SPLANCHNOLOGY. 197 
to take up any chyle that may have escaped those in the ileum, as also the 
watery parts of the food, and the feces become hardened by degrees, and 
moulded or figured according to the length of time they are lodged in the 
cells of the colon; The great length of this tube, as well as its yielding 
structure, adapt it as a reservoir capable of retaining a considerable quan- 
tity, and thus obviating the inconvenience of frequent defecation. The 
rectum also contributes to the same effect, being retained in a closed state 
by the sphincters and supported by the levatores ani muscles. When the 
evacuation of the bowels is called for by the peculiar sensations in the part, 
the contents are expelled partly by the muscular action of the rectum and 
the concurring relaxation of its sphincter, aided by the voluntary contrac- 
tion of the diaphragm and abdominal muscles. 
Pi. 130, fig. 11, stomach with its fleshy fibres: **, longitudinal fibres from 
the cardiac orifice ; “*, circular and transverse fibres. ig. 12, cesophagus at 
its entrance into the stomach: ', mucous membrane of the csophagus; 
*, do, of the stomach; *, line of separation between the two; the imequall- 
ties indicate the cardiac orifice. J/g. 18, valve of the pylorus. fg. 14, 
intestinal tract: ’, coils of the small intestines; *, ccecum with its vermi- 
cular appendage; °, ascending, *, transverse, °, descending colon; °, sigmoid 
flexure; ’, rectum; °, appendices epiploice, folds of the peritonzeum filled 
with fat. Jig. 15, portion of the small intestines opened to show the val- 
vulze conniventes. J/g. 16, cceecum opened: *, end of the ileum; *, vermi- 
cular appendage; *,its opening into the ccecum; *, opening of the ileum; 
* °, folds of the mucous membranes, forming the lips of the valves. 
The glandular viscera of the abdomen which are subservient to digestion 
and assimilation are, the liver, spleen, and pancreas. 
_ 6. THe Liver is the largest and heaviest secreting gland in the body; it 
is situated below the diaphragm, and above the right kidney, the stomach, 
duodenum, and lesser omentum ; and is supported in this position by several 
folds of the peritonzeum, inaccurately termed ligaments, viz, the falciform, 
round, right, left, and coronary. These connect it to the diaphragm and to 
the abdominal muscles, and the lesser omentum attaches it to the stomach 
and omentum. Its weight varies from three to five pounds, depending on 
the amount of blood included; its transverse diameter is about ten or 
twelve inches, the vertical about seven in the deepest part of the right lobe. 
The liver is of very irregular form. The superior or anterior surface is 
smooth and convex, and divided by the suspensory ligament into a right 
and left portion. The inferior surface looks backwards and downwards ; it 
is very irregular, and marked by several projections and depressions. The 
former are called lobes, and are five in number: first, the great or right 
lobe ; secondly, the left lobe, which rests on the stomach; third, the spegelian 
or middle lobe, situated behind the lesser omentum; fourth, the lobulus 
caudatus, immediately behind the transverse fissure; fifth, the lobulus qua- 
dratus or anonymus, at the anterior part of the right lobe. 
The principal depressions or fissures on the inferior surface of the liver 
are: the transverse fissure or porta, situated between the lobulus quadratus 
and caudatus; the horizontal fissure, extending from the notch in the 
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