Bull14_5.pdf STATE. OF ILLINOIS DEPARTMENT OF REGISTRATION AND EDUCATION DIVISION OF NATURAL HISTORY SURVEY STEPHEN A. FORBES, Cheif Vol. XIV. BULLETIN Article V. The Helminthosporium Foot~rot of Wheat, with Observations on the Morphology of Helminthosporium and on the Occurrence of Saltation in the Genus BY F. L. STEVENS PRINTED BY AUTHORITY OF THE STATE. OF lLLINOIS URBA A, ILLINOIS June, 1922 Original isolation of the foot-rot Helminthosporium made in May, 1919, from bits of ti ue from wh at grown in Madison county, Illinois. _ TATE F ILLI~ L DEP . .\RT:\IE~T OF REC~L'TRATl ~ . ~D EDl1C TI N \\', IL II. I\llLLER, Director B RD F "ATL R L RESOURCE Ai D CO.'. ER\' TIO • \\'. I I. 11. I\lrLLER, Chuir111a11 \YtLLI.UI TRELE.\ E, Biology Jo11:si i\il. Ol'LTER, Forestry RoLLI:-.' D. _ . .-\LbBeR,, Geology \\' 1LLL\M . NOYES, Chemistry joH. \\'. AL\'ORD, E11gi11eeri11g KENDRIC • B .\BCOCK, Represe11tillg /he President of the l 11i11ersity of Jlli- 11ois THE NATURAL HI TORY . RVEY Dl\'1 IO TEPHEN A. F kllE , Chief (51919- 1200-7-2 1) TE T l',\f,t:: J ntroductory 77 I. Afoot-rotorwhat ndit auslrungu · : ymptoms 78 Fungi pr nl 78 rowth of the au al fungu on variou media 79 ariou agar a 111 dia . 0 • ummary on erning growth on agar 85 Rice and similar ub tanc a m dia, wilh p cial note of color ph nomcna 6 ~ummary concerning growth on rice and imilar suh tance 88 Mi cellancou vegetable media 8 Summary oncerning the foregoing vegetabl media 90 Cereal hoot grown from a ptic ed as media 90 Environmental factor which induce variation 91 Quanlily of nutrim nt 91 Inhibitory inAuen s 9J Humidity of m dia . 93 Humidity of air . 94 T mperatur relation 9, Light . 99 arbohydrate 100 Nutrient a affecting conidial length, eptation, and shap 101 ummary concerning enYironm ntal factor which induc variati n 102 l\lorphology or th foot-rot fungu 103 l\lycelium 105 ·ene cenc phenom na of aerial mycelium 107 onidiophores 109 ·onidia l JO Etiology of f ot-rot: Evidence of tiological r lation of H. 1o. 1 124 on tant presen e of the pathogen 124 bsen e of oth r con tant para it l .24 Identity of pathogene proved by ulture 124 £yiden ·e or inr ctiou ne 124 onidia produc d in moi t-chamb r culture 125 Evidenc from inoculation 115 Reco 'ry of organism Infection phenomena on wh at u ·c ptibility or various hosts to infection • umm ry on erning etiology of foot-rot 128 12 137 JJIJ I\ 11. Evidenc and di cu . ion of the occurr nee of altati n within the gcnu 11 lmin­ tho porium: In troductory hara t rs of saltant a hown in tran fcrs T nd nci s in a ltation tability of th altant Stability of the altants through the conidia pparent re ersion :uppo 1t1t1ou au es of the va riant sector altations from single onid ia Frequ n y of altation a ltations o · urred on nrious media "altatioJ1s and modification occurring in te t-tube ultur • ltations in natur · 1ot nc rning s le ted individual saltant Gen ral dis us ion of saltation Taxonomy ondusion ummary Lit rature cit d ppendix: leth d List of H lmintho porium u d for purpo c f omparison i cu · ion of for oing Ii t with e,·eral brief d criptions ;raph : Fi ur - Y. Plates: 11- XXXIV. P.\ E 1 9 141 HS 1-!S H6 1-!7 14i 1-!9 150 152 152 15-! 15~ 1·7 16-l 16 16 lil 179 181 1 -l ARTI LE V.-The Helminthosporiwm Fool-rot of ll'hcat, with bservations on the }.forpltoloRY of Helmi11t'1osporium and on the rrurrc11re of altatiou in the Genus. B ' F. L. TEVE s. 1NTROOl1 T RY The pr ent ·tudy of wh at di i, ba- d upon f t-rot, or rot uf th ba al portion of th . t m , f wh at plant · , a it curr d in Madi on c unty, Illinoi , in 1919 and sub equ ntly. Thi Ii.ea wa fir tr port d in nited tate ,ov rnment publication. a "take-all" ( Opltiobo/a gram­ iuis); later, rnerel a "take-all ," no cau e being a igned; and f r me time a t, in Government publication · it ha u ualI b en de ignated a " - mil d tak -all." n annotat d biblio raphy of n arty on hundr d tit! cone rning foot-rot dis a f wh ct, pr par d by th writ r, \ a pr ent d before th C r a l Path lo i t · of m ri a at St. Loui in June, 1919, and thi , xpand d to ne hundred and i ht_ - i ht tit l s, wa rubli h d in Octob r, 1919 ( 116). early a Ma ' , 1919, cultural studies quite clearl pointed to H lminthosporium as th tru c u e of th dis a , and at th Dec mb r m ting of th m rican Ph , t pathol gical oci ty r announced thi fungu a th probabl cau . Tn lVJa , , 1920, in a not in cience (117), I publi h d th .tatement that it had b n onclusiv ly tabli hed that thL foot-rot of wheat i c u d b H lmin tho porium. One purp of th pr ent paper is to pr . nt th cvid n e on whi h the foregoing c n lu ion i based and c rtain fact c ncerning the mor­ phology and para. iti -m of th fungu ; but far tran ~c nding in int r 1 th di ea it elf- which now app ar to b o ne of mu h I s alarmin nature than wa at fir t f ar d- i th fact th t v ry triking ph n m na of variability are found in this and r lat d fungi. 1 n th following pag , ther fore, app ar ( 1) an count of th Illin is f t-r t of wh at and it causal fungu ; and (II) eviden and di cu · ion of the o currence f lta- tion within the nu H lmintho. porium. A K OWLEDGi\lE T In thi tudy I ha e been a -. i t cJ financially by granls fr m th lllinoi atural Hi t r . urv y and fr m th Uni,· rsit _· of Illinoi .. . I am ind bt d f r p cim n. to p r on. menti ncd in 1·h list of -peue us d for c mpari on (pag s 1 1-1 84), and t \Y. P. Snyd •r fr mpu­ tation of data embodied in .everal f th graph . l wis h a lso to ·xpr ~~­ my thank to Prof. J. . DetleLen, who kindly rea I lh Ill , nu-; rirt an I off r d aluahl . ugge tions r garding gen tic riu ·. tions. i I. A Foot-rot of Wheat and its Causal Fungus ~ \'l\lPTOl\tS As the Ile m impli , th mo t obviou yrnptom i- a r tting of the ba al portion of th tcm of th wheat plant, that i:,, th e lowe ~t p rtion of the low t int rn d . In arlicr tage:; than that of a tual rottin , minute y !low or br wn lesi ns occur n the ::-tem (Pl. \.II), whil the root , if di as d, are lightly yellmved and largely or quite devoid of functional root-hair . ~o weft of uperfi ial my elium ur I I ck in ru - tation, uch a i~ ·o frequ ntly de ·cribed in articl · con rnin take­ all, wa~ seen. Th di a d ti~. u s, how v r, w re inYariabl) ramifi d hy an internal m celium . ·rtain a of di · a: cl ·wh at am under obs n·ation in which the plant had attained a nc rly nom1al growth and wer eight n inche high, when they sudd nly di cl thr ughout. In such ca e th r wa_ a light darkening f th lo\\· r node and a myc lial im·asion at this point. The pinion of those who ol _en-eel thi whe t in the field v,, that th d th \\a du to frost injury. It i pr bable that the actual cau e of death wa foot-rot following the fro t injury. F u er FRESE T Direct micro. copic ob Cn'ation of the di ea d ti ~_ u , in all ca:.e. of foot-rot xamin d, r veal d the presence of an internal hyalin r faintly tinted myc lium in gr at alJundance p rmeatin~ the disea cl tis. ue . My elium of different hara ter was al o uccasionally found, but o incon tantly a - apparent! ' to ha\'e no actual r lation t the di ·ea ·e. I ola tion of the fungi pre en t in the di ·ea~ d ti sue wer mad by two m thod : 1. ir ct planting of bit of di · d ti . u on pour d a_ ar (c rn- meal ag r or wheat- trcrn· agar) . Th di. a d ti , u ,yas r ured in a clean condition a p s ible I y trippin Lack th n lo -ing heath , ex­ ci ing th di as d part with terile tool , and t arin it a1 arl in < t rile Petri-di h. 2. Dir ct planting of · imilar bib of Ii ea · d ti-;su aft r ._ ur[a c­ terilization in m r uri chloricl (1-1000, 10 min. ) . Dilution plating was unsati~f a t ry owing t th· paucity ,f c nidia and th pre~ence of numernu soil bact ria, parti ulc rly " ::.pr ad rs ." A ~ might b exp ted, the methucl . , mploy I g. \' ri to ol ni · f many g ncra and p _. i · , including Phyllo. ti eta, S ptnria, Fu. arium, Epico um, \tern ria, and H lminth porium. triking fa t, how " r, 79 wa th a t with th ex "Ption of th H e lmintho.,p rium, th . , fun g i w re · nt , and th ' ll onl · a ·ing l ol ny r pa rt of a mix d col my plat s. ltc rn a ri a oc urr d with r ma rka l le ra ril ; nly two Joni . am n . , . ral th u a nd. Fu. a rium w • . found in onl , a f w colonie · a nd so mix d that it, as i. olat d , ith liffi ulty . Ep- urred i11 t,, o ol ni Phyllo ticta in two oloni · - ( two Hdminth sp rium, h \V v r, a ppear d in Y ry plat and from n a rl y , . ry bit f tis ue u ed , no malt r h w r t th car m . curing th inoculum. n m, ny plat thi H lminth ~porium (whi h throughout thi a rti I J d ig nat a- H. 1 1) app r d in pur ultur Thu it ma , I ·a id that th H lrnintho, po riurn wa univ r ·a ll y pr ·e nt in the plat s: that it was the nly or a ni m that, a pr nt with a ny o n tan y; nd th t a ll th r fun i ,v r bviou ly tray .* Thou h c nidia were nev r fuund in real nurnb r on plants broug ht in - Com-meal a?,ar in Frcudenre1cli flask\·. h fla -k · , uf ,dmut 100 c.r. cara ity, c hr i,· cl 50 c.,. of agar and,,. •r lant d. Th· larg •, mount of nutriment available amJ the sust ined 1111,i. turc g,n · n1 t ·wnrth charn<-lers. J\t 7 d y., \\itlt Ji. ·o. 1, the ~urfm · r,f th· -.l.11 t ,,,1-; com • 1 pl t ly oYergrown "nd of a n v n I la k l r, larg ly urtain d by an abundant, , ·n ov rgrowth f whit a rial my lium. t ·onta t with th gla a harp, black lin gave lcar \'id n f th bla k urfa e-coat. o lump or balls of my' Ii um w r ~ re nt. t 22 day a few clump - d v I ped, thou h n t o many a on H . No . 9, 13-16. ultures f H. . 1 n rn-me l a ar in larg flask , a tho of K II or f iorkow. ki( l. ... r l-./ · fl[) g vecol nie v rydiff r ntfromth e on th o rdinary Petri di h, du rrc umal ly to th larg r quantity of nutri nt avai lal I and to diff r nt humidit r lati n.. Th fla k · g v in r a d d n ·i ty o f o lony and onidi -formation, mor a rial myc lium, a nd so111 c lum pi n of th my lium. Though ol ni of H. a nd H. J . 1 d :ff re I in th . e character in th • flak (Pl. XII, ...l-l lI ) , p rti ns f th ol ni s f the c . tra in. w r indi tinguishable . or11-meal a.e.ar mCLde at various temperature .- C rn-m al a a r wa mad in th u. ual mann r xc ptin that th t mp ratur in three a e wa h Id at 43°, 5°, and 100° re pecti , · ly, in t ad of at 60°, befo re fi lterin . Duplicat plat w -re med . Th f ur r ulting agar ar d . i nat d ac rding to th t mperature held , and colony data f r a h ar pr ent d in the following tabl . Temperatur 60° 60° 50 100° 100° ll. -ME L GAi{ ~IAL) E Ar ARIO T MPERA'r RES rowth in da_ i . - i 2 Zona tion Den ity olors _ ______ , ________ , ____ _ d i tin t thin pale ,------ ------- -------- -. s 6 6.: C 7 · ha rp thick dark In a bove character , ranks b tween -I, 0 and 60° agars non ,. ry thin very pal Th 100° agar is mo t fa\' rab l to Jin a r r wth, 43° a. a r tand n xt; 4 ° and ~o a ar · gi, · •r wth of p or r I r than 60° a a r, but 100° ag r rank · low -t in thi . r ard. dir tly du to quantity of c nidia, and it i, uniform in t h tn) lium n th four a ar . utrition in 100° ag r w v r, li tt l belt r th, n in pie in ag r. [ n general, it 82 appear, that th ir ord r f nutriti,· v lue f r thi - fungu , from po re t to best, i. 100°, 43°, 8~ 0 , 60°. E,·id ntly a t mp ,ratur of 4 ° i in- uffici nt to extra t th nutri nt prot id uffici ntl , whit 1 0° pre- cipitat t o many f th rn. \Vhil I uc in, a prornin nl prot id of the embry , i larg ly pr cipitate I t 52° and a cond coagulum o-oe. down at 82°, n mor i pre ipitat d '" n by I oiling ( . born , 9). Graph 1-4 ( Fig. • , indi a tin unidial length n th s f ur a ars, ·how that 1th ugh the quantity of onidia produced vari d materially, th length and general ,·ariabilit are not great! influ nc d 1 y varying the composition of the agar-don in this ca by change of t mp ratur . The conidial I n th of a ll the agar i , how ,. r, con iderabl • le than that on \\.·h at hoot ( cf. raph in Fig. and Fig. K). raph of nidial breadth and ptation on 43° and 60° agar given in Fig. B al o how but little influence of the e a ars n the e two character . A " if o" corn­ meal agar, prepared according to my direction by the Dig tiv F rm nts Company, ga,·e gro, th- haract rs almo t identlcal with tho of my wn 60° a ar. n "Difeo" b ef-agar the conidia w re h rt, and were fr quently deform d (M, 17..J.-l±.2_, <1, 2.46±.16, , 14.1 - ±.93). Plain agar (shredded agar only, 12 g. per liler ).- Th fungu - gr w rapidly, and in 6 day - the olony wa • - -!5 mm . in diameter, but wa · thin and colorle , with but few -cattered onidia, and nly 1 to 3, or at the mo t 7 to 10, conidiophore - per Jow-p wer fi Id, er pt at growth-inhibition points, a at the d e of the di h or wh re two ol ni approached each oth r, wh r the numb r of conidiuphore ro e t al out 12 per low-p w r field. Th ·onidiophore bor only one r two c nidia ach. C nidi phore - , onidia, and my Ii urn a - w 11, w r · ry f intly ·traw- ol red, mu h paler th n on m re nutri nt agar. o zonation oc urr d. ro differ nee in rate or chara t r of grmvth wa b rYabl in 1. o/ and 2.6 plain agar. Grm..th on plain agar, 011 rorn-meal agars, and 011 various combinations of these nutrients.- orn-m al a ar f Yariou , ·omp ition, wa u ed, 12 c.c. to ach P lri di h. n r c rn-meal a ar ( mad f parts plain agar plu 1 part ordinary rn-meal c rar) the colon) wa much darker and d n r than on pl in agar: wa. wn d m r tr ngly; c nd 111 1.1 wer much mor abundant, th ·r I> ing about O conidioµhorc. p r le w-pow r field, each with on to fin: nidia. Th mycelium w much dark r than n plain a ar. ·01 ni s on -oc c and 7· orn-m ~al a rar h w d no e ential diff ren fr m th· ol ny on 2S r n full c rn-m I 3 a ar th co lo n wa mu h dark r and mor d n and th my elium wa dark r. Th r lativ rat f lin ·ar grmvth n th e ag,. r , a shov,;n in millim t r of colon diam ·t r at th nd of 9 clay at ro m-t mperatur , wa a - fc llo ... v : On plain a ar. . . . . . . . .. iO mm. n 2- corn-m a l agar. 6 mm. n 50 orn-m a l a ar. 62 mm. On orn-m a l a:rar .. 57 111111. orn-mcal a ar . 5-! mm. \\'hen the fungu. wa r,lant ·d n plain a of rn-meal agar of the above-m ntion cl urfc ce at the dge of a well-cl \'el p produ tion incr a. d with th in r a 1 ngth on th ~ agar i hown in Fig. length w s I a t n pl in agar and in r of the medium. It lo h n t cl th e r high n the 75 orn-meal gar. , c nidial length i · n to be appre iabl _ s (1 m. quar) ,Yer I id on th a ar ( re ph 1-4, Fig. ) , and mark di h rown und r t ndard onclitions (. · 'rn ph , Fig. K; a l Pl., pc gain, c rn- m al agar wa. mad in th ' usual vvay but th amoun t of agar wa , ·ari d, 6, 12, and 25 grams µer lit "r bein us d. In eneral, in P t ri di h . , 12 gram p r lit r prov d mo · t suital 1 . mparis n · b tween H. - . 1 and H. . 3 nth - thr rn -clia h w 1 tll cl y -a hthatH. _ .3 had grm.vn m r rapidly lhan H. No. 1 th rati b ing 6. : .5. Th r , a u ually a mark d difference bctwe n t h two strain n 12-gram c rn-rn a l a ar, m r mark d than on th th r -, H. T • 3 . h wtn m r d finit zonation and m r aerial mvc lium . In r ud nr i h fla k , \\'ith th 6- r m ar, H. o. 3 mad much a rial my lium on th wat ry . urfacc; H. o. t made nly a black pellicl and no aerial m _ c lium . n L-gram agar H . . 1 made mall growth f a rial m c lium and th ol ny urfac wa · bla k, \\'hi! H. No. had mu h lo . e. woolly rnyc lium. t 11 day H. o. 3 n each ag r had mor a ric I m c lium c nd mor lump th n did H. N . l. Th most on I icu­ ou cliff rcn wa n 12-gram a ar, whil on 25-gram agar H. ='Jo. 1 had no lump and H. o. 3 a f w. Th r 1 1 ur, d finit t nc.lenc in II. ~o. cw e lium nd rnor lump than H. . 1 , bu thi. t mak mor " a ri I d ·p nd nt on on- dition of rnoi·ture, in air and medium, that it is far from being a r liable character for cp rating the two. Gree11-'wlzeal Of!.ar.-( Formula a for corn-meal agar, ub ti tu tin f r the corn-meal li,·e wheat I a\' s and t m which had been pa - cl through am at-grind r.) H. Ko. 1 r w w II, producin a derre olony, but with weak zonation and with much woolly, whit aeri I mycelium, and but few and scattered conidia. Thi medium, while apparently " ry nutritiou , fayor d abundant ve etation rath r than porulation, and wa a poor m dium for th differentiati n of rac s. To determin the effect of r ducin the nutri nt · in green-wheat a ar, thi wa · combined. in varying proportion~. with wa · hed a uar with varying r ult . n ,Yash cl a ar the rowth of H. N"o. 1 wa scant, color- le , and with n onidia, the colony diameter r chinu nly 5. - cm. in 9 day . A th c ntent of gr en wheat wa increa etl, there \\·a a radual in r ase in den ity f colony and of aerial rnyce lium. In CJ wly lrnt w,t'> ,··rr d en.c; urfar e,· n; littJ, aerial my ~lium. 85 larch agar.-Thi medium pro d t be ut light differential value. Th growth was of a dark I r and m what bluish tinge. Bean agar.- H. To . 1, 3, 5, 13, 20, r w ,, ll n b an agar, all de­ ping a d n e, w ally, gray a rial my elium. Z nati n wa poor, or ob ur d b the aerial m celium. Th fi e train -howt!d no difference in ro,\ th n thi m di um, whi h wa - th r for poor for differential u e. 1n Fr ud nr i h Aa-k th r ,va a d finit bla k urf -!in and much tawny aerial m_ celium in lump . Brazil-nnt a11,ar.- ( ormula according to pen er, 108.) H. o. 1 in t t-tube r w Y r rapid! and luxuriant) , , ith ~mall d lopment of a rial mycelium and a di tlnct bla k ba I lin . Th agar wa rapidly !ear d of prot id pr cipitat Ly th d lopm nt of a pr t o1ytic nz) me. In P tri di he a thick, d n e, wooll_ now-whit a rial my lium d v l­ op .d whi h ntir ly curtain d th urface-blackenin . Th colon wa urrnund d by a br ad tran lucent z ne du t pr teolytic ction. Thi~ agar i , ·alual le f r the pure-whit aerial m c lium that d · el ops on it, and t d m n trat r adily th prot olytic a ti n, th ugh it did not, ev n in th e r gard , pr v to b differ ntial, in c all of fifte n train t ted up n it av n a.-ly id nti al r p n at agar.- H. o. 1 at 10 day ga,· a distinct black urface-lin and Y r) h avy a rial gi-a grov th. H. . 1, 4, and 14 wer indi tin- ui habl n it. 1pple-fruil a •ar.- H. ooty a rial m . Jium. H. pr du ed larg ... cl r tia. . 1 gav a I lack ba al lin and abundant, os. 1, 4, and 14 w r alik xc pt that o. 4 Apple-bark agar.- H. 1 . 1, 4, and 14 r w ,·er lowly and wer Y ry d n and la ·k with but little a rial my ljurn. Crnpe agar.- H. o. 1 ave a black urfa e-line and no aerial my­ elium. H. o . 4 and 14 w r f th am hara ter xc pt that o. 4 produ d a c n idcrabl quantit of moky aerial myc lium. Prune a.f!..ar.- H. . 1 and 4 ave a d n e, bl ck · urfa -growth but n a rial my lium. U MMAR CO ER I GROWTH O AGARS rn-meal agar mad by th u ual 60° formula pr \' cl mo t u ef ul, and the b t diff r ntial agar. Tf mad at 100° or at 43° it lack d nutri­ m nt. Th amount of gar u d- Yen 25 g. p r 1000 .c.- had but littl ff t n r wth hara t r · . r en-, h at agar in var. ing tr ngth I d t luxuriant Y g tation, to littl conidia-produ ti n, t much abnormalit · 86 in morphological chara ter , and was of littl diff r nti I , ., lue. n either wa hed agar or plain agar thPr wa. xccllent linear growth but poor color and littl onidia-production. Bean agar gav too luxuriant vegetative growth. Brazil-nut agar was us f ul f r th d ,. I pm n t of white myc lium for u in nutrition tudie and for tudy of prot lyti · action. Th ther agars used ·hawed no ·pecial f ature of value. RICE A ro SIMILAR SUB TAN ES AS MEDIA, WITH PE IAL OTB OF COLOR PHENOMENA Rice in test-tubes.- Ri e wa pr pared in the ustomary.,; ay, by placing it in test-tube to a d pth of on centim ter, adding nough water to tand 1 cm. above it, and then autoclaving. Thi medium, so useful in the study of many fungi, notably of Fusarium, proved very interesting here. t the xpiration f about two v.,eeks from the time of inoculation­ generally the m t profitable time for fir t ob ' rvation- three z ne or region ould u ually be re ognized: ( 1) the r gion recently invaded by the fungu , whi h I designat a the recellt r gion; ( 2) the r gi n first invaded, which had a um d n arly its final app arance, and which I call the old region; and ( 3) th region midway b tw n 1 and 2, whi h I hall call th median r gion. Each of th r gton showed characters of its own. Within all of them, but parti u larly in the old and in the median region , there wer three points to ob erv : (a) the place where the rice grain cam in contact with the glass, which places I call contact; (b) the pace b tw n ric grain , at first filled by water, which I call the interstices; and (c) the line between inter tice and contact -, which J term th border. ually th fungu grow down into the inter tice , con um their cont nt -, and fill the remammg pac m r r le s complete! with mycelium. Pen tration of the conta t i very low and may not occur at all, th r for th y are usually but lowly di colored by the pas ag of variou ch mi al int them. The border is the region of greatest de,·elopm nt, and ft n pr ent a fharp, di tinct line of pr nounced character. It i- the ontra · t - furnish d by the con ta t · , int r tic , and borders, oft n att nd d l.,y th d v I p­ ment of beautiful and ivid ·olor , that giv to these cultur th ir trik­ ing app aran e. In addition t th e characters th final app arance of the rice c lumn h ulcl b n ted. It i ometime dig t d a\ ay in char t ri ti mann r. Th d v lopment or b. n of scleroti i - al o n t worthy. H. No. 1, in ric t t-tub . , at two weeks, aave, in th rec nt reg-inn, almon-color d int r ti . , con ta t , and bord r ; in th m •di n re :i- i( n th 7 inter ti ~ and ontact w r gray, the Ii\· ; in the old region . th int r ti • w r dark, ontact ray , and border. d p bla k. ro I r tia d \' lop d. H. · . 2 gay quit di tin ti\· c I r-charact r , a · diility for the , ariou · c I rs f und in n ultur , tub w r mad in th u ual way, u 111 nc haff, wh I ric , ric from th p arling n , nc from th bru h, and rice poli h. Of the e, ric chaff and wh I r action ; but all th th r a,· th usual on s. Jay cl ric wer pla don wa h d auar, under a co, er- la , and inocul Led with ol r-pr du ing H lmintho porium. . Direct mi ro.c pi ob erYa­ tion how d the m tint n c c lor nth unbrok n ri e- ~urfac , and le int n n n int rior r gion. "XP .~'.)d by breakin . It i therefore probabl that th pr t id , which ar m t bunclant in the urfac layer , ary to th color r -pun - , though th color it -elf of ten, if not alway , c ri fr m the rn ·celium. Pearl-barley (prepared like rice tubes).-The general chc racter of th r " ·th a to ntact , int r lie ·, and bord r ~ wa a on rice but with different and I pronounc d colorin . H. T • 1 at two w k- gave, m aim n int r~tic ~, nta t , and border in the m dian r gion, ray int r ti e and ont t an liYe border in old r ion , dark int r tice , gray on tact , and black border·; c nd th aerial lium ·wa gray and the barle: c lumn n 1. hrunken. 1 m,y bean (prepared like rice tubesL- H. n thi - medium two w eks gay onta t unchang d, int r ti -ray t br wn, b rd rs I rmyn to bla k. Littl of differ nti I valu I v I p d, though H. Jo . 11 and 19 ga, pink col r . TT llcal grai11s (prepared as above).-H. T • 1 in tacts unchan d, int r tice dark ray, bord c bla Id r gion ave con­ k, and a v ry f w cl rotia d v I p d. H. o. "' av th am hara t r but m re num r- ou clerotia. Almond inte"111ne11ts (prepared as abm1e) .- H. 1 o. 1 a, ea den. e, black rnyc limn and abundant coni~·.:_.~ .. •.r ·~t ...... ~.,. ~-;::.;_ ~ ..:io. : • • - :,:-=- • . ·:;: . .• ., . • ' I. . -:: ., " ~--.. : .;: •. -. :,~;:t~i,i~;it~~~,,:; F ig. 1 - lllu tra ting inhibitory influence nn porul. l ion. Two colonies of II. o. I . on wa·hed agar. showing da rk ba nd . due to a bunda nt poru­ la cion where the colonies a pproach each o th •r. porula tion a l~o somewhat inc reased nea r ma rgin of colonies. owinl! to drying, Hl;MIDJTY OF :MEDIA Ric wa pla d in tubes with water equ I lo twi e th olum of the ric , and with wat r equal to four tim it volum , b ing then autoclaved and ino ulat d with ari u Helmintho porium . N te at two week hO\v b tter character f border, int r tic , et ., in Lh w tt r tube_, and while with many train s lerotia de I p d abundantly in th drier tube 94 they did not app ar at all jn the w tt r on ·~ (Pl. X ) . Thi w notably true of H. To . 1 and -. £y n at the n I of five we k no d rotia wer produc din th wet tube u H. To. 1. It i appar nt that the mall r amount of water i the m r fa, ·orabl fur ob. n ·ation of clcr tium­ formation, ith rat two r four week ·, and that ob rvatinn of wet tub at the end of tw w k i . uffi i nt f r oth r hara ter.. Ra, n (91) ha ugge · ted cl rotial formation a hara t r for th eparation f c rtain ~pecie . I ti bviou · thatifthi - hara teri · mploy d ar mu · tb giv n t th humidit f th media. H i\JTDJTY OF IR Te t-tube we.re pr par d with water in the but tom nd a gla ::-lip i11-erted a i hown in Fig. 2, and autocla, ed. If filter-pa1 er or a wheat I af i. laid on th gla lip th humidity i u tained throughout th I ngth of th tub by Yaporati n from th I f or th pap r, but if n u h on­ du tor of ,:vat r i. u d, and r al ( .. wh at) sh ot ar laid cro ·_ wi e on th gla lip (a indic-ated in Fig. 2) and ino ·ulated, the growth f th f ungu ma · be ob erved und r differ nt ndition , of air-humidity. Determinati n kindly mad for me by r. ,. L. Pc:lti ·r with e p - ially accurat apparatu cl vi. d by r. ·. F. Hotte:-., how ads under~oing dissolution. 1 5 tlY ELlUilf 1 h youn , vi orou myc lium g r wing within th a r m oth, quit tr ig h t , 11 arly r quite h · line, a nd f y r , unif rm diam t r. The g neral a p ct n a r the d g fa I 11 , Fig. 6, d. In older part f th c I n th ubm \ h t thi k r and is I ss ri h in protoplasm. Th d my lium ha in ar a bar ly p r eptible ling I r. II ar quite tr ngly con tricted at th pta a nd th onl nt i highly vacu lat . Ra n ( 91) tat that in th Id imm r~ cl m lium b th pla ll- , a ll may be bla kis h r en, rayi h br \.\·n , o r ntir ly bla k in It rnaria. u h colo rati n thi ha bee n o bserv din m y ultur . Th .am author (91) di u ing olony zonalion, a ttribute it to v riation in th color of them - cclium, whil e in my cultur · it a pp a r , t b aim ' t entir I duet variati n in quantit of onidia and of a rial m c lium. Th f a ri l m y lium w hi hly d p nd nt u p n a1r- nditi n \i\ h n th e f Y Or d th r wa m - , hat e, whit a ri I m y lium 2 t 3 mm. hig h, con I trng f ith r mooth, n, ·ing l fil a m nt r, ,;,,hen quite abun- v r I filam nt twin dint a r p (Fi. S, c). \i\h n ondition fav r I I th a rial m yc lium, th u h in n picu u , wa till pre~ent in n id r bl <7u a ntity . Th differ n b twe n vari u pecie of H lrnintho p rium nd th ir ·a lt nt · a r ·a rd · the abunda nc f lium i well sh ,, n in Plate_ IX-XIII . H. o. 36, a v r y di - ,_.a hi fl) c h re ct ri z d by the gr · at .. ) . Thi h r ct r i th only n t r t H . o. 1 a nd H . . 3, a nd it (Pl. IX-XIII) , th di tin tion ften failing in Th charact r i · apparently so much mod- , v ryi ng humid ity a t m<. k it utility f r dia no i f v ry qu tion bl Y lu ( pp. 95, 97 . R avn ( 1) how , . r. di ting ui hes l-1. aveuae, II. gramiue11111 , nd I-I. leres, rowing on t rili7 d tr w , b the diff r nt indiYidu 1 ch ra t r ~ of th " ria l my lium and cl rotia; and H. ,,,amincum nd 11. m,euae on I rwo rt by th f t that H. gramineurn n w-whit unif rm m s o f ria l h yp lt , , whit E-I. aveuae ha. p rs , whit a ri a l m •lium which f rm. solid lump , th hlack -ub- tr tum-m , lium be in~ vi ibl b tw en th m. The m c lium in wh al ti s u i • m \\ hat m r irr g ular in contour than hat r wn in age r nd is ft n mu h thi k r. asi na lly upon the wh it I r n h I in . I , . f, n-lik f hi n ( Fig-. _2, pag 13-!). The 106 F1G. 6.-H. Ko. I : r/, ~howing l)r nchini; ;;ind i.: ner,11 "flr> :ir.1nc, al edi:e ut a colony growing on corn-menl og r: r, puni,111 uf a m,·c Ii.ii dump s howmi: peculiar twisted charact1.>r 01 llw m)•, •liu m. with m re u~u,11 str,inds 1n r com ruri• ison. 1 7 ri· I my lium f om ra pr du d lump PI. XTIT, .,""J.-- II , ~X rJl}, whi h und r th micr n to b du to a p uli r di - tortion and abundan of th a rial my lial tip (Fi 7 • 6, d). Thi · p cu liar b ha\'i r f th t"rmin I part of th my lium h , m imilarity t th bran h- ing ligur d by \Vard ( 123) in B tr) ti in th rly tag -::: of d " I pm nt of att hment rgan-. na t mo 1 1 ,·er: omm n with thi f ungu ( Fi . , a and b), and" ard ( 12 , fig . 19) ha Ii ur d ana tom ~i- f v ry ·imilar haract r for Botryti . 1an , citation f it~ giv n I y B ndGuilli rm nd(1 ) . 4 .) xtr m ly mall, but may l en r adily ntian vi I t, nd till b tter if tained with ir n-h - mat xylin. They vary in number, but are n , r I than tw and u~ually m r ; th y d not typi ally aroup in pair. ; nd th y r irr gula rly clis­ tribut d in th u I i appar ntly in mit i ar fr qu ntl) II no d tail wer n ted ex pt that th mit · 11 u ·, and mit i ti fa t ondition in th h encsceJLce pheJLomena of aerial myalium (Fi . 7, a- b) .-\\'h n th a rial my lium is young it con titutc a mor or 1 bundant, loo e ara hn id, Auffy ma . In quit old cu lture it i b ern:d t m, t down cl t th surfac f th mt:!dium in a thin, alaz d, d ad lay r. Int r­ mediat h tw en the e tw xtr m ondi i n. int r s in ph nom na o ur. Th first oh ervabl chang fr m th t f th m liUin i - that rtain cell m n arly r quit d Y id at a h nd f u h n qu ntly th f ungu r -gr w thr c d , a s, an l ~11u h mar com- m nly, th mpt c ll m); and wh r , , ral me t, rath r I r am rphou. un r c niz d ma · ar n, up rficially much r ml ling pla. m lial lru ture (a). Th r wa , ind d, at fir t, u pi i n that t h r might u present 1 I~ ,;m ,di, l 10 para ite pr ymg upon the H lrnintho poriurn rnycclium; but num r u te. ts conYinc d me that uch wa not the ca but that what r a lly o cur i that the old a rial my lium di . oh· ( pr balJly by auto-dig · tion). . \II tage of this disorganizati n a n b follow cl under th irnm r ion l ns in tain bit · of mrc:clium, as se n with the imrner,,ion lens, showing the nuclei. oh r\'ed on many train ~ f 11 lmimho::.porium. • utodig ..,ti1111 of nw­ c lium I ul ti . o ur 111 r "ood-r tting fun i, a is e\ id ·n d hy th ab nee of m,-c lium "h r i t was pr Yiou. ly kn wn to \J , nnd it may be of ommon o cu rr nc:- rn other fungi. It ertainl) nc ur-. wh Jn two hypha j in by ana l m si , and in th . uni n f exual organ.... ~nrn - ing-through of the my lium , a n ted above, and , n ·nnidi.1-fnr111ati11n within th ,,Id II mm n in Saprul, nia, and hc.1, I ·en not ·d in 109 v ra l 1ther (B a uv ri a nd ,uilli rm nd , 1 "' ); lte r- is a lwa · a s ia t cJ with cl r ti , a r ) an l l1y ~ k ( 7), who · m t , ha v f 11ncJ th m omm n n o ld tra w- ulture , va ry in in I n th fr m _() Q t 600 µ. I h v n t f und th m a t a ll n tr w, th ugh n Id ri -cul t ur th y a r a bunda nt. Py nidia a nd pycnoconidia, a n by R vn (9 l) in H . Ines nci as d rib d I y Ba kk ( 6) , I hav not n. 0 IDIOPHORES On standard wli eal-sli ools.- Th o nidi ph r a r in n s ns dust r d bu t a ri in ly a lat ra l l ra n h , a h fr m a n ordina r m) Ii I II, a nd cliff r fro m t h myc lium chieA y in that t h y r w r ct a nd s tra i ht in tead f d lin d a nd e r ok d , a nd a r d rk r in c I r t ha n t he my elium. ua lly thi I r nch in its I a I r io n i my lium-lik , but it rapidly t hi, k n a nd d a rk n to t ru onidi ph r ha rac t r, a nd i usua lly 2.5 to 5 µ in I ng th. om tim th m y lia l c II fr m whi h th onidiophor a n · a l. da rk ns. Th conidiophor -c II · nta in protopla m, a nd the pr to t la ·t p la · m li7 und r the u-ua l r •:icr n t · . \\ hen matur th co nid- F1G. 8 . - 11. o. l , howing va ria tion in conid iophorcs. gcniculation, conid ia-s • r~. and eptation. 110 iophores are pc I traw- I r to . 111 kv brown from ti(1 to, ur nc rl} to, theba· ,th colorb ingdu toth outcrwall- whi ·hi, rybrittl. l ' p n the pr durtion of th lir-..t conidium , whic-h i~ . tri ti · terminal, th _. nnicl- iophorc r ws onward, with a ·light 11 n, Lwo i:?crminal­ in~ conidia with gt:rrll- LUUt:'~ ana . tomosing. alway~, s hrink, of the protoplas t · u h as i · h uwn in Fio. 11. thi - hrink­ a being u -ually mo. t pronounced in the e nc.I of t he co n idium :.how ing rno -- t , ·igorou g rowth. To a ll appea ra nce th ndo - po riurn . n- s a · t red food and i n um din g rmina ti n , .... incc it pr nc, in mur h Iiminished quantity in germinal d onic.li a i e,·iu cnt wh en sur h ·o nidia a re crushed . 1 he conidio phor -c ll s al o oc a~iona lly function a con ic.l ia I y endi ng out a g rm-tuh . H re , too, the inne r c II-wa ll eem.; to sen · a · r ..;en-e food. Lon!!,e,•ily of co11i1liu.-lt i · nu t kn mYn how long conicl ia !in:, bu t on wheat traw th '" t h, I r ma in •d a ir- Irr fo r fo ur t n mo n t h-, t hey g •rmi ­ na ted norma ll y. ... ' o ck (8 7) m ntio n. g rminat ion "after man y m nt h., .' ' Ra, n (91) a y: o f thr . pecil' ..; th a t at ig ht m o n t h -. t hey g rminated lr.JL sparin, ly or no t a l a ll. Frequency of co11irlial septa.- H . . o. t under appendix , pacre 1 U) ga , · t he ·raph in Fi . J, whi t U-16 ar g i,- ·n in Fig. T . Lanrlar I cond ition~ (-.;e ·imi lar da ta for H. '.\'o . . 117 epla Differences of 111ea11s of sepia H. ' os. l and . . . . . . . . . . . . . . . . .27 ± .16 H. 1os. 1 and 15 . ,.. . . . . . . . . 0.80 ± .12 H. o . 1 and 16... .. .. . . .... . . . 0.5 = .11 H. .22 ± .11 It i t b not d that th · diff r nc bctw en . 15 and 16 are quite a Jar e relati,· t th pr babl rr r as are th diff r n e b tween Io . 1 and . Ra,·n (91) , p aking of thr p i of Helm.in th p num, a that the pta ar ry variabl , and that pecifi differ n can n t bed ri ed from th m. ry abn rmal ptati n wa fr qu nt; f r xampl , on green- wh at a ar (Fig. 14) and other uncongenial m dia. FIG. 1-1.- ariou a bn rmal conidi. of H. · o. 1 a grown on green-wheat :igar. 011idial shape.- Th - hap of th onidia, tog th r with th ir ize and eptation, r in th ~ g nus H lmintho porium th thr c mo t-u ed charac­ ter in de ription. Inde din publi h d de ription of man ~P i the e ar the only imp rtant character · mentioned, and ften n f the i la king. nidial hape in c rtain p ci i v -ry haract rist ic, parti - ularly in II. i11aeq11alis, H. f!.e11irnlat11m, H. ravenelii, and al o in my H. To. 29. uch tr s ha b n laid on nidi I .·hape a a mean of di tin- gui hin rtain r al Helminth ~P rium , parti ·ularl) in distin ui hin H. sativum fr m II. teres. M rely to lo k at two lot. f onidi wi h th m1 ro th aid f a ompari on cular, i not a ati f tory m an rtainin th pr vailing conidial hap . Many train f H lmintho porium Yary r atly a t c nidial hape, and conidia f n hap ar mixed with tho ·e f anoth r (Pl. TIX- X ..1_.,. ( . Th important qu tion i , what i th relativ fr qu ncy of the Yari u . hap ? But b for any fair t im t of thi can b mad , t ndard mu t be tabli hed to what ar th e n­ f th vari us hape . n fa t r f pr p nd rating in flu nc in determining th e conidial hap i th po~ition that th p int f r at t di m t r cupi son the 118 a C e I9 Q' C d e f n g h c ___,;9---=--,0~-==------!:l=':;?'------ d e f ill 9------+--------------,h a' X 7 a ---;7 e V-.. v- ,,,., ,..v- -i--. Ng / " "'i--.... :.---~ ....... a' FIG. 15.-Diagrams elucidating conidia! shape. -- ' J d f h longitudinal a xi of the conidium. In diag ra m I and II , Fi . 1 S, th point of greate t diameter on the line a- a' i~ midway between th ba e and ap x of the onidium; whit in diagram Ill and l 1t 1 n a rer to it ba . If th conidi um tap r. from th point o f g r at . t thickn - toward each end a fu iform (Diagr. Ill) or lliptica l (Diagr. I, 1, 2) onidium r - . ult . If for a ufficient di - tan n ea h s ide f the Jin a-a' t he coniclium remain of uniform diam ter it approache. more nea rl th form of a cyl­ inder (Diagr. II, 1, 2). \r\h nth m ax imum diam tr i n arr t th ha than to the ap x , m what rap id tap ring g iv . a f u if rm onicliu m ( Dia r. Ill), but if (a in Diag r. I ) th di a met r I n very gradually,~ , fr 111 th point a to pointy, the ( nidium may be aid t be ub linclrical. 119 I r Cc sual lJ n dion of many strain - f H ·lminth p rium. h wed tha t th I oint of maximum diam t r ,va u. uall · n < r th ba - I r gion of th ni lium, c asi n. lly ne r th middl r gion, \\ hil in ~,tr nPly rare a. it wa. n ar th api a l quart r, th ' ratio of thcs c c being for H. ·o. 1 ab ul 30:14:4. \ m r a ur t ~ d t rmination f ,,·hat may b t rm d th I n itudinal c ntricily f th' r niclium- that i th ran of, riati n in the po ition of th Jin o( gr ct • t diameter (a- a', Di r. J- 1\) may b mad 1 y m , uring (al ng th· 1 ngitudinal ax i5) the di - t nc fr m th ba c f th con idium to th inters cti n of th lin a- a' with th Ion itudinal axi ·. 1 hi. distanc Ii,·idecl l y th t tal 1 n th of th nidium niay b known a · it. coefficient of /011 !!. iludinal ecce11lricity. 1hi o ffi int for H. 1· 0. 1, be d n 65 nidic tak n at rcndom, wa foundbyth a ~o, emthodtobe.43±0. lnothrtrm th pintof ma..,imum diam t r wa. di. tant from th ba.-e of th onidium 4."' 10 of th nidium. akk (6) .ays that th nidi f II. le- res ar wid t t the middle. 1 he effi i nt of longitu lina l eccentri ~it_ as- d on 11 coni lia f H. ro. 1 whi h were oi t ·pi al ub lindri al ap- r aran (a pr a hing that h wn in Diagr. I ) \\a · A- a ntra ~t d with ffi i nt f .4 f r 11 nidi f llipti I app r n ( Die r. I). o- ntririty f r H. . 5 _Q, , n I 4 f . ubcylin- dri al hap , W "r r . p ti ly .35, .39, an.'imat •ly mod I I n ... th w r u d, and to ol>Yiate uncons iou . J, tion, mea~ur - mcnL wcr mad f only the J ft id of the conidium, th 11, •• I encl b in toward the oh en· r. Determin,. tion from 11 conictia of H. N J. l of . uh­ cylindrical -hap gaYe a cocffici nt of . 74, \\ hil that fr< m 3 llipti al conidia wa'- .67. Th ab Y findin s for H. :'\o. 1 ar s follm,v. : Cncffici1•11t of l011git11di11ul cccrnlricily All conidia.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43 Elliptical conitlia....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 . ubc~ lindrical coniJia... . . . . . . . . . . . . . . . . . . . . . . . . . . . .45 Cocffinc11/ of cylindrwty II coniuia........................................ .iO Ellipti al conidia................................... .67 _ ubcylinclrical coniclia... . . . . . . . . . . . .. . . .. . .. . .74 D t rminati ns of the oefti ient of cylindri ity macl from drawing uf Dr. RaYn (91) ga,e for II. gra111i11e11111 and H. ave11ae r ·~1 ctin:lr. 6 and .r, ·ho\\ ing a much higher coeffi ient than is given Gy ny of the f rm in my coll J tion. . com· ni nt m ·th d of mca. urin. coniclia f r o -rti i nts i. pag 179 of th app ndix. Conidial /e11t1.lli.-From fn·e s parat plat s, a, b, c, d, and e, inoculat d \\"ith H. _ · . 1 under standard mditi ns, ;raph_ 36-40 (Fi,. K) of conidial len th \\ ere made. Two additional graph w r mad from plc. tc e, n c1f \\ hi h i d ignat d a e'. Th data p rte ining t, th ~ grn1 hs .tr gi,en with the other (Fig. K). Th cliff r n e b tw n th m ·an of nit.lial I n. th n I lat u t e and e' ar a - follow : Plates a-1.i a-c a -d a-e a-e' h-c IJ-d b-e D1if1.' rences belwee11 mea11s +o.7o""' .21 +D.62 ± .24 -0.i ± .23 +2.0 ± .24 +0.50""' .Hi -0.07 ± .22 +o.os ± .2J +1.32 ± .2-1 Plates b-t' c-d c-1.· r-e' d-11 d-t!' r-i:' D1.ffrre11ces hl'lwec11 menn., -0. l :1:: .16 +0.16 ± .2.3 + IAO ± .14 +0.11 ±.17 + 1.2-1 ± .2- -0.28 ± .1' -1.-2±.19 .,incc: the ,ariou pl nting:,; on the ·e plate w~r all from the am 111- n ulum, mad at th cm tim , and und •r a. n , rly id Jnti ·al • nditi n · a. po ..:ii l , and s k pt, th rather I r diff r nc in means se ·n, particu- 121 larl in a-e, b-e, c-c, d-e, and e-e' i nifi ant. If plat e b I ft ul of n id rati n, th th r agr r a onably v,r II, with difference reat r than th prohabl rror in ix out f t n a , th diff r nc being but slight) abov th probabl rr r in tw a. , ab ut twic th probable ; and about thri that, in two a~e , the large t xce , a- b, b ing 0.70=.2l. iate wid I , with a differ nc in ca e of a- e of 2.03 :1::24, b ing mor than ight tim th pr babl error. The great diff r n in plat e must indicat variability f the fungus on thi plate ( cf.with pag l 2), modifi ation du to in Au n of om unknown factor of en ironm nt, or error in ampling. But inc u h a variation did occur in a ri f plat made with the great t car and with the ame organ­ i m, it i cl ar that th oc urren f u h a diff r n an not prop rly be int rpr t d a m aning sp cific diff r n . Data from th c mbined rec­ ord fa, b, c, d, a nd e' (omitting ea qu tionable) the mo t r liabl data 1 hav on l ngth of onidia of H. I o. 1 under . tandard condition ( cf. with raph 42, Fig. I ) . Tod t rmin how wid a variability ur in p cim n II t d in the o n, on the natural ho t, H. ravenelii (Pl. XX aw II-marked, a il r cog­ niz d p ci ofwid ographiccli tribution,growing n p rob lu ,wa tud­ ied in conidial-1 ngth graphs mad fr m ~P im n ~ Ii ted in onn ction with th graph ( ig. L). Th tabulat d r ult of thi tudy of H. rai,euelii follow: Nos.* Differences brtween mea n os.* D ijfere11ces between means 43-46 0.4 = .26 46-50 0.50 = .28 43 i 0.59 ± .24 46-51 0.70 ± .2 43-49 0.62 = .2 46-52 1.46 = .2 43-4 0.62 ± .29 46-53 2.43 ± .27 3-50 0.98 ='= .27 47-51 0.59 = .26 43 - 51 1.18 ± .27 4i - 52 1.3- = .26 43-52 1.94 = .27 47- 3 2.33 ± .25 43- 53 2.92 ± .26 48-51 0.56 :::1:: .3 4-48 0.45 ='= .31 4 -52 1.32 ± .30 44 9 0.46 ± .31 4 -53 2.30 :::1:: .29 44- 50 0. 1 ='=. 0 49-51 0.55 ± .29 44- 51 1.01 :1: .30 49- 52 1.31 .:1: .29 44-52 1.77 ± .30 49-53 2.29 :::1:: .29 44- 53 2.75 :1: .29 so- ~2 0.96 ± .29 45-50 0.80 :1:: .24 51-52 0.76 = .29 45- 5] 1.00 ± .25 ~J - 5 1.73 = .28 45-52 1.76 = .25 52-53 0.97 ± .28 45- 53 2.74 :1: .24 *For s iRnificance of numbers. see Figure L. 122 diff ren of 0.97 :1::: .28 b lwe n th m an of n o sample from th "" ame p cim n ( 1 o . 52 and 53) - a differ n more than thr e time th probable rror- ho clearly th difficultie of ·ampling, and that u h diff rence betwe n ample of the Lam p ci - grown und r th . am on­ dition may be expected. Th differ nee in v ral in tance , notably betwe n o . 44 and 49, 44 and 48, and 46 and 5 l, r n gr at r than tho. e betw en two amples of the sam pecimen and may well b du to ampling, and to thi extent how the f ungu , er a wide g ographic range, to b remarkably uniform. In se rat other in tance , how ver, th re is a wid difference of rn an , abo e the prol,able rror- notably in all ca e involv­ ing ample o. 53. These cliff r n c are oft n four, fiv , or ix time th probabl rror, and ca ionally run a high a lev n or tw 1 time the probable error even with thi remarkabl unif rm fungu ~. \ Jtile the. differenc s ma ' in part be attribut d to -ampling they pr bably r pre ent al o morphological changes due to n ir nm ntal diff rence , and differ­ ence of nutrition or humidity, but do not n a rily indicate racial dif­ ference in the fungus . To d termine whether various cer al , aut laved, influence conidial length differently, plates of H. o. 1 were prepar d und r standard condi­ tion ex ept that in the ame Petri di:a.hes w r plac d shoot of wheat, ry , barley and corn. The resulting graph of conidial le ngth are gi n in Fig. M. The differ nc tn mean ar a follow. : n rye and wheat, 0.40 :t: .29 n rye and corn, 0.45 :1: .20 On wheat and corn, 0.02 ± .22 Th m an len th on rye, corn, and l,arle i in clo agr em nt with that on wh at, and, apparently, und r thP. c ndi i n th p i f , hoot count for littl in it inftu nc on conidi I I ngth. oniclial-1 ngth graph ( Fig. ) mad from H. o. 1 gro\: n on fr h wheat-st ms, n y ung -wheat hoot , on wheat leave-, a nd on y ungwheaL plants, all autocla ed in te t-tube with a f w ntim t r f water, h w a ronsicl rabl incr a e ov r tho und r tand rel onditi n ( ,ra1 h -1-2, Fig. K); al o, in raph 58, 60, and 61 (Fig. N), th y sh w a mu h I rg r . tanclard deviation and coefficient of a rial,ilit , prol , I ly Ju to th va­ riable humidit und r these condition . The sma ll number of onidi<­ mea. ur I, and the lack of control over humidity m. y b pr um d to ac­ ·ount f r . u h variation a i seen. LiY wh at in cu lated in rag doll how ~d t th ' 6th cla 100 c inf• ·- tion. Th infected s dling wer I I P tri di h on mni:t Iii t r - LJ pap r ancl th ~ conidia "llow d t d , elop to maturity. onidial l ngth h re ( , raph 64, Fig. ) wa ~ m what le. than und r tandard onditi n · ( ,raph 42, Fig. K), and th ffi i nt of variability wa a little high. Conidial hreadl/1.- H. . 1 was quit on t nt rn nidial br adth - foll w : l\I 6. 3 = .04 CT 0.55 ± .3-! ·v 9.1 :t:.57 Th r tio f c nidi I I n th t onidi I br adth 1, an important on a d terminati, · of . hap . Thi. rati for H. o. l a. f II w : m an 1-ength 22.62 == .05 = J.74 :1: .03 m an breadth 6.03 ± .0.t In d ription f H. . 1, writt n in lay, 1919, fr my wn u e, an I pr pared with onsid rably m re ar than i~ or lin, rily med in cifi cl · ription _ f fungi, In t d th onidia a 3- ~ ptat and a _ 52.6- 67.2 X 19.~-24 µ long n wheat; and as 48- 84 X l - 21.6 µ on nrn-m al ar, wh r a my m r xt nd d tucly n w sh w · th m c.l n ,Yh at 7 .2 µ., th m an a 76. µ, anc.1 th ran from 4 t 9 .6 µ; th breadth a r nging from 17 to 23.8 µ , with th m an :,, 20.-l µ; th Lepta with a mod f , a m an f 7. 9, and r ngi ng fr m -! t lO. I m y h r not a 1 that Bakk ( 6) in hi l · ripti n f H. teres giYe th ' 15 (or105';:]- l OX 1 - _Oµ.,anlth . pt-t si- 1--1. f und nidia on sid rably long r than I did, as al o narr w r one~ . . houlcl IJ . aid that th data obtain d by thi ·tudy f r ph . r H. 1 . 1, though im h ing ... , ral th u and m a ur m nt-, fail t record the long . t oniclium b · n d, and the on with th m t pta, becau e thee w r oth ~ n durin b n · ti n \\'hi h r n I r 'd th ir in lusi n impos ibl · whi h i to my th t to inrlu i th 111 w ulcl haYe be n to con iou ly elect th - uniqu conidi f r in Ju -ion. A11 nt the hort oming f my wn ri f d · ription it d may b qu t d th ccardian d - . ription f II. rav 11 elii: 'Spon io~um; h ·phi. n·iccidis . xu is nodo i- ramo i -, inarticul ti ; onidii yml if rmibu , J-4 pt~ ti , fu ii;, -o µ I ngi cndo- hromotibu isthmo onn xis." Though th mod i apprnx­ imat ly at ""0- -!µ th onidia r all ran 1 e fr m 13 t 71µ e Fi. L) . ery imilar err r~, due t f d cripti n, xi · t regar ling man or all kno·wn ~ p ies. tc Pa inmel , "mR, and Bakke (90 , p . l 0 ) . 124 ETIOLOGY OF FooT-ROT E IDE E OF ETIOLOGlrAL REL TI N OF H .• 0. 1 Co11slan! Prcse11ce of the Patho (1c11e Tn all ca of m rican f ot-rot of wheat that ha , c me under m · ob ervation th rotten basal portion of the . hoot h r and wa • to a la rg xt nt occupi d by a my lium, which r w luxuri , ntl ' within th wh at ti ue though -v ry sp· ringly upon its , urf ace, cnur. ing I ngthwi . within the di -ea d r II · . 1 hi mycelium wa hyalin , eptate, ya uolat , irr gul r in thi kne , and, in . hort, a red in all hara tr with tho. e of H. . 1 wlten gr win in rotting wheat-Li. ue (page 105). Ab wee of oilier Co11stant Parnsiles o th r r ani m which mi ht b c n id r d a. a po-· ibl para -it was pre.ent in any lar · numb r of c e in or on the whea t ti .. u ~. Amebae and nernat d • "' r pre cnt in great number in the oil, but appeared to bear no relation to th rot of th \\"h at. \ ariou fun i, a Fu ·arium ( two pecie ) , Rhizoctonia, Epi oc um, Alt maria, w r~ cca ionally found on th root or terns, but each only rarely, in fraction of t O o[ the a e-, and with no , ·idenc f etiol g-i al r lation t th _ r t f th ldr:11/ily of Patho 0 ene pro'ved by 11l!ure \ ery nunProus i!-i lation w,re mad by t. king bit of ti -u 1) from di ea_ed _ h ath , (2; from disea d _ tem-le iun. , an I ( 3) by , tripping wa ' the heath, di inf ctin th remaining . urfa \\'ith 111 •rcu ric ·hlorid and taking out di-- a ·eel lJit., \\'ith pr cauti ns a aim,t ·ontamination . 11 !>uch diseased bit were laid m the , urf of om-meal ag r 1 lat · . Hun­ dred · of the wer made, with th r suit that in pr, ctically eY ry instance the di -ca- d hit a · ri e to H lminth porium c nidia in g ·neral p t like thos of H. No. 1. Jth r organi 111 , a . m nti n cl, a si nally occurr d on th plat , but in nly mall p r c nt. of in t. nc •-. It se m · ntirely condu iY that th mycelium con tantl) f und in th r ttin. ha al portion f th t.li ·ea_ cl wh at-. tern is that of a Ilelmintho ponum. Ei·ideuce of J11fecliouslless ,eral liag. of i-- ii that b r di ,a als test d. C rn and wh at w re mo~ t. often fir t in . u c ptiuility to ertain of th~ train , and were I o highly su ceptibl to more . train than were barley and rye. eedlinus in Petri dishes inornlated.- ·eptic wheal- dlin . wer placed n moi t filter-paper in t ril P tri-di h • and were ino ul ted in their ba al region in thr e way : by pl cing up nth m ( 1) wh al ti ·u rot­ t d by H. 1o. 1 (pur culture), (2) c nidia of thi org ni m, nd (3) agar bearing an abundanc f gro,;,,·ing my lium. cliff r n \\'a ol rY d in the ff ctiYene s of th three m des f inoculation. Ea h ·aye a 1 0 0 infection, alway yj -ibl with a hand len in 2 day - ( ig. 16) a . malt pot, which could u ually b een at the ame tim with ut a gla . I nger time than two day wa_ nece ary t demon trate that this p t w uld develop into a general rot, but . o it did in all ca s ,vh n th 1w1ron­ ment wa favorable . . eedlings in rag doll inornlaled.- \\'h at dling with h t 2-3 m. long w re placed in pecial form of ra doll (Pl. _ -'- Ill) and inoculated with H. ·o. 1 by placing an oe ·e of conidia- uspen ion on the ba f a h . hoot without wounding. Inf ction \\"a appar nt to th nak d y in Yery ca e in two da , and the re ult in ix da are ho\vn in Pl. XL~IV. Rotting c urred in 6-12 day · under favorabl onditi n . At 6 day th ro t w r oft n mor or 1 . bla k n d f r I n di and the cortex fill d with ni_ c lium. \ iew of ~rr,s -. tion showed a h avy infection of th _ ond I nf, and the h ath ompletel cupi d. \Yith x e siY moi ture, dlin s w re killed by th Helminth porium in 6 day ; but if in comparatiYe dr ne , only mall le i n r ult d. Se ·dling similarly plac d in rag-doll but atomized with onidi - uspc>n ion al · a\' 10 inf ction, and the infection wa much more, id I_ di tribut d. Inoculation I y di. a d ti_ u or by fungu - -b arin o- agar wa inn way rior to ino ulati n with conidia. ontrol. or heck, rag-doll , mad in the ame mann r I ut with ut in culum, at 2 and 6 r ' wa inf ti n h ' H 1- mintho. porium in the h k., and in a f w instan · overgrowth hy H lmintho porium imilar t H. 7o. 29, with niculc t onidia . Roots of whFal inornlated.- C onidia of H. o. 1 w re plac ·d n th rout- hair. of wheat- dling in rag d II. t the end of 4 day. II r t ·u in- 127 ocu lated w r II wi ·h o r pal tra, - olor, a ntra. t d with the whitr, unin cu lated ro t , and th y had cant r t-hair ·. nd r the microscope Fie. lo.-L , ion on unwound ed whe111- ced ­ lings two day , fter inoculation with conidia of J-1 . o . \. Th . haded portion of the hoot was )•ellow to brown. 128 the cnrtical ti.;; u \\c . • een to b, r wdcd with H lmintho porium myceli­ um rour ing mainly in th longitudinal clirecti n of th~ roul. The my lial thr ads within th rent ort x were r~markab!y thi ' k- 1 Jµ. \\'h e, t ·cedling 2 cm. Ion , , t1,miz cl with conidia su. p nsion of H . • 'o. 1, in (l day wcr O\· red with inf lion spot OYer their \\hole -urfa.c ·. J11ornlutio11. in oi/.- Vial 12 X 70 111111., prepar-"d a . de,c; r ribed on pag 180, "·ere u t1 a:-; ntain r ~. \\'heal -;eed-s w re ermin tccl a . cp­ ti ally, L ncl "h •n th shoot w,:.. ab ut 2 cm. long they \\ere inoc ulat d and transf ·rr cl t th· .oi l in a Yial. Th re. ult.;; cliff r cl in n , -ential way from th11.c rl ·scrih,d for th rag-doll inoculation, though th plant cnulcl he k pt l n. er uncl r ob rn1tion -in, it wa. nit . l ly kp n lent on the e d for f I d. . eptic ,vheat- . rain~ were • lso plant cl in th · ,·ial- with th ino ulL!m placed in three different po~itinn. : (a) on th • , d: (b) 1.5 cm. ab ,. the s ed: (c) 1.5 111. b I ,,. the ·eed. \\ 'hen on the . cl, le ·ion ccurr<:::cl I w; \\h nab th d, th y wer hi hr; " ·hen below th . d, no I sion-; n , rly d ys but the rant were h ayily inf ct cl. Durlication, m pot and 111 bench s, of all th abo,·e cxpcnm nt ­ made in \'i,tls , ay • iJ ntical r ~ult:;. Recoi1ery of Orgo11is111 ~ ft r a ll th types of in culatinn mentioned ab Ye, llie organi m u. ed in th in culatiun wa - !early , ident in the ti sue and proclucin nidia upon th m, and IJy diluti n-plating it was r c , red fr m th m. During . uch r , n· th r ·\\as c.-nm tim evidenc f bact rial or oth r ont. mi­ nation, 1,ut in mo::,t a of h type uf inocul, tion no ontamination oc urr d, and th· pathogenic chang nnted wer cl arly attributahl to th f ungu us cl in th ino ·ulation. TNFE ' TIO f-HE i\JE A U \\'HEAT ·onidia of H. ~o. 1 nd of H. Xo. 1-! when placed on \\ heat in rL clnll rminat d from ne CJr Ii th en I a d riled l·ewher . The •rm- tubc ~r~w rapi lly, bran hing fre 11 , an 1 ori nt ,cl itself I ngthwi~ f th . honl nHJr fr ·qu ·ntly than ro. wis nr ol liqu ly, oft ·n following; I •ngth­ wi:~e the boundary I, ·tw 'Cr. t\\·o \\·h ·at- lls. . t certain pla e · where Lhi · my clium tou heel the " ·h at- urface it wellctl sli~ht ly, producing. round ,ir ul,long appr<',;sori11111. Th 'f. appr .oria som tim '!>, prob. 11) 11111-,t nft ·n aro. e hy the impl · '-i\\'elling of a ell of th main t hr ad ( Fig. 1 i), lhou. h f requentl) al...,,i from -.;hnrt I. t ral bran Jw-. (Fir. l i, d1 or" h •re lh • t rmin.1! c II of a thr ob ned the appr , ona ar only c: f ter th ca e with . om I . I ,. I~" 129 d abutt d again t th wh at ti .. ue (Fig. 17, g). o far as cliff r d fr m th u, ual m elil c II nly in h p . The ver r nuni rou ( Fio-. 17, b). Th y are u ually produc d my lium ha grown to on id rah! I n th; n t, a - i the fungi, immedi t ly on m -rgence from th conidium. In \ ' I I \ - I I I I I I ' I \ l I ~ I - 7 I ---= -~"\.1... r- ~ I 1 \ I \ - \ ,, '-"' i \ ' I l I a.. f F1G. 17: a. H. o. l on wheat. U hours after inoculation. showing my dium ari ing from a conidium. an appr orium. and pcnclraling my clium: II. c, d, H . o. 14, showing appressoria, penetrating points. and "callus"; e. f. 11. h. lJ. No. I : c, mycelium wilhin cell. and wi h a penetrating mycelium reaching into an adjacent ell , a "callu " th r · r ·ulling; f. my lium endini: squarely against a ceU­ surface. penetra t ing it and then being overed by " aJlus", a nd v ntu lly p n trating this and the next cell-wa ll, the latter being thickened; g and/,, imilar to,•. mo t th p n trating m c lium, vi \1' d from aboY , app ar a a minut bri ht p int, or a if a minut hole had h n pi r d in th wheat c II-wa ll, mu h a n in th hyphopodia of M liola ( 82) or on th appr , oria f I o poriu m ( 64) wh re p netra tion organ ari i wed lat rally, the bright point of the appr orium i s n to mark th emer- n of a ha ustorium-lik trand which I h II ontinue t call th pene- trat in myc lium. Thi tructur i much thinner th n th u ual m celium (. e Fi . 1 ) and f diff rent s tainin r a tion . It p n trat th wheat 130 ell-wall, and i, som tim impl , som tim branch d. t the pla e wh r th penetrating myc lium pierc a wall and nters a h a lthy whe t- ell th re i de, eloped, on the inside of the wh at-c II and surrounding a nd overing th penetrating m ·celium, a callu -like tructure (Fig. 17, e-g) which for br vity I hall term th "callu ". A the penetrating my lium continue to grow, th "callu "grow pari passu. ,, here man p netrating myc lia d Y lop near clrh oth r thi . "callu." may b com v ry large C a,·-. ~ .,\ ~ - = s ~'~ r ·, , \. b Fit,. 18.-11. No. I: a, large .. rallus" -formalion, with many penet r ling mycelia pi •r ini:: th· rpll walls: h, m~•celium spreading over Lhe wheat surfa e. and at many contact points producing appre oria and peneLrating myc lia; ,, peneLrating m~•celium of unu uat form. and lire "callu ·" rou~h. ( Fig. 1 , a) an (99), and :\derhold (1). 1 he lat thr named, beli ye thi - tc.1 I., du t h motaxi influen e-;. o k in de cril>­ ing the entrance of II. gramineum into the ho t men ti ns the appr .. ri,. imilar tructur ha,· I. h ~n d . cribcd in th , nthr no c fungi by Ha elbring (64) an I t,y Carrin ·r (5 '), th pre: in th s' -;tructur being uch a I find in Helrnintho porium, though th ~ appre orium in th anthrac­ no e fungi i a m r :;;wellin and L hyalin . Similc1.r xtreme narrnwn :; .:; of th mycelium at the artual p int of p n tration of hwt-,Yall i · shown - - ~ -~~· VIC,. 22.-H. Xo . 11 o n whca.t, ~hO\\lllg fan -lik t• 111 0,t,. oi t,r., ni.:hi nis , ~l,t' IJ. l!li , al o 1.,y v,ard (L~. fig. - i), .. ardner (58, pa e 271, l-Ia ·~elbring (64\, Bu. gen ( 30), and ~ ark ( 87). Eakk ( 6) ay f JI. teres that th myc lium "p netrat d the pid rmi directly and made it~ w y hrough the interc llular pace ," but he give no further d tail . onditi n Yery lo ly 1·esembling th "callu ·" formation are figured by Da tur (-11. fi -. , 9), depi tin the entran e of : mut into ugar­ can . Thi app ar to ha,·e occurred only occ ionally, and r astur r - gard th "callu " ("plug") a .. prol.iabl a mean of pr \'entin. infe ti n. ondition som wh t r ' embling that of th ''callus" f rmation re d - criLed and figured by \\'olff (128, fig .. 2, J) an I hy 13refeld (r. fig. 2) in the p netration of mut · into cer al tissu ·. \\'ulff ( 12 , p. 20} cl - cribing thi ay - : ''F.:-, tritt hi rlJ i der eigcnthlimli ·h • l'm-,tc.llld in, d der Fad n, bald eine . pitze in da · Inn re d r Z Ile tritt, nicht frei in di ses hin in~·a h~t, ond rn von d n inn r n chi hten d r Z 11- wand, w Ich i h I i h~am au . ttilpen, wi in ine • cheide von bald gro rer bald g ring r r, ft hr b tra htli her tarke inge chlos en wird und in die er bis zur nach t n Zellwand w iter wachst." Bref Id de rib s ver ·imilar condition , in luding much thickenin whi h i. of ellow color, but inst ad f int rpr ting it a an nclo ing heath h regard it a wh lly du to thick nin of h wall f the m c lium it If. He mor o r tate~ that thi ph nom n n i~ indicati,·e of condition in th ho t, a t gr at age, that are un uita le to inf cti n, and that it i n tin evid nc wh n th ho t i in full) u c ptible condition. \ hich- ver ma b th tru int rpr tation in th a f c r al rnuts, I am onvinc d that in ca~ of H lmintho porium th "callu '' i • produced bY - - . 7 F1 . 2J .- 1nf ct ion by H . No. 1, 24 hour. after inocula tion. ~hawin g t h ickening of the wheat cell-wa lls by deposition on their inner surfaces. {T ex t itat io n a t to p of p. IJ I .) th wh at-c II, and i n t part f th my elium. Ra,·n (91), d scribing th reaction to the int r ellular m celium f Helmintho porium in cereal , tat that a thi k ninu app ar upon th cell-wall of the ho t, re embling a drop egr gat d from th c 11, and that ral u h thickenings may b e n upon ne II, om tim filling th inter ellular paces completely. They seem to differ fr m tho that I de rib (Fig. 17), how ver in posi- tion, ince they are without, not within, th ell, and in compo ition, a tho e n ted by Ravn t k aniline tain readily. Ravn (91, fig. 23 d crib s an appr . rium Y ry mu h like that \ hi h I find and tat that the mycelium from it ent r the epidermal ell, wh re it o incr a e that it ma) fill the cell; th n m k . it way to the intercellular pace and grow there ex Ju ivel ' n ver again nt ring ny f th c II , . n by m an of hau toria. It th ref re appear from hi tat m nt and figur that th H lminth sporium with which he 136 worked, diff r d in a v ry fund a m ntal way, a pathog n · , from tho · which I am studying, hi f rm b ing intracellular ( .· ept regard the fir t cell inYaded), and not at one killing the adjac nt c II ·. That i , the condition pictured i much like that present d by lbugo, P ron - pora, Puccinia, et ., x pt for th ab n f hau toria. The form with which I deal, on the oth r hand, though t hey enter through the middl lamellae, immediately becom intra llular and at one kill he protopla t of the invaded c ll, and proceed imilarly with other ell . The differing- ondition , if ub tantiated by further tud_, prol abl indicate fund - mental differences in the fungi in regard to their produ ·tion of toxin or enzymes, and certainly indicate an ntirely differ nt typ of pathogeni ity . In the e early tage the di ase i prop rly a pot and n ta rot. \ heth r it will d velop into a tru , g n ra l rot dep nd upon nditiun , . h n m na like tho e d cribe 1 und r the pre nt h adin , th ugh cliff ring in d - tail, wer noted with H . • o . 6, , 9, 14, 21, 36, 9, 40, and 41. Action of va rious strains of H elminthosporium on i •heat shoots.-Te ts in rag d II, at medium moistur , with H. No. 1 and H. 1 • 3 gave at 2 day 100 0 infecti n for both; at 6 day there wa n appre iable difference between the two; while at 10 day all ·hoot wer rotten under H. o. 1 and om , but not o ma ny, und r H. 1 o . 3. Th te t wa. repeated with 14 ~t rain of H lmintho porium. • 11 trains at - day how 100 inf ction; the control , no infection. The infection phenom na with a ll of the e train were all of the haract r described on page 12 , 129, howing penetrating my lium," a llu ," tc. At 6 d::iys H. :-.; . 1, 4, , , 13-16, 2 , and 21 had all pr duced me rot. The r t al v er di. tinctly y I­ I , c:d b H . o . 1 a nd 16, whil H. No. 20 ho, ed le r tting than the other number mentioned abov H. No . 29 and 9 produc d no r tting, and th I ions wer Yi ible only through a Jen , but thus v i w,d, how ct 100 ~ infe tion, as indi ated by the u u I inf ti n phen mena . H. 1 To . , 6, 9, li , a nd 18 rema in d lo al , a at 2 day . H . . 29, a Helmintho porium with geniculat c nidia, g rminat d abundantly fr 11n both end of the c nidium , a nd n wheat produced many pen trating rnyc lia and an abundant mycelium within th ho t, thou h th myc Ii I inva ion reach d onl a f , e ll , and while extending for n id rnl I di tan 1 ngthwi , made but littl progre lat rally. Th appr ~ ria w r · u ua lly pyrif rm, a wa a l o the p netrating myc lium, differing thm, from II. • o. 1 ( Fig. 17) . "imilar tc t w r made with thr ltant , ~16, I , and 3 . ote at 2 da_ how d 1 00',., inf lion, n ~ t > cla, mu h rot by f6, and c n id ral le rot hy th othn t\\o . 137 1h u h inf ction n l> d termin d with c rt inty, I hav a y t no m an of accurat ly m a uring rotli1P ,wer, or of determinin wh ther diff r n n t d in r tting ar due t nvir nm nt, ho t, or fungu . I t a m I ar, h w , . r, that H. o. 29 i. c pabl of cau ing only local pottin ; and that the oth r numb r -, perhap v~n th saltants, vary om what am ng thems h· in rotting apacit ·, most of them causing rot- tin to m xt nt under favorin conditi n . h fact that o many and di er5 ra e f H lmintho porium are , 1,1 au e rot f wh at, I d me t t t th abilit, f lternaria to para- itiz wh at e dling . n It rnaria. f uncl common ly on wh at eed, wa isolat d and in ulation mad in rag doll on wh at se dlings. At 2-1 h ur::; man wh at 11 - showed di ased spots , b in in e,·ery way like tho~c cl riled on page. 12 , 129, including th wol len middle and inner lamellae, browning of th c II -content , and f rmati n of th " allu '' and p netrating myc liU1n. The I rn a ria myc lium cro- ing eY ral middle lamellae, u ually pr du d a n appr orium and p n tration at ach middl lam Ila. 1 h It maria m 'C lium \\"a. aLo . n t nt r the \\"h at-c II , killing a few f th m, but in n in tan wa thi fungu b en·ed to au e rotting or t µr du a p t ta r enou h t b vi ible t th naked ·e. It wa. n, how v r, t p n trat th c II of th root c rt x quit exten. i,· ly, au. in c Ii ht browning. ~ teri mat y ti , P ni illium, and , . ral oth r fungi . uppo ed to be m r ~apr phyte , w r treat d in imilar mann r, but produc d none of the ph nom na r inf ti n. l EPTJBILJTY OF VARI l' H T T l FE ' TlO~ Test · in rag doll with H. No. 1 orn.-Thre e dling - h ""e I no inf tion at 2 day , though c nidi v.er pr ent and had g rminated. t 6 day · 11 thre pl nt wer in­ f ct d, the inf cti n b ing confin d lo n r tw II , thou h th my e­ lium wa. I a rly vid nt in hese. P mm 1, l ing, and Bakk ( 90) r port ne a tiv re ult reg rcling infection tri I of H . satiz,um on rn, but th ir t<> t w r J;mited to I a,· . Barley.- t two day one plant We. s Ii htly inf t d, . bowing ev­ ·rnl I ion . In th e them celium, a~ a bundant within th cell.. Eight wer not inf ct d. t 6 day th inf ti n ho\\· d no further pr . re ~ . Rye.- t two da thr plant w r inf t d; ix not infected. At 6 da I th infection h w cl no pr g r The my elium wa ob erved with- in th cell and infection phenom na on wheat. Sorghum (llolcus sp.) .- 1 her w · 10 c inf tiun of b th root, and stem , with pronounced rot. 1 he ~ame ph no mena w re l s rved n \\ h at, in luding th appr oria, pen trating my lium, an J '' allu -. " 1 he c;ap of th infe t d cell. was strongly tin 1 with r d, and the "cal­ lu " and appr sorium " ·ere deep red. dja nt olorl . wall on b - came sw lien and redd ned . 1 he red ol ring-matt r i- al ~ rt d by th 1.: nucleu~, " ·hich b come · a brilliantly col red a ~ by an anilin y . ~ t · ix days the hoot and r ot w r h a,·ily inf ted, the di ·ea ·eel re ic n. a urning a d ep r d, almo t black, color, nd onidia formed abundantly O\'er the le ion ,. \\ 'h n uch . p im n w re plac cl in al oh I, the red olor diffu.ed to th ' al ·oh 1, ol rin it stron~ ly. Thi r I c 1 ration by th host i a r sp n e common on inva ion of ither bacteria r fungi n the oq~hum and sugar-can , and on corn in the a e of m cJi e· e . S11da11 grass (Holms snrgh11111 s11da11e11sis).- t t n day 1 edling gay po itiv and 5 ga,· n gati,·e re ult ; at · ix day , - po itiv and -l­ n gativ . Inf ti n wa . light n a few c II , but the mycelium wa \'id nt within th ell . nd inf tion ph nom n.=t a on wheat w r ob rv rl . Cor11mn11 mi/lei ( '/Jaelochloa ilalica ).- t two day.· l () gay po itiv(' re ·ult. At ix day · th rol was progre.sing into the ro t fast r than into the stem, th ugh black pols 3- 4 m. I ng were appar nt . Infect ion phenom na were ob_en·ed a on wheat, and muc-h my lium wa within th ti . u . Cennan millet ( Chaelochloa ilalira germa11ica ).- The re . ult · were pra - ti allv th am a with c mm n mill t. Amber cane (Holc11s sorglrnm).--R ult · wer mu h a on ·orghum Red top( .- l gro tis paluslris ).- ro phe nomena of infe ti n wer b -erve I Beans.- 1'\o rot wa · pr due d, no "callus", nor any ther f the u · ua l s igns of inf ction; nor ,,·a it certainly determined that th my lium ent r d th ho. t-cell , though it eem · probA.bl that th fun us kill d nme of th b an c II . Inoculation of leai•e· .- Pots of w II- tabli h d dlings of wheat. oat ·, rye, barley, ,rn, ; rman and ·om111on millet, nd o r!rhum we r · placed in a humid atmo ph re (abo\'e 90 ,_ relativl' humidity) nd tornized with u · ri n. ion of H. No. 1 conidia. \\' 11 -d lined ~riot occurred fre­ quently on 1,arl y, 1 ·· fr qu ntly on wh at. 1. af-_ pot du to a lI lmin ­ tho porium, apparently H. o. 1, a l o ccurrecl natur lly on wheat in th e greenhou ·e. . uch rot. w r fir_t pale; later with a mummified dar. · ent r urrounded l1y a pale zone; e nd were m I in outline. In ry • th .. • mycelium wa . n to h abundant within th· cc- ll , a nd com lete d .:.1th f the aff ted I af, and al o rotting without . potting, re ult d. 011 th 1 a\' in th humid air f the rag doll cca ional sp ntaneou inf tion wer noti d. ln u h ca ·es th infection re pidly pr ad, involving nearl) II of the l af, ,, hich fir t turned pal , th n v ry Ii htly brown. erial m •c lium and c nidia were profuse \'er th di a ed portion. . ,1JMARY ON ER ETIOLOGY F F T-R T 1 he vid nc is con lu h· that Helmintho p rium is th cau, e f th ba al rot f th wh at- t n1.. It i the nly par it on. tantly J re nt, and ha been r p atedly, and by many m th d , pr v d capabl of cau ing u h rot. Thi - ondu ion i • in ac rd with th finding of B ck­ with (14, who a · arl 1 a · 1911 ·h wed that H lminth p rium i· a very comm n para~it within th f wh at-plants. Bakk ( 6) in 1912 r port d that wh n conid ia f H. teres w r pla d on barley seed - , " t the nd of two we k ' tim th r w r not over ven eedling t th row [originall ther w re twenty-fiv ]. The roots were not in any indicative of a h alth) tate of row th." ats and fe cue-gra s w r not LI ceptibl . eedling blight of wheat ob. erved sin e 1910 hes b en de cribed by takmnn (11 ~) in Iinne ota, wher in 1918-19 it became • ri LI I lI1JUrt u . The ymptc m inclL1d dwarfing, f ot-rot, and root- rot. Th di a , pp ar t b lo I) lik , if not quit id nti al with, th one "hich i. th f thi pap r. h pr v onclu iv ly that th 1 a H lmin tho rorium. foot-r t f wheat du to a Hel­ minth sp rium haYin quit different morphol gical charact r 1s al o known in udan ( e . 46, pag 1 -1). ertain of Ravn' xperim nt (91) ndu t d I y inocul ting n w t filt r-pap r in P tri di h, av ondition much lik tho in the rag doll He make no m ntion, h ,:v v r, f inf cti n f th . heath n r f th urren of rottin f the ba 1 regi n. II. Evidence and Discussion of the Occurrence of Saltation within the Genus Helminthosporium J TRODU TORY Ea rly in my . tudy of thi H lminth p rium of foot-rol f wheat (h r ind ignated a H. o. 1) it wa n t d that ca ion lly c rtain s ctor f a col n growino- on an agar plate diff r d m re or le from th rest of the colon (Pl. ..,TII, 5; Pl. XXIII,1). Thi ph nom non i of rath r c mmon o curr n in work invoh·ing P tri-di h ultur - f either fun i r ba t ria, and littl . ignificanre "a.;; c: t fir. t tta hed to it; Lut lat r, when 1-!0 the frequent recurr nee of th e variant ctor command dattention, tran - fers were mad from s Yeral of them to freshly p ur d agar-plate , and a transfer from the normal portion of the colony wa aJd d to a h of th plates at a di tance of about 2 cm. from the other tran fer. Th variant transfer wa then marked on th bottom of th doubly occupied plat a M (indicating mutant), and the normal transfer as O (indicating riginal). In aJl the early tran fer the M transfer r suited in a colony ( 1) of decid­ edly slower gr wth and more profu e conidial production than that pro­ duced by the O tran fer. The two colonies al o diff red markedly in general appearance owing to minute single differ nee whi h were oft n diffi ult t analyze, but v. hi h in the aggregate con, tituted di tin tion whi h w r -o well-marked and ol.Jviou that at fir t ight one "ould ay that the two colonieswer tho e f tw di tinct fungi (Pl. XXIII,lowerfig.; Pl.XX II) . 'A1hen these colonie. grew to fill, or nearly to fill, the plate, tran f r from them were made to new agar plates, and later, tran -fer from the ec nd plate , and o on, the eries of tran fer b ing a long on . It wa found that the diff r nee appearing in the M 1 and 1 I ni s were usually maintained n uc eeding plate . The e finding - I d to the t ntativ a umption that form in th variant ector w r mutant or alt.ant of a more or less permanent nature, and a more eriou ~ tudy of thi phe­ nomenon wa · undertaken. In their origin the Yariants or altant always appear a ectors whi h differ from the portion of the parent colon_ adjac nt to th m ( ee Pl. X.'-:ll ) . To the naked e_ e the mo t common deYiation fr m th ng­ inal type are in den ity, color, and rate of growth. Clo er hservation, with the microscope, fr quently how Yariation in the grouping, siz , and hap of the conidia, and in the Lran hing f the mycelium. Quite oft. n many small ectors of divergent character appear at the edge of a large colony, e pecially on a plate that i beginning to dry. lany f the e di,·erg ncie are merely modification due to local environm ntal chan , and whether they are m r an be d t rmin d only by clo .. e tudy of th ir behaYior in ub equent tran f r or tran, fer . lo ,r on ideration of the charact r involved in the e _a ltati ns i b t cl ferred t th f llowing topic . In following thi di cu ion it mu t be born in mind that l\[ ref r · t th Yariant. ctor on th plate on which it originat d; Ml, to the I ny re- ulting from th first tran f r from M; M-2, to that re ulting fr 111 th fir t tran fer from 11, and o on; and that refer - Lo the 1riginal olony in which the tJ ar It is my custom t give the altant a rinl number (writing thi , on th, plat in which it, a · found), nd, u. ua lly, t tran ·f r l-t-1 th th :altant nd the original to lh : am plat . o that th y may ha,· th . a m m ·iror.ment I condition , th i lentical 1uantity and quality of agar , and IJy r wing clos tog th r 111ay ren I r rnparis n a Not on the rigin,-11: cl . ub~ ~qu·ntb ha\'i rofthe . altant \er mad underthP. • rial numb r, ard th e tran-f r w r d . ignat d by dditional numb r. 1 hu _, 19 -7 r f r · to rn lt '" nt ~o. 9 , trc n fer 7 . • HARA T ER . F TN TRAX FER ,rncral appcarance.- 1 he altant and f th original "h n r wn on th _ame plate wer u uall o trikingly differ nt in g n- ral api: ara1: ( f I. XXTT, XX TTI) that m r glan uffi ed to 1Ye th imµre ion tha th ·y ,, ·r f tw diff r nt p 1 - . Thi - clif­ f r n in n ral api..;ea ranc i · , n analy i · , r feralJI tu on or m r of th indi\'idua l differenc' · m nti n db lo\\·. Pale I linear !!.ro,..th.- Fr qu ntly th _altant ,rn f mu h -t wer . rowth than th ri in I, resulting in an M than that of th O c I ny, b ing ft n le . I ny f mu h 1 ss diam ter a mple: on i, n in Pl. X ... ,. 11 and one in Pl. ~ r _,_ JII ). howe, r th I ulony re\\· fa . t r than th !om·. f it ( - two x.­ In om in tance , C uidial prod11ctio11 .-Fr qu ntly th 1\1 colon , '-pecially when low­ gr wing, wa mu h mor produ ti,·e of onidia than the O olony, o much rn a to iY the colony a lecid dly per eptil I dark r color. In ·ev ral in · tante · , how er, th I c lony ·wa. of the ppo it• haract r, producing f w c nidia r, in m as . , goin to the xtr m f app arin to pro- du C' n n at all. ,enerally ·peaking-, rate [ linear rowth wa in im·er rati t th t f conidic -production; while tho. . a ltants that w r pale and po - es~ d mu h a rial my elium \\ r u, ually f r picl lin ar growth and low onidial produ tion. Couidial clusters.-.~ m saltant , ·ari d . trikin ly fr m a h olher and from th ori inals in th m an numl r of c nidi" born per conidio- ph r . cuidial length, breadll1, septation and shape.- Th - ' h racter , a Yid n d by a. u 1 l 1Tati n r by a tudy f ra1 h and the data I ri d f rorn th m, ar :-hown to b · . trikin ly diff rent in ,. rious alt n ts. For 1 arn I pre-=ent in thi onnection r cord nc rnin on ly a f w ~altant, , giYing graph · and data f r thers lat r. raph or (GITidiol lenyJI, f _altants M35, f36, and ,r .. w, tho. e whi h , how great . t d Yiati n fr m original - in thi r gard. are giY n in Fig. P with th ntialdat-t. lti tob b.:n-dthatth mnd:;of l3Sand l-!-2 1140 ar Si. ml 64.6 µ re p cti,· I), far b low th mod· of th n rm I, whi h wa 81.6 µ. 136 how - le. . lriking cliff r nc but this i. Lill marked. omparis n f th m ans hmv thm,c f r 6 and l\I-l.0 to be approximately 17 and 18 division ( 1 diYision = 3...1 µ), whil the original wa 23 di,·isions. In other words, th c nidia uf 1\136 were only ah ut three fourths th Jen th of th normal conidium of H. o. 1. u h clif­ f erenc a they appeared in the microscope ar hown in l'l. XXVI. The differ nee in Yariability i al o · trikingly large . triking \'ariation in co11idiol breadth, both r lativ and ab lute, " ·as obsen·ed. Graphs and data of the mor pronounc d ca .. ar pre nt d in Fig. Q and other are g-iven later. In conn ction with Fig. Y ( ,raph:a; l 14-138) ar 1v n ummary data on th coniclial leng th f altants in - lucl d in this tud ' · It i to b not cl (Graph 6. , Fig. B ) that whereas th mode of the ordinary conidium Rtood at 20.4 µ and no onidia exec decl a thickne of 23.8 µ, the modal thickne of 1\18-7 ( Crarh r, Fi . ) i. 23.8 µ,, ith many conidia 27.2 µ in thickn , on ev n 30.6 µ. uch lif­ ferences between altants and the parental form ar pr s nt d tu the ) in Pl. XXVI. The ratio of conid1·az lc11glll lo co11idial bread/I, i p rhap · till more triking than th m r variation in I ngth. J n . uch Yariant a 16 ( Pl. XXVI, b) ancl 18, whil increa ed greatly in thickn ~- th c nidia were at the arn time ab olutely hort r, thu empha izing to th y, both difference . Th ratio of I ngth to br adth in H . .No. 1 is a follow mean I ngth mean breadth while in a ~ample of one of it mean !en th m an br adth = 22.62 :± .05 _ * = 3,1,I: :± .03 6.03 ± .0,1: altant this ratio 1s 20.67 = .22 i.82 :t: .11 = 2.t>.J. = .04 * and in another sample of th am altant it i. m an I ngth mean breadth E=± = 2.oi = os* (✓( ~a r+lJ'' ) A +Probable rror was compuu,d according to the above iormula kindly furni,hcd me by Dr . .l <\. IJ ·l­ lersen, whcr" a =probahl,· error or A; b =probable error or B; and E =prtih,slilP ·rror of~- 143 V riati n in septalio11 w re a l n ted; thu in i . R, ,.,re ph 79- 2 ar 1uit cliff r nt from Craph 83 and , whil a ll f th s ar low r than the r ult gott n fr m H. o.1 in raph -, Fi . J. I ttach but little r, to t h . c ,-·'lri ti n. b cau e th y m i neon tan t. ri ti n in couidia/ shape i - mm n, me a ltant · -bowing th s ide · m r nearl parall I t han 0th r , and th conidium a · a wh le I ss llipti a l r fu . iform. l'arialion in submerged mycelium.- ide fr m rat f gro,vth and variati n in branching , hi h re ult d in chang s in den it f t h olony, diff r n e in the ubm rg d m c lium wer ol.J en ·abl in but tw case , rn t lrikingl o in 126. In thi saltant rtain hyphal thread near th d f th I ny , pp ar d to b mu h mor \'ig rou than th ir n ighl1nr , I omin trifl thi k r, and I n th njng with u h rapidity ut trip the th r , r a hin ut in I tr nds to a on~id r- di tc nc I y nd th u uall I en fr ntier f th I ny, b mnmg then d ns , bushy bran bing in a ll directi n~, r minding on of \Vitches'­ broomL in tr :'\um rou outp t of thi kind I\' p uliar lump appcaran to the olony a n by th nak d y . Thi p cu liar mod r l rnn .hin wa I rl) t b e n in 1126, wh r it originated, and wa fr qu ·nt i.hrou h ut ubs qu nt tran f r . In t ad cJf -in I threads r a hing out in thi way, the my lium om times fc rmed f scicle which would 7r w ut ra1 idly in to n w t rritor with ut I.Jr n hing, th n ud­ d nl _ I ran h pr fu I , forming ad n e bru h. Th . two rar charact r \\- r ~triking in ff' t I th t the naked ye and und r th mi r cope. a rl y every tran fer from M26 or it des ndant gave colonies with , ·ery · trikingly mL rked -e t r ·, chara teriz I e enti lly by abundant ni ial pr duction, and th r fore dark in olor. Th other ector bore f w onit.li a , w r pal , and b ing a trifl I r pid in growth th y were u • a lly rowd d ut ( Pl. XXX, I w r fig .). Th chara t r wer main- 1 in cl through rn ny tr n f r . ( PI. X XI.) I 'ariatio11 in aerial myceli11111.- c It nt e tor · an I their prog ny )ft n diff r d fr 111 th original in the abundance nd character of th e < ri < I my lium . In . me a . it wa. scant a s t b unn ti ceal I ; in oth r c . . • I undant and A c se a. t ob ur from vision the colon) benea th . In_ chara t r it vari d from lo and fluffy to "ro1 y," the lLtll rt r;11 incli ating at nd n y lial Ltr nd · t twin tog ther (Fig. - , c, p. 1 4) . In oth r ·a it ol lcct din cl urn pt-,, the proc · h ing-a tt nd rl ly p culiardi. t rtion (Fig. 6, e . In . nm sall.nt · th · · lump. w ' r ahunda n t a nd r at I; in ther · f w an I -ca t r ·d (I I. 1-!4 XXII, X.:·II I). Th occurr n f dump- of mycelium upon the urfaec of the culture ha been tre sed by R .. vn (91) - uf taxon mic im1 rtan ·e (cf. also with Pl. XI, XIII, X .. /111 (bet w), '~ VIII). H. o. 1 , in one ·mall sector, howed eight white clumps; the balance of th plat , non . In tran f r 171 th clumping hara ter. m d lo t, but the following tn.n~ fers wer pale in typ . In oth r a. th~ lumping habit emed to b fix d and chara t ri tic ( Pl. .L X JI l ). 1 ariabilily in colony color.-Th olor i mainly due to al undc n r carcity of conidia or to abundan ur la k of a rial myc liuni, or to both. The white aerial mycelium i pra lically without conidia. Tr n fens from ector with much whit , terile aerial m_ c lium w re not !way - con tant in th e character , but in many in · tanc th y were ~ ; for example, M72, derived from ingle c nidium ' 1-1, and 78, d riv d from M26. Differen e quit omparabl with th w r not d by rabill (36). Zonation wa well marked in altant nd almo t entir 1. lacking in others (Pl. IX, 3, 4, 5, 20). . om altant form d sclerotia abundantly though th original did not do o. Density of colo11.y al o differed, m a ltants pr ducing coloni . of much cl nser r wth than th rs. l'ariability.-· ariability its If w a distinctiv chara tcr 1n c rta in instances. Thu , whil the original of any giYen altant i u ually f irly con tant in it hara ter and only u 'Ca · ionally giY ri e to . altant , n altant, 126 (Pl. XXX, below;XX-~I), wa definit ly chara teriz d by the fact of it - incon tancy ( ee pa e 1-!3). Many altant were t ted a - t th ir inf ting pow r nd their rotting power, but no r al diff r nee in the e r p ct wa noti abl b tw en th different al tan ts, or bet\ve n tl1e sal tan ts and H. 1 o .. 1. inc many· sp i .. of Helminthosporium can inf ct many r reals thi pow r me y b rath r fundamental in the g nu and thu not b o r ad ily ubj ct to all tion a are le fundamental chara ter - . T haY no mean a yet tom a ure light differ n e in either virulence or rotting r wer. It may he mention d her that Ra n (91) stat s that culture up n cl ad -ub trata cJiminishe the vir­ ulence of Helmintho poriurn. \\'h ther uch diminuti n was p rman 11 t or m · r ly a temporary modification he did not det rmin . Etlg rton ( -1) report that different rac of lomere ll a diff •r in virul nc Correlation of characters in saltatiun.-Cerlain currelati n f har cter:5 ar notic able; thu , colonie of -low lin .. ar growth w ~r ' usually hiah in onidial pr du ti n and 1.·1rc z·u a. ~- f 11 w~: orr lation · b n · d ar indic:at cl . low linear growth._-high conidia-produ tion 1 uch aerial mycclium~low conidia-pr ducti n Pa le colon r----ra pid growth 1 hickening uf conidia--.shortenin of onidia Pale olony- low c nidia-produ tion ' lumping of myc-elium~low coniclia-produ tion 1 he differ n in colony-col r and rm th-rapidity her noted , are much lik th cl cril cl l y Edg -rton ( 51) in ,lorn r Ila plus and minu ·train . "rabill (..,6) n te al o a corr lation in that hi - minu train. -were a lway of more rapid gr , th than the plu train . T E DE CIES IN ALT.'\.TION c:al tant hO\,ving very Jow nidia-pr duction, v rg111g on terility, oupl d with pal n of col 11), urr d with the r ate t frequency. typ ith in r a d coni lia-production and of 10\v growth wa n xt 111 Th latt r f th -e type - wa the mo t fr qu ntl thrown dur- arl) p ri d of my work though it ha b n ra re r ccntly. n th oth r ha nd, th form r typ , which rar ly appeared at fir t, i now th mo t ommon. typ hara t riz d by thi kn of onidium, a M6 , M , et ., ha - b n fr -quent all th tim . Th , thr t) p ,Yere by far them t c mmon, and may be aid to h w the thr t nd n i . :Markedly hort­ onidia altant w re few, a w r a l - clump-bearing typ that po ~e ,ed perman nee. train that thr w ith r of th two typ s fir t mention d b Ye v. rev r like! to c ntinu to throw imil r typ . Th sam may be aid of lump-bearing t p . TABlLlTY OF THE ALTA 'TS Man altant hav been te t d in ariou way to d termin , to some d on tan y. Through nurn rou tran fer on corn-meal agar nd the I col ny of man altant hav been carried ide by id . ondition , thoug h th ri inal may 1v ri e to new "altati n r the altant ma altate furth r, th m in p rtion of b th th and M col ny, a a rul , maintain it chara t r . It i manif tly impossibl to t t all the altant · l a c rtain what th ir futur b ha i r will b . All that can bed ne a t pre ent i to record e rtain b rvations concerning th m. ral ,altant p sing trongl di tincti chara t r ha b n r p at dly tran f rr d and haYe maintained th ir charact r through all f th ~ tran f r ; a nd a. far a can be fore en 1-!6 tabl in th ir pr nt form as ar other fungi. Thu , altants with hort conidia (as M35 and 140) and altants with br atl conidia (M6 and 18) ha ueen cultured and graph of conidia repeatedly made, th al- ant maintaining it character. For exampl , ad t rmination of mea ure­ ents of conidia of M35- made after cv ral tran f r and th lap e f ome we ks-gave th following data: :'.\I H.31 ± .r (1 2.51 ± .17 C 14.50 ± 1.05 omparison of the aboYe data with data of Jraph 65, Fig. P, how· hat this saltant not onl r mains far below H. o. 1 in len th but is al o onstant. It i parti ularly to be noted that all comparative oniclial m a - r ment were made under tandard conditions. Other haracter ~ ex­ ibited by saltant , uch as c lor, zonation, and aerial m •c lium, are ·im­ larly permanent when strongly marked. Saltants are, howe er, .ubject o further saltation and ind d in om in tan e ar excepti nally Ii bl o it, for example, M26. ot all u pect d xampl of altation afford d y variant ector prov d to be permanent in ch ract r, and om lo t th ir i tingui. hing mark after one or a few tran f rs. Su h in tabilily wa not b erved in ca e o( onidial length and br adth, or of pronounced pale olon. - olor, but wa more ommonly noted in ca of light differen of erial mycelium, lightly pale color of colony, clumping, tc. vVhile all cul­ ure were carried, for c nvenience, on com-meal agar, and their differ nc :vcr ob er ed on thi m dium, all that wer tudi d ritically were pa ed hrough other media- autoclaved wh at- hoot and live-wh at-to d t r­ ine wh ther uch p age would alt r th charact r of the altant. Th altant chara ters w re appar nt on oth r media, a · r en-wh at agar or eef agar, though the g neral col ny-character of both original and saltant va changed by the m dium. fter pa age through the e conditionL, r hrough wheat, they w r in culated under tandard condition for all raphic compari on . Ther i no vid nc of alt ration of th character f the saltant by . u h procedur . In oth r words, th saltation is not a henom non a ociat d with the medium and ended wh n the f ungu g t ack to it normal habitat. TABILITY OF THE ALTANTS THROUGH THE ONlDIA Dilution plating of conidia f w II-marked altant gave coloni all lik and with all th hara t r of th saltanl, hawing JJ rm n nee of th chara ter through the c nidia. 1+7 PPARE T REYER S In everal in tan olon ' col r, a n I myc lium, r I artial t ri Ii ty wa th a l tan t he rar ter, mall . of th lony were o hang d a t r mble cl ly th ori inal , and far a t . t w r app li d ould not be di tingui h d from th m ( Pl. XXXII); in n a , h , v r, wh r true altant character wa I r ved b n tanc through everal tran - fer ' id th wh I tock r ,. rt; what app ar d a rever ion wa limited to a ional ct r f h c l ny, nd in n e did u h h ng ccur 111 the ntir margin of a olony. PP ITJTlOl "S Al E OF THE ARIANT E T R the r than hat f a It tion may IJe hri ll · au r . Th my lium at a c rtain point may becom w k n d, or di , and th han in quilib- rium re ultin may au th yariant ct r. p r f an th r H lmin- tho p rium r f ome th r or ani m may fall int th c I ny fr m th air, nd th v riant ector may r pr nt m r Iy a ont minati n. The in - cu lum u d on a plate that ho,\· a ltation m . hav ron~ i. t d of mor than on , train or I mentary pc i . of H lminth Th fir t . upp · 1t1 n i p n nly to crude ~p rim ntation, whil c nd, if \·ali i, imr li e a \\ nd rful H lminth p rium-richne in th air of my lab ratory a \\ II a , ery faulty techniqu . • inc altation ccurred aft r th fungu ~. H. Jo. 1, had been tran ~f rr d many tirn ~ by liftin a mall l it f agar fr m the dg ot a lony, th pr umptiY videnc that no rnixtur th n xi ted i v ry ·trono-. Th f 11 win xp riment - b arin on th se ·u e · ti n may, h wever, b \\. rth re rdin . TY-o,rnding.- cu ltur of H. No. 1 on c rn-m a l ao-ar we s llow d to gr w to a di e m ter f b ut 4: m. h n by m an of a h t iridium wir th 111)' lium wa ki ll d at the point indicat din Pl. .,r:x.1x, abOY . [n al l ca ntir ly ut r w th wound · , and the "h I rd r with no ,·it.l nc f ~ It ti n. m in Lance xt nd d rrom th p int of wounding n arly to th dg Evid ntl~- di~turb, nee f qui li rium uch a. t hi · lid not cau. J1Ji:red planting. - tin on th· know! cl that the ~altant \,er freq u ntly I w-growing, and lhinkin that p -ibly rdinar~ tran~f r mi ht be mixture~ of two r mnr r c , f whi h th -1 ,,. r-gr \\'ing one o rclin .. rily remained ma · ked, I , a\\ 11-charact riz I s< ltant, \Ve:, planted 1-!8 111 a orn-m al a_ ar plate and a llowed 2+ hour:,; t 1 ruw, I y which tirn a ·igorou my elium had develor d. rroodl~- qu , ntit)' of onidia of H. ·cJ. 1 ,,·as then plac din th mid.t of thi_ young- hut w II- ·tal li-..hed M o'ony, but it remain d uniform to full occupation of the plate, sh wing no altatiuns. l111pla11li11g conidia of H. ;Yo. 1 in a partly dez•eloped colony of the rnm ~ Ira i11 .- Thi · exp rim nt wa onduct lv thi · al.:;o ha natur lly h pp n ·d, and that in th• Ii ·Id.:;\,., ha,, , tciday larg numl er-.. of races or ~train of clo · ly r lat d f nrm. d ri, ed more nr les~ re n ly from a common par nl ·tu k. To te:t lhi - hypoth :-i <·xpt'rim ~nt, 11~, in field or rr enhuu •, 1,y 1n ulati n with pure cultllr • , ind l.:1.t •r i olating m 1 a11- 1~111- t :-c ar h f r diff ren es, do s not !:' !in f re:-· r h e au. n ati, e , id nc " uld b v, lu I p iti, viclenc would b btain d only mo, 1 rar ly, , n though -altation i Y ry com- m n. ince, ey n in m · m st rapidly ·alt ting train , hang o ur in nly 1 ut f - , 00 ,000 ll , and re-i lati n fr m oil would gi,· col- fr m ingl onidia nly, that i., fr m a mall gr up of II.:;, the of altation by thi m tho<;! f inv tigation could r a onal ly u nly one m Yeral thou and platin - · TOTES O CERN l!\'G • ELE TED L DIV10lfAL ALTA T of the al tant chara ter C I ny-ch w r d t rmin d nidial char t r ~, rigin Ii ht! 1 z nat ti (Pl. ... -• -ui, 1), few conidia. 11-1 grew fa t r than it · ri in; rati , 6. : ; hara t r maintain d thr ugh . en:ral tr n f r . Mo-1. Much lik ill, IJut with d ided diff r nc in conidial br ·arlth ( ,raph 70, ig. Q). rowth . I w; few. Th squarihcll · v onidia few, 1 al , and thick (fig. Q) ; sc·pta ry triking; diff rcnc appar nt al o n gre n- whe ta ar. 112-3. uite di . ti net in ~ Jp tation and I r adth. t nidi< 11 ·ngth, :cc ; raph 121 1 Fi . Y, and data. 117- . di tin t variant in thi kne · , -•ptation 1 and hape. lo conidial I ngth, e Graph 13 , Fig. Y, and d a ta. 1_6. ( pag 14 , and P l. XXX and XXXI.) M35. haracteriz d b it v ry -hort corudia ( e pa 1-+1 and Fl.XX l,c). l 6. D riY d from a ·in J -c nidium cultur ; onidi thick. 1\13 . The olony h d mu h a rial my, lium and wa quit " ·hite, thou h h d ar show d through (Pl. XX.YT I) . lt ontinued through many tran fer pale f rm ,,•ith nidia. 15 r diff r nt fr m it rigin, b ing c , . reel with mu ch I s , white, a rial rn c liurn, r nd ring th who] col ny whi1e t1n I ' uff) in pp aran , whil th ri inal c I ny wa neith r whit nor fluff~,. 54 and 55. The al o wer t\\·o whit , wo lly loni 1156 ( rigin, Pl. ;r XX) and 60. 1 heL w r fr m a dark fa"-t- '[26 and maintained chara t r. 1 6 l\lS7 ( I. .XXX, eluw} 161 w re from pa l •, tfoffy. lrl\\-gnrnint1, ~ectors of 126. 161 ,·entuall ·plit up into many pal· aml dark:-- c tor,,. [62. Th lony r w fa. t r than its ori in and hor hut fL·w ronidia. 16-l- ( I. XXVII). The nlony \\·a entire ly whitl' .ind Auffy from mu h aeria l my e lium . It originated a , pale - tor in 1\115-1. £65 and 1£6 . The w re much lik 1\16-, and maint. in~d charac ter through many tr nsf r . [70. Thi a ro ~e wh re tw coloni of H. ).;o. 1 h< I I , n implankd ju.tout id th of a col ny fH. 1o.l(Pl.XXX,upp rfig.). Both these colonic wer trikin ly different from th riginal. with much whit · and fluffy a ria l myc lium Tran ·fer from on f them ho\\ ed th har­ acter perman nt through seyeral tran -fer. (Pl. ~r~~V), I ut ,,h th r thi~ . a ltat ion wa actually induced b. the implanting or wh •ther a _altant wa--. uncon c iou ly e l cted for implanting can not be told. 172. rigin am . t triking, fluffy, whit , . t ril ctor. ' haracter tran mitted. 175. • non-clumpy tor fr man riginal that bore many lump , ~rc:w fa ter than it original. 17 , . \ ry loo~ ly growing, tringy, white, f w oni lia. Charac t r ma:ntain d, hut th ~altant oon thr w many . tron~ ly ontra. ting light and dark tor , " ·hi h, howe,- r, did not _how p ·rm n n e after 5 v •ral tran fer . 179. rigin lik 1\17 , but haracter oon lot in tran~f rs . M 0. \ ' ry fluffy and white and rapid-growin . I 1. H ad a narr ,,. ( 1 mm.) pink line parallel to th about 5 mm. fr m it. Thi - Jin advanced, remaining narrn\\·, as th grew. M 3. ri inat cl c n gr n-wh at agar a a b l, ck irr gular - rtor of !'mooth urface, the remainder of th original having a fluffy surfac . I "" and 1 6. Two v r fluffy '"·hite ·ector ·. On nf the e main - tain n r more em:ration aft r th au~ of the alteration ha - cea d to op rat " inc th Yariation her in rerort d oc ur in tructure · purely Yeg - tatiYe and re ult from no interYening xual a t, th y ar in kind omµar­ abl with Ye etafrve variation known ~! ewh re- bud -variation, etc.- with the xception that ince the mycelium, con i tin f a in I r w of cell , i the eat or origin of the variati n th ca · mnrphologi ally simpler than wh r tissues are involv d, a in bud Yariation. D \'rie (122) cla bud variation in g n rnl with mutati n. in that th y pp ar a cl ar- ut di c ntinu u variation . I ny xampl , of yeg tativ Yariation have be n tudi cl extensively and rep ,rt d up n under th• t rm mutation, altation, portin , etc. ramer ( 37) 1ve a very om­ plete summary of th known ca e in 1907. Ea t (-16), tout ( 120 , hy ­ (61) and ham I, ott, and Porn roy (102, 103) giver p rt · , with x- tend d bil1lio raphi , n t:rning bud variati n in th p tat , chry anthemum, nd lemon amon the phaner am -. Th tran mi i n of uch Yariation · in the p tato ha been carefully · tudi d by E. t (-17, -! , 49) ,, ith the en ral conclu ion that th e ,wally app aring varia­ tion concern character that l\Iendelize in exual reproduction. In th Pteridophyt , B n diet (16) r port saltation in th Bo ton fern. D b II (-l-3) ummanz th evidence from om tw nty-eight pap r- con ern­ ing variability amon th ha teria, di. cu ing th m in tw ategorie : ( 1) phy iological mutation , that i-, chan in p ,,. r t produce f rm nt or pi ment : and (2) morphological mutation -. He clo e the first part f hi di cu - ion a· follow : "It e m I gitimat · to n lud fr m th foregoing fact that ~ome ra e of bact ria arc able p rman ntly to acquire new charact r und r c rtain ondition ." H on id r. only two a · e.:­ of m rpholo ical mutation, citing the ". rk f Barber ( i), whu pr due d a race of I n ba teria by ingl -cell I ction, and of R \·i. 9-l-), wh, claim to have produced an w race of Bacillus coli by th m, · f m, la hit gr n. Both Laurent ( 76) and Le Pou tr ( i7) con lud th t by r a-,sa a harm! . ba terial p i may a quire real Yirul nc . .\n exten · i ·' re um' of the qu ti n f mutation in th bact ria i als gi,· n hy B rth- 1 in ( 5). • -umerou Yariation of y a ts, b th morph I wi · l , ncl phy ·­ iolo ical, ar r port errant typ from an nrigin ·tll~ mi, · I r 1 ulc1 - tion. Th , ry I ro ma _, of r a lly n lus i,· nly wh n ba. xtremely probabl , to .ay th cl oc ur in the e group . corroboratin ·iti , . d n s ingl - r. a nism I ast, that ·uch s It Yid n e, thou o- h ultur 'Ill k.., it tion. r 01!.Jt tion m ng th Eumycete e , · nl xamplc. ccur f what appear · tn b ~ ltati n. Fd rton (-0) in 190 , writing f Glomere/la rufomarnla11 s , tat . tha "of th more than thirty 11 studi cl from ov r tw nt~· ho t , with les. than , ha lf -dozen a ll < , . < t I a t lightly diff r nt har< rter . E , · 11 th two c n appl ,. fr m Ii ·ouri and Illinois did n t giY exactly th . am' charact r,;;, but the diff r nc ., \\. r Ii ht . 1 h t,Y coll ctic n. from appl in the n rth, hm, e,· r, gav ntirely di ti net character from Lh m r • uth rn form - on the .am ho t. Th ~ uthern form, pe ic lly on · ug r 111 dium, \\·a harac teriz d by , r · rapid g r wth and a ry dark gr ni · h-hlacl- col r of th ub­ . tratum anl a rial hyphae; whil · the north ·rn form r w m re . lo\\'I)' and had , ery littl dark col r. J n rally in the latt r th a rial hypha were c I reel pink from the J ro(us d velopm nl of onidia. •ye n th f rm on quin ·e all cted in w York did n t g i,· th ,, m ch ra ter; a · th n rth rn f rm n apple. Th f rm · on rchid, , off a, and ar­ ra nia, · II t d in the am r nh at the . am tim , ,,. r not Xe ctl alik in cultur m dia.'' 1ther c:-..ample wer iv -n by ~r ,bte I F,.bruary 7. 19:! L, he writ s rei::arding thi5 ,H folluw5 : " II of the rnlture~ that I us din th,u worl. \\ t>rf' ohLainc>rl h>• tlP dilution pl t met ho • nrl pr,• 11mahl >• • me from in~le -pon•f.'' 160 tudit>d th ~train , and r rnr I th elief that th ulture nH:ntic n ~d ah , ·p '·as a po ihl mut tion \\a rt:.tlly th minu~ ... tr, in of th bitter-rot fun us. In 1909 I rep rt cl "ith r. H all (~.t , . n , n I Hall, 11 l for thL genus • cochyta , ·ariant s clors in I' tri-
  • . Both :-train. ha,·e r p ateparl'nlly occur:. in th· por an I not in the nl\ elium. which i-. quill' till' ontr,1r~ tom~ finding. He find-.., in ,g rc:l'm,nt " · ith m) \\ork, 1-;n "'ith Kl ·t,· ... la\\ 17-l), that th minu-., ... Lrain, rh.t j.., tlw · t' nrifl'r<111 n11•,Km\\-.f<1..,t 1 161 th n th plu train. Th nn nd th c I ny diff ren e which h pi tur ar mu h lik th shmYn f r H lminth p rium in thi paper. H al o adduc vid n t -ho,).- th t th _ lu and minu train occur in natur and have be n i lat d b ind p nd nt ,vork r . H attempted in four way t indu e altation artifi iall ' but m t with no uccess. rabill (. 5 ha r p rted, in ab tract, "a mewhat imilar mutation in fungu · b long in appar ntly to th nu Phy II ti ta." Blake lee (-1) rep rt.:" . in 1912-1 [ found num u ~variant ofvariou d - r t::. f di ~tin tn in th off prin of a in 1 plant ( 1Tu or obtained by mving non- xual spor -. ,. \\ riting f J.Iucor geneunsis h a (20 ) : "In all, . mewhat o,· r 3 ,000 col ni from individua l p rangiophore b n in. pe ted and a r I tiv ly la r numb r of ,·ariant of different f di tin tion ~ hav be n obt in d th mutant , . ntuall y t r , . rt to the normal typ . Tw , howev r, hav eemed more tab) ." H n Jud . : "Th y add to th e id n e, alread obtained fr m oth r group , that mutatio n re n t r strict d to proc e involv d 111 xual r produ tion." Brierl (27, 2 ) r port d an albino Bolrylis cinerea which wa a form with pal cl r tia th ugh th p rent f rm alway had lack ler tia. Thi albino wa b rv d to a ri from a col ny d riv d fr ma sin le c nid­ ium and fr m a ra e that had b n und r culture for con id r ble tim , a lway pr ducin bla k cl roti a. Th purit f hi cultur eem to have b n ar fully uard d, and thi cas , thou h tandin al n , would furni h po iti e viden f th udd n f h r ditary diff r n · in thi · fun u . Da tur ( 40) in 1920 d crib cl altc ti n in Cloeosporium piperalll?n con i ting in th ab en or I re ence f p rith cia, a rvuli, or eta , and in th dev lopm nt f aerial m c lium. H y : ' 'Thu - all of ud n th rigina l t ril culture broke up into two diff r nt train , on produ in nly perithecia n t riliz d hilli t m and the oth r f rming ac rvuli with and with ut eta ." m f the train w r not con tant in chara t r , l ut oth r p r i ted throu h many tran f r . He tates that r at or udd n variation hav ne r b n ob rv d from conidial train , but that ''in culture mad from p rith i of th train of Gloeosporium piperalum in redibly lar and [ten ver udden variations ha been btained." Burger ( 2) in 1921 r port d mutation of v ral t p rn oll totrichum, im-olvin p rman nt hang in many chara t r . H e f und th o urring in ulture d riv d fr m in I p re nd h "\ d that they wer p rman nt through th Jenning ( 70), wh "ork d 162 with th hell I rhizo1 od Diffiugia, tat that mo~t of th · work on urn­ parental r production ha yi Id d th r ult that during -,u ·h r •proclu tion th hereditary c n titution ( notype) appear not to chang thou 1 h th , rgani m may diff r mu h in outward chara l r. l\lany pap r it d support thi Yi w though. ome ar oppo ed. J nnings ay with regard to hi~ own re ult : " fter many g n r, tion of d cent fr ma ingle pr genilor, -uch a ingl family ha diff r ntiat d int many he- reditarily div r to k ." div,r:i :c;t k::.diff ,.. rh·r ditarilynotonly with re p t to parti ular jn. I har t r but al:.o with r -pe t to th combination of chara ter . ilany indiYiclual · of uniparental r produc- tion ha,·e shown a mark d permanenc of h reditary ch<1racl r in ingl Jin of d scent, all th pr geny b ing like the parent in her ditary cnns ti­ tution; and further, many such lines, diver in her ditary constitution mc1y exi t in a population, and th ff t of I tion c nsi _ t mainly, if not ntir ly, in the i olation f ~uch di,· re lin - · Ea t e s n r a n t b liev bud variation cliff rent from g ·rminal mutati n and ay th t it may be progr ·siy , digr s iv , or r trogr i,· . Bat on ( 10) h kl that bud variation ar du to ciu ·1lit tiv 11-divi i n in mati ti ue ~, gi\'ing ornatic e r ati n of unit fact r . East point · out that in th larg majority of cas s of bud Yari tion th r ha be n imply the lo 4 of a dominant haract r and h nc th appearan of a r - lated recc · iY character. Tn ome a e there i ab olut di app aranc 3 of th dominant chara t r; in oth r ca e it appear to be latent, and it may reappear. Variati n in col r con titut oY r 70 c of all bud variation. Colony color in Helmintho porium i also a Yery ommon vari ble but thi· i, in all probability, entirely inc mpar bl with ol r Yarialion in flow ring plant . Bri rley (2 ) hold , for Botryti , that ,·en if exualil occur , th f ungu i- "on all eYid ntial criteria, an a exual homozyg tic organi m in which the i olation of a ingl p r strain n arily impli th isolation of a 'pur lin ' ". g notypic hang in a pur lin i a mutation." imilarly, hear and \\ ood ( 105) regard indi,·idu I orig­ inating from ingle pore of Glom r Ila a homozygous , th u h on rea ·on­ ing differing om what from that of Brierley. Crabill ( 3 ) al o hold · that ince hi f ungu "r produc a xu._ lly from h t rozy ug parent cannot explain th rigin of th train ." cc pting Brierl y' . criteria, my Helmintho porium ~ingl •--pore i olation re equally homo- zygotic. In at lea t three f rm n er al Helminth p num I known to be th conidial stag of the a rig r u renu Pl ospora. A a~ igcrou~ 163 ta wn rn man to ari ~ .·ually, it may b xpected that all p ri th cia r pr ent e ' ual tage and a xual act. The particul r form with which I am working, that i H. o. 1 and d ri ative , ha e gi n no e id nee of p rithecial formation nor is it actuall known that they po e xual stage . The pre umption, however, i that the do, o 1t 1 quit p ibl that my ultur f H. o. 1 i d ri, d from an a o- pore, that i , may be the re ult of xual parentage; and thi exual act ma ha e oc urr d in the not di tan t pa t. Thi i all h poth tical but it app ars to me to point to a po ibilit of an heterozygotic condition in H lminthosp rium, a well a in lomer Ila a r ported by hear and Wood (105) and in oniothyrium a r ported by rabill (35), inceso few g n rati n may have 1ap d f rtilizati n that the h t rozygo i - ha not yet be n liminat d. u h uppo~i ion in th a e of Botryti j les tenable. I i ugg tiv to not here that a tur ( 40) f und variation a com­ mon ph nomenon only in train that wer re ently deri ed from p rith cia; al that bud variation i more common in hy rids (Eat, -16). It i th re­ for thinkabl that uch of my train of Helmintho porium a are altatin are of r cent a cig rou origin, whil others that ar not altating (for xampl H. ravenelii and H. gem·culalum) are of di tant a cig rou origin. [f h t roz g i be eliminated fr m the di u ion h o oth r po ibl xplanation , ugge ted b Brierley regarding B tryti , may b con id red h re, namely, that of nucl ar tran fer nee during my elial ana tomosi ( Fi . 5, p. 104) or that of cytopla mic contamination by uch ana tomosis. Evi­ d n on th qu ti n., b th from t I gy f th myc lium and from knowl dg f xuality, i iuit la kin . pting non of th bov hypoth se , th saltation w uld be a mutati n in the strictest sen e f th t rm. R port d mutation in A per illu and P ni illiurn d cribed by rcicho kij (2), Wat rman (125), nd hi mann (100), and aid to be in- due d by n ir nm ntal hange , a r quite xt n i ly di cu ed by Bri rl y ( 28), who, repeating much of th ir w rk, conclud that wh n th fungi hm ing the change are r turn d to their ori inal envir n­ m nt th y r . um th ir ri inal a p t; that in fa t th hang w re m r modifi tion due to em -ir nm nt. The ca e re1 orted b Brier! , Burg ff, Bl ke lee, and rabill, and m o, n work r p rted h rei n, all ba d on in 1 - pore culture a nd car- ri d und rob rYation f r . uffici nt tim t : uran ~ f p rman n c. n ti tut mpl t pr of of th f th , phen m •non f :.ud- 16-1 den chang in h ra ter mong the fungi. The evid n from F.dgert n, hear and \\'ood, and Oa tur, while not o complete, i trong c !lat rally. It would eem from all thi evidence that thi phenom non i common and widely distributed among the fungi, th ugh unque tionably it i m re common in som sp i and rac than in oth r -. TAXONOMY The clas ificati n f th e H lmintho porium '•form ," indeed f all the fungi imperfecti, pr sents unusual diffi.culti -. That th y ar nly "form " of which we do not yet know the "perfect" ta e i n m re relief from the nece ity of cla sification than i incomplet know) dge adequate rea on for delay in attempt to la if oth r plant . ln the present in tance ome w 11-d fin d " pecie ," in th old en e of th word, tand out-f r example H. ravenelii-whil , on the oth r h nd, of the strain of H lminthosporium in my llecti rn differ in n r more slight wa_ yet agr with each other do ly in eneral typ . F r x­ ample, my H . . o. 1, H. o. 11 (i olated by takman from wheat in Min- nesota), H. . 13, i elated by Durrell in Iowa, H. ~ . 23, i elated by \Veniger in orth Dakota, and an unnumb r d on isolat d by Hoffer in Indiana, are all l arl th am g n ral typ of organi m, and t they differ from ach oth r in minor particular . It is evident that we have in the genu Helmintho porium larg number of race that vary con i tently and con · tantly, though but Ii rhtly, from each other. The e variation may be morphol ical in th u ual ense of the term, or a hown in culture , or a demori-trated biom t­ ricall . It i quit probable that here, too, th re are, a el , h re in th fungi, difference in Yirul nee, and therefor in biolo ic relati n hip, and phy iologically. Exam pl ar numerou among the fungi wher uch comparatively minor difference are regarded a of pe ific rank and the new group i d ignat d by a new binomial. There ar al o num rou examples wh r u h lightly ariant type. ar r gard d a vari li r races of the peci . Th arieti r ra e haY b en Yari u ~) roup which hall compri-.. · man~ t·leml'nl.tr p ,e - a cour - that I h ,, hum ( l 15) and whi h w t rnaria. 167 Ir d f II w d in th f f II w d by Elliott (53 in d alin lletotri­ with 1- My H. o. 1, H. o. la, H. o. lb, H. o. le, and H. 1 o. 1d, the cau e of foot-rot in Madi on county, Ill., a well a m H lmintho porium num­ ber 3-9, 11-19, 22-27, 34, 37, 8 42, and 43, all belong to the ame g neral type and are charact riz d by a conidium that tap r toward a h nd from a point f greate t thi kn which i n ar r to th ba than to th ap x of the onidium. The nidia are ther for not t_ picall lindri al or e en subc lindrical. \\ hi! all f the e number agree in g neral typ , many of them cliff r m what from other in the collection. Thu o . 1 and 3 differ a i h n in Plat I , "I- III, and, o far a ob erved, in thi character on! and only under th c ndition de rib d. Other differ in modal p re-I ngth or eptation, in di tin tn f z nation, or in other minor col ny-chara t r ( Pl. I '"). Number 13 differ lightly ev n from o. 14, though both ar deri ativ from th ame original culture; and the same may b aid of o_. 15 and 16. Th e diff r n e which now actually exi t, are probabl due to uncon cious election of altanl in tran - ferring from tub to tub . II of th number Ii t d above which how on tant, though but light, diff r nces from other number I regard a elem ntary pecie th Jordanon f Lot y. They ne d not be further characterized or differ ntiat d than ha been done in previou pages. One of these lementary pe ie , H. o. 3, i d ri d from an I wa culture prob­ abl id nti al in hara t r, ith that fr m \: hich amm I, Kin , and Bakk de crib d H. salivum, and thi ultur , o. 3, till agree e entially with their de cription. 11 of thi gr up o( I m ntar_ p cie may th refore be r gard d a belon in t the Ilelminlltosporium sativ111n group, or Lin­ n n. The que ti n of th p i le id ntity of thi group with the H. teres and H. sorokinianum groups I ha ll not now discu s further than to point out that o far a n be judg d from th pictur of H. sorokinianum given by rokin ( 107) that p i s i not haracterized by longitudinal! eccen­ tri onidia; also that ub qu nt t the publication of th pecies H. sati­ v11111, Bakke (6) tate that ''cultural expcrim nt hav determined that the di a e i due to Ilelminlhospor,ium teres acc." He add : "He [Dr. Ravn] further ub tantiat d my pinion that the di ease wa due to H. le res and imilar to what had b n o pr val nt in Denmark during the ar 1898 a nd 1899." Bakk , in a f t-note, how r, add : '' . . John on, of Madi on, i con in, consider I-I. salivum. and H . leres distinct forms." ac a rdo, who examin d H. saliv11m, sent to him by Bakk , xpre ed the 1 c.' opinion that th di a wa due to Helminthosporium leres. l t ma • be remark d here that Ravn (91) ay that leave are the onl · ub trat on which conidia ar deyeloped; whi h i certainly a mark d di tinction from the H. sati-1mm group which porulate o freely on agar of man kind . There i no qu ti n what ver in m mind that by m an of biom try and a tudy f biologi r Iation and ultural chara t r , t nab! di tin tiv diagno es can be drawn up for many race of Helminth p rium on th fiv leading cereals. How many of th e hould be de ignated by binomial and how many left unnamed app ar:, on final analy i , to ea qu tion of thf' utility of such naming, which, in turn, may hinge upon their economic or other importance rather than upon the magnitude of their morphologi al or other differences. H. 1o. 20 i particular!. intere ting in that it i -if n err r ex.i t in it hi tory-an example of altation o great a to remoY the organi m entirely from the group under di cu ion ( the form with tapering conidia), and onsequently to pla it in a group (Linneon) different from that t which its known relativ s (H. To . 13 and 14) belong. The pre ent tudy wa und rtak n with tv;o I adin object : ( 1) to det rmin the effici nt cau of the rotting at the lower part of the wh at tern; and (2) to throw light on que tion of morpholog and para itology in th genu Helmintho porium. The que tion ari ing from altation injected an additional interesting series of observation . The e idence i complete that Helmintho porium can and doc cau e foot-rot at the ba of wheat tern . The tudy ha al h wn th H lmintho porium (H. 1o. 1) to be a root para ite. Thi phase of the di ea e ha been tudi d only incidentally, but it i worthy of sear hing inve_tigation ince it may lead to the ros ttin of ten a sociated with foot-rot. and thu predispo the plant to foot-rot. 1. In the rotting ba e of the wheat a Helmintho porium i the onl 1 organi m con tantly pr nt ( p. L4). 2. The culture haracter of tbi fungu w re tudied on many me­ dia (p. 79) and under man· and various m ir nm ntal condition . ' light change of nutriment, a afford d by mall diff r nee in agar formulae or by the temperature at which th agar wa - made, pr du d mark d eff ct on growth-chara t r . f many gar tri d, orn-m ~al agar pr v d mo t u _ f ul. C r al hoot au t I n!d, . n ·ed a . till m re fa , oral I m dium. 169 3. I! rpholo ic., I har t r~ r I r ly c It r d b n\'i r nment. uantity a , ell a quality ff ocl pr du e: chang in chara r . Humid- ity ha an important on the r duction of c nidia, on th a rial my clium, and n tial formation ( p. 93), inAuencin even onidia length ( p. 95). 4. The optimum t mp ratur for growth i about 25° ( p. 9 ) . 5. arbohydrat in th m diurn favor produ tion of a dark c I r (p. 100). 6. M.alked eff ct of nutrition condition on onidial I ngth, ptation, and ha1 e was noted. 7. From the aboY finding it foll \\' that collection t b comp r­ abl mu t be mad uncl r imilar ondition a r gard th factor. men­ tion d ( p. 102). procedur t · cur wa de i d ( p. 1 O). tandard c ndition for tudy of th fun us 9. The myc lium, a bear e era) nuclei. Th (p. 10 ). rial and ubm rg d, i d rib d. Th n ent m celium und rgo aut dig ells Li n 10. onidia sh w di tinct ba al and api al marking . Th w II is in two lay r : the out r ( pi p rium), thin and brittle; the inner ( ndo r:: - rium), thick and g la ti nou ( p. 11 t). 11. ermination i. u u 11 • terminal; ana tomo. i of germ-tub - i · ommon (p. 115). 12. Th onidia are thi k tat a point b tween the ba f th nid­ ium and it middl point. Th cone pt " ffi ient of longitudinal ntri ity" and "c effi i nt of ylindricity" ar introdu d for purp ~e · f more ac urat de ription ( pp. 117-120) . 13. Conidial !en th, br adth, and eptation are tudied biometrically. 14. For compari on, a bi m tri tudy ·wa made of H. ra·venelii (p. Ll). 15. The eti logi al r lati n f the H lmintho porium ( H. . 1) t foot-rot wa demon trat d b it on tant pr s nc , by the ab ence of th r para ite , and by it pr v d abilit to cau infe tion and rottin und r arious condition , a by inoculation f edling in Petri di h , in rao- doll, and in oil (pp. 124-12 ). Th fun u wa hown to nter c II f I f- h ath, stem, and root. th 16. stud of the inf cti n phenom n h w important chan ~ in II-, all of th ho t· and th d , . lopm nt f appre oria and a callu~- like formation ( p. L ] 7(1 17. :\I any strains f H lmintho porium, . om ,· ry diff rent morpho­ logi ally from oth r , can produc ·orne or all of the ph n m na of infec­ tion ( p. 136). 18. ~ lternaria produce ome of th mark of inf cti n, in ludin th changes in the ho t-cell, the "callus," and ntranc into the ho t-cell. Penicillium can not do this ( p. 137). 19. \,\'h at, corn, barley, rye, orghum, udan-gra , and millet are more or less u ceptible to rot by Helminthosp rium. 20. Saltation, po ibly mutation, j_ comm n in certain race of Helmintho porium ( p. 1 9). 21. altation i evidenced in gen ral colony-character; rate of growth: conidial production; onidial clu t r ; conidial length, breadth, eptation, and shape; mycelial characters, color, zonation, and cl rotial formation ( pp. 141-144). 22. ertain altant differed so markedly from their parent a to far exceed the u ually accepted pecific limit (p. 1'4:1). 23. ertain correlation and tendenci 111 altation were noted ( pp. 14--1-14-). 24. The altant -were, in th main, permanent in haracter ( p. 1-!9). 25. They -were permanent through th conidia ( p. 1-16). 26. \\'hat appeared to be rever ion ometime occurred ( p. 147). 27. Efforts to produce altation artificiall f ii d (pp. 147-148). 28. The altation wa not due to mixed planting , and can not be induced by implanting or wounding ( pp. 1-17, 1-l ) . 29. altations are not due to para ite ( p . 1-l ) . 30. altations in abundance were deri,·ed from single-conidium cultures (p. 149). 31. altation i Yery frequent a c mpared with bud-,·ariation noted on potatoe and tobacco (pp. 1-0-1-1). 32. umerou Yariations in te t-tube cultur are reported a prob- able examples of saltation ( p. 152). 33. The Helmintho porium that cau e wheat foot-r t belong t the H. salivum group, which c n ist ~ of a I .. r e number of lementary pecie (p. 167). LITER T RE ITED ADERHOLD, R. (1) 1900. Die Fu icladien un er r b tbaum . Landw. Jahrb . 29: 541-5 'i. ARCICHOVSKIJ I (2) 1908. Zur Frage Uber d van Aspergillus 11iger. ARTH R,J. n Einffus on Zn 0 4 auf eine Reih ntr . f. Bakt. 11, 21: -!30. van en rationen (3) 1917. (4) 1920. ultur orth of redin a in 1916 a nd 1917. 111 rican Flora. i (pt. -!) : 296. l\ly ol. 9: 295-312. BAERTHLEI • K. (S) 191 . eb r bakt ri II \ 'a riabilitat, in b ondere og nannten Bakteri nmu- tationen. ntr. Bakt. J. bt. rig. Bd. 81: 369-JT. BAKKE, A. L. (6) 1912. The late blight Acad. i. 19: 93-102. BARBER, M. of b rl y (Hel111i11thospori11111 leres ·a c. ). Proc. I • (7) 1907. On h r dity in ertain micro-organi ms. Kan. niv. ci. Bui. 4: t. BARY, . DE ( ) 1886. ber in1ge lerot i n und clerotienkrankheit n. Bot. Zeit. 44: 378-387, 410-426. (9) 1887. Comparative morphology and biology of the fungi Mycetozoa anrl Bacteria. Translation by H. E. arn y. BATE 0 (10) BA R, E. w. 1902. M enucl' principl of h redit (11) 1914. Einfi.ihrung in die experiment lie BEACH, \J ambridg. rerbung lehr . B rlin. (12) 1919. Biologic pe ialization in th genu ptoria. m. ]our. Bot. 6: 1-3 '. BE ERTE,J.,and 1LLl·R1 o, (13) 1903. f::tude ur la tructur du Botrylis ci11erea. entr. f. Bakt. 11. 10: 275- 11. BE KWITH, T. D. (14) 1911. Root a nd ulm inf cti n of wheat by oil fungi in ·orth Dakota. Phytopathology, 1: 169-li6. BEHRE I J. ( 15) 1 95. Phytopathologi~ch 'otiz n I. Z it. f. Pflanz nkrank. 5: 136-141. BE ' EDICT, R. (16) 1916. The origin of n w varieti of N phrolcpi by orthog n ti a ltation. Bui. Torr. Bot. lub, 43: 207-234. 131 BY, G. K. (17) 1916. The redinales found upon the nagraceae .. m. Jour. Bot. : 52i-561. BLA KMA , V. H., and WEL FORD, E J. (18) 1916. tudies in the physiology of parasitism. 1 I. Infect ion by Bolrylis ci11erea. Ann. Bot. 30: 9-39i. 172 BLAKE LEE, . F. {19) 1913. .:\lutations in i\lucor. 12 : l 04-105. Year Book, Carnegie J n titution, \\ a hington, (20) 1920. Mutation in lucor. (21) 1920. · exuality in l\lucor -. BOLLEY, H. L. ]our. H eredity, 11 : 278-2 4. cien , n .. , -1: 3;-_ 82,403-409. (22) 1912. [Th work of he Department of Botany anIY notes from lrus important articl were made from a photoi:raphic ro>prot!u tinn of :i. trrewrltt •n tran lation kindly loa ned to the niver~tl}' by the Librar}' of the . . Depart111 •11L of A1:riculture. 177 PEN ER, E. R. (10 ) 1921. ome of th ay f Brazil-nut . Bot. ~az., 72: 265 -292. TAKMA 'E. (109) 19 14. tud) in c real ru . t . . Ph ·. iolo ical races. l\linn. •r. Exp .• ta. Bui. 138. _ TAKMAN, E. ., and LE\'l E, i\1. . . ( 110) 19 19. Effect o f c r tain cological factor on th morphology of the urcdin­ io por of P1u;ci11ia gra111i11is. ]our .. gr . R s. 16: -U-ii. _ TAKMAN, E. ., and P1EMEI EL, F. J. (111) 1917. Bi logic form of P11cci11ia grami11is on cer al and gra . Jour. gr. R s. 10: 429-49 . . TAKlllAX, E. ., PrnMEJ •L, F. J ., and LE\'JNE, i\l. N. (11 2) 1918. Pia ticity of biologic form of P11ccinia gra111i11i . J our. gr. Res. 1-: 22 1-2-19 . • TAKMAN, L. l. (113 ) 1920. • Helmintho porium di ea e of wh at and ry l\ linn . gr. Exp . . ta . Bui. 191. TEI ' BERG, R. (114) 19 17. A tud of ome factor s influen ing the st imulative action of zinc ulphat on th growth of Aspergdlus niger. I. Th effect of th pre ence of zinc in th cultu re flak. :vi m. Torr. Bot. lub, 17: 2 7-293 . .. TE EN ' , L. ( 11 5) 1919. Two lllin oi. rhu barb di eas . 111. . gr. Exp. ' ta. Bui. 21 ( 116) 19 19. Foot-rot di a of wheat-hi tori a l a nd bi t liographic, Bui. Ill. ?\at. Hi t. urv. 1 : rt. 9. {11 7) 1920. Foot-rot of wh a t. e, n. s., 1 : 517-51 . TEVE · , F. L., and H LL, J. G. (11 ) 1909. ariat ion f fungi due to nvironment. Bot. az. 4 : 47-71. TEWART, F. ., and Hoo Kl , H. E. (119) 1908. Th porotrichum hud-r t f carnation and the ilver top of June gras- . r. Y. ( n va) gr. Exp. :t<. Tech. Bui. 7. ST L' T, . B. (120) 191 -. The e tablishment of \'ari ti in ol u by th • I ction of omatic va riations. \ 0 A • HA 'V. (12 1) 191~. \ 0 RI E , H . DE a rnegi In t. f \1 a h. Pub. 218. fotation in bact ria. Jour. Lab. a nd (122) 1901. Die Mutation Theorie . \\'ARD, H. l\ I. (l 2") 18 Iii di a e. . nn. Bot. 2: 19- 2. \\'ARTE , W IL R, (124) 1918. B itrag zur . y temati k und Biologi nn. l\fyc. 16: 249-299. \\' TERl\lA ' , H. J. lin. Med. 1: 145. inig r Pia mopara-art n. (L ) 19 12. Mutati bij Pe11icilliw11 glaurnm n spergillus m'f!.er ond r in\"loed ·an b k nd factoren. Js;:on. Akad. \\ ten h. Am terdam, Ver lagen Natuurkunclige, 21: 33- . 178 \\'1EDEM.\t--:--, (126) 1907. rlcn. ;\lorphol i chc und physiologi che Beschreibung einiger Penicillium ·entr. f. Bakt. I I. 19: 675-690. \\" LF, F. (127) 1909. eber 1 lodificationen und experimentelle au geloste Mutationen von Bacillus prodigiosus und ander n chizophyten. Z it. indukt. bstamm.- u. \ ererbungsl hre 2: 90-1 2. \\"oLFF, R. (128) 1874. D r Brand des etreides. Halle. ZOPF, \ • (129) 1 1. Zur Entwi klung ge chichte der scomyceten. haetomium. ova Acta der k. Leop.-carol-deutschen kad. aturf. Vol. 42. APPE DI T METHODS For m asuring con·idia.-The f Bowing procedure wa found on- nient. An rdinary ba teriological iridium wire wa plunged int a elin and th n o laid acros a micro cop lide a to I ave on it two ompl te, narrO\ , thin tr ak of va line about 6 mm. apart. mall drop of wat r was th n pla ed b twe n the two a lin lines and th conidia- ampl add d and ev nly di tribut d. \i h n the cov r-gla s wa placed th a line pr vented the oniclia from catt ring, and ren­ dered it pos ible b mean f th mechanical tage to mea ur eYery conid­ ium, thus curing a rnor repre ntativ ample than would be the a e if ome conidi , p rhap of rn parti ular la, , w r allow d t float away. In ampling fr rn tandard ultur f r purpo f conidia-mea ure- ment, a portion of a hoot about 6 mm. I ng that wa venly and den ely o red with conidia wa remov d to the lide. hoots w re all evenly and abundant! porif rou x pt in ca es wh r ntir . hoot r parts f sh ot w r pal r and bor mor a rial myc lium. To a oid uncon ciou el cti n in rn a urin onidia am chanical t g wa u d, and all onidia en ounter d in c rtain predet rmined p ~i­ tion in th _fi ld of vi ion w re mea ur d. L ngth was mea ured from xtrern tip to xtrem ba ; br adth, at the thick t p int. lea - ur men ts falling xactl between two cla e were t mporarily or ordeu, and lat r di tribut d equ lly between th two adja ent cla e . M a ur m nt for o ffici nt ar a ii · mad b pr jecting the outlin of th onidium, b mean f a amera, upon quarter-s cti n pap r f nvenient rulin . Th pap r may readily b rient d with th onidium in any de ir d relati n. The rag doll.for inornlalions.- An adaptation of th ra -doll e d-te · t - wa found u ful in ino ulation . Th d 11 wa made of a trip of loth, 6X50 cm. whi h wa roll d to a cylind r about 6X2.5 m. and plac d in at st-tub 2.5X25 m. with wat r, and autocla d. In u -e the r 11 was rem v d lo a t ril Petd-di -h 17 cm. in diam ter, the ,vater r m d to the d ir d d gre by wringing, and th doll unroll d by the u f t ril f r p (Pl. XXXII I ) . dlin rai d a pti ally wc:rt' 180 th n laid on th unr II d d II and inoculation made 1n the cle ir ·d man­ ner. Th doll wa then r lied up, inclo ing th dling~~, and plac d again in the tc t-tube. For purpose of r ot inoculation th cl II wa. suspended in the t st-tube about fiv centimeters from it bottom. Inoculations ·in soi!. - In addition to the u ual pot and bcn h inocu­ lation , it was found com· ni nt to u e wide-mouth ,·ial , UX70 mm. (see pag 128), which w re lined ·with tiff pap r (. cut a _ to p n asily, Pl. XXXIII), filled with oil, and autoclaved. The pap r n lope , ith the enclosed soil could readily b withdrawn from th Yial, and op n d in order to in er.t th eed, eedling, or inoculum, and lat r r peated exam­ inations could be made without greatly di turbing lhe plant. lmbeddirig co11idia.- onidia were rai ~ed under ~tandard condition ­ (see n xt para raph) and th ntire hoot b ring th m, together with the adja ent agar-a strip about -l mm. ·wid -was remov d to hr me­ acetic killing-fluid, and imbedded in the u ual way. Procedure lo sernre standard condition.s.-Petri
  • (.'.) - V) Ql LJ18 co 2 ::, z I Q. <1: a2 ~ 17 (X) I<) (\J (\J \.0 0 'o:t r- 0 -:t r- C\J I<) t<) \t") co C\J U> - ~ (X) :\l U) 0 ~ co 0 ~ r-,: - s:f t-= - '-3'" 00 - ,;t- q- ,;t" s:r- It) If') It) (.1) U) U) t- r- MICJ20 5 Conidial length of H. No . 1 grown on corn-meal agars of different quantities in standard 100 mm.-Petri-dishes: Graph 17, on 66 c.c. of agar; Graph 18, on 12 c.c. of agar. Graph M 17 17 . 20 ± . 22 18 19 . 85 ± . 25 CT 4 . 03 ± . 15 3 . 07 ± . 17 CV 23 .45 ± . 95 15 . 51 ± .91 (\J U) 0 ,;t" co l\l 00 - \fl 00 - If) r- co co 00 0) CT> µ.. t::l :i:: ::;i (.'.) ~ V') Cl! w IO ~ :) z :r 20 a. ~ (!J 19 / co l"i N ~ ~ / ........____ C\l IO 0 ~ r- 0 Sf" ,- l\l I") I') I") V - V \ V I ~ ----~ V ~ ./ ---- / "' L--"-. V I\ V ~ r----..._ __J co I\! IO ~ V co (\I ID 0 ~ (X) C\J U! 0 V ci ' <.9 t- t- C() co c:o M1c120N.s Conidial length of H. No. 1 on old wheat straw at different humid­ ities: Graph 19, grown in comparatively dry conditions near the top of t he test-tube; Graph 20, grown in humid conditions near the bottom of the tube. Graph 19 20 147 M 15 . 67 ± .33 22.39 ± . 18 q .i . 77 ± . 24 3. oi ± . 13 CV 30.46 ± 1 . 66 15 . 22 ± . 61 .............. (X) (\J co - on co O'\ O'\ <.,, ro c., c.., I\) ru ()\ (., °' fl> ---1 O> \ I I 23s \ / -27 2 \ " 306 ~\ I 34 0 37 4 / / \ I / \ I I 40.8 I I I 44 2 \ \ 41 G I I I 51 0 I \ I / .54 4 1 "' _\ I "" ~57 8 I I ' 0 I / / /I \ I 11 I ~61.2 z , '\ ~ I / \ I I I l.o 64 6 I \ I I "" I \ 68 0 I 71 4 \ \ I/ ''----- I ~ ~ I \_ ~"" ~ \ I \_ 74 8 / /,,,. I ~/ \ I "- I 78 2 ~ I \ "" I " ~/ /v \ 81.6 l/ ~\ I / 85 .0 / / I\ / I I I / 884 \ / I / ~/ \ 918 I I I I 95 2 I I 1 I 98.6 I ' I ,02 0 : FIGURE I ' \ I \ J\ I \ I \ I I \ ' I ' I I I r-,.... I J I \ I \ I \ i-,...., ~ l \ I \/ \ ' \ \ \ \ \ \ '/\ \ ' \ ...... ,.._ '"-34 o~~~-00~~~-00~~ru-OO~~~-OO ~~~-OO t--'.o\tjJ--'.d'-it--:d~t-,:...:ir--:-.: · ..:lr)rj....:ioajt\l -~~~~~~~ ~~ ~~i~~~~~~~~~~o MICRONS - Length of 1646 conidia of H. ~ee also pp. 1~0-121. 7raph M 34 14 . 34 = .08 o. 1 grown on corn-meal agar. tT 5. 5 = .06 V 37.35 = .70 Graph JS N0.35 f c; FIGURE j onidial eptation of H. No. 1. ~I u ' \" 7 . 91 ± . 08 . Ql) ± - 12 . 51 == . i9 FI URE K Graphs of conidial length of H. No. l grown under standard con­ dition (sec app. p. I 0): Graph 36-40 repr nt re p ctiv ly plate - : Graph 41 r presents plat e'; and raph 42 i a ompo ite of plate a, b, , d, c' ( ee p . 120) . .;raph 36 123 37 107 142 39 1 0 40 41 647 42 1199 23 . 21 ::1: .15 22 .51 = .15 22 . 59 = . 1 6 22 .42 = . 17 21.] 22 . 71 == 22 . 62 :I: • 1 . OS .05 (T 2 . 36 :1: . 10 2.54 ::1: . 10 2. 7== . 11 3.42= . 12 3 .55 ::1: . 13 2 . 26 :1: • 04 2 . 76 :1: . 03 10. 02 :1: .46 11 . 28 :1: .49 12 . iO ::1: . 51 15 . 25 = . 55 16 . 0 == . 6 9 .95 == . 01 12 . 22 ::1: . If Gr2APH NUMBfl25 ~ ~ N -. 27.2 30.6 34.0 I I I ii 37.4 1• \ 40.8 I J 44.2 , \ 47.6 : ~ I' 51 .0 ' 11 ' I ~54.4 .... ...... ...... ...... .... - 0 57.8 -- --- ' -~ 61 .2 -- ...... ---Z 64 .6 -- vi 68.0 -- ~ ---, 1.4 74 .8 78.2 81 .6 85.0 ----88.4 -------91 .8 -- --- ----95.2 -- / 98 .6 -- / ~ ~ (JI 0 (!) 0) I \ \ ,, \ \ I ~ \ \ ...... ~ '\. -.............. "'---.. ~--./ \ ~ \ I' ..... ' - ...... - ~--\- .. __ / \ ,V ' "--- I ~// ""~ --r- _....-::::;:: ~ -\ L'----7 _/ / I I / I <,l -.:i \ I '\. "' .......... ~ -_><_ '-~-,,; ~ \ ~ \ I c.. Q) \ \ \ r--...l /.............._ '\---1 v---, / / I I 'Tj ..., Cl C :::::, t-1 ~ FtG RE L Graphs of co11idial length of H. Vo. 2 (H. ravenelii). raph 43, eymour and Earle, Economic Fungi, No. 399, Florida, 1890. Graph 44, Ellis, orth Americam Fungi, o. 368. orth arolina. Graph 45, A. B. eymour' pecimen a grown by me on corn-meal agar, Graph 46, d Th;i men, Mycotheca niversalia, o. 1468. Caro- lina, 1876. raph 47, . B. ymour' pecimen from Loui iana, 1919. Graph 48, Bartholomew, Fungi olumbiana, o. 3026. ova cotia, 1909. raph 49, Ravenel, Fungi Arnericani Exsiccati, o. 165. Florida. raph 50, Elli and Everhart, Fungi olurnbiani, o. 46 da, 1914. Flori- raph 51, Elli and Everhart, Fungi olumbiani, No. 465. Caro­ lina, 1894. raph 52, Rabcnhor t, Fungi Europeai, o. 3082. rgentine, 1 78, sample 1. raph 5 , Rabenhorst, Fungi Europeai, o. 3082a. Argentine, 1878, sample 2. Graph 43 M 14 . 97 :1:: . 18 14 . 0± . 22 14 . 79 :t . 14 14 . 49 :1:: . 19 14 .38 :t . 16 1-1 . 35 :t . 22 14 . 34 :t 21 13 .98 :t . 20 13 7 = . 20 13 . 02 :t . 20 12 . OS :t . 19 2 . 53 (1 ± . 13 . 15 . 10 . 16 .11 CV 16 . 89 ::t: . 89 44 45 46 -! 7 4 49 50 51 52 53 3 .5 * 2 . 27 ± 2 . 19 * 2 . 3 :I:: 3 . 02 = . JS 2 . 7-t ± . 15 2 2 * . H 3 49 :1:: . 1-1 3 16 ± . U 3 . 10 * . 1 24 . 17 :1:: 1. 73 . 69 15 3-1 ± 15 11 :1:: 16 5-1 ± .97 . 4 21. 0-1 :1:: 1. 15 19 . 10 :t l.lc: 20 . 15:1::J . SO 25 . 31 = 1.0 24 . 25:t:1.18 25 . 72= t.22 FIGU RE L V "'-- V \ V _/ r-- ~ - ~ - - ~- "" / '\ V i--V \ V \ v--V ~ V ~ / V ◄◄ I --V ~~ \ "' ~ "' / I'-,.. V / V I'\ ~ / ~ 45 --- V I \ \ ILJ "'6 ? \ cO ~ :, - ~ z - ~ _/ ~ 1: I -n. / - "' ~ ◄7 / "' V / \ ~ V ~ ~ _v r-----... " 48 ~ / - .r "r---.._ 49 t-,....._ / V '\ V Vi\ I ~ ~ V I'---I/ r---- - ~ 50 - / --V I"-.. ' V \ i"'-.._, V r---...... V ~ "' / / \ V 51 II. -- ,r / \ ~ ...___ V -V 1---- ......- / ............ V .52 - ' V "' ,-- --53 UI 0 V co N (0 0 V co (\I ID 0 V ex, I'! ID 0 "': ,.; r- 0 .,; i..: g 'O" r- 0 ,,. ,.: - .,. i-- - V cri -- N N ti.I it) it) V ,,. V "1 II) 11'1 ID 1$1 CD r-- M1cl20N.5 FIGURE M Conidial length of H. No. 1 grown under standard conditions but on various cereal shoots : Graph 54, as grown on corn; Graph 55, as grown on rye; Graph 56, as grown on barley ; Graph 5 7, as grown on wheat . Graph M (T CV 54 22 .49 ± . 06 2 . 83 ± . 04 12 .57 ± . 20 55 23 . 06 ± . 19 2 . 64 ± .13 11 . 44 ± . 59 56 23. 00 ± . 19 3. 09 ± . 13 13 .43 ± . 60 57 22 . 66 ± . 22 3 . 36 ± . 15 14 . 82 ± . 69 Fie 1rn M lJI G12-"P!-1 NuM6E 12.:) lJI u <.n 23 8.l,. "'-I 0- lJI 2 72 J0.6 34.0 374i/ 40 ti ' 44 2 e---, I 4 7 (, / I :,10 ' ' 54 'l - --- "' ..... ---~ 578 ..... : \ I ' n ' !!]61 .~ --- "' "\_ / 0 -tiG4 6 - - I \ "" .._ - --E-8 .0 -- I ~ -- --? 1.4 ~ / I ~ .... 74 8 / I 1/,...._ 782 1.-J..---- . t:11€ I // \ "" 850 -----17 \ I --88.4 / I V / --✓ 918 -- I J/ -----95,2 -~ - I / \ .,,. .,. 986 , I I 1020 z ~ a:: ::> r.., ~ 'I) 01 IL.I IO ~ ::, z - ~6 1 .5q ~ (!) 60 l{JO ~ I') (\J ~ (\J ~ c::i N l.l) ~ r-: ~ - (.IJ I.!) l.t) \'0 0) C1'I FIGURE P ' onidial lengt h of M35, M36, a nd M40, with that of H . No. I for comparison: Graph 65, M35-1; Graph 66, M36-2; G raph 67, M-1-0-2; ; raph 68, H . No. 1. Graph f M (T CV 65 179 16 . 80 ± . 18 3 . 75 ± . 13 22 . 35 ± . 83 66 156 22.31±. 16 3 . 14 ± . 12 14 . 09 ± .54 67 97 17 . 70± . 17 2 . 51 ± . 12 14 . 19 ± . 70 68 123 23 . 21 ± . 15 2 .36± . 10 10.02 ± . 46 *1199 22 . 62 ± . 05 2 . 76 ± . 03 12 . 22 ± . 16 *H. No. I of Gra ph 42 (Fig. K). Sec a l~o fl. I >o . FIGURE P Gl2APH NUMBEl2.5 & °' °' ()I ~ () OI 2.J.8 27.2 30.G \ .34.0 \ 37 4 \ 40.B 44 ,2 \ I \ ~ 47 6 "' ~ 51 .0 \ "" ~544 \ '~ -------n s1.8 "'~ -------10 0 Z 6 1.2 --\ ~, ~ "' 646 /\ / GBO - I / \ \ --71.4 ,... ~ ~ / \ 74 8 >- . / \ \/ 18.2 ,-... "' \ I 816 ~/ / 850 / · ! I 88 4 I '31 8 J . I / 9~ 2 I I I I 9 8 6 I FIGURE Q Graphs of conidial breadth of saltants and originals under standard conditions: Graph 69, Ml-5; Graph 70, M6-1; Graph 71, original from same plate as M6-1; Graph 72, M6-S, a week later; Gra ph 73, M8-3; Graph 74, original from same plate as M8-3; Graph 7 5, M8-7; Graph 76, M8-10; Graph 77, M36-2; Graph 78, H. No. 1. Graph f M --+--+-+-+- ~ ~ " ~ ~o /"'-r-.--,-,---,--.--.---,.---.--.-..-.----.----.-,-.,-.--.-.....,.-.-...-,....,.-,--.---,,....,.-,-.-----.-----,-,-,,.-,-,-.-,,-,---,, 0 I I z z 3 J 4 4 5 5 6 6 7 7 e, a Q q 10 I Graph f 86 134 FIGURE 5 Graph of conidial length of H. No. 11. M 18.85 ± . 20 (1 3 . 58±.14 CV 19. 03 ± .81 FIGURE s Gr2APH NUMBE'2 a, a, Z7.2 I :,o.e. 34 .0 J7.4 - 40.8 44,Z "' 47.6 I 51.0 ~ 54.4 \ 57.8 ~ \ c'i 61.2 \ Ill 0 z 64.6 - / (/1 68.0 / 71.4 ~ 74 .8 / 78 .2 \ 81 .6 / 85.0 88.4 I 91 a 95 2 98.6 102.0 \ FIGURE T Graphs of conidial septation of several Helminthosporiums under standard conditions: Graph 87, H . No. 11; Graph 88, H. No. 20; Graph 89, H. No. 13; Graph 90, H. No. 14; Graph 91, H. No. 15; Graph 92, H. No . 16. Graph f M (1 CV 87 30 6 . 13 ± . 14 t . 20 ± . 10 19 . 62 ± I . ii 88 48 6 . 10 ± . 04 . 50 ± . 03 8 .35 ± . 57 89 90 7 . 90 ± . 07 1 02 ± . 05 13.01 ± . 66 90 83 6 .95 ± .10 1. 36 ± . 07 19 . 58 ± 1 . 06 91 81 7 . 11 ± . 08 1 . 19 ± . 16 16 . 82 ± .91 92 57 7 . 33 ± . 07 . 86 ± . 05 11 . 79 ± . 75 FIGURE T No89 136---,-,-r,-,-,-,--,,--,-...---,,-,--,-"T"'""O~~~~ 1 -r.o -i--t-t-ir++H+-HH-+H++-l-+++-1+-WW--l-W-l--WW-+W~-~W-U 20.4 2.3 8 272 306 340 102 13.6 204 23.8 27 2 J06 34 0 170 20.4 23 6 27.2 No 87 No 88 Fie RE Graphs of conidial length of several Hclmintho poriums under standard conditions: Graph 93, H. o. 14; Graph 94, H. o. 1 I Graph 95, H. No. 15; raph 96, H. o. 16; Graph 97, H. No. 17; raph 98, H. No. 18; Graph 99, H. o. 19: Graph 100, H. o. 20. Graph f I (T C 93 404 22 04 ::1: . 10 3 .03 ::1: . 07 13 . 76 ::1: . 3 94 597 24 7 ± . 09 . ·3 ± . 06 14 . 24 ::1:: . 2 95 461 22 . 54 = . 10 3 . 49 = . 07 15 . 51 ± . 35 96 445 23 . 75 ::1: . 12 ' . 0 ± . 08 16 . 03 :1:: . 37 97 252 24 .39 ± . 15 3 . 63 ± . 10 1-l .8 :I: . 45 9 97 2 . 03 ::1:: . 28 4 . 10 ± . 19 17 . 1 :I: 99 205 24.59 = . 19 .!_ 15 ± . 1 16 . 9 ± . ·7 100 15 18 . 84 ± . 12 3 . ~ ± . 0 17 .53 :1: . -18 6.8 R ~ ~ ~ GIUI .. H Nu~e EflS c.o c.o co --.J c.o 0, 10.2 13.6 17.0 20.4 I 23.8 272 30.6 34.0 i 37.4 \ \ T 40.8 \ I I 44.2 "-...._ \ :/ I I I 47.6 '\ \ I ' "' 51.0 ' "'- ' \ ,,, ' ,' I \ , '\ :$ 54.4 I n 57.8 ---- \ ~ ""- I I \ I ~ 61 .2 /', "'- ' \ '\ I I --~ 64.6 -- \ '', \ \ "\: - 68.0 / -- .... -...........__ -----::- - \ "' '\ 714 ./.,, -- -.\ -- ~\ I 74.8 / / --- ----- ~ I /- 78.2 I ---- ----- ~-- ------ I - / .,, .-,/ 81.6 -:)- - --- ~ \ I 85.0 _,_ .,, -( ·- - - - \ /-_ \ / 884 -- /1 I ---- ---- / -'\- -,, r 91 .8 ----- / / \ I ' 95.2>- / -=~ -- / - - --\ -7 - 98.6 / \ ,,.-- / I I / 102.0 I 7-= / I I / -- 105:4 - - . ,,- I I I _.,, 108.5 r--· / \ / T ,, 112.2 f- · I I / 115.6 I I 119.0 · I ~ Cl C ::::: ~ c:::: Fie rm V Graphs of conidial breadth of several I-lelmintho porium under standard conditions: raph 101, 1-1. o. 11: ;raph 102, H. o. 20; raph 10 , H . • o. 13: (;raph 104, H. 1 o. H; ,raph 105, H. No. 15; raph 106, H. No. 16. Graph f M fT 101 39 - . 19 ± ,04 .40 ± . 03 i . 7-! ± . 59 102 58 S . 11 ± . l-! . 52 :::1:: . 03 10 . 27 ± .65 103 79 5 .97 ± . 0 1.06 ± .05 ti . 85 ± .9 104 32 5 .59 ± .0 . 7-! ::I:: . 06 13 . 30 ± 1. 14 105 5 .39 ± . O+ . 56 ± . 02 10 . 50 * . 5 106 45 S .88 :1:: . OS .56 :1:: .04 9 .61 :1:: .68 FIGURE V FIGURE W Graphs of conidial length-under standard conditions-of H. No. la (107) ; H. No. lb (108 ) ; H. No. l e (109) ; H. No. ld (110). Graph f M u CV 107 111 21.20 ± . 17 2 . 66 ± . 12 12 . 58 ± .57 108 130 21.52 :±: . 16 2 . 86 ± . 11 13 .30± .56 109 160 20 . 09 ± . 12 2 . 29 :±: . 08 11.42 ± 43 110 153 19 . 26 ± . 11 2 . 12 :1: . 08 11.03 ± .43 FIGURE W GBAPH NUMBE.125 - 0 0 0 0 lj) 0 I'\ ,... 0 I"\ r- ci 0 ~ r- I') I.P 6 It') ,.: 0 ~ r-: 0 - N N N I') (IJ (\J (\J C\I (IJ I') M1Cr20N5 FIG RE Saltant raph f (J C Ml-5 114 160 23 .40 :1:: . 1 " .53 :1:: . 13 1 . 11 :I:: . 8 M2-4 115 154 21 . 77 :1: . 17 3 . 17 :1: . 12 14 . 56 :1:: .57 M3-4 116 131 22 .66 :1:: . 20 3 .50 :1:: . 1-l 15 .4 :I:: . 66 M4-6 117 168 22 . 72 ± . 21 4 . 04 ± .14 17 . 0 ± .67 M5-5 11 14~ 23 . 72 :1:: . 19 3 .52 :1:: . 13 1-l . 6 :1:: . 60 M6-5 119 166 23 . 65 = . 20 3 . 85 = . 14- 16 . 2 ± . 61 M- 120 156 23 . 92 :1: . 18 3 . 3 ± . 12 l-l . 35 :1: .5 112-3 121 1-l 23 .64 ± . 20 . 73 ± . 14 15 . l ± . 6 M13-3 122 173 22 . 73 :1: . 1 3 . 61 :1:: . 13 15 . 0 ± . 69 M14-3 123 126 22 . 2 ± . 17 2 .9 :I:: . 12 13 . 7 :I:: _~7 MlS-3 124 134 23 .51 :1: . 20 3 .51 :1: . 14 14 .93 :1: . 62 M36-2 125 156 22 . 1 ± . 16 . 1-l :I:: . J 2 1-l. 09 :1:: .5-l M37-2 126 131 22 . 03 :1:: .21 3 .64,.,, . 15 16 . 55 = . 70 M32-2 127 6 23 00 :1: . 16 2 .33 = .12 10 . 1-l = .52 M33-2 128 155 22 . 37 = . 16 " . 02 :1: . 11 13 . 52 = . 52 40-2 129 97 17 . 70 :1:: . 17 2. 51 :1: . 12 14 . 19 = . 70 130 14 22 .92 ± . J 9 .45 :1: . 13 15 . 05 ± .60 131 125 22 .36 =1:: . 21 3 .53 ± . 15 15 . 81 = .69 M43 -2 132 139 22 . 0 ± . 19 . 36 :1: . 13 r . 29 =1= . 63 M44-2 133 134 22 . 18 :1:: . 15 2 . 72 ± . 11 12 . 27 :1:: .51 M45-2 134 142 22 . 8 = . 21 3 . 76 ± .15 16.43 = . 67 146-2 135 158 22 . 4 :1:: . 17 3 .34 :::1: .1- 14 .66 :1:: . 56 M47-2 136 112 23 .S :I:: . 22 3. 56 :1:: .16 1 • . 12 :1:: . 69 M4 -2 137 146 22. 00 :1:: . 16 3 . 02 :1:: • 11 13 . i :I:: . 55 M 17-3 13 128 22 . 56 :1:: .14 2 .38 :1:: . 10 10 .56 :1:: . 45 FIGURE Y V r-.... >-- v I\ / i--.._ (, - v r-- ['._ / ....._ - I\ 114 ./ r---. / i " / -- V "r-,.._ \ / -115 ~ ---- J r-..... I'-.. __.., II' V I\ I\ / - ,- 116 I ' V - - r--... " 1/ I\ r-- / I v '-.. " 117 __... >-- / - V \ I'--.. i-- " / I/ - - r-- ........ 116 - ./ I',_ r---. I/ I \ V ' \ 119 -...--i-- - r...... ...... / - V I I'- '\ i-- ....._i'.. ........ 1ro ./ --- I'... v V ' ....._ v " v ~ ,- ..,,---- ' ........ I'-121 / / - V I'\ I'- I:,:, .,,,- v / I'... ........ .- r-... ' 1e~ ~V ......... _,, I/ " " -v' '-.. ' / -'-'/ v I\ I'- !Z4 -- v / ' ....._ V V "i--.._ - I\ / / -----'1) lz.5 _. - I i\ ' -DI V I ' "-.. lJ 12"' ---!O 7 ...... ~ V "' ...--i-- \ \ :::> z IZ.1 / ":: -- I ~ I\ ......... a. I ::i.11 - ~ " -~ V \ Qt V (9 !eel v ....._ / r--.. v " v V \ \ V i-- y ' V >-- V I'-... -r--.. 130 ----- v ---- v -" -v 1.31 _ ..... I \ r--... ---- 1; ........ v ~ V I\ ...--i-- / -- ....._ 13Z / - I/ j ~ ....._ v-- ~I \ ........ 133 ---- V - :-.... I/ V ..-I\ V I\ '\ - "" 1341 --- - I ...._ -- "- .._ 13) ...... V I'-. I I \ \ -- - ,.,61 .,,,.... i--- :,.,- r- >--~ I ['...~ ' - / ....._ [ ~ I"-V ...... -...- V "' \ V i-- /- I\.. ,-,7, IJJ I '\ I'-.. L---o~~N~Ov~NWOv~N~OV~N~OvwN ~~o~~-i~~v~~v~~~~ ~ ~~N~~N ~~v~~ ~~~~~~~~~~m~~~~2= M1c120N.s PLATE VII Several wheat stems showing characteristic diseased spots; also diseased portion at the node in one shoot. PLATE Vlll Di eased plant, showing numerous dead leaves and I af- heath , al o more than a dozen new shoots i uing from below the di ea ed portion . These shoots varied in height from a f w millimeter to everal c ntimet rs. PLATE IX ✓ ,-------._ / ' I H. No . 1, 3, 4, 5, 20, and 22, growing on corn-meal agar. PLATE H. o. 36, showing very floccosc mycclium. PLATE XI H. No. 3 (left) and No. 1 (right) as grown in Piorkowski-flask culture . PLATE XI PLATE XII H. 1o. 1 as grown in Kolle-Rask culture. PLATE XII PL TE .. ' III H. o. 3 as grown in Kolle-fla ·k culture. PLATE XII I PLATE XI Petri-dish cultures of H. o. 1 on different amounts of agar: 14, on 12 c.c.; 15, on 30 c.c. I PLATE XI ) I I PLATE xv H. o. l growing in tub of rice with different amounts of , ater. ote abundance of sclerotia in the drier tubes at the left. Corn· rnea.l a..so.r PLi\TE XV I Bra.z. i l- nu. t':> lo...pi.oca.. H. ro. 1 grown on washed agar with nutrients added as indicated­ fragment of Brazil-nuts, rice, tapioca, and corn-meal agar. ( ircles indicate approximate limit of growth at variou period .) PLATE 'VII Photomicrographs of H. o. 1, showing attachment of conidia to conidophores. PL TE XVIII Photomicrographs of IJ. No. 1, showing the fragile nature of the outer brown spore-wall and the g latinous texture of the hyalinc ma nclo ed. (Three difTcrent magnifications.) PL TE XIX Photomicrographs of I-I. o. 1, showing conidia under diff rent magnifications. PLATE xx . .., , , / . i Photomicrograph of conidia of H. ravenelii. • b PLATE r I .. , ,, Ii e C Conidia (a) of H. Ko. 36, showing variation in size and shape; band c, conidia and a conidiophore of H. o. 39. C, Two ·altant·: 11pp ho,,inra of ;\ 15 ; lo\1-er one lo,, gro,, th. ~------------------------------ Two saltants; upper one showing odgin of 11; lower one of slow growth and bearing clumps. PL TE XXIV Cpp r figure showing ori in of 12 ; lower figure ho,dn ori in of i\l 0- 134. PL\TE XX\ ltant growing with th ir r p ctive originals. PLATE XX PL \ TE .·.- \ 'I Photomicrograph ( ame scale) of conid ia uf se\'eral Helminth ~porium a, IL No. l : h,::\ l t>: c, :\135 ; d, H. 20. PLATE xx [ , a., C Pl.ATE XXVI I altants growin with their re. pecti\'e original . PLATE ~ III i\134, characterized by abundance of clcrotia and white mycelial clump , th latter a con tant character of thi altant. Above, II. ro. 1 wound d by hot wire at point hown; below, H. o. 1, with H. No. 1 implanted at various distances v. ithin and without the colony. ' ' PLAT Abov , two implants of H. To. 1-0Me of th m th ongm of 170-in H. o. 1 colony, showing some white Aocco e aerial mycelium; below, l'vl26, with origin of i\153, M56, and :.\'157. ' PLATE XXX PuTE XXXI )1 26-1 as it a ppeared on two separate plate . PLATE XXXI M 26 -1 PL. TE XXXII 1125. Pale colonies, showing dark sectors which were apparently rever ions to the original form. PLATE XXXII PLATE XXXII [ howing method of using rag doll in inoculations (a, b, c) and also (d) Yial and pap r cylinder for soil inocu lation: a, the rag doll unrolled in sterile Petri-dish, and aseptic wheat seedlings in place, ready for inoculation; b, doll in place in tube a nd seedlings growing; c, showing d velopment of root hairs in condition for inocu­ lat ion below the doll; d, as stated above. PLATE X .. /XI 11 d Alf .. • Rag doll opened for examination 6 days after inoculation. All the eedlings show beginnings of foot-rot.