MARSUPIALIA. 
a fold of peritoneum continued from the con- 
vexity of its depending curve. I found the 
cecum in this species disposed in a spiral 
curve in the left lumbar region: the colon 
ascended a little way in front of the stomach, 
receiving a branch of the superior mesenteric 
artery, and was then continued straight down 
to the anus; thus we are again reminded of the 
oviparous character by the shortness of the 
large intestine. ‘ 
In the Pet. taguanoides the duodenum is 
tied down to the iliac region, as in the Da- 
syure; the cecum is four inches long, and 
the colon is relatively longer than in the Acro- 
bates ; it makes the tour of the abdomen much 
as in man, but is continued into the rectum 
without forming a sigmoid flexure. 
In the Phalangers the duodenum winds round 
the root of the mesentery, descending pretty 
low down on the right side, and becoming a 
loose intestine or jejunum on the left side. 
The long cecum is suspended by a broad du- 
plicature of peritoneum continued from the 
mesocolon; and the colon is closely attached 
at its transverse arch to the duodenum and root 
of the mesentery. 
In the Koala the cecum and large intestines 
arrive at their maximum of development. The 
duodenum commences with a small pyriform 
sacculus nearly an inch in breadth, and soon 
contracts to a diameter of five lines, which is 
the general calibre of the small intestines. The 
large intestines, where the ilium terminates, 
have a diameter of two inches. The end of 
the ileum (a, fig. 129) protrudes for the extent 
Fig. 129. 
Tleo-ceecal valve, Koala. Half its natural size. 
of a quarter of an inch within the cecum, 
forming a very effectual valve: near this part 
there are two wide and deep glandular fosse : 
the longitudinal valvule conniventes of the 
large intestines have already been noticed. 
In the Potoroos the small intestines are dis- 
posed nearly as in the Phalangers: the short 
and wide ccecum lies in the right hypogastrium: 
the colon makes the usual tour of the abdomen, 
303 . 
but is disposed in long convolutions through 
its whole course, being suspended on a broad 
mesocolon. The diameter of both small and 
large intestines is nearly the same: in Hyps. 
setosus 1 found this to be half-an-inch. 
In the great Kangaroo the descending por- 
tion of the duodenum is attached posteriorly, 
by means of a thin peritoneal duplicature, to 
the spine, and anteriorly to the ascending co- 
lon: it makes an abrupt turn upon itself, and 
a fold of peritoneum is continued from the con- 
vexity of the curve to the right iliac region. 
The small intestines are strung in short folds 
on a rather narrow mesentery. The cecum is 
in part suspended from the same mesenteric 
fold. The colon, besides its posterior con- 
nexions with a mesocolon, is attached, as be- 
fore observed, to the duodenum ; and also, by 
means of the great omentum, pretty closely to 
the stomach, whence it passes down, forming 
many large and loose convolutions to the rec- 
tum, being attached by a broad mesocolon to 
the left hypochondriac region. 
The zone of glands at the commencement of 
the duodenum has been already noticed ; 
they are present in other Marsupials, even in 
the most carnivorous species; but [I have not 
met with a similar structure in the placental 
Mammalia. The villi of the small intestines 
in the Kangaroo are of moderate length, com- 
pressed and close-set. Glandule aggregate 
are arranged in narrow patches in the ileum. 
There are seven groups of siinilar follicles in 
the cecum; and a few long and narrow patches 
of glands occur in the colon intermingled with 
numerous glandule solitariz ; the surface of the 
rest of the lining membrane of the large intes- 
tine is disposed in a very fine net-work. 
Two faint longitudinal bands extend along 
the first ten inches of the colon and are con- 
tinued along two-thirds of the cecum: the 
sacculi produced by these bands are but very 
feebly marked. I have not met with any ex- 
ample in the Macropus major of a cecum, 
which, either naturally or when inflated and 
dried, presented the sacculated structure repre- 
sented by Cuvier in fig. 8, pl. xxxix. of the 
Lecons d’Anat. Comparée. 
The contents of the cecum in the great Kan 
garoo are of a pultaceous consistence, and the 
mass continues undivided along the first two feet 
of the colon, gradually becoming less fluid and 
then beginning to be separated into cubical 
feces about an inch square. The diameter of 
the large intestine in this species exceeds very 
little that of the small intestines. 
In all the Marsupials two sebaceous follicles 
open into the termination of the rectum. The 
anus has its proper sphincter, but is also sur- 
rounded, in common with the genital outlet, 
by a larger one. When the penis is retracted, 
the fecal, urinary, and genital canals all ter- 
minate within a common external outlet; so 
that in the literal sense the Marsupials are mo- 
notrematous. 
The following is a table of the length of the 
intestinal canal, and its parts in a few species 
of the different families of Marsupialia, 
