1921] 
WEBB—GERMINATION OF SPORES OF CERTAIN FUNGI 289 
In the test-tube cultures from which the spores were taken, B. 
cinerea, A. niger, P. cyclopium, and Fusarium sp. were grown on 
potato agar made according to Duggar, Severy, and Schmitz 
(17); i. e., 280 gms. of potato were cut into small pieces, auto- 
claved in 1 liter of water for 1 hour at 15 pounds pressure, and 
filtered while hot. Fifteen gms. of agar were then added, and 
the mixture was autoclaved for 15 minutes at 15 pounds pressure, 
and, correction having been made for loss of water, was finally 
tubed, sterilized, and slanted. Penicillium italicum frequently 
produced spores with difficulty, and the limiting factor seemed 
to be the reaction of the medium. A medium of relatively high 
acidity is essential for sporulation with this organism, and the 
medium here employed was 1.5 per cent agar made up in Czapeks’ 
full nutrient solution as outlined on page 290. Colletotrichum 
Gossypi was grown on agar conforming to a formula suggested 
by Professor Barre: peptone, 10.0 gms.; glucose, 15.0 gms.; 
MgSO, 0.25 gm.; K,HPO,, 0.25 gm.; agar, 15.0 gms.; and H,O, 
1000 ce. Cultures grown in the light produced abundant spores; 
those grown in subdued light, relatively few; and those in the 
dark, none. All cultures were allowed to grow at room tempera- 
ture, and the spores were always taken from cultures ranging 
in age from 10 to 15 days. 
In the case of P. graminis, wheat seedlings were inoculated 
with uredospores and allowed to develop within a cheese-cloth 
cage. Spores to be used for germination were always taken 
from fresh sori, usually appearing from 10 to 18 days after inocula- 
tion. Spores of L. saepiaria were obtained according to the pure 
culture method outlined by Zeller (16). The sporophores were 
first rinsed several times in sterile distilled water in large test- 
tubes and then allowed to stand for about an hour in sterile 
distilled water. Following this they were removed with sterile 
forceps, the surplus water being removed by drying with sterile 
tissue toweling, and were finally placed, hymenium downward, 
in large, dry, sterile Petri dishes. After 24-48 hours the sporo- 
phores had discharged sufficient spores to make & white spore 
print. 
