92 Report of the Department of Bacteriology of tue 



present vary within wide limits. This is well illustrated by the 

 work of Hastings and Hoffmann. They obtained the following 

 results from a study of the freshly drawn milk from three cows: 



Name. 



Days 

 sampled. 



Average 

 per cc. 



Maximum 

 per cc. 



Minimum 

 per cc. 



Brownie 

 Dorine. . 

 Merney . 



61 

 33 



27 



31,000 



191,000 



810 



305,000 



3,500,000 



4,250 



1,700 



2,500 



50 



Two-thirds of these samples were taken from the pail at the 

 close of the milking, the remainder being taken at the middle of 

 the milking in sterile flasks. The variation in the method of 

 sampling did not seem to affect materially the observed germ 

 content. 



It has long been held that cleanliness in the stable would 

 influence favorably the germ content of udders but direct evidence 

 on this point has only recently been available. Atwood and 

 Giddings 10 tested the influence both of sealing the opening of the 

 teat so as to exclude all external contamination and of injecting 

 various substances into the milk cistern. Where the end of the teat 

 was treated with carbolized vaseline and covered with adhesive tape 

 the germ content was but little reduced. Where the cistern was 

 treated with chemicals there was first a reduction of germ content 

 but this was followed by a marked rise and accompanied by an 

 inflammation of the gland. 



PRESEXT STUDIES. 



These studies of the normal flora of cows' udders have extended 

 over a considerable period. During 1900-02 examinations were 

 made of the strippings from 17 cows. At each examination 

 samples were taken from each quarter of the udder and 324 sam- 

 ples were studied. These examinations were made, for most part, 



9 See footnote 1. 



io Atwood, H., and Giddings, X. J. Experiments in tlie production of sani- 

 tary milk. W. Va. Agr. Exp. Sta. Bui. 134. 1911. 



