270 DIGESTIVE SYSTEM, 



With regard to diabetes, the disease which first gave rise 

 to the whole question, and to which it must always be re- 

 ferred in physiological investigations, as well as in pathogenic 

 researches, it must be admitted that the liver is the chief 

 actor, without, however, attributing to hepatic glycogeny the 

 important physiological function at first ascribed to it by Cl. 

 Bernard. 



Does the glycogenous substance, however, which in path- 

 ological cases is undoubtedly changed into sugar, constantly 

 undergo in a more or less decided degree the same trans- 

 formation when in the physiological state? When the 

 animal is living and in perfect health, does the liver elabo- 

 rate sugar incessantly ? Here this vexed question of glyco- 

 geny rests for the present. Cl. Bernard has no hesitation in 

 supposing this incessant physiological transformation. In 

 this opinion he is opposed by Schiff and Pavy. These two 

 experimenters maintain that the sugar found in the liver is 

 always formed after death : in a fresh liver, taken from an 

 animal just killed (Pavy, Schiff, Ritter), 1 or, better still, from 

 a living animal (Meisner, Jager), no sugar will be found, but 

 only glycogenous matter which is not transformed into 

 sugar in the living animal, either for want of a ferment 

 which is capable of producing this transformation (Schiff), 

 or because this ferment, though existing, cannot act during 

 the life of the animal on account of certain influences arising 

 in the nervous system which are opposed to it (Pavy). 



This view is, evidently, an exaggerated one. These ex- 

 periments merely show that in the normal condition the 

 transformation into sugar is very trifling, and not easily 

 exhibited by means of the reagents which we possess. An 

 American physiologist, however, Dalton, experimenting with 

 a care and rapidity at least equal to that displayed by 

 Pavy, has succeeded in demonstrating that the living liver is 

 not entirely without sugar. 



The liver thus forms glycogenous matter : this matter is 

 changed into sugar by the action of a ferment the origin of 

 which is as yet undecided. 2 



1 See Schiff, " Nouvelles Recherches stir la Glycogenie Ani- 

 male." (In Journ. de PAnat. et de la Physiol., de Ch. Robin, 

 1866, Nos. de juillet et aout.) 



2 Claude Bernard's researches on the subject of glycogeny may 

 be summed up in the following manner: " In 1848 he discovered 

 sugar in the liver; it is always found there, whatever may be the 

 nutrition of the animal. In 1855 he demonstrates that the sugar 



