sooloo islands; and european mice on very many of the smallest islands far from the habitations of man{387}. nor let it be assumed that quadrupeds are more slowly created and hence that the oceanic islands, which generally are of volcanic formation, are of too recent origin to possess them; for we know (lyell) that new forms of quadrupeds succeed each other quicker than mollusca or reptilia. nor let it be assumed (though such an assumption would be no explanation) that quadrupeds cannot be created on small islands; for islands not lying in mid-ocean do possess their peculiar quadrupeds; thus many of the smaller islands of the east indian archipelago possess quadrupeds; as does fernando po on the west coast of africa; as the falkland islands possess a peculiar wolf-like fox{388}; so do the galapagos islands a peculiar mouse of the s. american type. these two last are the most remarkable cases with which i am acquainted; inasmuch as the islands lie further from other land. it is possible that the galapagos mouse may have been introduced in some ship from the s. american coast (though the species is at present unknown there), for the aboriginal species soon haunts the goods of man, as i noticed in the roof of a newly erected shed in a desert country south of the plata. the falkland islands, though between 200 and 300 miles from the s. american coast, may in one sense be considered as intimately connected with it; for it is certain that formerly many icebergs loaded with boulders were stranded on its southern coast, and the old canoes which are occasionally now stranded, show that the currents still set from tierra del fuego. this fact, however, does not explain the presence of the _canis antarcticus_ on the falkland islands, unless we suppose that it formerly lived on the mainland and became extinct there, whilst it survived on these islands, to which it was borne (as happens with its northern congener, the common wolf) on an iceberg, but this fact removes the anomaly of an island, in appearance effectually separated from other land, having its own species of quadruped, and makes the case like that of java and sumatra, each having their own rhinoceros. {385} the comparison between new zealand and the cape is given in the _origin_, ed. i. p. 389, vi. p. 542. {386} in a corresponding discussion in the _origin_, ed. i. p. 393, vi. p. 546, stress is laid on the distribution of batrachians not of reptiles. {387} the whole argument is given--more briefly than here--in the _origin_, ed. i. p. 394, vi. p. 547. {388} see _origin_, ed i. p. 393, vi. p. 547. the discussion is much fuller in the present essay. before summing up all the facts given in this section on the present condition of organic beings, and endeavouring to see how far they admit of explanation, it will be convenient to state all such facts in the past geographical distribution of extinct beings as seem anyway to concern the theory of descent. section second. _geographical distribution of extinct organisms._ i have stated that if the land of the entire world be divided into (we will say) three sections, according to the amount of difference of the terrestrial mammifers inhabiting them, we shall have three unequal divisions of (1st) australia and its dependent islands, (2nd) south america, (3rd) europe, asia and africa. if we now look to the mammifers which inhabited these three divisions during the later tertiary periods, we shall find them almost as distinct as at the present day, and intimately related in each division to the existing forms in that division{389}. this is wonderfully the case with the several fossil marsupial genera in the caverns of new south wales and even more wonderfully so in south america, where we have the same peculiar group of monkeys, of a guanaco-like animal, of many rodents, of the marsupial didelphys, of armadilloes and other edentata. this last family is at present very characteristic of s. america, and in a late tertiary epoch it was even more so, as is shown by the numerous enormous animals of the megatheroid family, some of which were protected by an osseous armour like that, but on a gigantic scale, of the recent armadillo. lastly, over europe the remains of the several deer, oxen, bears, foxes, beavers, field-mice, show a relation to the present inhabitants of this region; and the contemporaneous remains of the elephant, rhinoceros, hippopotamus, hyæna, show a relation with the grand africo-asiatic division of the world. in asia the fossil mammifers of the himalaya (though mingled with forms long extinct in europe) are equally related to the existing forms of the africo-asiatic division; but especially to those of india itself. as the gigantic and now extinct quadrupeds of europe have naturally excited more attention than the other and smaller remains, the relation between the past and the present mammiferous inhabitants of europe has not been sufficiently attended to. but in fact the mammifers of europe are at present nearly as much africo-asiatic as they were formerly when europe had its elephants and rhinoceroses, etc.; europe neither now nor then possessed peculiar groups as does australia and s. america. the extinction of certain peculiar forms in one quarter does not make the remaining mammifers of that quarter less related to its own great division of the world: though tierra del fuego possesses only a fox, three rodents, and the guanaco, no one (as these all belong to s. american types, but not to the most characteristic forms) would doubt for one minute classifying this district with s. america; and if fossil edentata, marsupials and monkeys were to be found in tierra del fuego, it would not make this district more truly s. american than it now is. so it is with europe{390}, and so far as is known with asia, for the lately past and present mammifers all belong to the africo-asiatic division of the world. in every case, i may add, the forms which a country has is of more importance in geographical arrangement than what it has not. {389} see _origin_, ed. i. p. 339, vi. p. 485. {390} in the _origin_, ed. i. p. 339, vi. p. 485, which corresponds to this part of the present essay, the author does not make a separate section for such cases as the occurrence of fossil marsupials in europe (_origin_, ed. i. p. 340, vi. p. 486) as he does in the present essay; see the section on _changes in geographical distribution_, p. 177. we find some evidence of the same general fact in a relation between the recent and the tertiary sea-shells, in the different main divisions of the marine world. this general and most remarkable relation between the lately past and present mammiferous inhabitants of the three main divisions of the world is precisely the same kind of fact as the relation between the different species of the several sub-regions of any one of the main divisions. as we usually associate great physical changes with the total extinction of one series of beings, and its succession by another series, this identity of relation between the past and the present races of beings in the same quarters of the globe is more striking than the same relation between existing beings in different sub-regions: but in truth we have no reason for supposing that a change in the conditions has in any of these cases supervened, greater than that now existing between the temperate and tropical, or between the highlands and lowlands of the same main divisions, now tenanted by related beings. finally, then, we clearly see that in each main division of the world the same relation holds good between its inhabitants in time as over space{391}. {391} "we can understand how it is that all the forms of life, ancient and recent, make together one grand system; for all are connected by generation." _origin_, ed. i. p. 344, vi. p. 491. _changes in geographical distribution._ if, however, we look closer, we shall find that even australia, in possessing a terrestrial pachyderm, was so far less distinct from the rest of the world than it now is; so was s. america in possessing the mastodon, horse, [hyæna,]{392} and antelope. n. america, as i have remarked, is now, in its mammifers, in some respects neutral ground between s. america and the great africo-asiatic division; formerly, in possessing the horse, mastodon and three megatheroid animals, it was more nearly related to s. america; but in the horse and mastodon, and likewise in having the elephant, oxen, sheep, and pigs, it was as much, if not more, related to the africo-asiatic division. again, northern india was much more closely related (in having the giraffe, hippopotamus, and certain musk-deer) to southern africa than it now is; for southern and eastern africa deserve, if we divide the world into five parts, to make one division by itself. turning to the dawn of the tertiary period, we must, from our ignorance of other portions of the world, confine ourselves to europe; and at that period, in the presence of marsupials{393} and edentata, we behold an _entire_ blending of those mammiferous forms which now eminently characterise australia and s. america{394}. {392} the word _hyæna_ is erased. there appear to be no fossil hyænidæ in s. america. {393} see note 1{390}, p. 175, also _origin_, ed. i. p. 340, vi. p. 486. {394} and see eocene european mammals in n. america. if we now look at the distribution of sea-shells, we find the same changes in distribution. the red sea and the mediterranean were more nearly related in these shells than they now are. in different parts of europe, on the other hand, during the miocene period, the sea-shells seem to have been more different than at present. in{395} the tertiary period, according to lyell, the shells of n. america and europe were less related than at present, and during the cretaceous still less like; whereas, during this same cretaceous period, the shells of india and europe were more like than at present. but going further back to the carbonaceous period, in n. america and europe, the productions were much more like than they now are{396}. these facts harmonise with the conclusions drawn from the present distribution of organic beings, for we have seen, that from species being created in different points or areas, the formation of a barrier would cause or make two distinct geographical areas; and the destruction of a barrier would permit their diffusion{397}. and as long-continued geological changes must both destroy and make barriers, we might expect, the further we looked backwards, the more changed should we find the present distribution. this conclusion is worthy of attention; because, finding in widely different parts of the same main division of the world, and in volcanic islands near them, groups of distinct, but related, species;--and finding that a singularly analogous relation holds good with respect to the beings of past times, when none of the present species were living, a person might be tempted to believe in some mystical relation between certain areas of the world, and the production of certain organic forms; but we now see that such an assumption would have to be complicated by the admission that such a relation, though holding good for long revolutions of years, is not truly persistent. {395} all this requires much verification. {396} this point seems to be less insisted on in the _origin_. {397} _origin_, ed. i. p. 356, vi. p. 504. i will only add one more observation to this section. geologists finding in the most remote period with which we are acquainted, namely in the silurian period, that the shells and other marine productions{398} in north and south america, in europe, southern africa, and western asia, are much more similar than they now are at these distant points, appear to have imagined that in these ancient times the laws of geographical distribution were quite different than what they now are: but we have only to suppose that great continents were extended east and west, and thus did not divide the inhabitants of the temperate and tropical seas, as the continents now do; and it would then become probable that the inhabitants of the seas would be much more similar than they now are. in the immense space of ocean extending from the east coast of africa to the eastern islands of the pacific, which space is connected either by lines of tropical coast or by islands not very distant from each other, we know (cuming) that many shells, perhaps even as many as 200, are common to the zanzibar coast, the philippines, and the eastern islands of the low or dangerous archipelago in the pacific. this space equals that from the arctic to the antarctic pole! pass over the space of quite open ocean, from the dangerous archipelago to the west coast of s. america, and every shell is different: pass over the narrow space of s. america, to its eastern shores, and again every shell is different! many fish, i may add, are also common to the pacific and indian oceans. {398} d'orbigny shows that this is not so. _summary on the distribution of living and extinct organic beings._ let us sum up the several facts now given with respect to the past and present geographical distribution of organic beings. in a previous chapter it was shown that species are not exterminated by universal catastrophes, and that they are slowly produced: we have also seen that each species is probably only once produced, on one point or area once in time; and that each diffuses itself, as far as barriers and its conditions of life permit. if we look at any one main division of the land, we find in the different parts, whether exposed to different conditions or to the same conditions, many groups of species wholly or nearly distinct as species, nevertheless intimately related. we find the inhabitants of islands, though distinct as species, similarly related to the inhabitants of the nearest continent; we find in some cases, that even the different islands of one such group are inhabited by species distinct, though intimately related to one another and to those of the nearest continent:--thus typifying the distribution of organic beings over the whole world. we find the floras of distant mountain-summits either very similar (which seems to admit, as shown, of a simple explanation) or very distinct but related to the floras of the surrounding region; and hence, in this latter case, the floras of two mountain-summits, although exposed to closely similar conditions, will be very different. on the mountain-summits of islands, characterised by peculiar faunas and floras, the plants are often eminently peculiar. the dissimilarity of the organic beings inhabiting nearly similar countries is best seen by comparing the main divisions of the world; in each of which some districts may be found very similarly exposed, yet the inhabitants are wholly unlike;--far more unlike than those in very dissimilar districts in the same main division. we see this strikingly in comparing two volcanic archipelagoes, with nearly the same climate, but situated not very far from two different continents; in which case their inhabitants are totally unlike. in the different main divisions of the world, the amount of difference between the organisms, even in the same class, is widely different, each main division having only the species distinct in some families, in other families having the genera distinct. the distribution of aquatic organisms is very different from that of the terrestrial organisms; and necessarily so, from the barriers to their progress being quite unlike. the nature of the conditions in an isolated district will not explain the number of species inhabiting it; nor the absence of one class or the presence of another class. we find that terrestrial mammifers are not present on islands far removed from other land. we see in two regions, that the species though distinct are more or less related, according to the greater or less _possibility_ of the transportal in past and present times of species from one to the other region; although we can hardly admit that all the species in such cases have been transported from the first to the second region, and since have become extinct in the first: we see this law in the presence of the fox on the falkland islands; in the european character of some of the plants of tierra del fuego; in the indo-asiatic character of the plants of the pacific; and in the circumstance of those genera which range widest having many species with wide ranges; and those genera with restricted ranges having species with restricted ranges. finally, we find in each of the main divisions of the land, and probably of the sea, that the existing organisms are related to those lately extinct. looking further backwards we see that the past geographical distribution of organic beings was different from the present; and indeed, considering that geology shows that all our land was once under water, and that where water now extends land is forming, the reverse could hardly have been possible. now these several facts, though evidently all more or less connected together, must by the creationist (though the geologist may explain some of the anomalies) be considered as so many ultimate facts. he can only say, that it so pleased the creator that the organic beings of the plains, deserts, mountains, tropical and temperature forests, of s. america, should all have some affinity together; that the inhabitants of the galapagos archipelago should be related to those of chile; and that some of the species on the similarly constituted islands of this archipelago, though most closely related, should be distinct; that all its inhabitants should be totally unlike those of the similarly volcanic and arid cape de verde and canary islands; that the plants on the summit of teneriffe should be eminently peculiar; that the diversified island of new zealand should have not many plants, and not one, or only one, mammifer; that the mammifers of s. america, australia and europe should be clearly related to their ancient and exterminated prototypes; and so on with other facts. but it is absolutely opposed to every analogy, drawn from the laws imposed by the creator on inorganic matter, that facts, when connected, should be considered as ultimate and not the direct consequences of more general laws. section third. _an attempt to explain the foregoing laws of geographical distribution, on the theory of allied species having a common descent._ first let us recall the circumstances most favourable for variation under domestication, as given in the first chapter--viz. 1st, a change, or repeated changes, in the conditions to which the organism has been exposed, continued through several seminal (_i.e._ not by buds or divisions) generations: 2nd, steady selection of the slight varieties thus generated with a fixed end in view: 3rd, isolation as perfect as possible of such selected varieties; that is, the preventing their crossing with other forms; this latter condition applies to all terrestrial animals, to most if not all plants and perhaps even to most (or all) aquatic organisms. it will be convenient here to show the advantage of isolation in the formation of a new breed, by comparing the progress of two persons (to neither of whom let time be of any consequence) endeavouring to select and form some very peculiar new breed. let one of these persons work on the vast herds of cattle in the plains of la plata{399}, and the other on a small stock of 20 or 30 animals in an island. the latter might have to wait centuries (by the hypothesis of no importance){400} before he obtained a "sport" approaching to what he wanted; but when he did and saved the greater number of its offspring and their offspring again, he might hope that his whole little stock would be in some degree affected, so that by continued selection he might gain his end. but on the pampas, though the man might get his first approach to his desired form sooner, how hopeless would it be to attempt, by saving its offspring amongst so many of the common kind, to affect the whole herd: the effect of this one peculiar "sport{401}" would be quite lost before he could obtain a second original sport of the same kind. if, however, he could separate a small number of cattle, including the offspring of the desirable "sport," he might hope, like the man on the island, to effect his end. if there be organic beings of which two individuals _never_ unite, then simple selection whether on a continent or island would be equally serviceable to make a new and desirable breed; and this new breed might be made in surprisingly few years from the great and geometrical powers of propagation to beat out the old breed; as has happened (notwithstanding crossing) where good breeds of dogs and pigs have been introduced into a limited country,--for instance, into the islands of the pacific. {399} this instance occurs in the essay of 1842, p. 32, but not in the _origin_; though the importance of isolation is discussed (_origin_, ed. i. p. 104, vi. p. 127). {400} the meaning of the words within parenthesis is obscure. {401} it is unusual to find the author speaking of the selection of _sports_ rather than small variations. let us now take the simplest natural case of an islet upheaved by the volcanic or subterranean forces in a deep sea, at such a distance from other land that only a few organic beings at rare intervals were transported to it, whether borne by the sea{402} (like the seeds of plants to coral-reefs), or by hurricanes, or by floods, or on rafts, or in roots of large trees, or the germs of one plant or animal attached to or in the stomach of some other animal, or by the intervention (in most cases the most probable means) of other islands since sunk or destroyed. it may be remarked that when one part of the earth's crust is raised it is probably the general rule that another part sinks. let this island go on slowly, century after century, rising foot by foot; and in the course of time we shall have instead a small mass of rock{403}, lowland and highland, moist woods and dry sandy spots, various soils, marshes, streams and pools: under water on the sea shore, instead of a rocky steeply shelving coast, we shall have in some parts bays with mud, sandy beaches and rocky shoals. the formation of the island by itself must often slightly affect the surrounding climate. it is impossible that the first few transported organisms could be perfectly adapted to all these stations; and it will be a chance if those successively transported will be so adapted. the greater number would probably come from the lowlands of the nearest country; and not even all these would be perfectly adapted to the new islet whilst it continued low and exposed to coast influences. moreover, as it is certain that all organisms are nearly as much adapted in their structure to the other inhabitants of their country as they are to its physical conditions, so the mere fact that a _few_ beings (and these taken in great degree by chance) were in the first case transported to the islet, would in itself greatly modify their conditions{404}. as the island continued rising we might also expect an occasional new visitant; and i repeat that even one new being must often affect beyond our calculation by occupying the room and taking part of the subsistence of another (and this again from another and so on), several or many other organisms. now as the first transported and any occasional successive visitants spread or tended to spread over the growing island, they would undoubtedly be exposed through several generations to new and varying conditions: it might also easily happen that some of the species _on an average_ might obtain an increase of food, or food of a more nourishing quality{405}. according then to every analogy with what we have seen takes place in every country, with nearly every organic being under domestication, we might expect that some of the inhabitants of the island would "sport," or have their organization rendered in some degree plastic. as the number of the inhabitants are supposed to be few and as all these cannot be so well adapted to their new and varying conditions as they were in their native country and habitat, we cannot believe that every place or office in the economy of the island would be as well filled as on a continent where the number of aboriginal species is far greater and where they consequently hold a more strictly limited place. we might therefore expect on our island that although very many slight variations were of no use to the plastic individuals, yet that occasionally in the course of a century an individual might be born{406} of which the structure or constitution in some slight degree would allow it better to fill up some office in the insular economy and to struggle against other species. if such were the case the individual and its offspring would have a better _chance_ of surviving and of beating out its parent form; and if (as is probable) it and its offspring crossed with the unvaried parent form, yet the number of the individuals being not very great, there would be a chance of the new and more serviceable form being nevertheless in some slight degree preserved. the struggle for existence would go on annually selecting such individuals until a new race or species was formed. either few or all the first visitants to the island might become modified, according as the physical conditions of the island and those resulting from the kind and number of other transported species were different from those of the parent country--according to the difficulties offered to fresh immigration--and according to the length of time since the first inhabitants were introduced. it is obvious that whatever was the country, generally the nearest from which the first tenants were transported, they would show an affinity, even if all had become modified, to the natives of that country and even if the inhabitants of the same source (?) had been modified. on this view we can at once understand the cause and meaning of the affinity of the fauna and flora of the galapagos islands with that of the coast of s. america; and consequently why the inhabitants of these islands show not the smallest affinity with those inhabiting other volcanic islands, with a very similar climate and soil, near the coast of africa{407}. {402} this brief discussion is represented in the _origin_, ed. i. by a much fuller one (pp. 356, 383, vi. pp. 504, 535). see, however, the section in the present essay, p. 168. {403} on the formation of new stations, see _origin_, ed. i. p. 292, vi. p. 429. {404} _origin_, ed. i. pp. 390, 400, vi. pp. 543, 554. {405} in the ms. _some of the species ... nourishing quality_ is doubtfully erased. it seems clear that he doubted whether such a problematical supply of food would be likely to cause variation. {406} at this time the author clearly put more faith in the importance of sport-like variation than in later years. {407} _origin_, ed. i. p. 398, vi. p. 553. to return once again to our island, if by the continued action of the subterranean forces other neighbouring islands were formed, these would generally be stocked by the inhabitants of the first island, or by a few immigrants from the neighbouring mainland; but if considerable obstacles were interposed to any communication between the terrestrial productions of these islands, and their conditions were different (perhaps only by the number of different species on each island), a form transported from one island to another might become altered in the same manner as one from the continent; and we should have several of the islands tenanted by representative races or species, as is so wonderfully the case with the different islands of the galapagos archipelago. as the islands become mountainous, if mountain-species were not introduced, as could rarely happen, a greater amount of variation and selection would be requisite to adapt the species, which originally came from the lowlands of the nearest continent, to the mountain-summits than to the lower districts of our islands. for the lowland species from the continent would have first to struggle against other species and other conditions on the coast-land of the island, and so probably become modified by the selection of its best fitted varieties, then to undergo the same process when the land had attained a moderate elevation; and then lastly when it had become alpine. hence we can understand why the faunas of insular mountain-summits are, as in the case of teneriffe, eminently peculiar. putting on one side the case of a widely extended flora being driven up the mountain-summits, during a change of climate from cold to temperate, we can see why in other cases the floras of mountain-summits (or as i have called them islands in a sea of land) should be tenanted by peculiar species, but related to those of the surrounding lowlands, as are the inhabitants of a real island in the sea to those of the nearest continent{408}. {408} see _origin_, ed. i. p. 403, vi. p. 558, where the author speaks of alpine humming birds, rodents, plants, &c. in s. america, all of strictly american forms. in the ms. the author has added between the lines "as world has been getting hotter, there has been radiation from high-lands,--old view?--curious; i presume diluvian in origin." let us now consider the effect of a change of climate or of other conditions on the inhabitants of a continent and of an isolated island without any great change of level. on a continent the chief effects would be changes in the numerical proportion of the individuals of the different species; for whether the climate became warmer or colder, drier or damper, more uniform or extreme, some species are at present adapted to its diversified districts; if for instance it became cooler, species would migrate from its more temperate parts and from its higher land; if damper, from its damper regions, &c. on a small and isolated island, however, with few species, and these not adapted to much diversified conditions, such changes instead of merely increasing the number of certain species already adapted to such conditions, and decreasing the number of other species, would be apt to affect the constitutions of some of the insular species: thus if the island became damper it might well happen that there were no species living in any part of it adapted to the consequences resulting from more moisture. in this case therefore, and still more (as we have seen) during the production of new stations from the elevation of the land, an island would be a far more fertile source, as far as we can judge, of new specific forms than a continent. the new forms thus generated on an island, we might expect, would occasionally be transported by accident, or through long-continued geographical changes be enabled to emigrate and thus become slowly diffused. but if we look to the origin of a continent; almost every geologist will admit that in most cases it will have first existed as separate islands which gradually increased in size{409}; and therefore all that which has been said concerning the probable changes of the forms tenanting a small archipelago is applicable to a continent in its early state. furthermore, a geologist who reflects on the geological history of europe (the only region well known) will admit that it has been many times depressed, raised and left stationary. during the sinking of a continent and the probable generally accompanying changes of climate the effect would be little, _except_ on the numerical proportions and in the extinction (from the lessening of rivers, the drying of marshes and the conversion of high-lands into low &c.) of some or of many of the species. as soon however as the continent became divided into many isolated portions or islands, preventing free immigration from one part to another, the effect of climatic and other changes on the species would be greater. but let the now broken continent, forming isolated islands, begin to rise and new stations thus to be formed, exactly as in the first case of the upheaved volcanic islet, and we shall have equally favourable conditions for the modification of old forms, that is the formation of new races or species. let the islands become reunited into a continent; and then the new and old forms would all spread, as far as barriers, the means of transportal, and the preoccupation of the land by other species, would permit. some of the new species or races would probably become extinct, and some perhaps would cross and blend together. we should thus have a multitude of forms, adapted to all kinds of slightly different stations, and to diverse groups of either antagonist or food-serving species. the oftener these oscillations of level had taken place (and therefore generally the older the land) the greater the number of species would tend to be formed. the inhabitants of a continent being thus derived in the first stage from the same original parents, and subsequently from the inhabitants of one wide area, since often broken up and reunited, all would be obviously related together and the inhabitants of the most _dissimilar_ stations on the same continent would be more closely allied than the inhabitants of two very _similar_ stations on two of the main divisions of the world{410}. {409} see the comparison between the malay archipelago and the probable former state of europe, _origin_, ed. i. p. 299, vi. p. 438, also _origin_, ed. i. p. 292, vi. p. 429. {410} _origin_, ed. i. p. 349, vi. p. 496. the arrangement of the argument in the present essay leads to repetition of statements made in the earlier part of the book: in the _origin_ this is avoided. i need hardly point out that we now can obviously see why the number of species in two districts, independently of the number of stations in such districts, should be in some cases as widely different as in new zealand and the cape of good hope{411}. we can see, knowing the difficulty in the transport of terrestrial mammals, why islands far from mainlands do not possess them{412}; we see the general reason, namely accidental transport (though not the precise reason), why certain islands should, and others should not, possess members of the class of reptiles. we can see why an ancient channel of communication between two distant points, as the cordillera probably was between southern chile and the united states during the former cold periods; and icebergs between the falkland islands and tierra del fuego; and gales, at a former or present time, between the asiatic shores of the pacific and eastern islands in this ocean; is connected with (or we may now say causes) an affinity between the species, though distinct, in two such districts. we can see how the better chance of diffusion, from several of the species of any genus having wide ranges in their own countries, explains the presence of other species of the same genus in other countries{413}; and on the other hand, of species of restricted powers of ranging, forming genera with restricted ranges. {411} _origin_, ed. i. p. 389, vi. p. 542. {412} _origin_, ed. i. p. 393, vi. p. 547. {413} _origin_, ed. i. pp. 350, 404, vi. pp. 498, 559. as every one would be surprised if two exactly similar but peculiar varieties{414} of any species were raised by man by long continued selection, in two different countries, or at two very different periods, so we ought not to expect that an exactly similar form would be produced from the modification of an old one in two distinct countries or at two distinct periods. for in such places and times they would probably be exposed to somewhat different climates and almost certainly to different associates. hence we can see why each species appears to have been produced singly, in space and in time. i need hardly remark that, according to this theory of descent, there is no necessity of modification in a species, when it reaches a new and isolated country. if it be able to survive and if slight variations better adapted to the new conditions are not selected, it might retain (as far as we can see) its old form for an indefinite time. as we see that some sub-varieties produced under domestication are more variable than others, so in nature, perhaps, some species and genera are more variable than others. the same precise form, however, would probably be seldom preserved through successive geological periods, or in widely and differently conditioned countries{415}. {414} _origin_, ed. i. p. 352, vi. p. 500. {415} _origin_, ed. i. p. 313, vi. p. 454. finally, during the long periods of time and probably of oscillations of level, necessary for the formation of a continent, we may conclude (as above explained) that many forms would become extinct. these extinct forms, and those surviving (whether or not modified and changed in structure), will all be related in each continent in the same manner and degree, as are the inhabitants of any two different sub-regions in that same continent. i do not mean to say that, for instance, the present marsupials of australia or edentata and rodents of s. america have descended from any one of the few fossils of the same orders which have been discovered in these countries. it is possible that, in a very few instances, this may be the case; but generally they must be considered as merely codescendants of common stocks{416}. i believe in this, from the improbability, considering the vast number of species, which (as explained in the last chapter) must by our theory have existed, that the _comparatively_ few fossils which have been found should chance to be the immediate and linear progenitors of those now existing. recent as the yet discovered fossil mammifers of s. america are, who will pretend to say that very many intermediate forms may not have existed? moreover, we shall see in the ensuing chapter that the very existence of genera and species can be explained only by a few species of each epoch leaving modified successors or new species to a future period; and the more distant that future period, the fewer will be the _linear_ heirs of the former epoch. as by our theory, all mammifers must have descended from the same parent stock, so is it necessary that each land now possessing terrestrial mammifers shall at some time have been so far united to other land as to permit the passage of mammifers{417}; and it accords with this necessity, that in looking far back into the earth's history we find, first changes in the geographical distribution, and secondly a period when the mammiferous forms most distinctive of two of the present main divisions of the world were living together{418}. {416} _origin_, ed. i. p. 341, vi. p. 487. {417} _origin_, ed. i. p. 396, vi. p. 549. {418} _origin_, ed. i. p. 340, vi. p. 486. i think then i am justified in asserting that most of the above enumerated and often trivial points in the geographical distribution of past and present organisms (which points must be viewed by the creationists as so many ultimate facts) follow as a simple consequence of specific forms being mutable and of their being adapted by natural selection to diverse ends, conjoined with their powers of dispersal, and the geologico-geographical changes now in slow progress and which undoubtedly have taken place. this large class of facts being thus explained, far more than counterbalances many separate difficulties and apparent objections in convincing my mind of the truth of this theory of common descent. _improbability of finding fossil forms intermediate between existing species._ there is one observation of considerable importance that may be here introduced, with regard to the improbability of the chief transitional forms between any two species being found fossil. with respect to the finer shades of transition, i have before remarked that no one has any cause to expect to trace them in a fossil state, without he be bold enough to imagine that geologists at a future epoch will be able to trace from fossil bones the gradations between the short-horns, herefordshire, and alderney breeds of cattle{419}. i have attempted to show that rising islands, in process of formation, must be the best nurseries of new specific forms, and these points are the least favourable for the embedment of fossils{420}: i appeal, as evidence, to the state of the _numerous_ scattered islands in the several great oceans: how rarely do any sedimentary deposits occur on them; and when present they are mere narrow fringes of no great antiquity, which the sea is generally wearing away and destroying. the cause of this lies in isolated islands being generally volcanic and rising points; and the effects of subterranean elevation is to bring up the surrounding newly-deposited strata within the destroying action of the coast-waves: the strata, deposited at greater distances, and therefore in the depths of the ocean, will be almost barren of organic remains. these remarks may be generalised:--periods of subsidence will always be most favourable to an accumulation of great thicknesses of strata, and consequently to their long preservation; for without one formation be protected by successive strata, it will seldom be preserved to a distant age, owing to the enormous amount of denudation, which seems to be a general contingent of time{421}. i may refer, as evidence of this remark, to the vast amount of subsidence evident in the great pile of the european formations, from the silurian epoch to the end of the secondary, and perhaps to even a later period. periods of elevation on the other hand cannot be favourable to the accumulation of strata and their preservation to distant ages, from the circumstance just alluded to, viz. of elevation tending to bring to the surface the circum-littoral strata (always abounding most in fossils) and destroying them. the bottom of tracts of deep water (little favourable, however, to life) must be excepted from this unfavourable influence of elevation. in the quite open ocean, probably no sediment{422} is accumulating, or at a rate so slow as not to preserve fossil remains, which will always be subject to disintegration. caverns, no doubt, will be equally likely to preserve terrestrial fossils in periods of elevation and of subsidence; but whether it be owing to the enormous amount of denudation, which all land seems to have undergone, no cavern with fossil bones has been found belonging to the secondary period{423}. {419} _origin_, ed. i. p. 299, vi. p. 437. {420} "nature may almost be said to have guarded against the frequent discovery of her transitional or linking forms," _origin_, ed. i. p. 292. a similar but not identical passage occurs in _origin_, ed. vi. p. 428. {421} _origin_, ed. i. p. 291, vi. p. 426. {422} _origin_, ed. i. p. 288, vi. p. 422. {423} _origin_, ed. i. p. 289, vi. p. 423. hence many more remains will be preserved to a distant age, in any region of the world, during periods of its subsidence{424}, than of its elevation. {424} _origin_, ed. i. p. 300, vi. p. 439. but during the subsidence of a tract of land, its inhabitants (as before shown) will from the decrease of space and of the diversity of its stations, and from the land being fully preoccupied by species fitted to diversified means of subsistence, be little liable to modification from selection, although many may, or rather must, become extinct. with respect to its circum-marine inhabitants, although during a change from a continent to a _great_ archipelago, the number of stations fitted for marine beings will be increased, their means of diffusion (an important check to change of form) will be greatly improved; for a continent stretching north and south, or a quite open space of ocean, seems to be to them the only barrier. on the other hand, during the elevation of a small archipelago and its conversion into a continent, we have, whilst the number of stations are increasing, both for aquatic and terrestrial productions, and whilst these stations are not fully preoccupied by perfectly adapted species, the most favourable conditions for the selection of new specific forms; but few of them in their early transitional states will be preserved to a distant epoch. we must wait during an enormous lapse of time, until long-continued subsidence shall have taken the place in this quarter of the world of the elevatory process, for the best conditions of the embedment and the preservation of its inhabitants. generally the great mass of the strata in every country, from having been chiefly accumulated during subsidence, will be the tomb, not of transitional forms, but of those either becoming extinct or remaining unmodified. the state of our knowledge, and the slowness of the changes of level, do not permit us to test the truth of these remarks, by observing whether there are more transitional or "fine" (as naturalists would term them) species, on a rising and enlarging tract of land, than on an area of subsidence. nor do i know whether there are more "fine" species on isolated volcanic islands in process of formation, than on a continent; but i may remark, that at the galapagos archipelago the number of forms, which according to some naturalists are true species, and according to others are mere races, is considerable: this particularly applies to the different species or races of the same genera inhabiting the different islands of this archipelago. furthermore it may be added (as bearing on the great facts discussed in this chapter) that when naturalists confine their attention to any one country, they have comparatively little difficulty in determining what forms to call species and what to call varieties; that is, those which can or cannot be traced or shown to be probably descendants of some other form: but the difficulty increases, as species are brought from many stations, countries and islands. it was this increasing (but i believe in few cases insuperable) difficulty which seems chiefly to have urged lamarck to the conclusion that species are mutable. chapter vii on the nature of the affinities and classification of organic beings{425} {425} ch. xiii of the _origin_, ed. i., ch. xiv ed. vi. begins with a similar statement. in the present essay the author adds a note:--"the obviousness of the fact (_i.e._ the natural grouping of organisms) alone prevents it being remarkable. it is scarcely explicable by creationist: groups of aquatic, of vegetable feeders and carnivorous, &c., might resemble each other; but why as it is. so with plants,--analogical resemblance thus accounted for. must not here enter into details." this argument is incorporated with the text in the _origin_, ed. i. _gradual appearance and disappearance of groups._ it has been observed from the earliest times that organic beings fall into groups{426}, and these groups into others of several values, such as species into genera, and then into sub-families, into families, orders, &c. the same fact holds with those beings which no longer exist. groups of species seem to follow the same laws in their appearance and extinction{427}, as do the individuals of any one species: we have reason to believe that, first, a few species appear, that their numbers increase; and that, when tending to extinction, the numbers of the species decrease, till finally the group becomes extinct, in the same way as a species becomes extinct, by the individuals becoming rarer and rarer. moreover, groups, like the individuals of a species, appear to become extinct at different times in different countries. the palæotherium was extinct much sooner in europe than in india: the trigonia{428} was extinct in early ages in europe, but now lives in the seas of australia. as it happens that one species of a family will endure for a much longer period than another species, so we find that some whole groups, such as mollusca, tend to retain their forms, or to remain persistent, for longer periods than other groups, for instance than the mammalia. groups therefore, in their appearance, extinction, and rate of change or succession, seem to follow nearly the same laws with the individuals of a species{429}. {426} _origin_, ed. i. p. 411, vi. p. 566. {427} _origin_, ed. i. p. 316, vi. p. 457. {428} _origin_, ed. i. p. 321, vi. p. 463. {429} in the _origin_, ed. i. this preliminary matter is replaced (pp. 411, 412, vi. pp. 566, 567) by a discussion in which extinction is also treated, but chiefly from the point of view of the theory of divergence. _what is the natural system?_ the proper arrangement of species into groups, according to the natural system, is the object of all naturalists; but scarcely two naturalists will give the same answer to the question, what is the natural system and how are we to recognise it? the most important characters{430} it might be thought (as it was by the earliest classifiers) ought to be drawn from those parts of the structure which determine its habits and place in the economy of nature, which we may call the final end of its existence. but nothing is further from the truth than this; how much external resemblance there is between the little otter (chironectes) of guiana and the common otter; or again between the common swallow and the swift; and who can doubt that the means and ends of their existence are closely similar, yet how grossly wrong would be the classification, which put close to each other a marsupial and placental animal, and two birds with widely different skeletons. relations, such as in the two latter cases, or as that between the whale and fishes, are denominated "analogical{431}," or are sometimes described as "relations of adaption." they are infinitely numerous and often very singular; but are of no use in the classification of the higher groups. how it comes, that certain parts of the structure, by which the habits and functions of the species are settled, are of no use in classification, whilst other parts, formed at the same time, are of the greatest, it would be difficult to say, on the theory of separate creations. {430} _origin_, ed. i. p. 414, vi. p. 570. {431} _origin_, ed. i. p. 414, vi. p. 570. some authors as lamarck, whewell &c., believe that the degree of affinity on the natural system depends on the degrees of resemblance in organs more or less physiologically important for the preservation of life. this scale of importance in the organs is admitted to be of difficult discovery. but quite independent of this, the proposition, as a general rule, must be rejected as false; though it may be partially true. for it is universally admitted that the same part or organ, which is of the highest service in classification in one group, is of very little use in another group, though in both groups, as far as we can see, the part or organ is of equal physiological importance: moreover, characters quite unimportant physiologically, such as whether the covering of the body consists of hair or feathers, whether the nostrils communicated with the mouth{432} &c., &c., are of the highest generality in classification; even colour, which is so inconstant in many species, will sometimes well characterise even a whole group of species. lastly, the fact, that no one character is of so much importance in determining to what great group an organism belongs, as the forms through which the embryo{433} passes from the germ upwards to maturity, cannot be reconciled with the idea that natural classification follows according to the degrees of resemblance in the parts of most physiological importance. the affinity of the common rock-barnacle with the crustaceans can hardly be perceived in more than a single character in its mature state, but whilst young, locomotive, and furnished with eyes, its affinity cannot be mistaken{434}. the cause of the greater value of characters, drawn from the early stages of life, can, as we shall in a succeeding chapter see, be in a considerable degree explained, on the theory of descent, although inexplicable on the views of the creationist. {432} these instances occur with others in the _origin_, ed. i. p. 416, vi. p. 572. {433} _origin_, ed. i. p. 418, vi. p. 574. {434} _origin_, ed. i. pp. 419, 440, vi. pp. 575, 606. practically, naturalists seem to classify according to the resemblance of those parts or organs which in related groups are most uniform, or vary least{435}: thus the æstivation, or manner in which the petals etc. are folded over each other, is found to afford an unvarying character in most families of plants, and accordingly any difference in this respect would be sufficient to cause the rejection of a species from many families; but in the rubiaceæ the æstivation is a varying character, and a botanist would not lay much stress on it, in deciding whether or not to class a new species in this family. but this rule is obviously so arbitrary a formula, that most naturalists seem to be convinced that something ulterior is represented by the natural system; they appear to think that we only discover by such similarities what the arrangement of the system is, not that such similarities make the system. we can only thus understand linnæus'{436} well-known saying, that the characters do not make the genus; but that the genus gives the characters: for a classification, independent of characters, is here presupposed. hence many naturalists have said that the natural system reveals the plan of the creator: but without it be specified whether order in time or place, or what else is meant by the plan of the creator, such expressions appear to me to leave the question exactly where it was. {435} _origin_, ed. i. pp. 418, 425, vi. pp. 574, 581. {436} _origin_, ed. i. p. 413, vi. p. 569. some naturalists consider that the geographical position{437} of a species may enter into the consideration of the group into which it should be placed; and most naturalists (either tacitly or openly) give value to the different groups, not solely by their relative differences in structure, but by the number of forms included in them. thus a genus containing a few species might be, and has often been, raised into a family on the discovery of several other species. many natural families are retained, although most closely related to other families, from including a great number of closely similar species. the more logical naturalist would perhaps, if he could, reject these two contingents in classification. from these circumstances, and especially from the undefined objects and criterions of the natural system, the number of divisions, such as genera, sub-families, families, &c., &c., has been quite arbitrary{438}; without the clearest definition, how can it be possible to decide whether two groups of species are of equal value, and of what value? whether they should both be called genera or families; or whether one should be a genus, and the other a family{439}? {437} _origin_, ed. i. pp. 419, 427, vi. pp. 575, 582. {438} this is discussed from the point of view of divergence in the _origin_, ed. i. pp. 420, 421, vi. pp. 576, 577. {439} i discuss this because if quinarism true, i false. _on the kind of relation between distinct groups._ i have only one other remark on the affinities of organic beings; that is, when two quite distinct groups approach each other, the approach is _generally_ generic{440} and not special; i can explain this most easily by an example: of all rodents the bizcacha, by certain peculiarities in its reproductive system, approaches nearest to the marsupials; of all marsupials the phascolomys, on the other hand, appears to approach in the form of its teeth and intestines nearest to the rodents; but there is no special relation between these two genera{441}; the bizcacha is no nearer related to the phascolomys than to any other marsupial in the points in which it approaches this division; nor again is the phascolomys, in the points of structure in which it approaches the rodents, any nearer related to the bizcacha than to any other rodent. other examples might have been chosen, but i have given (from waterhouse) this example as it illustrates another point, namely, the difficulty of determining what are analogical or adaptive and what real affinities; it seems that the teeth of the phascolomys though _appearing closely_ to resemble those of a rodent are found to be built on the marsupial type; and it is thought that these teeth and consequently the intestines may have been adapted to the peculiar life of this animal and therefore may not show any real relation. the structure in the bizcacha that connects it with the marsupials does not seem a peculiarity related to its manner of life, and i imagine that no one would doubt that this shows a real affinity, though not more with any one marsupial species than with another. the difficulty of determining what relations are real and what analogical is far from surprising when no one pretends to define the meaning of the term relation or the ulterior object of all classification. we shall immediately see on the theory of descent how it comes that there should be "real" and "analogical" affinities; and why the former alone should be of value in classification--difficulties which it would be i believe impossible to explain on the ordinary theory of separate creations. {440} in the corresponding passage in the _origin_, ed. i. p. 430, vi. p. 591, the term _general_ is used in place of _generic_, and seems a better expression. in the margin the author gives waterhouse as his authority. {441} _origin_, ed. i. p. 430, vi. p. 591. _classification of races or varieties._ let us now for a few moments turn to the classification of the generally acknowledged varieties and subdivisions of our domestic beings{442}; we shall find them systematically arranged in groups of higher and higher value. de candolle has treated the varieties of the cabbage exactly as he would have done a natural family with various divisions and subdivisions. in dogs again we have one main division which may be called the _family_ of hounds; of these, there are several (we will call them) _genera_, such as blood-hounds, fox-hounds, and harriers; and of each of these we have different _species_, as the blood-hound of cuba and that of england; and of the latter again we have breeds truly producing their own kind, which may be called races or varieties. here we see a classification practically used which typifies on a lesser scale that which holds good in nature. but amongst true species in the natural system and amongst domestic races the number of divisions or groups, instituted between those most alike and those most unlike, seems to be quite arbitrary. the number of the forms in both cases seems practically, whether or not it ought theoretically, to influence the denomination of groups including them. in both, geographical distribution has sometimes been used as an aid to classification{443}; amongst varieties, i may instance, the cattle of india or the sheep of siberia, which from possessing some characters in common permit a classification of indian and european cattle, or siberian and european sheep. amongst domestic varieties we have even something very like the relations of "analogy" or "adaptation{444}"; thus the common and swedish turnip are both artificial varieties which strikingly resemble each other, and they fill nearly the same end in the economy of the farm-yard; but although the swede so much more resembles a turnip than its presumed parent the field cabbage, no one thinks of putting it out of the cabbages into the turnips. thus the greyhound and racehorse, having been selected and trained for extreme fleetness for short distances, present an analogical resemblance of the same kind, but less striking as that between the little otter (marsupial) of guiana and the common otter; though these two otters are really less related than the horse and dog. we are even cautioned by authors treating on varieties, to follow the _natural_ in contradistinction of an artificial system and not, for instance, to class two varieties of the pine-apple{445} near each other, because their fruits accidentally resemble each other closely (though the fruit may be called _the final end_ of this plant in the economy of its world, the hothouse), but to judge from the general resemblance of the entire plants. lastly, varieties often become extinct; sometimes from unexplained causes, sometimes from accident, but more often from the production of more useful varieties, and the less useful ones being destroyed or bred out. {442} in a corresponding passage in the _origin_, ed. i. p. 423, vi. p. 579, the author makes use of his knowledge of pigeons. the pseudo-genera among dogs are discussed in _var. under dom._, ed. ii. vol. i. p. 38. {443} _origin_, ed. i. pp. 419, 427, vi. pp. 575, 582. {444} _origin_, ed. i. pp. 423, 427, vi. pp. 579, 583. {445} _origin_, ed. i. p. 423, vi. p. 579. i think it cannot be doubted that the main cause of all the varieties which have descended from the aboriginal dog or dogs, or from the aboriginal wild cabbage, not being equally like or unlike--but on the contrary, obviously falling into groups and sub-groups--must in chief part be attributed to different degrees of true relationship; for instance, that the different kinds of blood-hound have descended from one stock, whilst the harriers have descended from another stock, and that both these have descended from a different stock from that which has been the parent of the several kinds of greyhound. we often hear of a florist having some choice variety and breeding from it a whole group of sub-varieties more or less characterised by the peculiarities of the parent. the case of the peach and nectarine, each with their many varieties, might have been introduced. no doubt the relationship of our different domestic breeds has been obscured in an extreme degree by their crossing; and likewise from the slight difference between many breeds it has probably often happened that a "sport" from one breed has less closely resembled its parent breed than some other breed, and has therefore been classed with the latter. moreover the effects of a similar climate{446} may in some cases have more than counterbalanced the similarity, consequent on a common descent, though i should think the similarity of the breeds of cattle of india or sheep of siberia was far more probably due to the community of their descent than to the effects of climate on animals descended from different stocks. {446} a general statement of the influence of conditions on variation occurs in the _origin_, ed. i. pp. 131-3, vi. pp. 164-5. notwithstanding these great sources of difficulty, i apprehend every one would admit, that if it were possible, a genealogical classification of our domestic varieties would be the most satisfactory one; and as far as varieties were concerned would be the natural system: in some cases it has been followed. in attempting to follow out this object a person would have to class a variety, whose parentage he did not know, by its external characters; but he would have a distinct ulterior object in view, namely, its descent in the same manner as a regular systematist seems also to have an ulterior but undefined end in all his classifications. like the regular systematist he would not care whether his characters were drawn from more or less important organs as long as he found in the tribe which he was examining that the characters from such parts were persistent; thus amongst cattle he does value a character drawn from the form of the horns more than from the proportions of the limbs and whole body, for he finds that the shape of the horns is to a considerable degree persistent amongst cattle{447}, whilst the bones of the limbs and body vary. no doubt as a frequent rule the more important the organ, as being less related to external influences, the less liable it is to variation; but he would expect that according to the object for which the races had been selected, parts more or less important might differ; so that characters drawn from parts generally most liable to vary, as colour, might in some instances be highly serviceable--as is the case. he would admit that general resemblances scarcely definable by language might sometimes serve to allocate a species by its nearest relation. he would be able to assign a clear reason why the close similarity of the fruit in two varieties of pine-apple, and of the so-called root in the common and swedish turnips, and why the similar gracefulness of form in the greyhound and racehorse, are characters of little value in classification; namely, because they are the result, not of community of descent, but either of selection for a common end, or of the effects of similar external conditions. {447} _origin_, ed. i. p. 423, vi. p. 579. in the margin marshall is given as the authority. _classification of "races" and species similar._ thus seeing that both the classifiers of species and of varieties{448} work by the same means, make similar distinctions in the value of the characters, and meet with similar difficulties, and that both seem to have in their classification an ulterior object in view; i cannot avoid strongly suspecting that the same cause, which has made amongst our domestic varieties groups and sub-groups, has made similar groups (but of higher values) amongst species; and that this cause is the greater or less propinquity of actual descent. the simple fact of species, both those long since extinct and those now living, being divisible into genera, families, orders &c.--divisions analogous to those into which varieties are divisible--is otherwise an inexplicable fact, and only not remarkable from its familiarity. {448} _origin_, ed. i. p. 423, vi. p. 579. _origin of genera and families._ let us suppose{449} for example that a species spreads and arrives at six or more different regions, or being already diffused over one wide area, let this area be divided into six distinct regions, exposed to different conditions, and with stations slightly different, not fully occupied with other species, so that six different races or species were formed by selection, each best fitted to its new habits and station. i must remark that in every case, if a species becomes modified in any one sub-region, it is probable that it will become modified in some other of the sub-regions over which it is diffused, for its organization is shown to be capable of being rendered plastic; its diffusion proves that it is able to struggle with the other inhabitants of the several sub-regions; and as the organic beings of every great region are in some degree allied, and as even the physical conditions are often in some respects alike, we might expect that a modification in structure, which gave our species some advantage over antagonist species in one sub-region, would be followed by other modifications in other of the sub-regions. the races or new species supposed to be formed would be closely related to each other; and would either form a new genus or sub-genus, or would rank (probably forming a slightly different section) in the genus to which the parent species belonged. in the course of ages, and during the contingent physical changes, it is probable that some of the six new species would be destroyed; but the same advantage, whatever it may have been (whether mere tendency to vary, or some peculiarity of organization, power of mind, or means of distribution), which in the parent-species and in its six selected and changed species-offspring, caused them to prevail over other antagonist species, would generally tend to preserve some or many of them for a long period. if then, two or three of the six species were preserved, they in their turn would, during continued changes, give rise to as many small groups of species: if the parents of these small groups were closely similar, the new species would form one great genus, barely perhaps divisible into two or three sections: but if the parents were considerably unlike, their species-offspring would, from inheriting most of the peculiarities of their parent-stocks, form either two or more sub-genera or (if the course of selection tended in different ways) genera. and lastly species descending from different species of the newly formed genera would form new genera, and such genera collectively would form a family. {449} the discussion here following corresponds more or less to the _origin_, ed. i. pp. 411, 412, vi. pp. 566, 567; although the doctrine of divergence is not mentioned in this essay (as it is in the _origin_) yet the present section seems to me a distinct approximation to it. the extermination of species follows from changes in the external conditions, and from the increase or immigration of more favoured species: and as those species which are undergoing modification in any one great region (or indeed over the world) will very often be allied ones from (as just explained) partaking of many characters, and therefore advantages in common, so the species, whose place the new or more favoured ones are seizing, from partaking of a common inferiority (whether in any particular point of structure, or of general powers of mind, of means of distribution, of capacity for variation, &c., &c.), will be apt to be allied. consequently species of the same genus will slowly, one after the other, _tend_ to become rarer and rarer in numbers, and finally extinct; and as each last species of several allied genera fails, even the family will become extinct. there may of course be occasional exceptions to the entire destruction of any genus or family. from what has gone before, we have seen that the slow and successive formation of several new species from the same stock will make a new genus, and the slow and successive formation of several other new species from another stock will make another genus; and if these two stocks were allied, such genera will make a new family. now, as far as our knowledge serves, it is in this slow and gradual manner that groups of species appear on, and disappear from, the face of the earth. the manner in which, according to our theory, the arrangement of species in groups is due to partial extinction, will perhaps be rendered clearer in the following way. let us suppose in any one great class, for instance in the mammalia, that every species and every variety, during each successive age, had sent down one unaltered descendant (either fossil or living) to the present time; we should then have had one enormous series, including by small gradations every known mammiferous form; and consequently the existence of groups{450}, or chasms in the series, which in some parts are in greater width, and in some of less, is solely due to former species, and whole groups of species, not having thus sent down descendants to the present time. {450} the author probably intended to write "groups separated by chasms." with respect to the "analogical" or "adaptive" resemblances between organic beings which are not really related{451}, i will only add, that probably the isolation of different groups of species is an important element in the production of such characters: thus we can easily see, in a large increasing island, or even a continent like australia, stocked with only certain orders of the main classes, that the conditions would be highly favourable for species from these orders to become adapted to play parts in the economy of nature, which in other countries were performed by tribes especially adapted to such parts. we can understand how it might happen that an otter-like animal might have been formed in australia by slow selection from the more carnivorous marsupial types; thus we can understand that curious case in the southern hemisphere, where there are no auks (but many petrels), of a petrel{452} having been modified into the external general form so as to play the same office in nature with the auks of the northern hemisphere; although the habits and form of the petrels and auks are normally so wholly different. it follows, from our theory, that two orders must have descended from one common stock at an immensely remote epoch; and we can perceive when a species in either order, or in both, shows some affinity to the other order, why the affinity is usually generic and not particular--that is why the bizcacha amongst rodents, in the points in which it is related to the marsupial, is related to the whole group{453}, and not particularly to the phascolomys, which of all marsupialia is related most to the rodents. for the bizcacha is related to the present marsupialia, only from being related to their common parent-stock; and not to any one species in particular. and generally, it may be observed in the writings of most naturalists, that when an organism is described as intermediate between two _great_ groups, its relations are not to particular species of either group, but to both groups, as wholes. a little reflection will show how exceptions (as that of the lepidosiren, a fish closely related to _particular_ reptiles) might occur, namely from a few descendants of those species, which at a very early period branched out from a common parent-stock and so formed the two orders or groups, having survived, in nearly their original state, to the present time. {451} a similar discussion occurs in the _origin_, ed. i. p. 427, vi. p. 582. {452} _puffinuria berardi_, see _origin_, ed. i. p. 184, vi. p. 221. {453} _origin_, ed. i. p. 430, vi. p. 591. finally, then, we see that all the leading facts in the affinities and classification of organic beings can be explained on the theory of the natural system being simply a genealogical one. the similarity of the principles in classifying domestic varieties and true species, both those living and extinct, is at once explained; the rules followed and difficulties met with being the same. the existence of genera, families, orders, &c., and their mutual relations, naturally ensues from extinction going on at all periods amongst the diverging descendants of a common stock. these terms of affinity, relations, families, adaptive characters, &c., which naturalists cannot avoid using, though metaphorically, cease being so, and are full of plain signification. chapter viii unity of type in the great classes; and morphological structures _unity of type_{454}. {454} _origin_, ed. i. p. 434, vi. p. 595. ch. viii corresponds to a section of ch. xiii in the _origin_, ed. i. scarcely anything is more wonderful or has been oftener insisted on than that the organic beings in each great class, though living in the most distant climes and at periods immensely remote, though fitted to widely different ends in the economy of nature, yet all in their internal structure evince an obvious uniformity. what, for instance, is more wonderful than that the hand to clasp, the foot or hoof to walk, the bat's wing to fly, the porpoise's fin{455} to swim, should all be built on the same plan? and that the bones in their position and number should be so similar that they can all be classed and called by the same names. occasionally some of the bones are merely represented by an apparently useless, smooth style, or are soldered closely to other bones, but the unity of type is not by this destroyed, and hardly rendered less clear. we see in this fact some deep bond of union between the organic beings of the same great classes--to illustrate which is the object and foundation of the natural system. the perception of this bond, i may add, is the evident cause that naturalists make an ill-defined distinction between true and adaptive affinities. {455} _origin_, ed. i. p. 434, vi. p. 596. in the _origin_, ed. i. these examples occur under the heading _morphology_; the author does not there draw much distinction between this heading and that of _unity of type_. _morphology._ there is another allied or rather almost identical class of facts admitted by the least visionary naturalists and included under the name of morphology. these facts show that in an individual organic being, several of its organs consist of some other organ metamorphosed{456}: thus the sepals, petals, stamens, pistils, &c. of every plant can be shown to be metamorphosed leaves; and thus not only can the number, position and transitional states of these several organs, but likewise their monstrous changes, be most lucidly explained. it is believed that the same laws hold good with the gemmiferous vesicles of zoophytes. in the same manner the number and position of the extraordinarily complicated jaws and palpi of crustacea and of insects, and likewise their differences in the different groups, all become simple, on the view of these parts, or rather legs and all metamorphosed appendages, being metamorphosed legs. the skulls, again, of the vertebrata are composed of three metamorphosed vertebræ, and thus we can see a meaning in the number and strange complication of the bony case of the brain. in this latter instance, and in that of the jaws of the crustacea, it is only necessary to see a series taken from the different groups of each class to admit the truth of these views. it is evident that when in each species of a group its organs consist of some other part metamorphosed, that there must also be a "unity of type" in such a group. and in the cases as that above given in which the foot, hand, wing and paddle are said to be constructed on a uniform type, if we could perceive in such parts or organs traces of an apparent change from some other use or function, we should strictly include such parts or organs in the department of morphology: thus if we could trace in the limbs of the vertebrata, as we can in their ribs, traces of an apparent change from being processes of the vertebræ, it would be said that in each species of the vertebrata the limbs were "metamorphosed spinal processes," and that in all the species throughout the class the limbs displayed a "unity of type{457}." {456} see _origin_, ed. i. p. 436, vi. p. 599, where the parts of the flower, the jaws and palpi of crustaceans and the vertebrate skull are given as examples. {457} the author here brings _unity of type_ and _morphology_ together. these wonderful parts of the hoof, foot, hand, wing, paddle, both in living and extinct animals, being all constructed on the same framework, and again of the petals, stamina, germens, &c. being metamorphosed leaves, can by the creationist be viewed only as ultimate facts and incapable of explanation; whilst on our theory of descent these facts all necessary follow: for by this theory all the beings of any one class, say of the mammalia, are supposed to be descended from one parent-stock, and to have been altered by such slight steps as man effects by the selection of chance domestic variations. now we can see according to this view that a foot might be selected with longer and longer bones, and wider connecting membranes, till it became a swimming organ, and so on till it became an organ by which to flap along the surface or to glide over it, and lastly to fly through the air: but in such changes there would be no tendency to alter the framework of the internal inherited structure. parts might become lost (as the tail in dogs, or horns in cattle, or the pistils in plants), others might become united together (as in the feet of the lincolnshire breed of pigs{458}, and in the stamens of many garden flowers); parts of a similar nature might become increased in number (as the vertebræ in the tails of pigs, &c., &c. and the fingers and toes in six-fingered races of men and in the dorking fowls), but analogous differences are observed in nature and are not considered by naturalists to destroy the uniformity of the types. we can, however, conceive such changes to be carried to such length that the unity of type might be obscured and finally be undistinguishable, and the paddle of the plesiosaurus has been advanced as an instance in which the uniformity of type can hardly be recognised{459}. if after long and gradual changes in the structure of the co-descendants from any parent stock, evidence (either from monstrosities or from a graduated series) could be still detected of the function, which certain parts or organs played in the parent stock, these parts or organs might be strictly determined by their former function with the term "metamorphosed" appended. naturalists have used this term in the same metaphorical manner as they have been obliged to use the terms of affinity and relation; and when they affirm, for instance, that the jaws of a crab are metamorphosed legs, so that one crab has more legs and fewer jaws than another, they are far from meaning that the jaws, either during the life of the individual crab or of its progenitors, were really legs. by our theory this term assumes its literal meaning{460}; and this wonderful fact of the complex jaws of an animal retaining numerous characters, which they would probably have retained if they had really been metamorphosed during many successive generations from true legs, is simply explained. {458} the solid-hoofed pigs mentioned in _var. under dom._, ed. ii. vol. ii. p. 424 are not _lincolnshire pigs_. for other cases see bateson, _materials for the study of variation_, 1894, pp. 387-90. {459} in the margin c. bell is given as authority, apparently for the statement about plesiosaurus. see _origin_, ed. i. p. 436, vi. p. 598, where the author speaks of the "general pattern" being obscured in "extinct gigantic sea lizards." in the same place the suctorial entomostraca are added as examples of the difficulty of recognising the type. {460} _origin_, ed. i. p. 438, vi. p. 602. _embryology_. the unity of type in the great classes is shown in another and very striking manner, namely, in the stages through which the embryo passes in coming to maturity{461}. thus, for instance, at one period of the embryo, the wings of the bat, the hand, hoof or foot of the quadruped, and the fin of the porpoise do not differ, but consist of a simple undivided bone. at a still earlier period the embryo of the fish, bird, reptile and mammal all strikingly resemble each other. let it not be supposed this resemblance is only external; for on dissection, the arteries are found to branch out and run in a peculiar course, wholly unlike that in the full-grown mammal and bird, but much less unlike that in the full-grown fish, for they run as if to ærate blood by branchiæ{462} on the neck, of which even the slit-like orifices can be discerned. how wonderful it is that this structure should be present in the embryos of animals about to be developed into such different forms, and of which two great classes respire only in the air. moreover, as the embryo of the mammal is matured in the parent's body, and that of the bird in an egg in the air, and that of the fish in an egg in the water, we cannot believe that this course of the arteries is related to any external conditions. in all shell-fish (gasteropods) the embryo passes through a state analogous to that of the pteropodous mollusca: amongst insects again, even the most different ones, as the moth, fly and beetle, the crawling larvæ are all closely analogous: amongst the radiata, the jelly-fish in its embryonic state resembles a polype, and in a still earlier state an infusorial animalcule--as does likewise the embryo of the polype. from the part of the embryo of a mammal, at one period, resembling a fish more than its parent form; from the larvæ of all orders of insects more resembling the simpler articulate animals than their parent insects{463}; and from such other cases as the embryo of the jelly-fish resembling a polype much nearer than the perfect jelly-fish; it has often been asserted that the higher animal in each class passes through the state of a lower animal; for instance, that the mammal amongst the vertebrata passes through the state of a fish{464}: but müller denies this, and affirms that the young mammal is at no time a fish, as does owen assert that the embryonic jelly-fish is at no time a polype, but that mammal and fish, jelly-fish and polype pass through the same state; the mammal and jelly-fish being only further developed or changed. {461} _origin_, ed. i. p. 439, vi. p. 604. {462} the uselessness of the branchial arches in mammalia is insisted on in the _origin_, ed. i. p. 440, vi. p. 606. also the uselessness of the spots on the young blackbird and the stripes of the lion-whelp, cases which do not occur in the present essay. {463} in the _origin_, ed. i. pp. 442, 448, vi. pp. 608, 614 it is pointed out that in some cases the young form resembles the adult, _e.g._ in spiders; again, that in the aphis there is no "worm-like stage" of development. {464} in the _origin_, ed. i. p. 449, vi. p. 618, the author speaks doubtfully about the recapitulation theory. as the embryo, in most cases, possesses a less complicated structure than that into which it is to be developed, it might have been thought that the resemblance of the embryo to less complicated forms in the same great class, was in some manner a necessary preparation for its higher development; but in fact the embryo, during its growth, may become less, as well as more, complicated{465}. thus certain female epizoic crustaceans in their mature state have neither eyes nor any organs of locomotion; they consist of a mere sack, with a simple apparatus for digestion and procreation; and when once attached to the body of the fish, on which they prey, they never move again during their whole lives: in their embryonic condition, on the other hand, they are furnished with eyes, and with well articulated limbs, actively swim about and seek their proper object to become attached to. the larvæ, also, of some moths are as complicated and are more active than the wingless and limbless females, which never leave their pupa-case, never feed and never see the daylight. {465} this corresponds to the _origin_, ed. i. p. 441, vi. p. 607, where, however, the example is taken from the cirripedes. _attempt to explain the facts of embryology._ i think considerable light can be thrown by the theory of descent on these wonderful embryological facts which are common in a greater or less degree to the whole animal kingdom, and in some manner to the vegetable kingdom: on the fact, for instance, of the arteries in the embryonic mammal, bird, reptile and fish, running and branching in the same courses and nearly in the same manner with the arteries in the full-grown fish; on the fact i may add of the high importance to systematic naturalists{466} of the characters and resemblances in the embryonic state, in ascertaining the true position in the natural system of mature organic beings. the following are the considerations which throw light on these curious points. {466} _origin_, ed. i. p. 449, vi. p. 617. in the economy, we will say of a feline animal{467}, the feline structure of the embryo or of the sucking kitten is of quite secondary importance to it; hence, if a feline animal varied (assuming for the time the possibility of this) and if some place in the economy of nature favoured the selection of a longer-limbed variety, it would be quite unimportant to the production by natural selection of a long-limbed breed, whether the limbs of the embryo and kitten were elongated if they _became_ so _as soon_ as the animal had to provide food for itself. and if it were found after continued selection and the production of several new breeds from one parent-stock, that the successive variations had supervened, not very early in the youth or embryonic life of each breed (and we have just seen that it is quite unimportant whether it does so or not), then it obviously follows that the young or embryos of the several breeds will continue resembling each other more closely than their adult parents{468}. and again, if two of these breeds became each the parent-stock of several other breeds, forming two genera, the young and embryos of these would still retain a greater resemblance to the one original stock than when in an adult state. therefore if it could be shown that the period of the slight successive variations does not always supervene at a very early period of life, the greater resemblance or closer unity in type of animals in the young than in the full-grown state would be explained. before practically{469} endeavouring to discover in our domestic races whether the structure or form of the young has or has not changed in an exactly corresponding degree with the changes of full-grown animals, it will be well to show that it is at least quite _possible_ for the primary germinal vesicle to be impressed with a tendency to produce some change on the growing tissues which will not be fully effected till the animal is advanced in life. {467} this corresponds to the _origin_, ed. i. pp. 443-4, vi. p. 610: the "feline animal" is not used to illustrate the generalisation, but is so used in the essay of 1842, p. 42. {468} _origin_, ed. i. p. 447, vi. p. 613. {469} in the margin is written "get young pigeons"; this was afterwards done, and the results are given in the _origin_, ed. i. p. 445, vi. p. 612. from the following peculiarities of structure being inheritable and appearing only when the animal is full-grown--namely, general size, tallness (not consequent on the tallness of the infant), fatness either over the whole body, or local; change of colour in hair and its loss; deposition of bony matter on the legs of horses; blindness and deafness, that is changes of structure in the eye and ear; gout and consequent deposition of chalk-stones; and many other diseases{470}, as of the heart and brain, &c., &c.; from all such tendencies being i repeat inheritable, we clearly see that the germinal vesicle is impressed with some power which is wonderfully preserved during the production of infinitely numerous cells in the ever changing tissues, till the part ultimately to be affected is formed and the time of life arrived at. we see this clearly when we select cattle with any peculiarity of their horns, or poultry with any peculiarity of their second plumage, for such peculiarities cannot of course reappear till the animal is mature. hence, it is certainly _possible_ that the germinal vesicle may be impressed with a tendency to produce a long-limbed animal, the full proportional length of whose limbs shall appear only when the animal is mature{471}. {470} in the _origin_, ed. i. the corresponding passages are at pp. 8, 13, 443, vi. pp. 8, 15, 610. in the _origin_, ed. i. i have not found a passage so striking as that which occurs a few lines lower "that the germinal vesicle is impressed with some power which is wonderfully preserved, &c." in the _origin_ this _preservation_ is rather taken for granted. {471} aborted organs show, perhaps, something about period which changes supervene in embryo. in several of the cases just enumerated we know that the first cause of the peculiarity, when _not_ inherited, lies in the conditions to which the animal is exposed during mature life, thus to a certain extent general size and fatness, lameness in horses and in a lesser degree blindness, gout and some other diseases are certainly in some degree caused and accelerated by the habits of life, and these peculiarities when transmitted to the offspring of the affected person reappear at a nearly corresponding time of life. in medical works it is asserted generally that at whatever period an hereditary disease appears in the parent, it tends to reappear in the offspring at the same period. again, we find that early maturity, the season of reproduction and longevity are transmitted to corresponding periods of life. dr holland has insisted much on children of the same family exhibiting certain diseases in similar and peculiar manners; my father has known three brothers{472} die in very old age in a _singular_ comatose state; now to make these latter cases strictly bear, the children of such families ought similarly to suffer at corresponding times of life; this is probably not the case, but such facts show that a tendency in a disease to appear at particular stages of life can be transmitted through the germinal vesicle to different individuals of the same family. it is then certainly possible that diseases affecting widely different periods of life can be transmitted. so little attention is paid to very young domestic animals that i do not know whether any case is on record of selected peculiarities in young animals, for instance, in the first plumage of birds, being transmitted to their young. if, however, we turn to silk-worms{473}, we find that the caterpillars and coccoons (which must correspond to a _very early_ period of the embryonic life of mammalia) vary, and that these varieties reappear in the offspring caterpillars and coccoons. {472} see p. 42, note 5.{note 160} {473} the evidence is given in _var. under dom._, i. p. 316. i think these facts are sufficient to render it probable that at whatever period of life any peculiarity (capable of being inherited) appears, whether caused by the action of external influences during mature life, or from an affection of the primary germinal vesicle, it _tends_ to reappear in the offspring at the corresponding period of life{474}. hence (i may add) whatever effect training, that is the full employment or action of every newly selected slight variation, has in fully developing and increasing such variation, would only show itself in mature age, corresponding to the period of training; in the second chapter i showed that there was in this respect a marked difference in natural and artificial selection, man not regularly exercising or adapting his varieties to new ends, whereas selection by nature presupposes such exercise and adaptation in each selected and changed part. the foregoing facts show and presuppose that slight variations occur at various periods of life _after birth_; the facts of monstrosity, on the other hand, show that many changes take place before birth, for instance, all such cases as extra fingers, hare-lip and all sudden and great alterations in structure; and these when inherited reappear during the embryonic period in the offspring. i will only add that at a period even anterior to embryonic life, namely, during the _egg_ state, varieties appear in size and colour (as with the hertfordshire duck with blackish eggs{475}) which reappear in the egg; in plants also the capsule and membranes of the seed are very variable and inheritable. {474} _origin_, ed. i. p. 444, vi. p. 610. {475} in _var. under dom._, ed. ii. vol. i. p. 295, such eggs are said to be laid early in each season by the black labrador duck. in the next sentence in the text the author does not distinguish the characters of the vegetable capsule from those of the ovum. if then the two following propositions are admitted (and i think the first can hardly be doubted), viz. that variation of structure takes place at all times of life, though no doubt far less in amount and seldomer in quite mature life{476} (and then generally taking the form of disease); and secondly, that these variations tend to reappear at a corresponding period of life, which seems at least probable, then we might _a priori_ have expected that in any selected breed the _young_ animal would not partake in a corresponding degree the peculiarities characterising the _full-grown_ parent; though it would in a lesser degree. for during the thousand or ten thousand selections of slight increments in the length of the limbs of individuals necessary to produce a long-limbed breed, we might expect that such increments would take place in different individuals (as we do not certainly know at what period they do take place), some earlier and some later in the embryonic state, and some during early youth; and these increments would reappear in their offspring only at corresponding periods. hence, the entire length of limb in the new long-limbed breed would only be acquired at the latest period of life, when that one which was latest of the thousand primary increments of length supervened. consequently, the foetus of the new breed during the earlier part of its existence would remain much less changed in the proportions of its limbs; and the earlier the period the less would the change be. {476} this seems to me to be more strongly stated here than in the _origin_, ed. i. whatever may be thought of the facts on which this reasoning is grounded, it shows how the embryos and young of different species might come to remain less changed than their mature parents; and practically we find that the young of our domestic animals, though differing, differ less than their full-grown parents. thus if we look at the young puppies{477} of the greyhound and bulldog--(the two most obviously modified of the breeds of dog)--we find their puppies at the age of six days with legs and noses (the latter measured from the eyes to the tip) of the same length; though in the proportional thicknesses and general appearance of these parts there is a great difference. so it is with cattle, though the young calves of different breeds are easily recognisable, yet they do not differ so much in their proportions as the full-grown animals. we see this clearly in the fact that it shows the highest skill to select the best forms early in life, either in horses, cattle or poultry; no one would attempt it only a few hours after birth; and it requires great discrimination to judge with accuracy even during their full youth, and the best judges are sometimes deceived. this shows that the ultimate proportions of the body are not acquired till near mature age. if i had collected sufficient facts to firmly establish the proposition that in artificially selected breeds the embryonic and young animals are not changed in a corresponding degree with their mature parents, i might have omitted all the foregoing reasoning and the attempts to explain how this happens; for we might safely have transferred the proposition to the breeds or species naturally selected; and the ultimate effect would necessarily have been that in a number of races or species descended from a common stock and forming several genera and families the embryos would have resembled each other more closely than full-grown animals. whatever may have been the form or habits of the parent-stock of the vertebrata, in whatever course the arteries ran and branched, the selection of variations, supervening after the first formation of the arteries in the embryo, would not tend from variations supervening at corresponding periods to alter their course at that period: hence, the similar course of the arteries in the mammal, bird, reptile and fish, must be looked at as a most ancient record of the embryonic structure of the common parent-stock of these four great classes. {477} _origin_, ed. i. p. 444, vi. p. 611. a long course of selection might cause a form to become more simple, as well as more complicated; thus the adaptation of a crustaceous{478} animal to live attached during its whole life to the body of a fish, might permit with advantage great simplification of structure, and on this view the singular fact of an embryo being more complex than its parent is at once explained. {478} _origin_, ed. i. p. 441, vi. p. 607. _on the graduated complexity in each great class._ i may take this opportunity of remarking that naturalists have observed that in most of the great classes a series exists from very complicated to very simple beings; thus in fish, what a range there is between the sand-eel and shark,--in the articulata, between the common crab and the daphnia{479},--between the aphis and butterfly, and between a mite and a spider{480}. now the observation just made, namely, that selection might tend to simplify, as well as to complicate, explains this; for we can see that during the endless geologico-geographical changes, and consequent isolation of species, a station occupied in other districts by less complicated animals might be left unfilled, and be occupied by a degraded form of a higher or more complicated class; and it would by no means follow that, when the two regions became united, the degraded organism would give way to the aboriginally lower organism. according to our theory, there is obviously no power tending constantly to exalt species, except the mutual struggle between the different individuals and classes; but from the strong and general hereditary tendency we might expect to find some tendency to progressive complication in the successive production of new organic forms. {479} compare _origin_, ed. i. p. 419, vi. p. 575. {480} scarcely possible to distinguish between non-development and retrograde development. _modification by selection of the forms of immature animals._ i have above remarked that the feline{481} form is quite of secondary importance to the embryo and to the kitten. of course, during any great and prolonged change of structure in the mature animal, it might, and often would be, indispensable that the form of the embryo should be changed; and this could be effected, owing to the hereditary tendency at corresponding ages, by selection, equally well as in mature age: thus if the embryo tended to become, or to remain, either over its whole body or in certain parts, too bulky, the female parent would die or suffer more during parturition; and as in the case of the calves with large hinder quarters{482}, the peculiarity must be either eliminated or the species become extinct. where an embryonic form has to seek its own food, its structure and adaptation is just as important to the species as that of the full-grown animal; and as we have seen that a peculiarity appearing in a caterpillar (or in a child, as shown by the hereditariness of peculiarities in the milk-teeth) reappears in its offspring, so we can at once see that our common principle of the selection of slight accidental variations would modify and adapt a caterpillar to a new or changing condition, precisely as in the full-grown butterfly. hence probably it is that caterpillars of different species of the lepidoptera differ more than those embryos, at a corresponding early period of life, do which remain inactive in the womb of their parents. the parent during successive ages continuing to be adapted by selection for some one object, and the larva for quite another one, we need not wonder at the difference becoming wonderfully great between them; even as great as that between the fixed rock-barnacle and its free, crab-like offspring, which is furnished with eyes and well-articulated, locomotive limbs{483}. {481} see p. 42, where the same illustration is used. {482} _var. under dom._, ed. ii. vol. i. p. 452. {483} _origin_, ed. i. p. 441, vi. p. 607. _importance of embryology in classification._ we are now prepared to perceive why the study of embryonic forms is of such acknowledged importance in classification{484}. for we have seen that a variation, supervening at any time, may aid in the modification and adaptation of the full-grown being; but for the modification of the embryo, only the variations which supervene at a very early period can be seized on and perpetuated by selection: hence there will be less power and less tendency (for the structure of the embryo is mostly unimportant) to modify the young: and hence we might expect to find at this period similarities preserved between different groups of species which had been obscured and quite lost in the full-grown animals. i conceive on the view of separate creations it would be impossible to offer any explanation of the affinities of organic beings thus being plainest and of the greatest importance at that period of life when their structure is not adapted to the final part they have to play in the economy of nature. {484} _origin_, ed. i. p. 449, vi. p. 617. _order in time in which the great classes have first appeared._ it follows strictly from the above reasoning only that the embryos of (for instance) existing vertebrata resemble more closely the embryo of the parent-stock of this great class than do full-grown existing vertebrata resemble their full-grown parent-stock. but it may be argued with much probability that in the earliest and simplest condition of things the parent and embryo must have resembled each other, and that the passage of any animal through embryonic states in its growth is entirely due to subsequent variations affecting _only_ the more mature periods of life. if so, the embryos of the existing vertebrata will shadow forth the full-grown structure of some of those forms of this great class which existed at the earlier periods of the earth's history{485}: and accordingly, animals with a fish-like structure ought to have preceded birds and mammals; and of fish, that higher organized division with the vertebræ extending into one division of the tail ought to have preceded the equal-tailed, because the embryos of the latter have an unequal tail; and of crustacea, entomostraca ought to have preceded the ordinary crabs and barnacles--polypes ought to have preceded jelly-fish, and infusorial animalcules to have existed before both. this order of precedence in time in some of these cases is believed to hold good; but i think our evidence is so exceedingly incomplete regarding the number and kinds of organisms which have existed during all, especially the earlier, periods of the earth's history, that i should put no stress on this accordance, even if it held truer than it probably does in our present state of knowledge. {485} _origin_, ed. i. p. 449, vi. p. 618. chapter ix abortive or rudimentary organs _the abortive organs of naturalists._ parts of structure are said to be "abortive," or when in a still lower state of development "rudimentary{486}," when the same reasoning power, which convinces us that in some cases similar parts are beautifully adapted to certain ends, declares that in others they are absolutely useless. thus the rhinoceros, the whale{487}, etc., have, when young, small but properly formed teeth, which never protrude from the jaws; certain bones, and even the entire extremities are represented by mere little cylinders or points of bone, often soldered to other bones: many beetles have exceedingly minute but regularly formed wings lying under their wing-cases{488}, which latter are united never to be opened: many plants have, instead of stamens, mere filaments or little knobs; petals are reduced to scales, and whole flowers to buds, which (as in the feather hyacinth) never expand. similar instances are almost innumerable, and are justly considered wonderful: probably not one organic being exists in which some part does not bear the stamp of inutility; for what can be clearer{489}, as far as our reasoning powers can reach, than that teeth are for eating, extremities for locomotion, wings for flight, stamens and the entire flower for reproduction; yet for these clear ends the parts in question are manifestly unfit. abortive organs are often said to be mere representatives (a metaphorical expression) of similar parts in other organic beings; but in some cases they are more than representatives, for they seem to be the actual organ not fully grown or developed; thus the existence of mammæ in the male vertebrata is one of the oftenest adduced cases of abortion; but we know that these organs in man (and in the bull) have performed their proper function and secreted milk: the cow has normally four mammæ and two abortive ones, but these latter in some instances are largely developed and even (??) give milk{490}. again in flowers, the representatives of stamens and pistils can be traced to be really these parts not developed; kölreuter has shown by crossing a diæcious plant (a cucubalus) having a rudimentary pistil{491} with another species having this organ perfect, that in the hybrid offspring the rudimentary part is more developed, though still remaining abortive; now this shows how intimately related in nature the mere rudiment and the fully developed pistil must be. {486} in the _origin_, ed. i. p. 450, vi. p. 619, the author does not lay stress on any distinction in meaning between the terms _abortive_ and _rudimentary_ organs. {487} _origin_, ed. i. p. 450, vi. p. 619. {488} _ibid._ {489} this argument occurs in _origin_, ed. i. p. 451, vi. p. 619. {490} _origin_, ed. i. p. 451, vi. p. 619, on male mammæ. in the _origin_ he speaks certainly of the abortive mammæ of the cow giving milk,--a point which is here queried. {491} _origin_, ed. i. p. 451, vi. p. 620. abortive organs, which must be considered as useless as far as their ordinary and normal purpose is concerned, are sometimes adapted to other ends{492}: thus the marsupial bones, which properly serve to support the young in the mother's pouch, are present in the male and serve as the fulcrum for muscles connected only with male functions: in the male of the marigold flower the pistil is abortive for its proper end of being impregnated, but serves to sweep the pollen out of the anthers{493} ready to be borne by insects to the perfect pistils in the other florets. it is likely in many cases, yet unknown to us, that abortive organs perform some useful function; but in other cases, for instance in that of teeth embedded in the solid jaw-bone, or of mere knobs, the rudiments of stamens and pistils, the boldest imagination will hardly venture to ascribe to them any function. abortive parts, even when wholly useless to the individual species, are of great signification in the system of nature; for they are often found to be of very high importance in a natural classification{494}; thus the presence and position of entire abortive flowers, in the grasses, cannot be overlooked in attempting to arrange them according to their true affinities. this corroborates a statement in a previous chapter, viz. that the physiological importance of a part is no index of its importance in classification. finally, abortive organs often are only developed, proportionally with other parts, in the embryonic or young state of each species{495}; this again, especially considering the classificatory importance of abortive organs, is evidently part of the law (stated in the last chapter) that the higher affinities of organisms are often best seen in the stages towards maturity, through which the embryo passes. on the ordinary view of individual creations, i think that scarcely any class of facts in natural history are more wonderful or less capable of receiving explanation. {492} the case of rudimentary organs adapted to new purposes is discussed in the _origin_, ed. i. p. 451, vi. p. 620. {493} this is here stated on the authority of sprengel; see also _origin_, ed. i. p. 452, vi. p. 621. {494} _origin_, ed. i. p. 455, vi. p. 627. in the margin r. brown's name is given apparently as the authority for the fact. {495} _origin_, ed. i. p. 455, vi. p. 626. _the abortive organs of physiologists._ physiologists and medical men apply the term "abortive" in a somewhat different sense from naturalists; and their application is probably the primary one; namely, to parts, which from accident or disease before birth are not developed or do not grow{496}: thus, when a young animal is born with a little stump in the place of a finger or of the whole extremity, or with a little button instead of a head, or with a mere bead of bony matter instead of a tooth, or with a stump instead of a tail, these parts are said to be aborted. naturalists on the other hand, as we have seen, apply this term to parts not stunted during the growth of the embryo, but which are as regularly produced in successive generations as any other most essential parts of the structure of the individual: naturalists, therefore, use this term in a metaphorical sense. these two classes of facts, however, blend into each other{497}; by parts accidentally aborted, during the embryonic life of one individual, becoming hereditary in the succeeding generations: thus a cat or dog, born with a stump instead of a tail, tends to transmit stumps to their offspring; and so it is with stumps representing the extremities; and so again with flowers, with defective and rudimentary parts, which are annually produced in new flower-buds and even in successive seedlings. the strong hereditary tendency to reproduce every either congenital or slowly acquired structure, whether useful or injurious to the individual, has been shown in the first part; so that we need feel no surprise at these truly abortive parts becoming hereditary. a curious instance of the force of hereditariness is sometimes seen in two little loose hanging horns, quite useless as far as the function of a horn is concerned, which are produced in hornless races of our domestic cattle{498}. now i believe no real distinction can be drawn between a stump representing a tail or a horn or the extremities; or a short shrivelled stamen without any pollen; or a dimple in a petal representing a nectary, when such rudiments are regularly reproduced in a race or family, and the true abortive organs of naturalists. and if we had reason to believe (which i think we have not) that all abortive organs had been at some period _suddenly_ produced during the embryonic life of an individual, and afterwards become inherited, we should at once have a simple explanation of the origin of abortive and rudimentary organs{499}. in the same manner as during changes of pronunciation certain letters in a word may become useless{500} in pronouncing it, but yet may aid us in searching for its derivation, so we can see that rudimentary organs, no longer useful to the individual, may be of high importance in ascertaining its descent, that is, its true classification in the natural system. {496} _origin_, ed. i. p. 454, vi. p. 625. {497} in the _origin_, ed. i. p. 454, vi. p. 625, the author in referring to semi-monstrous variations adds "but i doubt whether any of these cases throw light on the origin of rudimentary organs in a state of nature." in 1844 he was clearly more inclined to an opposite opinion. {498} _origin_, ed. i. p. 454, vi. p. 625. {499} see _origin_, ed. i. p. 454, vi. p. 625. the author there discusses monstrosities in relation to rudimentary organs, and comes to the conclusion that disuse is of more importance, giving as a reason his doubt "whether species under nature ever undergo abrupt changes." it seems to me that in the _origin_ he gives more weight to the "lamarckian factor" than he did in 1844. huxley took the opposite view, see the introduction. {500} _origin_, ed. i. p. 455, vi. p. 627. _abortion from gradual disuse._ there seems to be some probability that continued disuse of any part or organ, and the selection of individuals with such parts slightly less developed, would in the course of ages produce in organic beings under domesticity races with such parts abortive. we have every reason to believe that every part and organ in an individual becomes fully developed only with exercise of its functions; that it becomes developed in a somewhat lesser degree with less exercise; and if forcibly precluded from all action, such part will often become atrophied. every peculiarity, let it be remembered, tends, especially where both parents have it, to be inherited. the less power of flight in the common duck compared with the wild, must be partly attributed to disuse{501} during successive generations, and as the wing is properly adapted to flight, we must consider our domestic duck in the first stage towards the state of the apteryx, in which the wings are so curiously abortive. some naturalists have attributed (and possibly with truth) the falling ears so characteristic of most domestic dogs, some rabbits, oxen, cats, goats, horses, &c., &c., as the effects of the lesser use of the muscles of these flexible parts during successive generations of inactive life; and muscles, which cannot perform their functions, must be considered verging towards abortion. in flowers, again, we see the gradual abortion during successive seedlings (though this is more properly a conversion) of stamens into imperfect petals, and finally into perfect petals. when the eye is blinded in early life the optic nerve sometimes becomes atrophied; may we not believe that where this organ, as is the case with the subterranean mole-like tuco-tuco <_ctenomys_>{502}, is frequently impaired and lost, that in the course of generations the whole organ might become abortive, as it normally is in some burrowing quadrupeds having nearly similar habits with the tuco-tuco? {501} _origin_, ed. i. p. 11, vi. p. 13, where drooping-ears of domestic animals are also given. {502} _origin_, ed. i. p. 137, vi. p. 170. in as far then as it is admitted as probable that the effects of disuse (together with occasional true and sudden abortions during the embryonic period) would cause a part to be less developed, and finally to become abortive and useless; then during the infinitely numerous changes of habits in the many descendants from a common stock, we might fairly have expected that cases of organs becom abortive would have been numerous. the preservation of the stump of the tail, as usually happens when an animal is born tailless, we can only explain by the strength of the hereditary principle and by the period in embryo when affected{503}: but on the theory of disuse gradually obliterating a part, we can see, according to the principles explained in the last chapter (viz. of hereditariness at corresponding periods of life{504}, together with the use and disuse of the part in question not being brought into play in early or embryonic life), that organs or parts would tend not to be utterly obliterated, but to be reduced to that state in which they existed in early embryonic life. owen often speaks of a part in a full-grown animal being in an "embryonic condition." moreover we can thus see why abortive organs are most developed at an early period of life. again, by gradual selection, we can see how an organ rendered abortive in its primary use might be converted to other purposes; a duck's wing might come to serve for a fin, as does that of the penguin; an abortive bone might come to serve, by the slow increment and change of place in the muscular fibres, as a fulcrum for a new series of muscles; the pistil{505} of the marigold might become abortive as a reproductive part, but be continued in its function of sweeping the pollen out of the anthers; for if in this latter respect the abortion had not been checked by selection, the species must have become extinct from the pollen remaining enclosed in the capsules of the anthers. {503} these words seem to have been inserted as an afterthought. {504} _origin_, ed. i. p. 444, vi. p. 611. {505} this and similar cases occur in the _origin_, ed. i. p. 452, vi. p. 621. finally then i must repeat that these wonderful facts of organs formed with traces of exquisite care, but now either absolutely useless or adapted to ends wholly different from their ordinary end, being present and forming part of the structure of almost every inhabitant of this world, both in long-past and present times--being best developed and often only discoverable at a very early embryonic period, and being full of signification in arranging the long series of organic beings in a natural system--these wonderful facts not only receive a simple explanation on the theory of long-continued selection of many species from a few common parent-stocks, but necessarily follow from this theory. if this theory be rejected, these facts remain quite inexplicable; without indeed we rank as an explanation such loose metaphors as that of de candolle's{506}, in which the kingdom of nature is compared to a well-covered table, and the abortive organs are considered as put in for the sake of symmetry! {506} the metaphor of the dishes is given in the essay of 1842, p. 47, note 3.{note 173} chapter x recapitulation and conclusion _recapitulation._ i will now recapitulate the course of this work, more fully with respect to the former parts, and briefly