
64 BOTANICAL GAZETTE [JANUARY 
hundred times), and otherwise the coefficient of maximum ger- 
S 
mination is constantly above sca Parallel with the results 
cited above, flask cultures were made with the more variable 
Aspergillus. These cultures for the first two media showed at 
s he s : 
s and — complete germination, at Fen VOY good germi- 
Io 
: Ss naa 
nation, at ety small per cent., and at further dilutions 
1°) 
none. Equivalent cultures on sugar solution are interesting, 
ee mre n 5 
> Siving almost no germination; co nae Per cent. ; ae 
nn 

and perhaps about Io per cent.; and a very small 
I9000 To000 
percentage. From this it will be seen that a tenfold dilution of 
the ordinary culture media affords perfect germination, and a 
dilution below one thousand times gives practically no germina- 
tion except with very sensitive fungi. 
INDIVIDUAL VARIATION OF SPORES. 
No studies of importance seem to have been made upon the 
variation in capacity for germination of individual spores pro- 
duced under similar conditions, or of spores from the same 
conidiophore or sporangium. Nevertheless, great individual 
differences exist, and in any medium which is not a strong 
stimulus for germination, varying percentages of perfect germi- 
nation will invariably occur, whatever precautions of method 
may be observed. 
CAPACITY FOR GERMINATION OF SPORES LONG INCUBATED ON 
WATER SURFACES. 
Spores of Aspergillus flavus and Sterigmatocystis nigra were 
sown on distilled water in Erlenmeyer flasks. At the end of 10, 
30, and go days some of these were transferred to bean decoc- 
tion. Practically no germination had occurred on the water; 
and in nutrient solution of the new cultures these spores gave 
perfect germination. After 125 days, some germination had 
occurred among spores in masses, but this germination was by 




