EFFECTS OF INANITION UPON ORGANS OF RAT 91 



VISCERA AND REMAINDER 



The average for the total visceral group in the normal adult 

 rat, according to Jackson and Lowrey ('12; based upon only a 

 few observations) is about 13.3 per cent of the body weight. 

 In the acute nanition series (table 3; fig. 2) the average found 

 is 11.1 per cent; while n the chronic series it is 13.4 per cent. 

 This would seem to indicate that the loss in weight is relatively 

 greater in acute than in chronic inanition. As a matter of fact, 

 the great majority of the individual organs, as will be seen later, 

 show a greater relative loss during chronic inanition. The liver 

 and spleen are exceptions, however, and the large bulk of the 

 former overbalances the other viscera when all are grouped 

 together. On the whole, there is not much change in the relative 

 weight of the visceral group ; but there is, however, much varia- 

 tion among the individual organs, as will be seen later. 



Aron ('11) states that the organs lose more than the muscula- 

 ture during inanition in dogs. Data by Voit ('05 b) show a de- 

 crease in the relative size of the viscera in the rabbit, but not 

 much change in the dog. 



The 'remainder' is the amount obtained by substracting from 

 the net body weight the weight of the skin, skeleton, muscula- 

 ture and visceral group. It includes the loss by evaporation and 

 escape of liquids, a few small unweighed organs, and the dissect- 

 able masses of fat. In the normal adult rat, the 'remainder' 

 forms about 13 per cent of the body weight (Jackson and Lowrey 

 '12). In the chronic inanition series, the average is 9.4 per 

 cent. In the acute series the average is 7.3 per cent. The de- 

 crease in the relative weight of the 'remainder' is probably due 

 chiefly to loss of fat. 



BRAIN 



The average for the brain in the acute inanition series (table 

 1) is 1.18 per cent of the body weight. By means of the tables 

 and curves constructed by Donaldson ('09), the (theoretical) 

 normal weight of the brain can be derived, corresponding to any 

 given body weight. This gives an average of 0.78 per cent for 

 the assumed normal weight of the brain at the beginning of the 



THE AMERICAN JOURNAL OF ANATOMV, VOL. 18, NO. 1 



