INTESTINAL TRACT OF MAMMALS. 



483 



marked by ovoid masses of faeces, and a short straight rectal portion. The anterior 

 mesenteric vein sweeps round the Meckelian mesentery, receiving factors from the 

 duodenum and from the minor coils of Meckel's tract. Near the edge of the mesentery 

 it is joined by a large csecal vein, a vein from the colic loop, and the posterior 

 mesenteric vein. 



In the Australian Bush-Rat (Mus arboricola) the arrangement is much the same. 



Fig. 27. 



Intestinal Tract of Mas decumanus. 



X2. Out ends of folic vein. 

 Other lettere ns in fig. 20. 



The spiral curvature of the capacious caecum is less marked and the colic region tends 

 to display two loops. 



In the Hamster (OricetiiS frwmentarius) the duodenum is not so distinct as a 

 separate loop. The caecum is relatively very much longer, is irregularly convoluted. 



