668 APPLICATION OF METHODS OF BACTERIOLOGY 



methylene-blue. In this manner practically all the sediment 

 derived from one cubic centimeter can be obtained on the 

 cover-slip and a fairly satisfactory estimate can be made of 

 the relative number of pus cells in this quantity of milk as 

 well as at the same time an estimation of the relative number 

 of streptococci. 



Milk that shows pus cells along with distinct chains of 

 streptococci, either extra- or intracellular, is usually regarded 

 as dangerous in character, and boards of health usually 

 direct that the cows from which such milk is derived be 

 excluded from the dairy until such time as the milk is free 

 from these elements. 



