636 MILK. 



containing iodine was unchanged iodized fat of the food. The investi- 

 gations of SPAMPANI and DADDI, PARASCHTSCHUK, GOGITIDSE and others 

 on the passage of foreign fats into the milk also indicate the passage 

 of the fat of the food into the milk, although we are still uncertain on 

 this point. According to SOXHLET the fat of the food does not pass into 

 the milk directly, but is destroyed in place of the body-fat, which then 

 becomes available and is, as it were, pushed into the milk. HENRIQUES 

 and HANSEN could not detect any mentionable quantity of linseed-oil 

 in the milk after feeding with this oil ; the milk-fat was not normal, but 

 had a higher iodine equivalent and a higher melting-point, from which 

 they also concluded that a transformation of the food-fat in the glandular 

 cells is possible. The results of the experiments of GOGITIDSE 1 with 

 soaps also indicate that the mammary glands have the property of form- 

 ing fats by synthesis from their components. As a formation of fat from 

 carbohydrates in the animal organism is at the present day considered as 

 positively proven, it is likewise possible that the milk-glands also produce 

 fats from the carbohydrates brought to them by the blood. It is a well- 

 known fact that an animal gives off for a long time, daily, considerably 

 more fat in the milk than it receives as food, and this proves that at least 

 a part of the fat secreted by the milk is produced from proteins or carbo- 

 hydrates, or perhaps from both. The question as to how far this fat 

 is produced directly in the milk-glands, or from other organs and tissues, 

 and brought to the gland by means of the blood, cannot be decided. 



The origin of milk-sugar is not known. MUNTZ calls attention to the 

 fact that a number of very widely diffused bodies in the vegetable king- 

 dom vegetable mucilage, gums, pectin bodies yield galactose as a 

 product of decomposition, and he believes, therefore, that milk-sugar 

 may be formed in herbivora by a synthesis from dextrose and galactose. 

 This origin of milk-sugar does not apply to carnivora, as they produce 

 milk-sugar when fed on food consisting entirely of lean meat. The 

 observations of BERT and TniERFELDER 2 that a mother-substance of 

 the milk-sugar, a saccharogen, occurs in the glands, does not explain 

 the formation of milk-sugar, as the nature of this mother-substance 

 is still unknown. As the animal body has undoubtedly the power 

 of converting one variety of sugar into another, the origin of the 

 milk-sugar can be sought simply in the dextrose introduced as food or 

 formed in the body. Certain observations indicate such an origin, among 

 others those of PORCHER, who found that dextrose appeared in the urine 

 after delivery when the mammary glands of the goat had previously been 



1 Spampani and Daddi, Maly's Jahresber., 26; Henriques and Hansen, ibid., 29; 

 Gogitidse, Zeitschr. f. Biologie, 45, 46, and 47. See also Basch, Ergebnisse d. Physiol., 

 2, Abt. 1. 



2 Miintz, Compt. rend., 102; Bert and Thierfelder, footnote 1, p. 611. 



