[Vor. 7 
266 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
Bacteria per cc. 
(Logs. ) 
soll Pr a 
| po TN 
"d 
l N 
b. 
| | N 
6.0 l N 
EE." 
X 
N 
v 
4.0 ` 
N 
N 
N 
2.0 
0.0 
Pe 
4.0 
5.0 AA 
me i 
6.0 L/ 
| , 
/ 
TQ 4 
Y 
8.0 
9.0 
Hours o A8 96 144 192 240 
Fig. 4. Growth and hydrogen ion concentration of Bacillus coli at 30? C., dex- 
trose allan, reinoculated. 
Culture A, untreated. 
coo --- Culture B, sterilized. 
— — — — Culture C, acidity adjusted. 
