278 
ANNALS OF THE MISSOURI BOTANICAL GARDEN 
TABLE IX 
[Vor. 7 
GROWTH AND HYDROGEN 1ON CONCENTRATION OF BACILLUS AERO- 
GENES AT 30? C., PLAIN AND 1 PER CENT DEXTROSE BOUILLON 
Hours 
Plain bouillon 
2 
Plain bouillon and 
1% dextrose 
Bacteria per cc. Pu Bacteria per cc. Pu 
98,000 6.9 94,000 6.9 
171,000,000 6.9 272,000,000 5.5 
236,000,000 7.0 300,000,000 4.9 
306,000,000 7.4 139,000,000 4.8 
455,000,000 7.8 27,000,000 4.8 
307,000,000 8.1 7,600,000 4.8 
169,000,000 8.3 6,300,000 4.7 
8.3 5,000,000 4.9 
162,000,000 8.3 10,000,000 4.9 
121,000,000 8.3 23,000,000 4.9 
108,000,000 8.3 38,000,000 4.9 
125,000,000 4.9 
211,000,000 4.9 
539,000,000 5.8 
37,000,000 8.3 815,000,000 6.6 
44,000,000 8.5 836,000,000 6.9 
761,000,000 6.9 
36,000,000 8.6 775,000,000 6.9 
20,000,000 8.7 927,000,000 6.9 
22,000,000 8.7 1,017,000,000 T4 
8,640,000 8.7 690,000,000 T5 
2,520,000 8.7 643,000,000 7.0 
7,830,000 8.7 485,000,000 7.6 
concentration between Bacillus coli (table r, Culture 
1) and 
Bacillus aerogenes (table 1x, Culture 1). There is a similarity 
in growth of Bacillus coli in .3 per cent dextrose and Bacillus 
aerogenes in 1 per cent dextrose, the difference between the or- 
ganisms apparently being in the greater resistance of Bacillus 
aerogenes to acid. 
While the experimental data reported above have emphasized 
the importance of the H and OH ions as factors in inhibition, 
these ions do not represent the only products of metabolism 
which might be considered as inhibitory to growth. Ayers and 
