DIGESTION. 277 



rior vena cava, just before its passage through the diaphragm. The 

 sw#-lobular and hepatic veins, unlike the portal vein and its companions, 

 have little or no areolar tissue around them, and their coats being very 

 thin, they form little more than mere channels in the liver substance 

 which closely surrounds them. 



The manner in which the lobules are connected with the sublobular 

 veins by means of the small intralobu lar veins is well seen in the diagram 

 (Fig. 209 and in Fig. 208), which represent the parts as seen in a longi- 

 tudinal section. The appearance has been likened to a twig 'having 

 leaves without footstalks the lobules representing the leaves, and the 

 sublobular vein the small branch from which it springs. On a trans- 

 verse section, the appearance of the intralobular veins is that of 1, Fig. 

 207, while both a transverse and longitudinal section are exhibited in 

 Fig. 208. 



The hepatic artery, the function of which is to distribute blood for 



-Lobule* 



Lobulcw 



FIG. 2C9. FIG. 210. 



FIG. 209. Diagram showing the manner in which the lobules of the liver rest on the sublobular 

 veins. (After Kiernan.) 



FIG. 210. -Capillary network of the lobules of the rabbit's liver. The figure is taken from a very 

 successful injection of the hepatic veins, made by Harting ; it shows nearly the whole of two 

 lobules, and parts of three others ; p, portal branches running in the interlobular spaces ; ft, 

 hepatic veins penetrating and radiating from the centre of the lobules. X 45. (Kolliker.) 



nutrition to G-lisson's capsule, the walls of the ducts and blood-vessels, 

 and other parts of the liver, is distributed in a very similar manner to 

 the portal vein, its blood being returned by small branches either into 

 the ramifications of the portal vein, or into the capillary plexus of the 

 lobules which connects the inter- and twtfrfl-lobular veins. 



The hepatic duct divides and subdivides in a manner very like that 

 of the portal vein and hepatic artery, the larger branches being lined by 

 cylindrical, and the smaller by small polygonal epithelium. 



The bile-capillaries commence between the hepatic cells, and are 

 bounded by a delicate membranous wall of their own. They appear to 



