Occurrence of Fat. 411 



avers and on rabbits killed by starvation. Fat is present in the 

 epithelium of. the human lachrymal glands, pancreas, suprarenal, 

 thyroid, and testis.*^ Fat is present in the rabbit in the organs just 

 mentioned and in the liver and kidney. The marasmic condition in 

 man does not affect the intraglandular fat, though the connective 

 tissue fat may be greatly reduced. 



In rabbits which have died of starvation, the fat in the epithelium 

 is not lessened in quantity, though the cells be reduced to half their 

 normal volume, and the connective tissue fat depots almost com- 

 pletely emptied. Traina concludes that there is no connection between 

 the nutritive condition of the individual and the intraepithelial fat. 

 He regards this fat as a constant and integral constituent of the 

 cell protoplasm and considers it analogous to cell pigment. It is 

 not stored energy to protect the body from starvation as is the fat 

 deposited in the connective tissues. 



Significance of fat deposited in epithelium, cartilage, and muscle. 



Walbaum (37) showed that fat in the muscle fibers in children 

 is not directly connected with the nutritive condition of the indi- 

 vidual. Erdheim showed that the same is true of the fat in the 

 cells of the thyroid. Traina showed that practically all intraepi- 

 thelial fat is unaffected by malnutrition and starvation.^ 



My conclusions are essentially in accord with those of Traina. 

 The fat occurring in the epithelial tissues and in the cartilage 

 seems to be in no way connected with the nutritive condition of the 

 animal. It is neither removed by starvation nor increased by exces- 

 sive fattening. It is certainly not food stored to protect the body 

 against starvation as is the fat in the adipose tissues. It is not even 

 used by the cell in which it is deposited, since the cell may undergo 

 great atrophy without appreciable diminution of the fat content. 



Fat is not present in the muscle fibers of adult cattle under normal 

 conditions, but fine fat droplets appear in the later stages of atrophy 

 caused by a prolonged submaintenance ration. There is no evidence 



"The liver and kidney were not normal in his cases. 



'Traina believes, however, that a part of the fat in the liver is tem- 

 porarily deposited. He did not work on the kidney. 



