B. Alimentary system. 



1. Cut away the whole of the ventral wall of the abdomen between the pectoral 



and pelvic girdles, noting — 

 (a) The skin. 

 (6) The muscles, 

 (c) The internal peritoneal lining. 



2. Sketch the viscera thus exposed, in situ, indicating — 

 (a) The tri-lobed liver. 



(6) The stomach. 



(c) The large intestine (colon). 



(d) The rectum and rectal gland. 

 Note also the red lobulated spleen. 



3. Turn forwards the liver, and note in addition to the above — 

 (a) The duodenum. 



(6) The pale bi-lobed pancreas. 



(c) The gastro-hepatic and the duodeno-hepatio omenta between the liver and 



the stomach and the Uver and the duodenum respectively. 



(d) The gastro-splenic omentum attaching the spleen to the dorsal surface of 



the stomach. 



(e) The mesogaster and mesorectum suspending the stomach and rectum 



respectively from the dorsal wall of the abdomen. 



4. Examine the liver, noting — 

 (a) Its division into three lobes. 



(6) The gall bladder between the right and middle lobes. 



(c) The short cystic duct from the gall bladder, the two hepatic ducts, one 

 from the right lobe, the other from the middle and left lobes, and the 

 common bile duct into which they open, — trace the bile duct to the point 

 where it opens into the duodenum. 



5. Examine the pancreas and the pancreatic duct. Trace the duct to the 



duodenum into which it opens opposite the aperture of the bile duct. 



6. Cut out the liver, and ligature the alimentary canal in front of the stomach, 



and behind the rectal gland ; cut through the mesenteric attachments and 

 remove the whole alimentary tract. Make a sketch of the part of the alimen- 

 tary tract removed, and indicate the position of the pancreas and the pan- 

 creatic and bile ducts. 



7. Cut open the stomach and duodenum, and note the pyloric valve between 



them, and the longitudinal folds of the mucous membrane of the stomach. 



8. Wash out the colon, noting the external spiral line indicating the attachment 



of the valve inside. EiU the colon with air by a blow-pipe, and tie at each 

 end : allow to dry for some days, and then cut apertures so as to examine 

 further the arrangement of the spiral valve. 



