408 TOKUYASU KUDO 



In my chronic- thirst series the loss in body weight is remark- 

 ably greater than in acute thirst. The average body weight for 

 the seven test rats (tables 1 and 2) shows a loss of 52.4 per cent 

 (range, 50.6 to 60.2 per cent). The loss in body weight in this 

 chronic-thirst series is also markedly greater than that obtained 

 in albino rats in chronic inanition with water by Jackson ('15), 

 which averaged 36.1 per cent (extreme 37.5 per cent) in five 

 weeks. In a dog, given water only, Kumagawa ('98) observed 

 a loss of 56 per cent in the body weight in ninety-eight days. As 

 the result of a dry diet, Bowin ('80) obtained a loss of 50 per cent 

 in the body weight of dogs and rabbits; Scheffer ('52) a loss of 

 45.8 per cent in pigeons; and Pernice and Scagliosi ('95) a loss up 

 to 41.2 per cent in chickens. In rabbits, Skoritschenko ('83) 

 noted very irregular losses in body and organ weights. In the 

 acute thirst of experimental diarrhea, however, Tobler ('10) pro- 

 duced the death of dogs in three and one-half to seven days, with 

 loss of only 22 to 30 per cent in body weight. 



In the present experiments there is no constant relation between 

 the percentage loss in body weight and either the initial body 

 weight or the length of the thirst period. However, in each case 

 the loss in body weight during acute thirst is greater during the 

 first half than during the second half of the experiment. As 

 might be expected, the loss during thirst is invariably the great- 

 est on the first day, as found by numerous investigators in vari- 

 ous animals and types of inanition. This is probably due chiefly 

 to the reduction in contents of the stomach and intestines. 



LENGTHS OF BODY AND TAIL 



The body length is measured from the tip of the nose to the 

 anus and the tail length from the anus to the tip of the tail. 

 The measurements were taken immediately after death, the body 

 and tail being extended by very slight tension. 



The body length (table 1) in the acute-thirst series shows an 

 average loss of 11.4 per cent and in the chronic-thirst series a 

 loss of 14.7 per cent, in comparison with the controls. In the 

 rat (Si. 2) on total inanition the corresponding apparent decrease 

 is 12.5 per cent. This decrease in the trunk length, as noted by 



