BACJLLUS-COLI-LlKE BACTERIA FROM FECES AND SEWAGE 23 



I 



FLcrrin 

 H By Cou-Lncc BACTEKIA FKOM /In/HAL Feces 



similar results obtained with the 11 cultures from the collection of the 

 American Museum of Natural History. Four of the museum strains 

 were positive and 7 negative for the Voges-Proskauer reaction. 



The average quantities of acid formed from different substances 

 by the Voges-Proskauer-positive and -negative strains obtained from 

 the museum collection and isolated in this laboratory are shown in 

 Table 11 and Plot IV. 



The museum strains, both Voges-Proskauer-positive and -negative, 

 form less acid from lactose than the organisms freshly isolated from 

 animals and sewage, but in all other substances tested the differences 

 between the museum and freshly isolated strains are inappreciable. 

 To infer that the museum strains have lost their power to ferment lac- 

 tose does not offer an adequate explanation of all the phenomena, for 

 it becomes necessary to explain why the organisms should single out 

 and taboo lactose while retaining their power to form acid from the 

 simpler and more easily attacked monosaccharids. as well as the more 



