112 ZOOTOMY. 



minor turn, forms a long loop enclosed in a special invest- 

 ment of peritoneum and extending backwards posterior to 

 the anus ; passing forwards again, the ileum forms a loop 

 within and concentric to that of the duodenum, and is then 

 continued insensibly into the rectum (ret), which is only 

 marked by its somewhat greater diameter and by the dark 

 colour of its contained fseces ; the rectum passes directly 

 backwards to the anus {a), between the ileum on the right 

 and the stomach on the left. 



1 20. The way in which the viscera are supported by 

 folds of peritoneum : the stomach is suspended to the 

 dorsal wall of the abdomen by a vertical fold, the meso- 

 gaster : a similar fold supporting the small intestine is the 

 mesentery: one suspending the rectum is the meso- 

 rectum : the testes are kept in position by the mesorch- 

 ium, the ovaries by the mesoarium : the anterior border 

 of the liver is connected to the anterior wall of the abdo- 

 men by the coronary ligament and its dorsal surface is 

 connected with the stomach by the gastro-hepatic 

 omentum. 



121. The cystic duct (Fig. 31, c.d) from the gall-bladder 

 {g.h), joined by several hepatic ducts (Ji.d) from the liver : 

 from the point of junction the common bile duct {c.b.d) 

 passes backwards and opens into the small intestine just 

 beyond the pylorus. 



122. The portal vein (Fig. 32, p), taking blood from the other 

 abdominal viscera to the liver : it is a large vein receiving factors from 

 the stomach, intestines, spleen, and pyloric caeca, as well as a branch 

 from the air-bladder, leaving the wall of the latter at about the junction 

 of its anterior and middle thirds, and bringing blood from the rete 

 mirabile (x) {vide infra § 139). All these tributaries unite to form 

 a plexus of large veins in the gastro-hepatic omentum, from which 

 several veins go off into the substance of the liver [p'). 



123. The gastric branch of the vagus (tenth cerebral) nerve, i 



