MILK 43 



tain investigators have reported that complement is 

 always present in milk from apparently normal cows. 



The quantity of antibodies in the milk compared with 

 the quantity circulating in the blood is not definitely 

 known. The question has been more extensively studied 

 in connection with antitoxins than with the other anti- 

 bodies, and it was found that the milk contains only one- 

 thirtieth to one-fifteenth of the quantity of antitoxin 

 circulating in the blood. Agglutinins may be present 

 in the milk in the same quantity as in the blood, or in 

 greater or less amount. The immunizing value of the 

 milk has not been completely determined. It has been 

 demonstrated that antibodies in milk ingested by suck- 

 lings are absorbed through the intestines into the blood 

 when the suckling and the animal from which the milk 

 is obtained are of the same species. There is no direct 

 evidence, however, that the antibodies are absorbed into 

 the blood of the young animal when the milk is from a 

 different species, as when a child ingests cow's milk, al- 

 though many observations have been made which indicate 

 that antibodies are absorbed under such circumstances, 

 if only to a limited extent. It would therefore appear 

 that antibodies in cow's milk are of more value to the 

 calf than to a child ingesting such milk. The absorption 

 of antibodies from the intestines is greatest during the 

 first few days after birth and decreases with age. In 

 older animals, the antibodies are split up by digestion 

 like other proteids. 



Germicidal Action of Milk. Milk from cows in normal 

 condition always contains antibodies which destroy many 

 of the bacteria commonly present in milk. The intensity 

 and duration of this germicidal action varies with the 

 temperature. If the milk is kept at 37 C. (98.6 F.), 



