208 THE CREAMERY PATRON'S HANDBOOK. 



duplicated his work on twenty-three other cows, and found they secreted 

 on an average of 138,200,000 fat globules per second. Collier also recog- 

 nized the fact that milk contains ingredients that must be the result of 

 some special activity, as the casein and milk sugar are not present in the 

 blood, and the fat only in traces, thus precluding the possibility of being 

 derived by transudation. A good cow may produce two and a half kilograms 

 of albuminoids, fat and sugar, (five pounds) . The weight of the total solids 

 of a gland producing that amount of milk solids is only about 1.16 kilograms 

 (two and one-fourth pounds) which would necessitate a complete renewal 

 of tissue 2.09 times a day. He might have added that the epithelial cells 

 constitute only a small part of the gland structure, and it would therefore 

 require even more rapid renewal. This would require an almost incredible 

 cell growth, so that we are forced to assume that although the growth and 

 disappearance of certain cells is of the greatest importance, the organic 

 substances in milk are modified from substances in the blood and lymph 

 into the forms we find them in milk, by the functional activity of the cells. 

 The estimates upon the rate of cell multiplication as made by Dr. Collier 

 are only approximate, but are certainly near enough to the truth to warrant 

 drawing the conclusion that fat is not the result of fatty degeneration of 

 the cells. In fact such a process is incompatible with our knowledge of 

 the physiology of cell reproduction or disintegration. 



Soxhlet has recently advanced the theory 1 that milk is the result of 

 the disorganization of tissues, either as according to Voit, of the milk glands 

 themselves or, according to Rauber, of the white blood corpuscle. Thus 

 according to Soxhlet the constituents of food cannot be directly converted 

 into components of milk, but must first be used for the construction of 

 some tissue and afterwards be decomposed and then utilized in the produc- 

 tion of milk fat. A normal butter fat could then be produced by food de- 

 void of fat, and feeding any kind of food devoid of fat although rich in fat form- 

 ing constituents, would not have the effect of changing the character of the 

 milk fat present in mrlk. Abundant feeding with nutritive but non-fatty 

 foods, could only increase the percentage of decomposing milk tissue. 

 Carbohydrates could contribute to the body fat, but not to the milk fat, 

 because they contribute nothing to the milk producing tissues, but on the 

 contrary, when fed in conjunction with food poor in protein, they diminish 

 the milk fat because the total diminishes the amount of nitrogenous food, 

 that is, substances which produce tissue. It is only fat 'in food which renders 

 the exclusive increase of milk fat possible, by causing a migration of body 

 fat to the milk. 



A close examination of the theory, and the explanation given by 

 Soxhlet, shows that it explains many phenomena that could not be explained 

 by the transudation or cell disintegration theories. It must be admitted 



1 Journal Royal Agricultural Society, 3d Ser., Vol. Ill, pp. 655-662. 



