86 Report of the Department of Bacteriology of nit: 



From the results of an extended study of the udder content of this 

 same group of cows, it was concluded that the udder content was 

 responsible for an average count of about 500 per cc. When allow- 

 ance is made for this udder factor it will be seen that there is only 

 a small germ count in the milk remaining to be accounted for as 

 contamination from the outside of the cow and the barn air. 



Since these counts were practically all made of the milk at the 

 close of the milking process and the germ counts with which the 

 public are familiar are those of the milk as ready for the market, 

 it may be assumed that the after handling would bring the germ 

 content of this milk up to much higher figures. The results on page 

 230, from the 85 samples taken at various stages in its later handling 

 do not support this idea. 



Low counts in milk studies are frequently due to the technique 

 employed in their determination. In the present work the technique 

 has been given in detail. The possibility of the influence of accidents 

 in media making are fairly eliminated, since the low counts are dis- 

 tributed through a study lasting a number of years. On a number 

 of occasions the possible inhibitory influence of the media was tested 

 by using media prepared at the same time in determining the germ 

 content of these experimental samples and of samples of milk obtained 

 from other sources. In all cases the counts from the milk from 

 commercial sources were high while the experimental samples re- 

 mained low. 



There seems to be no escape from the conclusion that the germ 

 count of these samples was low, simply because the samples did not 

 contain many germs which were capable of growing in the media 

 ordinarily employed in such studies even when unusual care was exer- 

 cised in stimulating their growth. 



This milk was produced under general conditions which appear 

 to be no better than those surrounding a considerable number of 

 the ordinary city dairies, conditions which probably would not be 

 acceptable to any certified milk commission. Notwithstanding these 

 facts the extended study of the product indicates that in bacterial 

 content at least it is of the very highest quality. That milk of 

 this quality is not uniformly produced under such general conditions 

 is illustrated by the fact that a local commercial dairy in which 

 the methods and equipment resemble that at the Experiment Sta- 

 tion, except that steam is not available for treating the utensils 



