268 



CLEAN MILK 



Note : All media should be kept for use in a dark, cool, dust- 

 free place, i. e., a refrigerator or ice-chest. 



Fig. 67. 



Filling test tubes with a measured amount of culture medium. 

 (After Conn.) 



Note : These methods are those of the Committee on Standard 

 Methods of Water Analysis of the American P'ublic Health As- 

 sociation, except as follows : 



