EXPERIMENTAL DIABETES 355 



depancreated dogs, the percentage of the sugar in the blood rises 

 still higher. 



This hyperglycsemia. as it is called, may be due either to a 

 greater production of sugar, or to a lessened power of its de- 

 struction, by the organism. With regard to the former possibility 

 viz. greater production the rapid disappearance of hepatic 

 glycogen during the first few days of the condition and the 

 excessive decomposition of proteid tissues which soon supervenes 

 would seem to lend support. On the other hand, as we have 

 seen, there is abundant evidence that the organism has almost 

 entirely lost its power of utilising dextrose, the reappearance in 

 the urine of almost all the ingested dextrose being sufficient proof 

 of this. 



We may for the present conclude, then, that the primary 

 cause of the accumulation of sugar in the blood is the with- 

 drawal from the organism of some influence necessary for the 

 utilisation of dextrose. Now, the pancreas may influence the 

 destruction of dextrose in the organism in one of two ways, 

 either by the dextrose being brought in actual contact with the 

 gland tissue, or by the gland secreting some substance an in- 

 ternal ferment into the blood which brings about the destruc- 

 tion of dextrose elsewhere in the organism. The latter possibility 

 is the more probable one, since it is only when the gland 

 has been almost entirely removed that glycosuria follows. If 

 a small portion of the gland be left, or even if a portion of it 

 (the free portion of the vertical part below the large duct of the 

 gland) be pulled out and, without injury to its vessels, trans- 

 planted into the abdominal parietes and allowed to heal in there 

 an operation which is possible on account of the lower portion 

 of the gland being free from the duodenum and lying in the 

 mesentery and then the main gland excised, no diabetes will 

 follow. Only a very small fraction of the animal's blood can 

 under such conditions come in contact with pancreatic tissue, 

 and still there is no diabetes. It cannot, therefore, be neces- 

 sary for the blood to actually transfuse the pancreas in order 

 to be subjected to the glycolytic action. The diabetes is likewise 

 shown by this experiment to be independent of injury to the 

 nerve ganglia adjacent to the pancreas, which injury might quite 

 possibly occur during the excision of the gland tissue. 



There must, therefore, be some internal secretion furnished 



