480 Transactions of the Canadian Institute. [Vol. VII. 



noticed by Fokker,*^ and subsequently confirmed by Freudenreich,*^ and 

 quantitative studies of freshly drawn milk, inoculated with various 

 bacteria, show that an actual destruction of bacteria took place. This 

 germicidal property has been shown to exist in the milk-serum, and is 

 evidently allied to the similar bactericidal property of blood, for Brieger 

 and Ehrlich^^ and Wassermann*^ have found that the milk of immune 

 animals can confer immunity. 



If then, this germicidal power exists in fresh drawn milk, it is 

 certain to be present whilst the milk is still in the udder, and may 

 inhibit or prevent the rapid multiplication of adventitious bacteria, 

 which penetrate up the opening of the teat. Although we have fre- 

 quently found large numbers of lactic acid bacteria in freshly drawn 

 milk, yet the reaction of this milk is never acid. 



De Freudenreich*^ has also shown that the bactericidal power is not 

 the same for all species, that whilst the cholera vibrio, the typhoid 

 bacillus, and even B. Shafferi (a colon bacillus), are destroyed in large 

 numbers, the bactericidal action is less pronounced on lactic acid 

 bacteria. These facts may possibly explain why the germs of the colon 

 type are so seldom found in the healthy udder, for we know that the 

 teats and udder of the cow are constantly brought in actual contact with 

 particles of manure, and even the hands of the average milker are soiled 

 with stable filth, which undoubtedly contains colon bacteria. 



It might be reasonably asked if the advice, commonly given to 

 those who wish to procure milk as near sterile as possible, to milk the 

 first few streams in a separate utensil, is good. And in reply we would 

 say, decidedly yes, for not only is the number of bacteria in the fore- 

 milk much in the excess of the bacteria found in the rest of the milk, 

 but frequently the number of species found in the fore-milk is consider- 

 ably larger than that in the after-milk. {See Fig. 2). 



In reviewing the subject there can be no doubt that the number of 

 bacteria present in the milk as it exists before being drawn from the 

 udder is somewhat startling, and were nothing more than an enumera- 

 tion of the germs given, there might be some occasion for alarm. 



However, a systematic study of the germs proves that, with the 

 possible exception of rare cases, this source of bacterial life is much 

 more beneficial than baneful to the average consumer of milk and its 

 products. 



