416 TOKUYASU KUDO 



ingly variable. And yet the atrophy in both acute and chronic 

 tests is so profound that the results are unquestionable. 



Of previous investigators, only Falck and Scheffer ('54) record 

 an apparent increase of 9 per cent in the weight of the spleen in 

 a dog on dry diet (loss in body weight, 20.7 per cent). Bowin 

 ('80) found a decrease in both absolute and relative weight of 

 the spleen in dogs and rabbits with loss of about 50 per cent in 

 body weight. In three dogs, after experimental diarrhea (with 

 loss of 22.4 to 29.8 per cent in body weight), Tobler ('10) found 

 a loss of 32.5 to 75.9 per cent in the weight of the spleen. 



In albino rats, after inanition with water, Jackson ('15) noted 

 an average loss of 51 per cent in the spleen in the acute series 

 (body weight, —33.9 per cent) and of 29 per cent in the chronic 

 series, (body weight, —31.1 per cent). He cites similar results 

 by numerous observers in man and various animals subjected to 

 inanition with or without water. It thus appears that profound 

 atrophy of the spleen is not characteristic of thirst, but usually 

 appears also in inanition with or without water. As an effect of 

 vitamine-deficient diets, a marked atrophy of the spleen has been 

 observed by McCarrison ('19) in pigeons, and a less marked 

 atrophy in monkeys. 



Lungs 



The characteristic pathological changes due to lung infection 

 were rarely observed in my test rats, although slight infection 

 is probably responsible in part for the abnormally high weight in 

 the controls (table 1). The average weights (table 2) show an 

 apparent loss of 44 per cent in the weight of the lungs in the 

 acute-thirst series, and of 51.5 per cent in the chronic-thirst 

 series. In the rat (Si. 2) after total inanition the corresponding 

 apparent loss is 52.7 per cent. If, however, the normal weight 

 of the lungs given by Donaldson ('15) be taken for comparison, 

 the loss of weight in the lungs of the test rats would be only 

 about 16 and 22 per cent, respectively, in the acute- and chronic- 

 thirst series. 



Of previous observers on the effects of thirst, Falck and Scheffer 

 ('54) noted an apparent loss of 26.9 per cent in the weight of 



