v INTERNAL EESTITUTIVE SECEETIONS 303 



demonstrated indisputably that there is a marked difference 

 between the sugar content of the blood from, the portal and that 

 from the hepatic veins, without even temporary arrest of the 

 circulation through the liver. While the portal blood on an 

 average contains O'l per cent sugar, that of the hepatic vein 

 contains on an average 0'2 per cent. This fact seems to us to 

 decide the controversy in favour of sugar production in the 

 normal living liver. 



When we consider the large amount of blood that passes 

 through the liver every day and hour, we see that the marked 

 difference in the sugar content of the blood flowing to and from 

 the liver, while apparently small, must really indicate the pro- 

 duction of a very considerable amount of sugar. Seegen estimates 

 that in a dog of 40 kilos, weight, 400 litres of blood pass through 

 the liver in 24 hours, from which we must assume a production of 

 400 grins, sugar, supposing the blood flowing from the liver to 

 contain O'l per cent more sugar than the blood flowing to that 



organ. 



Seegen, however, raised another objection to Bernard's theory. 

 In 1876 he (and soon afterwards Nasse) determined the nature 

 of the sugar produced from giycogen by the liver, and that 

 formed artificially by the action of amylolytic enzymes, and 

 found that the liver manufactures glucose or dextrose, while 

 artificial digestions of giycogen with saliva, pancreatic extract, or 

 succus entericus yield maltose. This fact caused Seegen to 

 question whether Bernard was right in assuming the intervention 

 of a specific enzyme in the phenomenon of glycogenesis, and 

 whether the glucose formed by the liver might not be derived 

 from some substance other than giycogen. 



He accordingly undertook a series of experiments to estimate 

 the giycogen and glucose of the liver at different intervals after 

 death, to see whether as the former disappeared the latter is 

 manufactured in a corresponding ratio. In collaboration with 

 Kratschmer (1880) he obtained results unfavourable to Bernard's 

 hypothesis, since the quantity of sugar augments rapidly, directly 

 after death, while the giycogen does not perceptibly diminish, 

 whence he concluded that the sugar is not formed at the expense 

 of the giycogen. 



Seegen supposed that the peptones and fats are capable of 

 forming the sugar of the liver, and asserted in support of his 

 views that fragments of liver excised from the living animal 

 produce a larger amount of sugar when kept for 5-6 hours at a 

 temperature of 38 in a solution of peptones, or defibriuated blood, 

 or are plunged into an emulsion of fat and gum, while a current 

 of air is passed through the mixture. 



Seegen's results were contradicted by Delprat (1881), Chittenden 

 and Lambert (1885), Girard (1887), Neumeister (1890), Noel 



