90 MILK [vi 



principle. This is probably the case only when the 

 bitter taste is present in the milk immediately after 

 milking; when it is developed only after standing 

 for some time, it is due to some other cause. In 

 such a case the cure is obviously to change the 

 feeding. It may be yielded by cows which have 

 been a long time in milk, and in such a case it is 

 due to imperfect secretion of the milk in the milk- 

 glands. Lastly, it may be due to inflammation of 

 the udder. 



The older theory that bitter milk is always 

 accompanied by the production of butyric acid has 

 not been shown to be absolutely correct ; for, while 

 it is at times associated with the production of 

 butyric acid, it is also found to be produced by 

 organisms which do not produce butyric acid. There 

 are quite a number of species of bacteria which 

 effect this result, and it would seem that in all cases 

 the bitter flavour of the milk is independent of 

 butyric acid. Some of these organisms resemble in 

 their appearance the proteus vulgaris. To what, 

 precisely, the bitter taste is due is not as yet known. 

 One theory is (Hueppe) that it is connected with 

 the decomposition of the albuminoid matter of 

 milk, and with the production of peptones; and it 

 is to these peptones and similar products that the 

 bitter taste may be ascribed/ The fact that these 

 bacteria chiefly belong to the casein group of ferments, 





