REPORT ON THE MARSUPIALIA. 101 



The stomach has thick muscular walls, and the duodenum is marked off by a deep 

 constriction. 



Internally, the mucous membrane is rugose when the organ is flaccid, but the folds 

 disappear upon distention. Along the lesser curvature, and towards the pylorus, the same 

 alveolar depressions which were noticed in the stomach of the Tkylacine are observed in 

 the stomach of the Cuscus. The following are the measurements: — ■ 



Inches. 



Length of the greater curvature from the highest point of the I „ 



cardiac cul-de-sac to the pylorus, . . .J 



Length of the lesser curvature between the same points, . 2| 



Small intestine. — The small intestine measured 5 feet 4 inches in length. The calibre 

 of the gut gradually diminishes as we trace it towards the caecum. The bile-duct 

 (previously joined by the pancreatic duct) opens into the duodenum at a point 2^ inches 

 distant from the pyloric constriction. 



The mucous membrane of the small intestine is exceedingly thin and delicate in its 

 texture. It is covered by minute villi, which give it the usual velvety appearance. 



The Peyer's patches vary greatly in size and shape. The largest was fully one inch 

 long by half an inch broad ; — the smallest was a mere speck. They were nine in number. 

 The first was placed about twenty-two inches behind the pylorus ; the last was situated 

 five inches in front of the junction of the ileum with the caecum. 



Large intestine. — The large intestine may be divided into a caecum, colon, and rectum. 



The caecum is very long and capacious. It measured in length 2 feet 9 inches, whilst 

 its girth at its widest part was 5^ inches. From the entrance of the ileum to its 

 extremity, it tapers uniformly and terminates in a blind end which is little larger than 

 the stem of an ordinary tobacco pipe. It shows a slight sacculation along its convexity, 

 opposite the line of mesenteric attachment. 



The colon was five feet long. It is very wide where it is continuous with the caecum, 

 but its calibre diminishes gradually as it is traced towards the rectum, where it assumes 

 a diameter considerably less than that of the small intestine. 



Peritoneum. — In the Cuscus the great omentum is very short, and composed of the 

 usualfour layers of peritoneal membrane. The two inferior of these layers when traced 

 forwards, are observed to enclose the stomach, form the gastro-hepatic omentum, and 

 finally to invest the liver completely and bind it by a distinct fold to the posterior surface 

 of the diaphragm. The two superior layers of the omentum proceed directly upwards to 

 the spine where they separate. The anterior layer is carried forwards upon the upper 

 abdominal wall, whilst the posterior layer leaves the spine to form an extremely 

 voluminous mesentery (6^ inches long) for the colon. From the root of this fold the 

 peritoneum again leaves the spine to form the mesentery of the small intestine which is 



only three inches long. 



(zool. CHALL. EXP. — part xvi. — 1882.) Q 21 



