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 87° C. (98.6° F.), 
