GROWTH AFTER INANITION FOR VARIOUS PERIODS. 35 



8. Viscera and "Remainder" (Table IV.}. 



The relative weight of the visceral group (including the ab- 

 dominal and thoracic viscera, spinal cord, brain and eyeballs) 

 in the rats killed at the end of the fasting period corresponds 

 closely with the weight (20.5 per cent.) found by Jackson ('15) 

 for the normal rat of three weeks. Concerning the visceral 

 group, Jackson noted during maintenance a distinct tendency to 

 increase in weight, which was more marked at six and eight than 

 at ten weeks. The fact that my rats fail to show an increase 

 in the relative weight of the visceral group probably is due to 

 their longer period of stunting, during which the liver especially 

 tends to decrease in weight. 



According to Jackson and Lowrey, the relative weight of the 

 visceral group is 21.3 and 20.4 per cent, of the body at three and 

 six weeks of age, the net body weight averaging 24.8 and 64.4 

 grams respectively. In my rats refed one week and less, the 

 relative weight of the viscera (Table IV.) in all cases formed about 

 20 per cent, of the body, thus being approximately normal. At 

 the end of two weeks of refeeding however the visceral group 

 appears exceptionally light, the relative weight being 17.7 per 

 cent, as compared with 20.4 per cent, given above for the normal 

 rat of about the same body weight (64.4 grams). After four 

 weeks of refeeding the viscera collectively were relatively heavier 

 in the test rats than in the controls, whereas in the adult rats 

 the weights are nearly identical in the test animals and con- 

 trols. 



In general it therefore appears that the relative weight of the 

 visceral group was about normal during the refeeding. A 

 considerable variation in the weight of the visceral group is not- 

 unusual. 



The weight of the "remainder" (Table IV.), which includes 

 some small unweighed organs, fat, and body-fluids, was obtained 

 by deducting the weight of the integument, skeleton, muscula- 

 ture, and viscera from the net body weight. The data show con- 

 siderable variation but it is doubtful whether there is any material 

 change from the normal during refeeding in the test rats. 



