702 



REPRODUCTION AND GROWTH 



of woman's milk is 34 C., the congealing point, 20 C., and its specific 

 gravity 0.966. 



The most important carbohydrate of milk is milk sugar (cf. page 81). 



Bunge has made the very remarkable observation that in dogs and rabbits 

 the mineral constituents are present in the same relative proportion as in the 

 ash of newborn animals, while the percentage composition of the ash of 

 the blood and blood serum are quite different (cf. the following table). 



This agreement is wanting, however, when we compare the composition 

 of human milk with that of the ash of the human infant, as the following 

 summaries of observations by de Lange, Hugonenq and Soldner will show. 



Bunge refers this striking difference to the circumstance that the com- 

 position of milk ash agrees more closely with that of the ash of the young, 

 the more rapidly the animal grows in weight after birth, pointing out that 

 it is only by means of such an agreement that it would be possible for the 

 rapidly growing animal to get every necessary mineral constituent in the 

 proper proportion for its growth. In the slowly growing human infant this 

 agreement is not necessary. But it is important that those constituents of 

 the ash that serve to keep the composition of the urine normal should be 

 supplied ; hence the woman's milk is found to contain relatively more alkaline 

 chlorides than the dog or rabbit milk. 



In support of this view, Bunge compares the percentage composition of 

 milk in tissue-forming substances, proteid and ash (calcium and phosphoric 

 acid) in rapidly and slowly growing animals. It will be observed from the 

 following table that these percentages are much higher in the former than in 

 the latter. 



