New York Agricultural Experiment Station. 89 



the increasing emphasis which is being laid upon the germ content 

 of milk the germs in the cow's udder are becoming more and 

 more an important factor. They are especially important in 

 the production of " certified '' milk, and the small number of 

 germs found in the product of some " certified " dairies is 

 made possible by the selection of cows having few germs in 

 their udders. 



The problem of producing milk with a low germ content at a 



moderate cost is being studied at this Station. While the presence 

 of bacteria in the udders of healthy cows has been recognized for 

 some time there is very little information regarding the normal 

 flora of udders and less regarding the forces which regulate the 

 growth of the forms which are present. A beginning has been 

 made on this phase of the subject by examining 1,274 samples 

 of milk representing 83 cows. A continuation of these studies 

 along a number of lines which have as yet been hardly touched is 

 much to be desired. The removal of each of the authors to other 

 institutions makes necessary the publication of the results thus far 

 obtained even though the entire field has not been covered. 



acknowledgments. 



The careful collection of this large number of milk samples 

 would have been much more difficult but for the active coop- 

 eration of our colleague, Mr. G. A. Smith, and the men in 

 his department who willingly placed all the facilities of the 

 barn and the dairy at our disposal and actively assisted in the 

 work. 



The kindness of Mr. A. G. Lewis in assisting us to obtain udder 

 samples from a large number of cows, many of them recently 

 imported from the Island of Guernsey, materially broadened the 

 investigation. 



Acknowledgment should also be made of the sua-o-estions and aid 

 given by Dr. R. S. Breed, while he was engaged in a study of 

 the cellular elements in the milk of many of the same cows whose 

 udder flora was being determined. 



