352 VETERINARY PHYSIOLOGY 



cheese it is undoubted that, under the influence of micro- 

 organisms, proteins are changed to fats. (2) In all proba- 

 bility the same thing occurs in the formation of the fatty 

 adipocere in the muscles of the dead body during putrefaction. 

 (3) At one time it was supposed that, under the influence of 

 such poisons as phosphorus, the proteins of the cells of the 

 mammalian tissues are changed to fat. But careful chemical 

 examination has shown that the so-called fatty degeneration 

 is due to accumulation of already existinsf fats in the 

 affected organs. (4) If a dog be fasted till all the fat of the 

 body is used up, and then fed on lean beef, it will lay on fat. 

 But analysis of such beef shows that it contains enough fat 

 and glycogen to yield all the fat laid on. 



At present we have no direct evidence that the fats of 

 the body are formed from proteins, although the facts (1) 

 that carbohydrates are formed from proteins (p. 354), 

 and (2) that fats are formed from carbohydrates, make 

 it possible that proteins may be a source of fat, but that 

 their specific djmamic action prevents the fat from accumu- 

 lating. 



(2) In the Liver- — In some animals, e.g. the cod and the 

 cat, fats are largely stored in the liver. 



(3) In Muscle. — The salmon stores fats ivithin its muscle 

 fibres ; but in mammals such a storage is very limited in 

 amount, although large amounts may be deposited between 

 the bundles of fibres (p. 874). 



2. Proteins may, to a small extent, be stored in muscle, 

 especially after a fast or a prolonged illness, and during rapid 

 growth a suckling animal nia}^ store more than 40 per cent, of 

 the protein of the mother's milk. But in the normal mammal 

 it is difficult to induce such a storage, except in athletic 

 training, where the muscles may be enormously increased by 

 the building up of the protein-derivatives of the food into 

 their protoplasm. 



3. Carbohydrates are stored to a small extent in the liver 

 and in muscle (p. 354). Probably, at most about 10 per 

 cent, of glycogen occurs in the liver and 1 per cent, in 



