THE LIVER. 159 



with the terminal branchlets into which it finally' 

 breaks up, pass to the surface of the lobules ; there 

 they pour their blood into a rich capillary net-work 

 within the lobules, whence it passes directly into 

 the radicles of the hepatic vein at the centre. The 

 capillaries of the lobules radiate from the central 

 vein for the most part nearly at right angles to its 

 axis, and take more or less direct, slightly divergent 

 courses to the periphery, being connected with each 

 other by frequent branches. A net-work is thus 

 formed, in whose narrow and elongated meshes the 

 liver-cells lie, sometimes in a single row, sometimes 

 in several rows, depending upon the breadth of the 

 intercapillary spaces. The central vein does not 

 usually extend quite to the extremity of the lobules, 

 and here the capillaries are given off, brush-like, 

 obliquely from its end. A liver-lobule, then, is a 

 circumscribed portion of liver-tissue, having for its 

 centre a branchlet of the hepatic vein vena intralobu- 

 laris and at its periphery the terminal branchlets of 

 the portal vein vence interlobularis, while between 

 these tzvo sets of vessels, and joining them, is a ricJi 

 capillary net-work, in whose elongated meshes lie rows 

 of liver-cells. 



In certain animals, such as the pig, the lobules are 

 very distinct, being surrounded by connective tissue 

 which is directly continuous with the connective 

 tissue surrounding the larger trunks of the portal 

 vein, hepatic artery, etc., and called Glissons capsule. 



