OF THE STURGEON. 
339 
process of digestion is performed. From this point, after a 
slight bend upwards, the organ continues obliquely up- 
wards and towards the right side, crossing completely the 
mesial plane. At the curvature now mentioned, the organ 
begins to contract, and continues diminishing till it rises 
nearly to the level of the cardiac orifice, when it tapers, 
and, becoming conical, takes another bend, in order to 
form the pylorus and its valve. The portion of the organ 
included between the curvature and the pyloric outlet, may 
be regarded as the pyloric or second division of the sto- 
mach. 
When cut open, the breadth at the orifice of the sound 
or swimming-bladder, which is about two inches below the 
cardia, is six inches exactly ; and, a little below this, it 
amounts to seven inches, which may be regarded as the 
greatest breadth of the gastric membrane. From these 
measurements, however, it is impossible to calculate exactly 
the capacity of the organ ; for it is evidently very distensi- 
ble, and had contracted greatly after being laid open ; and, 
while the circumference now stated gives an average dia- 
meter of 2J inches only, I think it is likely, from the folds 
which, in the recent state, the inner membrane presented, 
that the caliber of the organ is at least four inches, and oc- 
casionally six or seven. 
The parietes of the stomach are thinner and more mem- 
branous than those of the oesophagus ; and, while its inte- 
rior is formed by a thin transparent membrane, correspond- 
ing to the peritoneum of the mammalia, the middle consists 
of a layer of circular muscular fibres, lined on its interior 
by a villous membrane of no great thickness, but firm and 
tenacious. Of this latter membrane, the most remarkable 
peculiarity is, that it is gathered into longitudinal folds, ex- 
tending from the cardia to the pylorus, not dissimilar to 
those of the Red or fourth stomach of the ruminating tribes. 
Y 2 
