226 ZOOTOMY. 



202. The splanchnic nerve, running parallel to the gastro-duodenal 

 artery, and supplying the intestine. 



203. The anterior (superior) mesenteric artery, 

 about a quarter of an inch posterior to the coeliac, and 

 supplying the greater part of the intestine : to bring it into 

 view the duodenum must be pulled outwards by dissecting 

 away part of its peritoneal investment. 



XXX. Tie a double ligature round the intestine a little 

 anterior to the caeca, including in the ligature the 

 coccygeo-mesenteric vein: cut through the pro- 

 ventriculus as far forwards as possible without 

 injury to the heart, &c. : remove the alimentary 

 canal between these two points by cutting the 

 mesentery, noting a fibrous membrane (the oblique 

 septum) connected with the dorsal and anterior 

 face of the pericardium in front, and extending 

 across the coelome like the roof of a tent : it is 

 attached to the margins of the sternum in front, 

 and to the body walls behind, in such a manner 

 as to separate a sub-pulmonary chamber, 

 containing the air-sacs, from the general body 

 cavity. Then observe : 



204. The arrangement of the different parts of the 

 alimentary canal : the proventriculus enters the gizzard on 

 its anterior edge : the duodenum leaves it at the anterior end 

 of its right side : following the duodenum is a distinct 

 single loop of small intestine, the jejunum, and after 

 this a coil, consisting of the greater part of the ileum, 

 bound together by a single fold of mesentery : next comes 

 the distal portion of the ileum, consisting of a single loop, 

 of less calibre than the remainder, and usually of a greenish 

 colour : leaving the distal limb of this loop, the ileum widens 

 again, and passes without increase of diameter into the rectum. 



