INTESTINAL TRACT OF MAALMALS. 



portion is straight except that it is involved in the spiral twisting of the caecum. The 

 caecum is very large and sacculated ; it is folded over the Meckelian mesentery and is 

 spirally twisted, the twist involving not only the terminal portion of Meckel's tract, but 

 the proximal portion of the hind-gut, including practically the whole of one of the two 



28. 



Intestinal Tract of Oavia porcellus. 



X:, X2. Cut ends of colic vein. 



X:\, X.3. Cut ends of coocal vein. 



Other letters as in fig. 26. 



crecal loops that are found in most other Rodents. There is an expanded portion of 

 the hind-gut distad of the entrance of Meckel's tract into the caecum, and sacculated 

 like the caecum. The hind-gut shows two definite regions. There are two colic loops 



vol. xvii. — part v. No. 7. — December, 1905. 



3 T 



