72 



Report of the Department oe Bacteriology of the 



and flanks of these cows were then clipped with an ordinary power 

 clipper and the germ content of their milk determined for six suc- 

 ceeding days. An effort was made to keep all of the barn operations 

 as constant as possible during the test. The dilutions employed 

 in making the plates were 1 to 5, 1 to 10 and 1 to 25. Six plates 

 were made from each sample and the plates were counted after 

 five or six days at room temperature. The results of these counts 

 are given in Table X. 



Table X. — Germ Content Before and After Clipping Udder and Flank. 



The results from this preliminary observation are not conclusive. 

 On the basis of the grand averages it shows that clipping increased 

 the germ content of the milk, but an inspection of the detailed results 

 shows that a majority of these germs were obtained from Hammond F. 

 on November 10. If this observation were omitted the balance would 

 be in favor of clipping. On the other hand there was nothing in 

 the plate growth from the sample of November 10 to indicate that 

 contamination had occurred. 



A more extensive test of the influence of clipping cows upon the 

 germ content of the milk obtained from them was undertaken. 

 Between February 29 to March 29, 1912, 22 samples were collected 

 in the regular way from the milk of each of four cows. Four plate- 



