460 
ters broad in the 1 :400,000 and 1 :200,000 
concentrations. Growth on crystal violet 
extended to about 1:5,000 or 1:4,000. At 
this point in the key the two species are 
separated by their reactions to brilliant 
green, brilliant green not being decolorized 
by F. orthoceras but being decolorized by 
F. oxysporum. Also, a difference in growth 
form of the two species on crystal violet is 
noted, growth being submerged with seri- 
ceous center for F. orthoceras and cottony 
for I. oxysporum. 
Diameters of the mycelial mats pro- 
duced in different concentrations of dye 
Table 4.—Reactions* of isolates of the gladiolus Fusarium to four concentrations of crys- 
tal violet in Coons’s agar. 
Ittinois NaturAL History SurvEY BULLETIN 
Vol. 26, Art. 6 
were used by the writer to compare abili- 
ties of isolates to tolerate the dye in the 
culture medium. Considerable variation 
in diameters was shown by the 40 isolates” 
of gladiolus Fusarium, tables 3, 4, and 5. 
Although of little diagnostic value, growth 
forms of the various isolates were probably 
the most striking characters, figs. 9 and 10. 
When these isolates were taken through 
Coons & Strong’s key, 26 keyed out to 
Fusarium orthoceras’ var.  triseptatum. 
Since no isolates decolorized brilliant 
green, they did not fall into F. oxysporum. 
Vascular isolates 49-4 and 49-23, brown 
CoNnCENTRATION OF DyE 
IsoLATE 
1:2,000 1:5,000 1:10,000 1:20,000 
GET ie Rieke Ne. aoe seme UN 2 pegs PN GE acy Ms es Maree tr 11.011 11.011 11.001 
AE RAS ects SO hn AP nh Soe Ace 0 11.001 12.001 11.000 
VW olla oo, Se ee Win nm Sana on 8 a Sei hea 0 11.001 12.001 12.001 
7 USE iEt Santee RIGO ae Se oa Sh a A aa 5 A Beg et cree 0 11.004 12.000 12.000 
BG Oi Set Se aay eile pO ah 8 thee er 0 11.001 12.001 12.001 
AB SARE Seer lieben deh cieeign cot helene Seren eee 0 11.001 12.001 12.001 
ATG fe teat pate ety Sige lie ai © pelea ik et 0 11.001 12.001 12.001 
ler Hit (Toes =. Steere ase cas Oa de tk Se EL ey a ee 0 11.001 12.001 12.001 
ya AE ol ie a ae rent oP Oe OU I gl Cat Cea MAS ORE on tr 11.001 12.001 12.011 
AON Gorey testa MIe eee ne hoa AOR MUR PR er rae, 0 11.001 11.001 11.001 
AQ OBA cree as SOR ont ae (0) 12.001 12.001 12.001 
Po Be gt re in as eg oer ng ne n tr 11.014 12.001 12.014 
Oo eh [il Oe eRe Nes een UR mRNA ASA AUN ten tr 11.001 12.001 12.001 
LQ SSP ol gee arson,” Satie Aa arm AL muta Ure 0 11.001 11.011 11.001 
Gt) EA). ote <a ape mina N eae REMY ates eat fe RAT se tr 11.001 11.001 11.001 
IA VSP fate Beek ce tral £ 9. Nae ne eee Ee ey OAS gp ag tr 11.001 12.001 12.001 
Ts) SA Tales Fea Ie arte yn) Bea ROA Setar tes 1S few 0 11.001 12.001 12.001 
7 APA 7 iy Rone gan. 8 Dea mm bene: AEs ere n by. Fae 0 12.001 12.001 12.001 
PEST FS ae hg et MRR ie CAND 2) CR eit sabe 11.001 12.014 12.014 12.014 
FESS ft at ASAE Mis oy Ee on SRR ASO es LIne Alt ato ae 11.001 11.001 12.001 12.001 
FET MY aN aii 2 aa a Ae GB ED aa Teh ee ae 0 12.001 12.001 12.001 
VAC Ser Es eee 1 Re a aaa ee He Seas 11.001 12.014 12.014 12.014 
PTS NG) Air ae sp ah NOP MT oeT Bea a Ba tr 11.001 12.001 12.001 
TATE [ype os ec ots yak Spee RISIg eon SIAL Sea A te tr 11.014 12.014 12.014 
TOR eet cr ae Ci ait gt fen en ta + tank MANE Ie: im re tr 11.001 12.001 12.001 
PTAC Vp Lae te Mle roe ORs ee eke ye a aa tr 11.007 11.007 12.007 
ZERO a ee ae Ra Brom tren bss ere ae UR RO i 0 11.014 12.014 12.014 
7M (SSG Je I Aa eit A a Oil De eet SARS Eo 0 11.001 11.001 11.001 
r Ro el Fis ale Aa ade kao ae oe Ra nL eae Dl 11.007 11.007 12.001 12.001 
NOES I 2 ge Writ oa 2 ad ARES © RE ct O28 Se RI oe 0 12.001 12.000 12.001 
YON (Co). SP Renae See Rk 3: See Rey = Bir on ZAP Sa Er 11.004 12.004 12.014 12.004 
7s ae a eae Ott COMER PRY Dake Roe Shor Om, PRIS tr 12.014 12.014 12.014 
SO ry eer a ee ners. |! SNORE pad atiwcet tr 12.004 12.004 12.004 
10 OP eta ak ore. tae tg. bs ANE Maa aE AR Ae mR tr 11.000 11.000 11.000 
BOD UE Brak ee eee, Panta ai: sc eee ae ew ooh: 11.001 12.004 12.004 12.004 
AES SORE} os; Bagh MRED Sh toe ka rN eon eoe Et Ae tr 12.001 12.001 12.001 
PR fs can OE Re APR Ran bya TT Ag ay tr 11.001 12.001 12.001 
7 Mo I) 1) i Sm ie oi cio St Mare Aa ek eal 6 et Ree DB tr 11.001 12.001 12.001 
15} S05 th ere ta bles Oa he Ue a er ol alee em RN tr 11.001 11.000 11.000 
UU cekea | Sime ee emer 28 KOPN RR ORR 3 Co RCT Wut a tr 11.001 11.001 11.001 
*Reactions are expressed in the numbering scheme of Coons & Strong (1931), as explained in the text. 
tSee table 3 for control readings. 
