66 Elements of Water Bacteriology. 



consider the standardization of methods for the Bac- 

 terioscopic Examination of Water (1904), recommended 

 the body temperature count as a standard procedure; 

 the American Committee on Standard Methods of Water 

 Analysis (1905) failed to adopt this method in its last 

 report. It is to be hoped that it will see fit to do so in 

 the future; and meanwhile individual bacteriologists wiU 

 find it of much service in supplementing the 20-degree 

 determination on gelatin. Under ordinary conditions it 

 is clear that organisms growing at the body temperature 

 and those fermenting lactose are not numerous in normal 

 waters. The absolute count at 37 degrees seldom exceeds 

 50, and is rarely over 10 per cent of the 20-degree count, 

 except after hot periods in the late summer; acid pro- 

 ducers are generally entirely absent. On the other hand, 

 the numbers on the htmus-lactose-agar plate wiU be 

 likely to run into hundreds with a good proportion of red 

 colonies when polluted waters are examined. 



