THE INTERNAL SECRETION OF THE PANCREAS 427 



bacterial impurity. Also J. de Meyer and Nanking were both 

 unable to confirm Cohnheim's results. 



Like Lepine, J. de Meyer (1904) believed that the decom- 

 position of sugar took place in the blood. According to his 

 experiments, the glycolytic ferment is situated, not in the 

 muscles, but in the white blood corpuscles, and is rendered active 

 by the agency of the pancreas. He believes that the pancreas 

 contains a " sensibilizing substance," which changes a proferment 

 which is present in the leucocytes and is secreted by them and 

 which possesses properties analogous to those of the fibrin ferment 

 into the active glycolytic ferment. De Meyer also believes that 

 the cause of diabetes after extirpation of the pancreas lies in the 

 suppression of the internal secretion, and that the latter is the 

 agent which activates the glycolytic ferment. The evidence 

 against this hypothesis is supplied by the arguments which were 

 advanced in disproof of Lepine's theory. 



Vahlen (1908) was also unable to demonstrate the presence 

 in the pancreas of a substance which splits up sugar and thus 

 promotes oxidation. He believes it possible, however, that the 

 pancreas may contain a substance, at present unknown, which, 

 without giving rise to direct fermentative decomposition, may 

 yet bring about an increase in the decomposition of sugar in the 

 organism. He succeeded in isolating a constituent from the 

 pancreas which appreciably accelerated the alcoholic fermentation 

 of sugar, and, in the case of phlorizin animals, effected a con- 

 siderable reduction in the excretion of sugar. Vahlen did not, 

 however, carry out conclusive experiments with pancreasec- 

 tomized animals. 



If we review the publications which, beginning with Lupine's 

 theory, have attempted to explain the nature of pancreatic dia- 

 betes, it is evident that conclusive proof of the assumption that 

 the pancreas supplies a substance which promotes glycolysis, or 

 which is essential to the general metabolism of sugar, is not 

 forthcoming. The generally accepted view, that pancreatic dia- 

 betes is a derangement of metabolism which consists in the arrest 

 of the normal conversion of sugar, has not, as yet, been suffi- 

 cientlv confirmed, and for this reason, has little positive value. 



The older hypothesis, that diabetes is the expression of an 

 increased formation of sugar, has recently been revived; it is 

 reinforced by certain new arguments and has received a large 

 measure of support. This tendency marks a return to the teach- 

 ing of Chauveau and Kaufmann (1893) which, at the time of its 

 inception, found few supporters. 



The central point round which the process of the metabolism 

 of the carbohydrates revolves, is what Claude Bernard described 

 as the " glycogenie animale " ; the process, that is, by which 

 glycogen accumulates and sugar is formed in the liver. From 

 the carbohydrates derived from the nutriment, glycogen is formed 



