67 6 ESSAY ON THE DESCRIPTIVE ANATOMY OF THE 
ing the lesser or gastro hepatic, the greater or gastro colic, and 
the gastro splenic omenta, closes in a space termed the omental 
sac, the interior of which is inaccessible except by an opening 
at the posterior part of the gastro hepatic omentum, whose free 
margin at the right side marks the point where it may be pene- 
trated : this passage is termed the foramen of Winslow. It is 
bounded anteriorly by the lesser omentum, above by the liver, 
and posteriorly by the transverse colon. 
Thus, supposing the inner layer of the omental sac to be 
separable from the outer, and drawn out through the foramen of 
Winslow, the following parts would be deprived of peritonseum, 
i. e., the posterior surface of the stomach, the gastro splenic 
omentum of its posterior layer ; so that the vessels going to and 
from the stomach and spleen would remain uncovered, the 
anterior part of the transverse colon, the anterior surface of the 
pancreas, and inner or posterior layer of the gastro hepatic 
omentum. 
Next to be described to the serous coat is the muscular 
one, which is constituted of involuntary plain fibres, whose 
thickness is very variable in different subjects, as well as in 
different parts of the same stomach. The cardiac end is more 
muscular than the pyloric, except at the right margin of the 
latter, where it is very powerful and thick, as it surrounds the 
pylorus. The thinnest part of the stomach is unquestionably the 
convex border of the lesser cul-de-sac. 
The muscular coat of the stomach is intricately arranged, and 
authorities differ vastly from each other in the description of 
the several layers constituting it. The number of layers en- 
tering into its composition is three : the outer and inner ones are 
mostly continuations of the inner layers of the oesophagus, 
while the middle one is proper to the stomach. 
The outer layer is composed of the longitudinal fibres of the 
oesophagus : as these reach the cardiac end of the stomach, they 
form a peculiar turn, whereby the distribution on the surfaces as 
a flat layer is facilitated. Some of the fibres of this layer dip 
down to join the deeper ones, while others continue onwards as 
the longitudinal fibres of the duodenum. As to the fibres which 
proceed on to the curvatures, they are not so intricate, as they de- 
scend directly from the portion of the oesophagus opposite the part 
they supply, so that the only alteration in direction is that of di- 
verging a little from each other, and pursuing the bent course 
of the corresponding gastric curvature. On the lesser one they 
soon become scanty, and are lost in the circular fibres of the 
body of the stomach : very few of them are traced on to the 
pylorus. The fibres proceeding on to the greater curvature 
are mingled with other considerable bundles taking the same 
