IX 



of lactose would have, as this sugar is not reduced by 

 B. typhosus, at least by none of the strains used by us. 

 From Table XI it is seen that in a y 2 % lactose bouillon 

 of different acidity and alkalinity, the power of B. coli to al- 

 ter the colour is much weakened, (compare Table I, normal 

 bouillon) but at the same time the power of B. typhosus to 

 alter the colour has increased very considerably, so that 

 in the course of a few days the colour of the tubes of 

 B. typhosus and B. coli has become almost the same. 



21 



