44 CHESTER A. STEWART. 



observed by Jackson ('15) for the empty tract (in controls at 

 body weight of 25.1 and 42.4 g.). This would indicate an 

 increase in the weight of the tract during maintenance, in agree- 

 ment with Jackson ('15). 



On refeeding, with the exception of the male refed four weeks, 

 the weight of the empty alimentary tract increased in relative 

 size, but remained below the Wistar norm in most cases. It was 

 higher in the refed rats than in the controls at the age of 16 weeks 

 (end of fourth week of refeeding). In the adult rats the weight 

 of the empty stomach and intestines was practically normal in 

 the test rats as compared with the controls, although below the 

 Wistar norm, especially in the males. 



The relative weight of the stomach and intestines including 

 contents (12.6 per cent.) in the two rats killed at the end of nine 

 weeks of maintenance averaged close to that observed by 

 Jackson ('15) in rats held at maintenance for seven weeks. This 

 is slightly higher than the normal relative weight (10.4 per cent.) 

 at three weeks, the beginning of the maintenance period. In the 

 female rats refed one week the tract and contents formed 16.2 

 per cent, of the body weight, as compared with 15.4 per cent, 

 noted by Jackson ('13) for normal rats of corresponding body 

 weight (50.4 grams net). At the end of four weeks of refeeding, 

 the relative weight of the stomach and intestines (13.5 per cent.) 

 for the test rats was considerably above that (9.0 per cent.) in 

 the controls. In the adult rats, the relative weight of the tract 

 and contents for the controls and test rats respectively was 6.0 

 and 6.3 per cent, in the males, and 8.5 and 8.8 per cent, in the 

 females. 



In general therefore it may be concluded that the stomach and 

 intestines including contents were heavier than normal for cor- 

 responding body weight at the end of the fasting period, but were 

 practically normal at the end of two weeks of refeeding, and 

 thereafter. Considerable allowance must be made for individual 

 variations, which probably account for the apparent increase 

 at the fourth week of refeeding. 



19. Suprarenal Glands (Table F.). 



The weight of the suprarenal glands in the male and female 

 rats killed after maintenance for nine wrecks exceeded Donaldson's 



