ALIMENTARY CANAL OF MAKSUPIALIA. 419 



being suspended on a broad mesocolon. The diameter of both 

 small and large intestines is nearly the same : in Hyps, setosus I 

 found this to be half-an-inch. 



In the great Kangaroo the descending portion of the duodenum 

 is attached posteriorly, by means of a thin peritoneal duplicature, 

 to the spine, and anteriorly to the ascending colon : it makes an 

 abrupt turn upon itself, and a fold of peritoneum is continued 

 from the convexity of the curve to the right iliac region. The 

 small intestines are strung in short folds on a rather narrow me- 

 sentery. The caecum is in part suspended from the same me- 

 senteric fold. The colon, besides its posterior connections with 

 a mesocolon, is attached, as before 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 rectum, 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. The villi of the small intestines 

 in the Kangaroo are of moderate length, compressed and close- 

 se't. Grlandulae aggregate are arranged in narrow patches in the 

 ileum. There are seven groups of similar follicles in the caecum ; 

 and a few long and narrow patches of glands occur in the colon 

 intermingled with numerous glanduloe solitariaa ; the surface of 

 the rest of the lining membrane of the large intestine is disposed 

 in a very fine net-work. 



Two faint longitudinal bands extend along the first ten inches 

 of the colon and are continued along two-thirds of the caecum : 

 the sacculi produced by these bands are but very feebly marked. 

 The contents of the caecum in the great Kangaroo 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 faeces about an inch 

 square. The diameter of the large intestine in this species ex- 

 ceeds 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 surrounded, in common with the genital outlet, by a 

 larger one. TVheii the penis is retracted, the faecal, urinary, 

 and o-eiiital canals all terminate within a common external 



o 



outlet ; so that in the literal sense the Marsupials are monotre- 

 matous. 



The following is a table of the length of the intestinal canal, 



E E 2 



