238 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 
Fic. 98.—JUNCTION OF SMALL AND Fic. 99. — SECTION OF THE ILEO- 
LarGE INTESTINE. COLIC VALVE. 
Fig. 98.—a, ileum; 4, ascending colon; ¢, caecum; @, position of ileocolic valve. 
Fig. 99.—a, caecum; 4, colon; ¢, ileum; @, longitudinal muscle layer; ¢, 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 
cecum (Fig. 98, ¢; Fig. 99, a). The cecum 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 cecum 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. 
