26 THE LIVER, BY EWALD BERING. 



receive their supply of both sets of vessels by a circuitous 

 route. The hepatic vein also differs from the portal in giving 

 off such direct intralobular branches into the adjoining lobules 

 from relatively larger trunks. As a consequence of this, fine 

 pores can be distinguished near the larger openings on the 

 internal surface of the hepatic vein, which lead into the intra- 

 lobular veins. The small hepatic veins (vence sublobulares) 

 which give off the intralobular veins on every side, apply 

 themselves to the bases of the surrounding lobules; only 

 isolated lobules are seated on the large veins ; elsewhere they 

 present their sides or apices to these veins. 



The branches of the portal vein never anastomose with one 

 another ; and even where two interlobular veins, coming from 

 opposite quarters, run between the same lobules, they do not 

 communicate, but break up into capillaries. In like manner no 

 anastomoses occur between the branches of the hepatic vein ; 

 and lastly, the portal and hepatic veins communicate in no 

 other way than through their capillaries. 



The hepatic artery exhibits a remarkable peculiarity, which 

 has an important bearing on the mechanics of the circulation 

 in this organ ; namely, that its branches anastomose with each 

 other, and form a wide-meshed plexus, that partly surrounds 

 the structures lying in Glisson's sheath (rami vasculares 

 arteriosi), and the large veins, and are partly distributed in the 

 capsule (rami capsulares arteriosi). From this arterial plexus 

 capillaries arise which are very narrow in comparison with the 

 capillaries of the portal vein, and, where they do not form the 

 close capillary plexus belonging to the larger biliary ducts, run 

 in wide loops, and form very wide plexuses. These capillaries 

 accompany the larger vessels, penetrate with Glisson's sheath 

 between the lobules, and are also distributed in the capsule of 

 the liver. The blood they transmit is collected in part, as was 

 first shown by Ferrein, into small veins which, constituting 

 the so-called internal rootlets of the portal vein, accompany in 

 pairs each arterial branch (Beale), and open into branches of 

 the portal vein, whilst a part is discharged directly into the 

 portal capillaries ; the latter taking place where both capillary 

 plexuses lie in close proximity, as in the capsule and in the 

 interlobular connective tissue ; the former, where thick layers 



