THE SPLENO-PANCRBATIC INTERNAL SECRETION. 417 



intestino-portal digestion. We have seen in Herzen's experi- 

 ment how rapidly albumin was digested with blood obtained 

 from the splenic vein during this stage. 



That the amylolytic ferment derived from Heidenhain's 

 zymogen is also carried to the splenic vein is probable. We 

 have seen that it was through the effects of this ferment that 

 the liver glycogen was converted into sugar, and that the im- 

 portance of the latter, when distributed to the muscles and 

 other structures in which it is consumed, was very great. That 

 the conversion of glycogen into sugar is a continuous process 

 and that it is independent of digestion are recognized facts, 

 and necessarily so, since the activity of the functions that 

 entail the use of glycogen may at any moment be increased, 

 the tissues requiring replenishment to a correspondingly great 

 degree at the expense of the liver reserve. How could this 

 predominating function be carried on in the perfect manner that 

 it is, were it connected with, or did it depend upon, any digestive 

 process? Again, if present views prevailed and the amylolytic 

 ferment were to only reach the liver after being secreted in 

 the duodenum by the pancreas, then absorbed by the venules- 

 of the villi, how could we account for the conversion of glyc- 

 ogen between the periods of active digestion? That the intes- 

 tinal tract is not the channel traversed by the portion of pan- 

 creatic amylopsin devolved to the conversion of glycogen into 

 sugar is also suggested by familiar experiments. 



We have seen that the insertion of a piece of pancreas 

 into the tissues of an animal showing marked glycosuria, after 

 removal of the pancreas, will cause it to disappear. This ap- 

 parently constitutes a direct contradiction of all the foregoing 

 statements; but such is not the case in reality. Minkowski 34 

 confirmed the fact, observed by other investigators, that glyc- 

 ogen quickly disappears after removal of the pancreas. This 

 indicates two important features: i.e., that glycogen is no 

 longer formed after removal of the pancreas, and that some 

 other agency converts it into sugar. Why removal of the pan- 

 creas should prevent the formation of glycogen may probably 

 be accounted for by the fact that the absence of trypsin causes 



3 *Minkowski: Berliner klin. Wochenschrift, No. 5, 1892. 



