102 ANATOMY OF THE RABBIT 



small intestine there is generally no abrupt change in the character 

 of the wall, although the first portion of the mesenterial intestine, 

 that designated as the jejunum, and the duodenum may be con- 

 sidered together as a more vascular portion with thicker walls in 

 comparison with the second portion, the ileum, in which the wall 

 is less vascular and more transparent. The rabbit, however, 

 presents an exception to the general statement at the beginning of 

 the previous sentence in that the terminal portion of the ileum 





Fig. 54. The caecum and vermiform process: c', c", c"', first, second, 

 and third limbs of the caecum; ca, beginning of the ascending colon; il, 

 ileum; pv, vermiform process (appendix); sr, sacculus rotundus. 



forms a rather conspicuous rounded sacculus rotundus, a structure 

 not found in other animals. 



The main portion of the large intestine, the colon, although 

 greatly specialized in the rabbit, may be considered to consist, as 

 in man, of ascending, transverse, and descending parts, that is to 

 say, the ascending colon lies on the right side of the body and passes 

 in a general way from its point of origin on the caecum forward to 

 a point where it becomes flexed to the left as the transverse colon; 



