32 CHESTER A. STEWART. 



The relative weight of the trunk (Table IV.) averaged 54.5 

 per cent, in the rats killed at the end of the maintenance period, 

 which corresponds closely with the weight (54.1 per cent.) 

 observed by Jackson for the trunk in normal rats at three weeks. 



At the end of two weeks of refeeding the trunk formed an 

 average of 62.7 per cent, (sexes combined) in the rats weighing 

 72.8 grams, as compared with 63.2 per cent, noted by Jackson and 

 Lowrey in normal rats at 79.2 grams net body weight. 



In the rats re fed four weeks, and also in the adult test rats, the 

 relative weight of the trunk was practically normal as compared 

 with the controls. 



The results concerning the different parts of the body there- 

 fore fail to show any decided deviation from the normal propor- 

 tions throughout refeeding after various periods of maintenance. 



5. Integument (Table IV.). 



Jackson ('15) observed that the relative weight of the integu- 

 ment in rats held at maintenance from three to ten weeks of age, 

 decreased from an average of 21.9 per cent, to 14.5 per cent, of 

 the net body weight. The data for my rats show likewise a low 

 relative weight for the integument (average of 16.0 per cent.) 

 in rats held at maintenance for nine weeks. 



At the end of the first half week, and first week of refeeding 

 the relative weight of the integument was still unusually low in 

 the test rats, although an increase is apparent in the females 

 refed one week. During the second week of refeeding the in- 

 tegument rapidly recovered the loss suffered during inanition, 

 forming over 20 per cent, of the body. This average is close to 

 the normal at corresponding body weight found by Jackson and 

 Lowrey ('12). In the rats refed four weeks, and also in the 

 adult test animals the integument was relatively slightly heavier 

 than in the controls of the same age. The difference, however, 

 is probably insignificant. 



It therefore appears that on refeeding the integument rapidly 

 recovers the loss suffered during maintenance, reaching the 

 normal proportions within the first two weeks, and remains prac- 

 tically normal at all subsequent periods. 



