UITITBRSITT 



the opinion expressed by PFLUGER has unqueSniEftjQnSeen mis- 

 leading. As the fat may be formed partly from proteids and partly 

 from carbohydrates by a synthesis after previous splitting, PFLUGEB 

 claims that the glycogen in the liver may also be produced from dif- 

 ferent substances by a complex splitting and synthesis. There is 

 no doubt that the glycogen of the liver, which surrounds the nu- 

 cleus of the liver-cells as amorphous masses, is formed in these cells. 

 Where does the glycogen occurring in the other organs, such as the 

 muscles, originate ? Is the glycogen of the muscles formed on the 

 spot or is it transmitted from the liver to the muscles by means of 

 the blood? These questions cannot yet be answered with positive- 

 ness, and the investigations on this subject by different experimen- 

 ters (on frogs by KULZ and on birds by LAVES and MINKOWSKY) 

 have given contradictory results. 



Glycogen is considered as a reserve nutritive substance deposited 

 in the liver, and, according to the ordinary view, it is transported 

 by the blood from the liver to the other organs, especially to the 

 muscles, where it serves as a source of material for work. The im- 

 portance of glycogen in the formation of heat follows from the fact 

 that on cooling the animal body the glycogen is quickly exhausted. 

 The possibility that fats may be formed from glycogen, as well as 

 from other carbohydrates, cannot be denied. 



The relationship of glycogen to the formation of sugar is of spe- 

 cial interest. In a dead liver the glycogen is rapidly converted into 

 sugar, and this fact naturally leads to the supposition that we have 

 a sugar formation from glycogen in the liver during life under nor- 

 mal conditions, a vitale Glykogenie (AUTHOR). As proof of this, CL. 

 BERNARD has found that the liver, under physiological conditions, 

 always contains some sugar, and also that the blood from the hepatic 

 vein is always somewhat richer in sugar than the blood from the 

 portal vein. The correctness of either or both of these statements 

 has been disputed by many investigators, such as PAVY, HITTER, 

 SCHIFF, EULESTBERG, LussANA, ABELES and others. It is not 

 denied that the blood from the hepatic vein may not contain some- 

 what more sugar under certain circumstances, but it is probably due 

 to the result of the experiment. 



It is impossible to discuss more completely the numerous works 

 which treat of this question, and it is perhaps sufficient to say here 



