504 MANUAL OF ZOOLOGY SECT. 



the gall-bladder and hepatic ducts from the various parts 

 of the liver runs to open into the duodenum near the 

 pylorus. 



The pancreas (pn.) is a diffused gland in the fold of 

 mesentery passing across the loop of the duodenum. Its 

 single duct, the pancreatic duct {pn. d.\ opens into the 

 distal limb of the loop. 



The heart (Fig. 284) is situated in the cavity of the 



sem,.-v 



TTl. 



FIG. 284. Lepus cuniculus. Heart, seen from the right side, the walls of the 

 right auricle and right ventricle partly removed so as to expose the cavities. 

 ao. aorta \f. <rv. fossa ovalis ; /. pr. c. opening of left precaval ; in. pap. musculi 

 papillares ; pt. c. postcaval ; pt. c'. opening of postcaval ; r. pr. c. right pre- 

 caval ; r. pnl. right pulmonary artery ; sem. v. semi-lunar valves ; tri. v. 

 tricuspid valve. 



thorax, a little to the left of the middle line, and lies 

 between the two pleural sacs enclosing the lungs. The peri- 

 cardial membrane enclosing the heart consists of two layers, 

 a parietal, forming the wall of the pericardial cavity, and a 

 visceral, immediately investing the heart. Between the two 

 is a narrow cavity containing a little fluid the pericardial 

 fluid. In general shape the heart resembles that of the 

 Pigeon, with the apex directed backwards and slightly to 



