122 PRACTICAL HINTS FOR TEACHERS. 



note the relative length and diameter of its various parts; and that 

 the small intestine forms by far its longest portion. 



Open the stomach; note, in the rat, that the mucous membrane lining 

 the fundus is thin and smooth, and is sharply marked off from the 

 thick corrugated mucous membrane lining the rest of the organ. This 

 is not the case in the stomach of dog, cat, or man. Pass probes 

 through the cardiac orifice into the gullet and through the pyloric ori- 

 fice into the duodenum. 



