402 



M. R. SMIRNOW 



TABLE X— Continued 



A study of the accompanying tables will best convey to the 

 reader the results obtained. It will be noted that, strain no. 

 1 is the "weakest" member of the group, giving but httle 

 indol in the controls and but traces in five of the ten sugar 

 media used. Strains 2, 4 and 7 are readily changed by all 

 sugars, with a rapid disappearance of indol formation. The 

 most interesting results, however, were seen in strains 3, 5 and 6. 

 These were affected similarly to nos. 2, 4 and 7 by all the sugars 

 except saccharose, in which medium the indol reaction con- 

 tinued in each case until the 18th transfer, at which time the 

 experiment was discontinued. It was suspected that these 

 latter were strains of B. coli communis, and since B. communis 

 normally does not ferment saccharose with the production of 

 gas, possibly not affected by this carbohydrate. Inoculating 

 the original agar culture of nos. 3, 5 and 6 into saccharose 

 media proved this supposition to be correct. At the time of 

 the seventh transfer, the amount of indol produced by these 

 three strains was markedly less than at the beginning of the ex- 

 periment. This, coupled with the fact that the bacteria were 



