CHAP. XVHI.] SECRETIONS AND EXCRETIONS IN PARTICULAR. 265 



cells are in contact with the 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 

 nucleus, b, with 

 double nucleus. 



FIG. 37. 



Arrangement 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 

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

 normal state, often in the pathological state, yellowish granules 



