MILK 



335 



The secretion of the mammary glands of the newborn of both sexes 

 is called "witches' milk." The name is centuries old and evidently 

 refers to the mystery of the useless secretion. Bj-isch 1 has recently sug- 

 gested that this secretion of "witches' milk" is brought about by the 

 passage of hormones (see Chapter on Pancreatic Digestion) from the 

 blood of the mother to the fetus. 



!j v FIG. 109. LACTOSE. 



Lactose, the principal carbohydrate constituent of milk, is an impor- 

 tant member of the disaccharide group. It occurs only in milk, except 

 as it is found in the urine of women during pregnancy, during the nurs- 

 ing period, and soon after weaning; it also occurs in the urine of normal 

 persons after the ingestion of a very large amount of lactose in the food. 

 It is not derived directly from the blood, but is a specific product of the 



1 Basch: Munch, med. Woch., 58, 2266, 1911. 



