3o8 Proceedings Columbia Biochemical Association [Jan. 



sucrose, salicin, raffinose, dulcite and inulin, in the order named. 

 Mannite, raffinose and inulin were found to be of minor or doubtful 

 importance as a basis for Classification. Sucrose divides the lactose 

 group into two distinct sub-groups. 



On subdividing the sucrose groups on the basis of dulcite- and 

 salicin-fermentation, respectively, it was found that the sucrose- 

 salicin groups gave better correlation with indol production, V and 

 P reaction, and gelatin liquefaction, than did the sucrose-dulcite 

 groups. 



The sucrose-positive, salicin-positive group corresponds to B. 

 aerogenes. 



The sucrose-positive, salicin-negative group corresponds to B, 

 communior. 



The sucrose-negative, salicin-positive group corresponds to B. 

 communis. 



The sucrose-negative, salicin-negative group corresponds to B. 

 acidi-lactici. 



Glycerol was found to be of value in separating the cloacae 

 forms from the aerogenes bacilli, y^ percent of the sucrose-positive, 

 salicin-positive, glycerol-negative strains being liquefiers. 



It must be borne in mind, of course, that this Classification was 

 obtained with a relatively small number of organisms and can at 

 best be considered only tentative. The results are, however, suffi- 

 ciently interesting to merit further investigation, especially on the 

 part of those interested in the bacteriology of water. 



Of the glucose-positive, lactose-negative forms, five liquefied 

 gelatin and fermented glucose and sucrose, but f ailed to f erment any 

 of the other substances, with the exception of glycerol, which was 

 fermented by two of the organisms. Of the other tests, all were 

 negative with the exception of indol, which was negative for the 

 two glycerol-positive organisms and positive for the glycerol-nega- 

 tive. For the present all the five may be grouped under the name 

 B. vulgaris. 



The sixty-two members of the colon group discussed may, there- 

 fore, be said to fall into six main species as f ollows : 



