PERITONEUM. 
passage to the transverse portion of the duo- 
denum. 
The mesentery is the peritoneal fold that 
connects the small intestine to the posterior 
abdominal parietes, giving transit to the vessels 
and nerves of that part of the intestinal tube. 
Numerous lymphatic glands, called mesenteric 
glands, are also included between its layers. It 
is eight inches in breadth at its widest part, and 
narrows off towards each end, where the small 
intestine becomes adherent to the parietes. Its 
parietal attachment, as mentioned above, is 
only a few inches in extent, whilst its visceral 
border is usually twenty feet long. 
The ascending mesocolon, descending meso- 
colon, and mesocecum, when they exist, and the 
iliac or sigmoideal mesocolon and mesorectum, 
which always exist, perform all the offices of 
mesenteries to those parts, respectively, of the 
intestinal tube which are indicated in their 
names. 
The appendices epiploice are numerous smal! 
masses of fat, somewhat pyriform, and having a 
peritoneal investment, attached along the large 
intestine. Their use is not known; perhaps 
they serve as packing to the sacculated bowel 
on which they are placed. 
The recto-vesical folds give transit to some 
vesical vessels and the umbilical arteries of the 
foetus. The cellular tissue enclosed by them is 
very lax, so that they are easily unfolded by 
distention of the bladder. 
The broad ligaments of the uterus are two 
folds of peritoneum passing from the lateral 
borders of the uterus to the opposite abdominal 
parietes. The line of their summits is about 
level with that of the superior border of the 
unimpregnated uterus. This summit or supe- 
rior border of the broad ligament is defined by 
the Fallopian tube which it encloses; a little 
lower down on its posterior aspect the ovary is 
sessile upon it, invested in a secondary fold of 
its posterior layer: and the round ligament of 
the uterus passing between its layers from the 
side of the uterus to the inguinal canal carries 
out another little secondary fold in front of it. 
The broad ligament, then, and its secondary 
folds, enclose the ovary with its ligament, the 
Fallopian tube, the round ligament of the ute- 
rus, and the spermatic vessels and nerves. The 
layers of the broad ligament itself, but not those 
of its secondary folds, are connected together 
by loose areolar tissue, and are separated (the 
broad ligament itself becoming effaced) by the 
enlargement of the uterus in pregnancy. 
_ There are a pair of recto-uterine peritoneal 
folds in the female and a pair of vesico-uterine 
Jolds ; the former pass across from the sides of 
the rectum to the sides of the uterus, and repre- 
sent the recto-vesical folds of the male; the 
latter pass across from the sides of the uterus 
to the sides of the bladder. The layers of both 
pairs are very loosely connected together. 
There is a slight median fold and two slight 
lateral folds of the peritoneum lining the ante- 
rior abdominal parietes, converging from the 
fundus and sides of the bladder to the navel; 
they enclose the remains of the wrachus and of 
the two umbilical arteries of the fetus. 
943 
At the point corresponding with each inter- 
nal abdominal ring in the male subject, there 
is a little infundibuliform depression or dimple 
of.the peritoneal surface ; it indicates the point 
from which a portion of peritoneum, being car- 
ried down with the testicle in its descent, was 
separated to form the tunica vaginalis—in the 
female; from the same points a cylindrical 
sheath of peritoneum accompanies the round 
ligament a little way into the inguinal canal ; 
this sheath has been called the canal of Nuck. 
With regard to our third proposition,—THE 
SEROUS COAT AFFORDED BY THE PERITONEUM 
TO THE VARIOUS VISCERA invests some of them 
completely, except along little linear spaces, 
imaginary rather than real, where it reaches 
them as mesentery, &c.: others it invests on 
one side only, and others again still more par- 
tially. 
The liver has an investment of peritoneum 
complete, except at its posterior, thick, rounded 
border, over a space of inconstant form be- 
tween the anterior and posterior layers of the 
coronary ligament, where the liver is in imme- 
diate contact with the diaphragm, the space 
corresponding with the gall-bladder, and along 
the little linear spaces where the falciform and 
triangular ligaments and the lesser omentum 
are attached to it. 
The gall-bladder is invested with peritoneum 
on its lower aspect only; that side which is 
presented towards the liver is in immediate 
contact with it. 
The stomach is completely invested with pe- 
ritoneum, except at the two little linear’ spaces 
along its curvatures, where the lesser and greater 
omenta are attached to it. 
The spleen is invested by the peritoneum 
completely, except at its hilus, where its vessels 
enter from the omentum. 
The first or-ascending portion of the duode- 
mum has a complete peritoneal investment, 
except at a little linear space along its lower 
aspect, where the great omentum is attached to 
it, so that this portion is free to move. The 
second, or descending portion has peritoneal 
investment on its anterior aspect only. The 
third or transverse portion is invested with pe- 
ritoneum along a very narrow portion of the 
upper, and a somewhat less narrow portion of 
the lower part of its anterior aspect ; the whole 
of its posterior aspect and the middle part of 
its anterior are destitute of peritoneal covering, 
the former being adherent to the posterior abdo- 
minal parietes, &c., the latter corresponding 
with the root of the transverse mesocolon. Its 
upper aspect is adherent to the pancreas, which 
encroaches upon the upper one of the two 
spaces mentioned as invested with peritoneum. 
At the point where the duodenum is crossed by 
the colon, which is just where from descending 
it becomes transverse, the two bowels are in 
immediate contact, so that the duodenum is, at 
this point, destitute of peritoneal covering around 
its entire circumference. Where the superior 
mesenteric artery crosses the duodenum, the 
peritoneum is borne off from it by that vessel. 
The pancreas is invested with peritoneum on 
its anterior surface only. 
