INTRODUCTORY 5 



In the case of the pituitary it has been supposed that the 

 secretion passes out into the cerebro- spinal fluid. 



The "consensus partium " of the older medical writers was 

 supposed by Cuvier to depend on the activity of the nervous 

 system, and upon this alone ; but in 1775 Borden put forward 

 the doctrine that each organ has its " humeur particuliere " 

 which is necessary to the body as a whole. 1 



The first experimental demonstration of internal secretion 

 was undoubtedly that of Berthold in 1849. This writer 

 describes how he removed the testes from young cockerels and 

 transplanted them to the surface of the intestine, and found 

 that when this was done the young cockerel did not develop 

 in the way that castrated animals usually did, but that they 

 grew into normal cocks. Berthold concluded that the " con- 

 sensus partium " depends on the fact that the testes affect 

 the blood and the blood affects the whole animal. 



The term " internal secretion " was, so far as I can ascertain, 

 first used in 1855 by Cl. Bernard, who described the glycogenic 

 function of the liver as the " secretion interne," while he 

 referred to the preparation of the bile as the " secretion 

 externe." 2 



The glycogenic function of the liver is not at the present 

 time usually treated among the internal secretions. It is 

 a special kind of arrangement for the storing of food material. 

 The glycogenic function of the liver is, however, intimately 

 related to certain internal secretions notably those of the 

 pancreas and the adrenal body. Moreover, there are reasons, 

 as we shall see, for attributing to the liver other kinds of in- 

 ternally secreting activities. 



. Since the time of Cl. Bernard there has been much loose 

 thinking and loose writing upon the whole subject of internal 

 secretion. A great tendency has often been manifested to 

 reach premature and unwarrantable conclusions. In mor- 

 phology and comparative anatomy ill-understood organs or 



1 According to Gley, Borden does not express himself quite so definitely 

 as some writers have alleged. 



2 " Chez les animaux la secretion glycogenique est une secretion interne, 

 parce qu'elle se diverse directement dans le sang. J'ai considere le foie, tel 

 qu'il se present chez les animaux vertebres eleves comme un organe secreteur 

 double. II semble reunir, en effet, deux elements secretaires distincts et il 

 represent deux secretions : 1'une externe qui coule dans 1'intestin, la secretion 

 biliare ; 1'autre interne, qui se verse dans le sang, la secretion glycogenique. 



