PRACTICAL HINTS FOR TEACHERS. 121 



APPENDIX TO CHAPTER XL 



The main points in the anatomy of the alimentary canal may be 

 easily studied on a kitten, puppy, or rat. Superfluous kittens and 

 puppies have so often to be drowned, that no unnecessary taking of 

 life is called for. The animal may be more mercifully killed by shut- 

 ting it up in a small tight box, for ten minutes, along with a small 

 sponge soaked in chloroform. A tin cracker-box does very well. 



Cut away, with strong scissors, the front of the chest and abdomen of 

 the dead animal, taking care not to injure the contents of those cavi- 

 ties. Dissect off the skin on the front and sides of the neck. Re- 

 move the larynx, trachea, lungs, and heart. 



The gullet, a slender muscular tube, will now be exposed in the 

 neck; trace it through the chest; note the relative positions of the 

 abdominal viscera as now exposed, before displacing any of them; 

 then turning the liver up out of the way, follow the gullet in the ab- 

 domen until it ends in the stomach. 



Note the form of the latter organ; its projection (fundus) to the 

 left of the entry of the gullet; its great and small curvatures; its nar- 

 rower pyloric portion on the right, from which the small intestine pro- 

 ceeds. Attached to the stomach, and hanging down over the other 

 abdominal viscera, notice a thin membrane, the amentum. 



Follow and unravel the coils of the small intestine, spreading out as 

 far as possible the delicate membrane (mesentery) which slings it. In 

 the mesentery are numerous bands of fat, running in which will be 

 seen blood-vessels and lacteals. 



The termination of the small intestine by opening into the large. 

 Observe the ccecum or blind end of the latter, projecting on one side 

 of the point of entry of the small intestine; on the other side follow 

 the large intestine until it ends at the anal aperture, cutting away 

 the front of the pelvis to follow its terminal portion (rectum). The 

 portion between the cacum and the rectum is the colon. 



Spread out the portion of the mesentery lying in the concavity of 

 the first coil (duodenum) of the small intestine; in it will be seen a 

 glandular mass, the pancreas. 



Observe the portal vein entering the under side of the liver by sev- 

 eral branches. Alongside it will be seen the gall-duct, formed by 

 the union of two main branches, and proceeding, as a slender tube, to 

 open into the duodenum a short way from the pyloric orifice of the 

 stomach. In a kitten or puppy the gall-bladder will be seen on the 

 under side of the right half of the liver. 



Note the spleen: an elongated red body lying in the mesentery, 

 behind and to the left of the stomach. 



Divide the gullet at the top of the neck, and the rectum close to the 

 anus, and, severing mesenteric bands, etc., by which intermediate 

 portions of the alimentary canal are fixed, remove the whole tube; 

 then cutting away the mesentery, spread it out at full length, and 



