1 86 MILK AND THE PUBLIC HEALTH chap. 



The strains A to J are essentially differentiated by their 

 fermentation characters. They all ferment glucose and lactose, 

 and as regards the others their characters are as follows : — 



When the results are worked out in percentages, as shown 

 in the above tables, it is possible to compare results. 



The essential differences between MacConkey's human and 

 animal excreta figures are the much greater prevalence of 

 strain B in human excreta, and the much more numerous 

 strain E in the animal excreta. Orr's results show the much 

 greater prevalence of B. lactis aerogenes in milk as compared 



