RELATION TO OTHER ENDOCRINES 213 



adrenal insufficiency induced by the methods just described 

 differs from that observed in acute adrenal insufficiency in 

 several important respects. Acute adrenal insufficiency re- 

 sponds readily to treatment with the adrenal cortical hormone, 

 is rapidly fatal in untreated animals, and is accompanied by a 

 rapid loss of weight and other symptoms characteristic of 

 adrenal insufficiency. Animals brought into the state of what 

 we have called a chronic adrenal insufficiency live for long 

 periods of time without treatment, do not respond to adrenal 

 cortical therapy, maintain a constant body weight, and are 

 free of many of the symptoms characteristic of acute adrenal 

 insufficiency. Such animals show a slight degree of asthenia, 

 fail to gain weight under a luxus diet, maintain a slightly 

 lowered body temperature, and show a diminished capacity for 

 reproduction. At autopsy evidence of pathological changes 

 are noted chiefly in the degree of inanition and loss of general 

 body fat, marked atrophy of the reproductive system, atrophy 

 of the thyroid gland, and a generalized hyperplasia of the 

 lymphatic system with regenerative enlargement of the thymus. 

 The growth of rats may be stunted by interference with 

 normal hypophyseal or adrenal function. Adrenalectomy 

 results in a permanent cessation of growth which can be en- 

 tirely prevented by adequate replacement therapy with the 

 adrenal cortical hormone. However, should the adrenal 

 cortical hormone be administered in small doses one is able to 

 prolong the life of adrenalectomized young animals without 

 supplying sufficient hormone to permit growth. Incomplete 

 removal of the adrenals, leaving only a minute portion of the 

 glomerulosa of the gland, suffices for regeneration of the gland 

 and prolonged survival. In many cases such animals assume 

 their normal adult size and manifest no symptoms of adrenal 

 insufficiency. In some cases, however, one observes that such 

 animals after a preliminary period of growth ultimately cease 

 to grow and maintain a constant weight for long periods of 

 time. The preliminary normal growth observed in these 



