MILK 367 



it will be seen that human milk contains less protein but 

 more lactose than cow's milk. 



The proteins are three in number — caseinogen, lactal- 

 bumin and lactoglobulin. It is the first which is precipi- 

 tated by rennet-ferment, being converted into casein and 

 leaving whey. 



Of inorganic salts, milk is rich in calcium and phosphorus 

 but is almost completely deficient in iron, the infant 

 apparently relying during suckUng upon the iron which is 

 present in high percentage in the liver. 



Immediately after parturition the gland secretes colos- 

 trum. This differs from milk in being a clear fluid con- 

 taining very little caseinogen. It coagulates on boiling, 

 and contains characteristic granular corpuscles which stain 

 with osmic acid. These are probably leucocytes. 



Interaction of the Female Sexual Organs 



The interaction between the uterus, ovary and mammary 

 gland may be thus summarised : — - 



In the first half of pregnancy the presence of the corpus 

 luteum determines, on the one hand, the hypertrophy of 

 the mammary gland, and on the other, the fixation and 

 early nutrition of the foetus through the formation of the 

 decidual cells. 



In the second half of pregnancy the foetus influences 

 the corpus luteum, and this in turn causes the further 

 development of the mammary gland. 



