1294 



PHYSIOLOGY 



We should expect that the milk, which is the sole food of the growing infant, 

 should contain a relatively greater proportion of protein than is necessary in the case 

 of the adult. In an experiment by E. Peer, quoted by Bunge, a child weighing 8226 grm. 

 at the thirtieth week took 951 grm. of milk. Human milk contains : 



Protein 



Fat . 



Sugar .... 



Ash . 



The child was therefore receiving daily : 



Protein 



Pat . 



Sugar .... 



Ash 



1-6 per cent. 

 3-4 

 6-1 

 ,0-2 



15-2 grm. 

 32-3 



58-0 

 1-9 , 



According to the same proportions a man of 70 kilos, would take in : 



Protein 

 Fat . 

 Sugar . 

 Ash 



129 grm. 

 275 

 494 

 16 , 



It is interesting to note that the protein of this diet differs but little from that in 

 the diets ordinarily accepted as standard, but there is a large excess in the fat and in 

 the total caloric value, as would be expected from the more rapid metabolism and the 

 relatively larger body surface of the young child. 



The fitness of caseinogen for building up the tissues of the body is evident 

 when we compare, as in the Table on page 89, the products of its hydrolysis 

 with those of all the proteins in other foodstuffs. It will be seen that 

 practically every amino-acid and allied substance employed in the building 

 up of the various proteins is represented in caseinogen. The only exception 

 is glycine, which can be easily formed from other amino-acids. 



In another point we find an adaptation of the milk to the growth of the 

 young animal, and that is in its lecithin content. Lecithin is probably 

 employed to the largest extent in the building up of the central nervous 

 system, where it forms the most important constituent of the medullary 



