GENERAL CONCLUSIONS. 359 



the portal vein. By ligating the latter vessel he created a 

 collateral circulation, and shifted the portal-blood stream into 

 the general circulation. Ten or 12 grammes of sugar were 

 then given to the animal, and sugar was soon found in the 

 urine. In a normal dog, on the other hand, 50 to 80 grammes 

 had to be administered before this result was obtained (M. 

 Duval 25 ). The absence of sugar in the latter animal's urine 

 until a very large quantity of sugar had been ingested dis- 

 tinctly shows that conversion of its glycogen only occurred 

 because its portal vein was open; in the other dog it was not 

 converted glycogen that passed into the urine, but maltose, 

 i.e., intestinal starch which had been submitted to the action 

 of the pancreas's intestinal ferment, i.e., amylopsin. If we 

 now couple the fact that conversion of liver-glycogen only oc- 

 curs when the portal vein is free with Claude Bernard's ob- 

 servation that increased speed of the portal blood through the 

 liver causes the glycogen to be converted more rapidly, it seems 

 clear that the conversion process is not due to an hepatic ferment, 

 and that the pancreas supplies, as an internal secretion, the fer- 

 ment which converts glycogen into dextrose. 



A perplexing feature of all this requires elucidation, how- 

 ever. If, as we have stated, the blood-plasma contains an 

 oxidizing substance, why is the sugar not oxidized on its way 

 to the tissues of distribution? Armand Gautier 26 refers to the 

 investigations of Jaquet, which demonstrated that sugars 

 mixed with blood containing the oxidation ferment previously 

 referred to, and which we found to be of suprarenal origin, 

 did not become oxidized. He ascertained, however, that upon 

 adding to the blood a small quantity of fine pulp of muscle, 

 lung, or of any other organ, the oxygen was absorbed. This 

 obviously indicates that dextrose passes through the blood with- 

 out being destroyed, and it can only become oxidized after combin- 

 ing with bodies produced by the organs to which it is distributed. 



General Functions of the Liver, Spleen, and Pancreas. All 

 the facts reviewed in this chapter suggest the following conclu- 

 sions as to the functions of the liver, spleen, and pancreas: 



1. The hepatic artery, owing to the oxidizing substance that 



25 M. Duval: Loc. cit., p. 378. 



26 Armand Gautier: "La Chimie de la Cellule Vivante," p. 98. 



