424 INTERNAL SECRETION 



Caparelli, Zuelzer, Dohrn and Mayer; negative results by Hedon, 

 Gley, Lepine, Forschbach, and others. For the reasons given in 

 the first part of this book, the failure of organo-therapy does not 

 necessarily disprove the internal secretory activity of the organ 

 under consideration. It is no more reasonable to expect a restora- 

 tion, by means of the administration of pancreatic extract, of the 

 injured metabolic processes of pancreasectomised animals, than 

 it is to expect the prolongation or the saving of life by means 

 of suprarenal extract in the case of suprarenalless animals. 



In face of the results obtained by a far more practical method, 

 namely, that of pancreatic transplantation, the uncertain and 

 contradictory results of organo-therapy lose their value as 

 evidence against the formation of a pancreatic hormone. Instances 

 are supplied by Minkowski's experiments, in which portions of 

 the organ were transplanted together with their vascular stem ; at 

 a later stage, the vascular stem was severed and the healed in 

 portions of pancreas sufficed to avert diabetes. Pfliiger's unsuc- 

 cessful implantation of the pancreas under the skin of the back in 

 frogs has no bearing upon the question. 



That the pancreas does possess an internal secretion has been 

 absolutely proved by Forschbach's parabiotic experiments. The 

 extirpation of the pancreas of one parabiotic dog was followed by 

 slight glycosuria only. The manner in which the wound healed 

 and the absence of cachexia further showed that the metabolic 

 derangements characteristic of diabetes were absent. The 

 internal secretion of the one pancreas sufficed for the needs of 

 both animals. After separation, however, the animal which had 

 been robbed of its pancreas developed diabetes. 



Lepine was the first to formulate a theory concerning the 

 nature and method of action of the internal secretion of the pan- 

 creas, and this supplied a new^eutlook in many directions and 

 offered a stimulus to fresh investigation. But a glance at the 

 results of nearly twenty years shows no discovery which in any 

 way elucidates the causes in which diabetes takes its rise. Accord- 

 ing to Lepine's theory, a substance is formed in the pancreas 

 which is necessary to the normal metabolism of sugar. The sup- 

 position is that the normal sugar in the blood is broken up and 

 conveyed to the tissues by a glycolytic ferment, \vhich is formed 

 in the pancreas, reaches the blood by way of the thoracic duct, 

 and attaches itself to the white corpuscles. By extirpating the 

 pancreas, the source of origin of this ferment becomes destroyed. 

 In both experimental pancreatic diabetes and in the spontaneous 

 clinical condition, the amount of the glycolytic ferment present in 

 the blood becomes very much diminished and, as a consequence, 

 the decomposition of the sugar molecule is less than in normal 

 blood. Thus an accumulation of sugar takes place in the blood 

 and the excess is excreted by way of the kidneys. 



If we inquire more closely into the fact upon which Lepine 



