28 ESSAY ON THE DESCRIPTIVE ANATOMY OF THE 
by a depression, for the adaptation of the anterior part of the 
right kidney. At the superior part of the right lobe is an 
excavation for the vena cava, which extends from behind 
forwards, and marks off the division between the right and 
middle lobe. The vena cava is here more or less imbedded in 
the substance of the right lobe, but, generally speaking, it is 
superficial in the horse, and only an imperfect channel is formed 
for it. 
Projecting from the inferior surface and posterior part of the 
right lobe, is the lobulus spigelii, which is of considerable size, 
being broad posteriorly, and attached by its superior and left 
border, so that it projects anteriorly and narrows; its apex 
gradually tapers, and has been capriciously designated, by the 
lovers of a quintuple hepatic arrangement, lobulus caudatus. 
The middle lobe of the liver is the smallest of the three; it 
is crossed on its inferior surface by the transverse fissure or 
porta of the liver, at which the vessels and ducts enter into 
and issue from the gland. The middle lobe in the horse is 
divided at its anterior part into five or six portions, and Mr. 
Percivall, in his Anatomy of the Horse, at page 259, has 
termed it the lobulus scissatus. It is traversed antero-pos- 
teriorlv by a channel for the remnant of the umbilical vein, 
which eventually joins the vena porta. 
The left lobe is the thinnest of the three, but occupies an 
intermediate position in length and breadth. It is very thin at 
its left margin, and gradually thickens posteriorly. At its pos¬ 
terior and left side is a depression in which the oesophagus rests. 
Sometimes the left lobe is divided into two at its anterior part; 
at others it is single. 
The superior surface of the liver is convex, and in contact 
with the pillars and expanded portion of the diaphragm. 1 he 
right, as well as the Spigelian lobes, are in relation posteriorly 
with the right kidney and right supra-renal capsule, interiorly 
with the head of the pancreas, duodenum, and transverse colon. 
The middle lobe is related inferiorly to the pancreas, but par¬ 
tially separated from it by the vena portae. It also suspends 
the duodenum, and its left edge is loose and in close proximity 
to the flexures of the colon. The left lobe is related posteriorly 
to the oesophagus, and inferiorly to the left end of the stomach. 
The pancreas also stretches across its posterior part, partially 
separating it from the transverse colon. 
The liver receives an incomplete covering of peritoneum. 
The latter, reflected from the diaphragm on to the concave sur¬ 
face of the middle lobe of the liver, forms a double membranous 
layer, known, in acordance with its shape, as the falsi form liga¬ 
ment, and holding in its free and concave margin the round 
