CHAP. XIV.] ALIMENTATION. 165 



into small polyhedral or many-sided masses, called hepatic 

 lobules; the blood-vessels form networks around and in the 

 lobules ; while the ducts which carry away the secretion (bile) 

 begin within the lobules in the form of tiny channels, running 

 between the cells. 



The whole liver is invested in an envelope or capsule of con- 

 nective tissue (Glisson's capsule), and the lobules are divided 

 from one another by very delicate partitions of areolar tissue, 

 each lobule being about the size of a pin's head and filled with 

 the special liver cells. 



The large portal vein and the small hepatic artery enter the 



FIG. 103. DIAGRAMMATIC REPRESENTATION OF Two HEPATIC LOBULES. The 

 left hand lobule is represented with the intralobular vein cut across; in the right 

 hand one the section takes the course of the intralobular vein, p, interlobular 

 branches of the portal vein; h, intralobular branches of the hepatic veins; s, sub- 

 lobular vein ; e, capillaries of the lobules. The arrows indicate the direction of the 

 course of the blood. The liver-cells are only represented in one part of each lobule. 



liver together on its under surface at what is called the " gate 

 of the liver," the bile duct passing out at the same place. The 

 branches of these three vessels, enclosed by loose connective 

 tissue, in which are lymphatics and nerves, accompany one 

 another in their course through the organ. The smallest 

 branches penetrate between the lobules, and, surrounding and 

 lying between each lobule, are known as the interlobular 

 branches. From the interlobular branches of the portal vein, 

 thus surrounding the circumference of each lobule, run capillary 

 vessels, somewhat like the spokes of a wheel. These capillaries, 

 converging towards the centre, merge into a veinlet, the intra- 



