2 3 8 



THE VISCERA. 



wall and is separated from the ventral body wall by the folds 

 of the ileum. It has a diameter about three times that of the 

 ileum. The opening of the ileum into it is on its side between 

 one and two centimeters from its cranial end (Fig. 98). The 



FIG. 98. JUNCTION OF SMALL AND FIG. 99. SECTION OF THE ILEO- 



LARGE INTESTINE. . COLIC VALVE. 



Fig. 98. a, ileum; b, ascending colon; c. caecum; d, position of ileocolic valve. 

 Fig. 99. a, ccecum; 6, colon; c. ileum; d, longitudinal muscle layer; e. trans- 

 verse muscle layer; /", mucosa; g. ileocolic valve (opened, as when material is pass- 

 ing into the colon). 



blind pouch thus formed by the cranial end of the colon is the 

 caecum (Fig. 98, c; Fig. 99, a). The caecum ends in a slight 

 conical projection which may be considered as the rudiment of 

 a vermiform appendix. The colon lies at first on the right side 

 and passes at first craniad ; then transversely to the left, then 

 caudad, lying nearly in the middle line and next to the dorsal 

 abdominal wall. The colon may thus be distinguished accord- 

 ing to its direction into ascending, transverse, and descending 

 colon. At its caudal end the colon passes without sharp limit 

 into the rectum. 



At the bottom of the caecum on its inner surface is seen 

 a collection of solitary glands forming one of the agminated 

 glands of Peyer, or Peyer's patches. The mucous membrane 

 is without villi. It presents a few considerable elevations, 

 probably solitary glands. 



