872
PACHYDERM ATA.
sac issuing from the posterior aspect of the car¬
diac extremity of the stomach and projecting
towards the right side. The construction of the
interior of this stomach is still more extraordinary
than its external appearance, for it is so divided
by septa, that food coming into this viscus through
the oesophagus may pass by different channels,
either into the central portion, which seems pro¬
perly entitled to the name of stomach, or into
either of the great diverticula appended to it.
The inferior walls of the central stomach have
nine or ten cavities in them, something like
those of the Camel and Dromedary. The lining
membrane both of the stomach and diverticula
is granular and wrinkled except near the py¬
lorus, where the parietes become smooth and
folded into numerous plicæ somewhat resem¬
bling those of the third stomach of a ruminant,
although there is no probability that rumination
occurs in the animal under consideration.
In the hog tribe the proportionate dimensions
of the alimentary canal are very great when
compared with the size of the animal’s body,
the large and small intestines of the Hog or
wild Boar measuring together from sixty to
sixty-five feet in length, the large intestines
alone being in the wild Boar thirteen and in the
domestic Hog fifteen feet long. The stomach
is capacious, the entrance of the oesophagus
being situated nearly in the centre of its lesser
curvature, so that the cardiac cul de sac is
exceedingly large, and is moreover prolonged
into a kind of cowl-shaped appendage, which
gives it a very peculiar aspect. On opening
the stomach the epithelium of the oesophagus
is found to be prolonged for some distance into
its interior, where it covers a square space of
considerable extent, the borders of which are
well defined. At the entrance to the pylorus
there is a large nipple-shaped projection up¬
wards of an inch in length in the full-grown
animal ; and moreover, however much the
stomach may be distended, there always re¬
mains a deep fold crossing it at its upper part,
between the oesophagus and the pylorus, and
another equally extensive bounding the com¬
mencement of the great cardiac cul de sac,
these folds evidently indicating a relationship
with the more complex stomachs met with in
ruminating animals, especially as the lining
membrane only assumes a villous aspect in the
pyloric region of the viscus.
The liver consists of four lobes, and there is
a distinct gall-bladder, either lodged in a deep
fissure, or imbedded in the substance of the
middle lobe. The spleen is long, flat, and
somewhat of a prismatic shape, and the pan¬
creas consists of three portions, which unite
near the pylorus.
The Hyrax Capensis has a stomach which to
a certain extent reminds the anatomist of the
complex condition of that viscus met with in
many animals nearly related to the Pachyder-
mata. The cardiac extremity is large, and
forms a capacious cavity, which is divided by a
deep constriction from a second compartment
of smaller dimensions, which opens into the
pyloric portion of the organ. The whole viscus
is moreover so bent upon itself owing to the
smallness of the lesser curvature, that the py¬
loric and cardiac extremities are almost in con¬
tact with each other. The cæcum is likewise
proportionably of enormous size, being larger
than the stomach itself, and from this a spirally
folded intestine of no very great calibre runs to
a kind of second cæcum of large capacity,
which has its commencement prolonged up¬
wards by means of two conical appendages like
horns, whence it has been named by Pallas
intestinum bicorne, and this last, after becoming
considerably diminished in size, terminates in
the rectum.
Salivary glands.—The salivary organs are
very large. In the Hog there are two sublingual
glands ; one, which is very long and narrow,
accompanies the duct of the maxillary gland,
and is composed of small lobes of a pale reddish
^colour ; the orifice of its excretory duct is near
that of the maxillary. The second sublingual
gland is placed in front of the former, and is
of a square form ; it discharges its secretion
through eight or ten short ducts, which pierce
the mucous membrane of the mouth. The
parotid is large, its duct opening opposite the
third molar tooth ; and in addition to these
there are the molar glands, which form two
elongated masses, situated along the alveoli of
the superior and inferior molar teeth, and
extending forward as far as the canines ; these
pour their secretion into the mouth through
numerous little orifices.
Os hyoides.—The os hyoides in the Elephant
has its body or central portion, which resembles
a flattened lamina, slightly arched from below
upwards, consolidated with the posterior cornua,
which divide into two branches as they curve
gently backwards and inwards. The anterior
cornua articulate with the styloid process of the
temporal. In other Pachyderms the general
disposition of the hyoid pieces is very similar
to the above, but in the Rhinoceros their ar¬
rangement approximates what is met with in
horned ruminants, the anterior cornua being
articulated to the styloid by an intervening
osseous piece.
The laryngeal apparatus exhibits nothing
extraordinary in its arrangement.
Circulatory and respiratory systems.—The
organs of circulation and respiration likewise,
in their general arrangement, differ from those
of other Mammalia in no important particular.
We may, however, notice one or two deviations
from the usual type in the origins of the chief
venous and arterial trunks.
In the Hyrax the arch of the aorta gives oft’
the arteria innominata, which divides into the
right subclavian and the two common carotids,
and then a second single trunk, which is the
left subclavian.
The Elephant in several points of its economy
exhibits remarkable affinities with the Roden-
tia, in proof of which the correspondence of
the structure of its heart with that of some of
the Rodents is very striking. Thus the right
auricle receives three venae cavæ, a right and a
left superior and an inferior, which latter pre¬
sents the usual arrangement. Moreover, the
Eustachian valve, which is placed between