BLOODVESSELS OF THE LIVER. 25 



of the liver undergoes metamorphosis by atrophy into a mass of con- 

 nective tissue, and a similar condition is exhibited by the so-called 

 tight-lace liver, where the pressure of the belt has produced a callous 

 furrow on the surface of the liver. 



Subsequently, Wedl,* Beale, and more recently and very fully, 

 Henlef and Riess, have described the mucous glands and the plexuses 

 of the biliary ducts, the last-named author particularly insisting upon 

 the circumstance, that on account of the glands being imbedded in 

 the walls of the ducts, they cannot be regarded " as appendices of 

 the ducts as a whole, but only as appendices of their lumen." 



THE BLOODVESSELS OF THE LIVER. The liver contains two 

 systems of capillary bloodvessels in its substance, belonging 

 respectively to the portal vein and the hepatic artery. The 

 former, which has been already described, usually exhibits 

 large capillaries and small meshes ; the latter, small capillaries 

 and large meshes; the former is distributed throughout the 

 interior of the lobules ; the latter is limited to their external 

 surface. Both are so far continuous with one another, that the 

 blood traversing the capillary system of the hepatic artery 

 enters, partly directly, and in part indirectly, into the capillary 

 system derived from the portal vein, so that ultimately the 

 intralobular veins carry off the blood which has traversed both 

 the portal vein and the hepatic artery. 



Both of these vessels ramify quite independently of the 

 hepatic vein ; the branches of the portal vein are invested by 

 the loose connective tissue of Glisson's sheath, whilst the 

 hepatic veins are firmly adherent to the substance of the liver, 

 only a small quantity of connective tissue being interposed. 

 The inter- and intralobular veins originate in part from the 

 terminal branches of small portal or hepatic venous branches, 

 but partly also as lateral branches of the larger trunks. The 

 larger branches of the portal and hepatic veins do not, how- 

 ever, give off any inter- or intralobular veins to the lobules 

 that immediately surround them. The latter, therefore, must 



* Sitzungsberichte der Kaiserliche Akademie der Wissenschaften zu Wien, 

 12th Dec., 1850, Band v., p. 481. 



t Handbuch der Anatomie, Band ii. Eingeweidelehre, 1866. 



