STANDARD AGAR FOR ESTIMATION OF BACTERIA IN MILK 535 



they were all composed of organisms of the lactic acid type. A 

 large number were isolated and all were found to coagulate milk 

 rapidly and to acidify glucose and lactose broths without the pro- 

 duction of gas. Most of them were Gram negative bacilli, but 

 diplococcus types were isolated from several samples. 



TABLE 3 



A number of pure cultures of these organisms were tested on 

 the standard agar, and in every case it was found that visible 

 colonies would develop when the organisms were plated from an 

 emulsion in 1-100 sterile milk and that they would almost in- 

 variably fail to do so when plated from an emulsion in water. 



