730 
Journal of Agricultural Research 
Vol. V, No. 16 
TabIvE X .—Effect of aeration: Tests with various nutrient solutions —Continued 
Solution. 
Raulin solution 
+ % c. c. M\i 
calcium nitrate 
(Ca(N0 3 ) 2 ). 
Raulin solution 
with levulose, 
on filter paper 
cones. 
Acid Dox solu¬ 
tion + I c. c. 
Ml io arabinose. 
Acid Dox solu¬ 
tion + i gm. 
potato starch. 
Size of 
flask. 
Sealed. 
Number of 
pycnidia. 
Growth. 
C. c. 
r 900 
0 
Fair, mat. 
J 500 
0 
Fair, no mat. 
0 
Fair. 
[ 5° 
0 
Fair. 
f 9 °° 
O 
Filter covered.... 
I 500 
0 
Filter covered.... 
j I2 5 
O 
Less than above... 
l 50 
O 
As above. 
f 900 
5 
Scanty white. 
J 500 
1-2 
Scanty white. 
125 
0 
Scanty white. 
l 50 
0 
Scanty white. 
r 900 
? 
Strong. 
J 500 
? 
Strong. 
1 I2 5 
0 
Fair. 
l 5 o 
0 
Fair. 
Check. 
Number of 
pycnidia. 
Growth. 
10 
Fair, thin mat. 
10 
Fair, thin mat. 
25+ 
Mat. 
25+ 
Mat. 
0 
Paper covered. 
0 
Paper covered. 
0 
Paper covered. 
0 
Paper covered. 
25+ 
Fair, white. 
25+ 
Fair, white. 
50+ 
Fair, mat. 
50+ 
Fair, mat. 
20+ 
Strong, mat. 
20+ 
Strong, mat. 
20+ 
Strong, mat. 
20+ 
Strong, mat. 
This experiment shows the effect of scanty aeration in repression of 
growth as well as an almost complete suppression of pycnidia in 
the sealed flasks. In the two cases where pycnidium production did 
take place in the sealed flasks, the fructification occurred in the larger 
flasks of the series. It must be said that the check flasks, especially 
the larger sized ones, were almost dry at the close of the experiment 
and the humidity conditions as well as the concentration were different 
from those of the sealed flasks. For the first three weeks, however, the 
cultures were approximately the same, and it seems safe to attribute the 
difference in growth and pycnidium suppression to improper aeration, 
rather than to the drying or concentration, especially since, as will be seen 
from later experiments, these factors play but little part in pycnidium 
production. 
From the many observations recorded here, and from the experiments, 
it seems safe to conclude that this organism is very sensitive to the 
oxygen supply, and it requires good aeration for optimum growth and 
for pycnidium production. 
HUMIDITY (TRANSPIRATION) 
From a number of indications in cultures, it was felt that transpiration 
might be a factor of more or less importance in the growth and repro¬ 
duction of this fungus. A study of the literature dealing with reproduc¬ 
tion, especially the work of Klebs (1898) with Sporodinia grandis , made this 
