THE LACTIC BACTERIA. 67 



few hours. Other variations are also found within the lim- 

 its of the same type, and the probability is that we have in 

 this list of species one organism, showing slight variations 



FIG. 13. 



Showing the action of different types of bacteria upon milk. , the aerobic type (B. 

 aerogenes); b, the anaerobic type {Bad. acidi lactici); c and d, the peptonizing type* 

 with the curd in different stages of digestion. 



as studied under different conditions in different localities 

 by different bacteriologists. Probably the best name to be 

 reserved for this species is Bacterium lactis acidi. 



Source of Bacterium lactis acidi. This microorganism 

 does not live in the milk ducts of the cow (40) . It was long 



