WHY cow's MILK? 51 



— entirely removes it from the digestive capacity 

 of the human species. So, too, in the case of the 

 elephant, whose milk contains more than five times 

 the fat contained in human milk. On the other 

 hand, the milk of the mare and the ass are deficient 

 in fat, though the milk of both animals has been 

 more or less extensively used as a food in some parts 

 of the world,' and the milk of the ass is even used 

 occasionally in this country as a food for very feeble 

 infants.' Now, the principal animals whose milk 

 has been used by mankind for food are the cow, 

 the goat, the sheep (ewe), the ass, the camel, and the 

 reindeer. Most of these would have been selected 

 from the foregoing table of analysis by any layman 

 called upon to select those which in their composition 

 most nearly resembled human milk. 



Let us, then, take the milks of these species and 

 compare them a little more closely with reference 

 to their food values. As we have seen in an earlier 

 chapter, the important task before the man of science 

 is to find some substitute for breast milk which 

 closely resembles it ; something that wiU make blood, 

 tissue, muscle, bone, and nervous energy in as nearly 

 as possible the same manner as mother's milk. In 

 analyzing the food values of the principal domestic 

 animals and comparing them with human milk, we 

 are taking the first important step toward the solu- 

 tion of our problem. 



