GENETIC TYPE AND THE ENDOCRINES 421 



crine glands, many of which are evidenced by changes in the 

 histologic structure of the gland. Much of the human material 

 collected after death from protracted illness has been mis- 

 interpreted histologically because of the assumption that the 

 patient had not suffered from endocrinic disease. The possi- 

 bility exists that a patient may die from the secondary 

 disturbance of the endocrine glands. For example, it is known 

 that suprarenal deficiency is very pronounced following cer- 

 tain systemic infections, and this deficiency brings about 

 cardiac and circulatory symptoms of fatal significance. We 

 have found that the endocrine glands from dogs dying of 

 distemper and other diseases are modified, and therefore are 

 not reliable material for a study of type or constitutional 

 glandular differences. These elementary facts concerning the 

 actions and interrelations of endocrine glands are of funda- 

 mental nature, particularly in establishing any existing re- 

 lation between the endocrines and the differences in physical 

 type. 



At the time this study was begun, it was not realized, at 

 Least not in so far as our knowledge of the literature goes, 

 that the widely different breeds of dogs might possess vari- 

 ously modified endocrine glands, and that there might be 

 some correlation between the specific characters of the breed 

 and the nature of its glands. The initial observations on 

 glands from different breed types collected from the Xew 

 York city pound showed wide differences in histologic struc- 

 ture, particularly among the thyroids. But, as stated above, 

 this material was unreliable from the standpoint of both 

 breed purity and individual physical history. The present 

 discussion of the histology of endocrines in the different dog- 

 breeds and types is based entirely on material from pedigreed 

 animals that were always, during life, under careful observa- 

 tion. 



Other than several preliminary reports on these experi- 

 ments (Stockard, '26, '27, '28, '31, '34, '35, '36), the only 

 record of the histology of endocrine glands from pure line 



