eae of the Human Liver. 73 
stance of the liver, furnishes small branches to supply its own walls, 
those of the portal vein, hepatic duct and lymphatics, and the 
neurilemma of the hepatic plexuses of nerves with blood, which is 
returned by similar branches to the portal vein. Besides these, 
there are others given off, which, in company of small branches of 
the portal vem and hepatic duct, enter the substance of the liver ; 
their distribution will be described hereafter. The duct here receives 
numerous branches of the ducts of the plexuses of hepatic glands, 
which have been mentioned above. 
The main branches of the portal vessels—as we may term the 
portal vein and hepatic artery with the accompanying hepatic duct 
—resulting from the divisions of the parent trunks, enter the sub- 
stance of the liver, and continue to divide and subdivide, while 
passing toward the surface of the organ, in a manner as has already 
been described. They are always found close to each other, held 
together and enveloped by that prolongation or process of the com- 
mon capsule of the organ, called the “capsule of the portal vessels,” 
which, of course, diminishes in proportion to the calibre of the 
vessels formed by the various subdivisions, until it finely disappears 
entirely by blending with the coats of the finest branches. 
All the branches of the hepatic artery resulting from its various 
divisions and subdivisions—excepting those finer ones that enter the 
parenchyma, usually termed “ lobular ”—send off a set of smaller 
ones, which are destined to supply the coats of the vessels, the 
nerves, and also that extensive system of hepatic glands with blood. 
The size of these branches is proportionate to the calibre of the 
vessel from which they spring, and the manner in which they are 
distributed is peculiar. Having arisen from their respective vessels, 
they divide and subdivide in accordance to their size, and then 
anastomose with each other on the inner surface of the capsule. 
From these anastomoses, a number of branches arise which are 
variously distributed (Fig. 3). Some of them proceed to the coats 
of the vessels and ducts, and also to the plexuses of nerves ; others 
to the plexus of hepatic glands; and others again pass directly to 
the parenchyma. ‘This division, however, must not be adhered 
to very rigidly, as we frequently observe one branch supplying dif- 
ferent adjacent parts. Besides those already mentioned, there are 
others which pass to the capsule of the hepatic veins, in order to 
supply the coats of the latter. Lastly, there are some branches 
which, penetrating to the external surface of the capsule, form there 
small anastomoses from which principally the smaller inter-lobular 
and lobular branches take their origin. The arterial branches just 
described, of course, are accompanied by similar ones coming from 
the portal vein, in order to return the blood carried to the various 
parts by the arteries. The arrangement of these veins, however, 
differs a little from that of the arteries. After they have arisen 
e 
