402 



OF SECRETION. 



structure that holds together the several elements. There is strong 

 reason to believe, that the blood which the liver receives from the 



Fig. 118. 



Liver of Taapole; showing distinct and free csecal terminations of the biliary ducts. 



hepatic artery is not destined to supply the materials for the biliary 

 secretion, until it has become venous by travelling through the network, 

 in which it is subservient to the nutrition of the tissues it permeates, as 

 it is in other parts of the systemic capillary system. The supply of 

 blood, from which the materials of the biliary secretion are chiefly 

 drawn, is afforded by the Vena Portce, which collects it as a Vein from 

 the chylopoietic viscera, and which then subdivides as an Artery to dis- 

 tribute it to the different parts of the Liver. Its branches proceed to 



Horizontal section of three superficial lobules of the Liver, showing the two principal systems of blood- 

 vessels; 1, 1, intra-lobul&T veins, proceeding from the Hepatic veins; 2, 2, twter-lobular plexus, formed by 

 branches of the Portal veins. 



the capsules of the lobules, covering the whole external surface of the 

 latter with their ramifications, and sending capillary twigs inwards, 

 which converge towards the centre of each lobule (Fig. 119, 2, 2). As 



