422 TOKUYASU KUDO 



Epididymis 



The epididymis in the acute-thirst series (table 2) shows a 

 loss of 30 per cent in average weight and in the chronic-thirst 

 series a loss of 64.8 per cent. In the rat (Si. 2) after total inani- 

 tion (table 1), the corresponding apparent loss in weight of the 

 epididymis is 55.8 per cent. In all cases, therefore, the loss 

 appears slightly greater (relatively) in the epididymis than in the 

 testis. Jackson ('15) concluded that in the albino rat after inani- 

 tion with water the loss in weight of the epididymis is relatively 

 not very different from that in the testis. 



Thyroid gland 



The thyroid gland in the acute-thirst series undergoes a loss of 

 23.9 per cent in average weight, and in the chronic-thirst series a 

 loss of 33.1 per cent. In the rat (Si. 2), after total inanition 

 (table 1), the apparent loss in weight of the thyroid is 41.7 per 

 cent. In a dog on a dry diet, Falck and Scheffer ('54) noted an 

 apparent loss of 30 per cent in the weight of the thyroid (body 

 weight, —20.7 per cent). In acute inanition with water, Jackson 

 ('15) found in the thyroid of the albino rat a loss in weight pro- 

 portional to that of the whole body (about 34 per cent) , and dur- 

 ing chronic inanition with water a loss of 21.8 per cent (body 

 weight, —36.1 per cent). The extent of the loss in weight of the 

 thyroid during inanition appears quite variable, due in part to 

 the difficulty in dissecting out the gland uniformly. McCarrison 

 ('19) noted a slight atrophy of the thyroid in pigeons and mon- 

 keys on vitamine-free diets. 



Thymus 



In the acute-thirst series the thymus (table 2) shows an appar- 

 ent loss of 78.1 per cent in average weight and in the chronic- 

 thirst series a loss of 90 per cent. There is some uncertainty 

 about these conclusions, however, as the age of the rats is un- 

 known in some cases. It has been shown (Jackson, '13; Hatai, 

 '14) that the thymus in the rat normally undergoes an age involu- 



