184 PRACTICAL DAIRY BACTERIOLOGY 



The value of a microscopic study may be somewhat increased 

 by a careful examination of the types of bacteria found, since 

 the presence of inflammation is accompanied by Streptococci 

 in the milk. But, as we have already seen, Streptococci are 

 practically always present in milk, it being almost impossible 

 to draw milk from the most healthy cow without these bacteria 

 getting into the milk. The presence of Streptococci in milk 

 can, therefore, not be considered as meaning much of anything. 

 The ordinary Streptococci of milk, however, are commonly not 

 found as long chains but as isolated spheres, or in pairs. The 

 pus forming cocci frequently grow in long chains. If, there- 

 fore, in a microscopic study there appear many long chains of 

 Streptococci, this again may render the milk suspicious. 1 



In short, if in making a microscopic examination, as described 

 in experiment No. 17, the number of bacteria per field appears 

 to be more than from 40 to 50, or if the number of leucocytes is 

 more than 50 per field, or if there appear many long chains of 

 Streptococci, the milk must be regarded as suspicious, requiring 

 further study, or, perhaps, an investigation of the dairy where 

 it was produced. 



DAIRY INSPECTION 



During the last few years there has been an increasing 

 recognition of the value of public dairy inspection. This plan 

 though first suggested some 12 years ago in this country was 

 first adopted by some of the large dairy companies in Europe. 2 

 In more recent years its value has been recognized, and the 

 practice has been slowly but surely extending until at the 

 present time it has become quite common in certain sections of 

 the country. Five years ago a dairy inspection was scarcely 

 known in the United States, but some of the larger dairy com- 

 panies began first to organize a system of inspection of the 



1 Briining. Exper. Sta. Rec., xvii., p. 496, 1905. 



Kaiser. Arch. f. Hyg., Ivi., p. 51, 1906. 

 2 Conn. Ann. Rep. of Ct. Bd. of Agri., 1895. 



