ORGANS AND PROCESSES OF DIGESTION 



XXXIII. — Dissection of a Rat's Digestive Organs. 



Apparatus. — Chloroformed rat/ dissecting tray with wax lining, 

 scissors, forceps, bristle probes, 10% alcohol or 1% formalin. 



Directions. — Lay the rat on its back in the tray, stretch, 

 and tie or pin the legs as in the diagram'. Cover with 10% 

 alcohol or 1% formalin. 



Locate the lower end of 

 the breast bone and slit the 

 skin from this point to the 

 anus. On each side at the 

 middle point of the slit, 

 make a slit at right angles. 

 Turn back the four flaps 

 and pin them. 



Note the thin membrane 

 (peritoneum) lining the abdo- 

 men. Is it flexible? Remove 

 this and, without disturbing 

 the underlying parts, locate 

 the stomach, the liver, and 

 the coiled intestine. 



Press the intestine downward and determine the size, 

 position, shape, and color of the stomach. Find the ends 



^ This exercise may be made a demonstration. In that case a larger 

 animal such as the rabbit would be preferable. 



53 



Fig. 27. 



