406 TOKUYASU KUDO 



The organs, after weighing, were dried to constant weight in 

 an oven at about 95°C., in order to determine their water content 

 (not included in this paper). 



Percentage losses in the various organs were calculated as fol- 

 lows. The average weight (table 2) for each organ or part in the 

 test rats was compared with the corresponding average for the 

 controls. The data in the column 'Difference' express the appar- 

 ent percentage change ( + or — ) as the result of the experiment. 

 In calculating these percentage changes the slight differences in 

 average initial body weights between the controls and the test 

 rats are ignored. 



For various reasons, the data obtained do not justify any final 

 conclusions as to the effects of thirst. The number of animals 

 used (especially for controls) is comparatively small, and in some 

 cases there are marked individual variations (due partly to un- 

 avoidable variations in technique), as shown in table 1. More- 

 over, it is obviously difficult to separate the effects of thirst from 

 the accompanying inanition due to inadequate food-intake. By 

 comparison of the results M'ith those obtained by inanition with 

 water or b}^ total inanition, however, it is possible to reach some 

 general conclusions of interest and importance. 



GENERAL OBSERVATIONS 



The symptoms noted in the albino rats during the thirst experi- 

 ments are briefly as follows. The skin becomes roughened and 

 the hairs are easily detached. (Likewise noted in dogs on a dry 

 diet by Bowin, '80.) Dryness and desquamation were observed 

 in the skin of the plantar surfaces. The fecal material is usually 

 hard, but sometimes diarrheal in character. The urine is scanty. 

 Opacity of the lens apparently caused visual disturbance in some 

 cases. The conjunctiva was observed in some cases to be con- 

 gested, and in one case hemorrhagic. Hemorrhage from the 

 nose was noted in several cases. Paralysis of the right posterior 

 extremity occurred in one case. During the period of twelve to 

 twenty-four hours before death the rats will take neither food nor 

 milk and are exhausted, apathetic, and convulsive. Some rats 

 apparently become mentally deranged and will bite, although 



