(Vou. 8 
78 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
of Pa 2.0 no growth occurred, and the limit on the alkaline side 
was found to be beyond P, 9.2. . Thus, the growth range fol- 
lowed the range for spore germination as determined by Webb 
(19), this being from P, 2.8 to 10.0 +. 
With the exception of the Pa 9.2 culture solution, the reaction 
of all the culture solutions, with starch as the source of energy, 
was changed during the growth of the fungus, this shift being 
toward increased alkalinity. The greater the acidity the greater 
the change produced. Thus, the reaction of the P, 3.0 culture 
solutions was shifted to 7.0 while that of Py 8.2 was shifted to 
Colletotrichum Gossypii 
produced visible growth 
/o at the end of 3 to 4 days 
7% at favorable H-ion con- 
centrations. Abundant 
8 spores were produced in 
E the cultures, and the 
$ ? mycelium from the first 
X . was very gelatinous and 
38 attached to the bottom 
"EL of the flask. The growth 
range was found to be 
from P, 3.0-4.5 to 9.2 or 
beyond for the product- 
ion of a fair quantity of 
mycelium. The final 
4, s F 7 g 7 H-ion concentration of 
Üe id dub d ee the solution, although 
ig. 1. ction of extracellular ( ) and : 
intracellular (---) amylase produced byFusar- shifted toward the alka- 
ium sp. grown in Czapek’s solution of Pg3.0. line side in all but one 
instance, gave results, in 
the corresponding solutions, much less than those of Fusarium. 
The greatest shift was from P, 4.5 to 6.7 in natural Czapek's 
solution. The alkalinity of the culture solution with an initial 
reaction of Pa 9.2 was somewhat lessened during the growth 
of the fungus, since the final reaction was P 8.6. 
Penicillium italicum was found to have a more limited growth 
range with respect to the reaction of the culture solution than 
o 
