81 
pletely overgrown and of an even black color, largely curtained by an 
abundant, even overgrowth of white aerial mycelium. At contact with 
the glass a sharp, black line gave clear evidence of the black surface-coat. 
No clumps or balls of mycelium were present. At 22 days a few clumps 
developed, though not so many as on H. Nos. 9, 13-16. 
Cultures of H. No. 1 on corn-meal agar in large flasks, as those of 
Kolle or of Piorkowski (Pl. XI-XIII) gave colonies very different from those 
on the ordinary Petri dish, due presumably to the larger quantity of 
nutrient available and to different humidity relations. These flasks 
gave increased density of colony and conidia-formation, more aerial 
mycelium, and some clumping of the mycelium. Though colonies of H. 
No. 3 and H. No. 1 d‘ffered in these characters in these flasks (Pl. XII, 
XIII), portions of the colonies of these strains were indistinguishable. 
Corn-meal agar made at various temperatures —Corn-meal agar was 
made in the usual manner excepting that the temperature in three cases 
was held at 43°, 85°, and 100° respectively, instead of at 60°, before 
filtering. Duplicate plates were made. The four resulting agars are 
designated according to the temperatures held, and colony data for each 
are presented in the following table. 
CORN-MEAL AGAR MADE AT VARIOUS TEMPERATURES 
Temperature Growth in Zonation Density Colors 
8 days 
43° USS) oc ; 
43° 72 distinct thin pale 
60° 5.5 F 
60° sharp thick dark 
85° 6.5 In above characters, ranks between 43° and 60° agars 
100° 8 : 
100° 7.8 none very thin very pale 
The 100° agar is most favorable to linear growth, 43° agar stands 
next; 43° and 85° agars give growth of poorer color than 60° agar, but 
100° agar ranks lowest in this regard. Color is directly due to quantity 
of conidia, and it is uniform in the mycelium on the four agars. 
In general, it 
in 100° agar was very little better than in plain agar. 
Nutrition 
