THE INTERNAL SECRETION OF THE PANCREAS 421 



and laborious investigation, as well as of lively discussion ; never- 

 theless, no final theory embodying a satisfactory explanation of 

 its causes has up to the present been forthcoming. We are com- 

 pelled, therefore, to confine ourselves to a short account of the 

 theories concerning the condition which have been advanced by 

 different authors. 



v. Alering and Minkowski, the discoverers of pancreatic 

 diabetes, believed the condition to be the outcome of the cessation 

 of a specific function of the pancreas, a function which is essential 

 to the normal employment of sugar by the organism. After con- 

 sideration of the possible causes, Minkowski concluded that the 

 pancreas supplies some substance which aids in the decomposition 

 of sugar within the organism. He believed the cause of diabetes 

 to lie in a cessation of the internal secretory, or positive, pan- 

 creatic function, using the term in the sense in which v. 

 Hansemann employed it. 



This conclusion was, however, opposed by de Domenicis, 

 whose discovery that glycosuria followed extirpation of the 

 pancreas was almost simultaneous with that of v. Mering and 

 Minkowski, though he worked independently of them. In his 

 opinion, glycosuria is not a constant result of pancreasectomy, but 

 is merely an expression of the serious nutritional disturbances 

 which are brought about by suppression of the external pancreatic 

 secretion. Owing to the absence of this external secretion, the 

 digestion of the nutrient material by the intestine is defective ; 

 toxins are formed and resorbed, and these disturb the chemistry 

 of the tissues, and thus give rise to the formation of sugar. In 

 the course of these earlier researches, de Domenicis discovered 

 that the intestinal extract of dogs without pancreas produces 

 glycosuria, though in a slight degree, in normal dogs. In a 

 recent publication he has asserted that severe, permanent glyco- 

 suria may be produced by the injection of the duodenal secretion 

 of dogs without pancreas. It is not to be denied that the external 

 pancreatic secretion has a certain influence upon the resorption 

 of nutrient substances in the intestine. Sandmeyer showed that 

 the administration of pancreatic tissue promotes digestion, and 

 resorption of nutriment. Similar results were observed by 

 Lombroso after the introduction of pancreatic juice into the 

 duodenum. In animals which have lost their pancreas, however, 

 this method merely increases the sugar excretion, and where 

 diabetes is present in the slighter form it provokes true glycosuria. 

 The transplantation experiments carried out by Minkowski, 

 He"don, and Thiroloix prove beyond any manner of doubt that 

 diabetes is not dependent upon the external pancreatic secretion. 



The possession by the pancreas of an internal secretorv 

 function was, however, denied for other reasons. In the case of 

 the pancreas, as in that of all organs with internal secretion, the 

 removal of which provokes pathological symptoms, the results of 

 extirpation were explained by the nervous injuries inseparable 



