474 



ANATOMY OF VERTEBRATES. 



is loosely suspended. In the Hog it adheres to the back part of 

 4he ascending colon before bending forward to become jejunum : 

 the small intestines form numerous short convolutions : their 

 lining membrane is not produced into folds. Hunter found 

 them twenty times the length of the body of the domestic Hog : 

 they are much shorter in the Wild Boar. The caecum is about 

 four inches in length and an inch in diameter, lying loose, but 

 attached by a peritoneal fold to the ileum. The colon in part of 

 its course is disposed in five spiral coils ( like a screw, coming 

 nearer the centre ; at the end of which it is bent back upon 

 itself, passing between the former turns as far as the first, 

 but in this retrograde course it gets nearer the centre of the 

 screw, so that it is entirely hid at last, then makes a quick turn 

 363 upward, as high 



as the first spiral 

 turn : thence it 

 crosses the spine 

 before the mesen- 

 tery, adhering to 

 the lower surface 

 of the pancreas, 

 and, as it were, 

 inclosing the fore 

 part of the root 

 of the mesentery : 

 then passes down 

 before the duode- 

 num, gets behind 

 the bladder and 

 forms the rec- 

 tum.' 1 



The spiral turns 

 of the colon, above 

 described, form 

 one of the cha- 

 racteristics of the 

 Artiodactyle or- 

 der : they are re- 

 presented, as they 

 appear in the Sheep, in fig. 363. The ileo-caecal valve consists 

 of two semilunar folds in the Hog. The csecum of the Babyroussa 

 consists of an expanded, sub-bisacculate part and a narrower short 



1 ccxxxvi. ii. p. 121. 



Intestines of the Sheep, xcvi' 



