284 



ANA TOMICAL TECHNOL OGY. 



Preparation Fig. 80. A cat which has been well fed five or 

 six hours before death is best. The mesentery should be removed, 

 and about 10 cm. of the small and the same length of the large 

 intestine should be left with the caecum and ileo-csecal valve. The 



contents of both large and 

 small intestine should be 

 carefully removed and the 

 large intestine ligatured. 

 Then both should be mod- 

 erately distended by inject- 

 ing 95 per cent, alcohol into 

 the small intestine. The 

 latter should then be liga- 

 tured and the whole put into 

 95 per cent, alcohol. After 

 two to three days the walls 

 may be removed with a 

 sharp scalpel. 



Caecum, az. See 742, A. Colon, 

 az. See 742, B. Ileum, azSec 

 % 738. Sphincter, az. See 739. 

 Villi. See 740, B. Valva ileo-caeca- 

 lis, az. Heo-csecal valve. See 739. 



FIG. 80. CL&CUM AND ILEO-CLECAL VALVE, VEN- 

 TRAL VIEW ; x 1. 



739. Valva ileo-cseca- 

 lis. The ileo-csecal valve in 

 the cat is quite unlike its 

 homologue in man. In the cat it is a sphincter, composed of circu- 

 lar muscular fibers like the pylorus, and like the pyloric valve it is 

 partly formed by an annular fold of mucous membrane, which in 

 the ileo-caBcal valve projects into the large intestine (Fig. 80). 



The thickest part of the sphincter is about 1 cm. cephalad of the 

 opening into the large intestine. The villi are not present caudad 

 of this point, hence about 1 cm. of the mucous membrane of the 

 small intestine of the cat is devoid of villi. 



740. Obvious Structure. (A) Cut out two or three square cm. of any part of the 

 small intestine ; rinse it with water if" necessary ; it will be seen to be composed of two 

 obvious coats like the stomach ( 736). 



(B) Villi intestinorum. Put a fresh, piece of intestine in a watch glass of water or 

 normal salt solution, and look at the mucous surface in profile. There will appear numer- 

 ous slender finger-like processes with their free ends pointing toward the lumen of the 



