CHEMICAL COMPOSITION OF THE LIVER-CELLS. 351 



mesenteric vein of a starving rabbit causes the liver, previously free from 

 glycogen, to contain glycogen (Nauuyn). 



During life, under normal conditions, the glycogen in the liver is 

 either not transformed into grape-sugar (Pavy, Eltter, Euleuberg), or, 

 what is more probable, only a very small amount of it is so changed. 

 The normal amount of sugar in blood is O'5-l per 1000, although the 

 blood of the hepatic vein contains somewhat more. A considerable 

 amount is transformed into sugar only when there is a decided de- 

 rangement of the hepatic circulation, and in these circumstances, the 

 blood of the hepatic vein contains more sugar. The glycogen under- 

 goes this change very rapidly after death, so that a liver which has 

 been dead for some time always contains more sugar and less glycogen. 



The ferment which effects this change can be obtained from the 

 extract of the liver-cells by the same means as are applicable for obtain- 

 ing other similar ferments, such as ptyalin; but it does not seem to 

 be formed within the liver-cells, but only passes very rapidly from the 

 blood into them. The ferment seems to be rapidly formed when the 

 blood-stream undergoes considerable derangement (Hitter, Schiff). A 

 similar ferment is formed when red blood-corpuscles are dissolved 

 (Tiegel), and, as there is a destruction of red blood-corpuscles taking 

 place continually within the liver, this is one source from which the 

 ferment may be formed, whereby minute quantities of sugar would be 

 continually formed in the liver. 



If glycogeu is injected into the blood, achroodextrin appears in the urine, and 

 also haemoglobin, as glycogen dissolves red blood-corpuscles (Bohm, Hoffmann). 



Ligature of the bile duct causes decrease of the glycogen in the liver (v. Wittich); 

 it appears as if, after this operation, the liver loses the property of forming glycogen 

 from the materials supplied to it. 



(3.) The following substances have also been found in the liver-cells: 

 Fats in the form of highly refractive granules in the liver-cells, as well 

 as in the bile ducts; sometimes, when the food contains much fat (more 

 abundant in drunkards and the phthisical), olein, palmitin, stearin, 

 volatile fatty acids, and sarcolactic acid are found. 



[Fatty granules are of common occurrence within the cells of the liver, and when 

 they do not occiir in too great amount, do not seem to interfere very greatly with 

 the functions of the liver-cells. These fatty granules are common in disease, con- 

 stituting fatty infiltration and degeneration, and in such cases the cells within a 

 lobule of the liver, next the portal vein, are usually most highly charged with the 

 fatty particles. Fatty particles occur if too much fatty food be taken, and they 

 are commonly found in the livers of stall-fed animals, and the well-known pdt-de- 

 foie gras is largely composed of the livers of geese, which have been fed on large 

 amounts of farinaceous food, and which have been subjected to other unfavourable 

 hygienic conditions. Fatty granules are recognised by their highly refractive 

 appearance, by their solubility in ether, and by being blackened by osmic acid. ] 



There are also found traces of cholesterin, minute quantities of urea, uric acid. 



