FUNCTIONS OF THE LIVER. 327 



about one-twentieth of an inch in diameter and which in 

 itself has been termed a "miniature liver": 



"A lobule of the liver is polygonal in shape, and is com- 

 posed chiefly of a number of gland-tubes, which radiate from 

 near the center of the lobule to the periphery, where they open 

 into their ducts. Thus, the blind terminal end of the tube is 

 turned toward the center of the lobule; the ducts at the pe- 

 riphery lie in the interlobular connective tissue, which to the 

 naked eye marks the boundaries of the lobule. 



"The blood brought to the liver by the portal vein 11 is 

 conveyed along its subdividing branches till the ultimate sub- 

 divisions are reached, which lie, together with the bile, in the 

 connective tissue surrounding the lobules. Here capillaries are 

 given off which pierce the lobule and pass between the radiat- 

 ing gland-tubes to reach the center, where they open into the 

 intralobular radicle of the efferent vein of the liver, the hepatic 

 vein. These small hepatic radicles open into the larger vessel, 

 the sublobular vein, and the sublobular veins unite to con- 

 tribute to the hepatic vein itself. The walls of the branches 

 of the hepatic vein are destitute of muscular fibers and the 

 adventitia is extremely thin. The radiating gland-tubes anas- 

 tomose laterally with each other, as do the capillaries also. 

 The meshes of the net-works are elongated in a radial direction. 

 Thus, a lobule is composed of a radiating system of gland-tubes 

 and a corresponding radiating system of capillaries lying be- 

 tween them. A very minute quantity of connective tissue 

 accompanies the capillaries as an adventitia and in this lym- 

 phatic channels are to be found separating the gland-tubule 

 from the blood-vessel. 



"The lobule is surrounded (in part or whole) with con- 

 nective tissue supporting branches of the afferent portal vein, 

 the feeder of the capillary net-work, and the bile-ducts, 

 which receive the secretion of the gland-tubules. Thus, the 

 blood flows from the periphery to the center of the lobule; the 

 bile, from the center to the periphery. 



"But in addition to the afferent portal vein and the bile- 

 ducts another vessel is found in the interlobular connective 



11 The italics are our own. 



