FORMATION OF GLYCOGEN 227 



the fact 16 that glycogen is uniformly distributed in the 

 hepatic parenchyma proper, and that any slight analytical 

 differences are related with the variations in amount of 

 connective tissue in the portions under examination), which 

 permits in the turtle artificial circulation to be maintained 

 for two completely separated portions of the liver. J. de 

 Meyer 17 has since succeeded in applying an analogous 

 method to the mammalian liver. It is thus possible to per- 

 fuse one lobe of the liver with blood containing sugar and 

 a second with blood free from sugar. We have learned 

 from observations of this type, that a marked new-formation 

 of glycogen takes place in a liver when perfused with blood 

 containing sugar; and the assertion 18 that the liver is able 

 to form glycogen from glucose only after the latter has un- 

 dergone a preparatory polymerization in the course of its 

 resorption in the bowel has been thoroughly disproved. 19 



We may go a step further and take up the question of 

 what must be the constitution of a sugar to fit it as material 

 for the formation of glycogen. Based upon an extensive 

 literature, the details of which cannot be taken up here, 

 this question would be answered somewhat as follows at the 

 present. 20 



Formation of Glycogen from Glucose, Fructose and 

 Galactose. Besides glucose, which has naturally occupied 

 the central place in the whole carbohydrate problem, there 

 are two hexoses which are undoubted glycogen-formers r 

 fructose and galactose, the stereo-chemical configurations of 

 which closely approach that of glucose. The capability of a 



17 J. de Meyer ( Solvay Instit., Brussels ) , Arch, intern, de Physiol., 8, 204,. 

 1909. 



18 A. C. Croftan (Chicago), Pfliiger's Arch., 126, 407, 1909. 



19 E. Pfliiger, Pfliiger's Arch., 126, 416, 1909; K. Grube (Pfliiger's Lab.), 

 Pfliiger's Arch., 127, 529, 1909. 



20 Literature upon Glycogen Formation from Sugars and Related Sub- 

 stances: M. Cremer, Ergebn. d. Physiol., 1' 896-901, 1902; R. Tigerstedt, 

 Nagel's Handb. d. Physiol., 1, 502-503, 1905; E. Weinland, ibid., 2, 433-499, 

 1907; J. Wohlgemuth, H'andb. d. Biochem., 3', 160-164, 1910; A. Magnus-Levy, 

 ibid., 4' 323-326, 352-353, 1909; H. Haffmanns, Inaug. Diss., Univ. Berne, 

 1910, cited in Jahresber. f. Tierchem., J t O, 414. 



