MILK AND ITS PRODUCTS 163 



for this rich development of germs is found in the favor- 

 able conditions provided by the milk in the milk-ducts of 

 the teats, to which the bacteria find ready access. 



Flies. Flies not only constitute a prolific but also a 

 dangerous source of milk contamination. These pests 

 visit places of the worst description and their presence 

 in a dairy suggests a disregard for cleanliness. Of 414 

 flies examined by the 'Bacteriologist of the Connecticut 

 Station, the average number of bacteria carried per fly 

 was one and a quarter millions. Flies should be rigidly 

 excluded from all places where they are apt to come in 

 contact with the milk. 



Experimental Data. To show to what extent the 

 bacterial content of milk may be reduced by adopting 

 the precautions suggested in the foregoing pages, a few 

 experimental data are herewith presented. 



In Bulletin No. 42 of the Storrs (Conn.) Experiment 

 Station, Stocking reports the following : 



1. When the cows were milked before feeding the 

 number of bacteria per c. c. was 1,233; when milked im- 

 mediately after feeding, the number of bacteria was 3,656, 

 or three times as many. 



2. When the udder and flanks of the cows were wiped 

 with a damp cloth, the number of bacteria per c. c. was 

 716; when not wiped the number was 7,058, or ten times 

 as great. 



3. When the cows were not brushed just before milk- 

 ing the number of bacteria per c. c. was 1,207; when 

 brushed just before milking, the number was 2,286, or 

 nearly twice as great. 



4. When students who had studied the production of 

 clean milk did the milking, the number of bacteria per 

 c. c. was 914; when the milking was done by regular 



