256 DIGESTION. 



they form little more thaD mere channels in the liver sub- 

 stance which closely surrounds them. 



FIG. 87. 



Section of a portion of liver passing longitudinally through a considerable hepatic 

 vein, from the pig (after Kiernan) 5.. H, hepatic venous trunk, against which the 

 sides of the lobules are applied ; b, sublobular hepatic veins, on which the bases of 

 the lobules rest, and through the coats of which they are seen as polygonal figures ; 

 a, a, walls of the hepatic venous canal, formed by the polygonal bases of the lobules. 



The manner in which the lobules are connected with the 

 sublobular veins by means of the small intralobular veins is 

 well seen in the diagram, Fig. 88, and in Fig. 87, which rep- 

 resent the parts as seen in a longitudinal section. The ap- 

 pearance has been likened to a twig having leaves without 

 footstalks the lobules representing the leaves, and the sub- 

 lobular vein the small branch from which it springs. On a 

 transverse section, the appearance of the intralobular veins is 

 that of 1, Fig. 86, while both a transverse and longitudinal 

 section are exhibited in Fig. 89. 



The hepatic artery, the function of which is to distribute 

 blood for nutrition to Glisson's capsule, the walls of the ducts 

 and bloodvessels, and other parts of the liver, is distributed in 

 a very similar manner to the portal vein, its blood being re- 

 turned by small branches either into the ramifications of the 



