THE COLON GROUP OF CACILLI 139 



tory Section of the American Public Health Associa- 

 tion at its Washington meeting in September, 1912, 

 by the adoption of a resolution recommending deter- 

 minations of numbers at 20 and 37 and the lactose 

 bile presumptive test as the standard routine procedure 

 in water examinations. The detailed study of particular 

 types of the colon group may, of course, be important, 

 in special cases; but the lactose bile test is sufficient 

 for general sanitary purposes. 



