130 Practical Zoology. 



this is the gullet, or esophagus. Just back of the stomach is a 

 small, red body, the spleen. 



4. Find now the connection between the stomach and intes- 

 tine. Make a drawing of the stomach, showing its shape and 

 the connections with the gullet and intestine. 



5. Trace the intestine ; that part which forms a long loop 

 near the stomach is the duodenum. Within this loop is an 

 irregular, fatty-looking mass, the pancreas. Find the pancreatic 

 duct entering the intestine. This is more easily found in the 

 dog. 



6. Observe that the intestine is held by a thin membrane in 

 which are branching blood tubes ; this is the mesentery ; find 

 its supporting attachment. In tracing its course drag the in- 

 testine out of the abdominal cavity, but do not tear the mesen- 

 tery. 



7. The large, greenish side branch of the intestine is the 

 cecum. All the intestine from the stomach to the entrance of 

 the cecum is the small intestine ; that part of the intestine 

 posterior to the entrance of the cecum is the large intestine. 



8. In handling the liver remember that it is very delicate and 

 easily torn, also that it contains much blood, and if torn is 

 likely to bleed enough to interfere with the dissection. Do not 

 touch the liver with any sharp instrument ; even the finger nails 

 may tear it unless one is careful. Pull back the liver to see 

 how snugly it fits against the diaphragm. Are the two attached 

 to each other ? Note the divisions, or lobes, of the liver. Tip 

 the liver up .and forward to see the stomach, and how the organs 

 fit each other. On the posterior surface of the liver find the 

 dark bile sac. If its duct to the intestine is not readily seen, 

 press on the sac and some of the bile may be forced along the 

 tube, thus showing its course. Later snip a small hole in 

 the bile duct, insert a bristle tipped with sealing wax, and find 

 where the duct enters the intestine. 



9. Tie the gullet in two places half an inch apart and cut 

 through between them. Do the same with the hinder part of the 



