76 The Microscopic Structure Non 
siderable size at the posterior surface of the liver, where it is devoid 
of peritoneal covering. 
The lymphatic vessels of the capsule on the surface of the liver 
are numerous, and form a beautiful and extensive network of large 
meshes (Fig. 2). The vessels composing these meshes are almost 
as fine, or in some places even finer, than a capillary blood-vessel. 
Some times one is seen for a short distance to enlarge in diameter, 
when, joining together, it will be reduced again to its former size. 
The larger branches, arising from the plexus, join another, formed 
by larger vessels; and the latter communicate with still larger 
meshes; the vessels of which can be distinguished by the naked 
eye. From the latter, those vessels arise that proceed to the lym- 
phatic glands in the vicinity of the liver. Some lymphatic vessels 
always accompany the branches of the hepatic artery. 
The nerves ramifying in the capsule under consideration, follow 
the course of the artery ; I have not traced them to their termination. 
In taking a final view of the distribution of the vessels, &c., 
within the different parts of the capsule, we find everywhere, 
branches of the hepatic artery forming anastomoses, from which 
all other branches, destined to supply the different components of 
the organ with blood, take their origin. The distribution of the 
portal vein is similar, except in the “ capsule of the portal vessels,” 
where the plexuses, formed by its branches, are most abundant in 
the vicinity of the “ hepatic glands,” which are exceedingly nume- 
rous in this situation, on account of the close proximity to the 
hepatic ducts into which they empty. The lymphatics are also 
equally distributed throughout all parts of the capsule. 
It is obvious that the main function of the capsule of the liver 
with its prolongations, is simply to support and bind together, or 
hold in their respective places, the various vessels, ducts, lymphatics 
and nerves of the organ; it is, therefore, analogous to the function 
of the various fasciz and sheaths of blood-vessels and nerves in 
general, 
Termination of the Portal Vein and Hepatic Artery in the Capit- 
laries of the Parenchyma. Convmencement of the Veins. Struc- 
ture of the Vessels. 
Some of the branches arising from the anastomoses, formed by 
the portal vein in the capsule of the “ portal vessels,” pass into the 
parenchyma and give origin to those which finally enter the so- 
called “lobules” —imaginary subdivisions—of the human liver. 
These inter-lobular and lobular vems are accompanied by one, or 
sometimes two, similar branches derived from the anastomoses of 
the hepatic artery. The mean diameter of the former is 3+> of an 
inch, that of the latter, y55 of an inch; but frequently the lobular 
branches of the artery are almost as large as those of the vein. 
