Chap, xviii .] SECRETIONS AND EXCRETIONS IN PARTICULAR. 265 



cells are in contact -witli tlie finest capillaries of the vena portse, 

 from which they borrow the materials necessary for the fabrica- 

 tion of their amylaceous product (Fig. 37). This product, 

 denominated glycogen, is analogous to the cellulose of vegetals ; it 

 is uncrystallisable, like starch, and, like starch, susceptible of 

 transforming itself isomerically into glycose, fermentiscible and 

 crystallisable. Once formed by the hepatic cell, the glycogen is 

 yielded by it to the blood of the super-hepatic capillaries, ' and 

 transforms itself into glycose, which normally is either destroyed 



Fig 36. 



Isolated cells of the 

 liver ; a, with simple 

 nacleus, h, with 

 double nucleus. 









Ajrangement of the cells of the liver in a lobule cut 

 transversally, with the section of the hepatic vein 

 in the centre. 



by oxydation in the blood or utilised for the nutrition of the 

 anatomical elements. 



It is by no means certain that the glycogenical cells do not 

 also contribute their share to the secretion of the bile. If they 

 are in contact with the sanguineous capillaries, they are likewise 

 in contact with the fine ramuscules of the biliary canals, a sort 

 of excretory capillaries. Finally, we , sometimes find in the 

 normal state, often in the pathological state, yellowish granules 



