INTESTIXAL TRACT OF MAMMALS. 



215 



spiral runs up close to the duodenal region, and then bends over 

 to form a relatively long but nearly straight rectum. The spiral 

 loop, which from its position is an ansa coli dextra, is very capa- 

 cious and very heavy, and the portion of primitive mesentery 

 that suj)ports it, and that cari-ies the enormous blood-vessels 

 supplying it, is reinforced by a strong band of fibres fastening it 

 partly to the duodenal region and partly to the omentum. A 

 similar, but much slighter secondary connection, ties the portion 

 of the hind-gut most contiguous to the dorsal middle line (distal 

 extremity of the pendant loop) to the duodenal mesentery. 



Text-fioure 17. 



Intestinal tract of Bahiriissa hahirussa. 

 Letteriiiff as in text-tiss. 15 and 16. 



Sub-orders Traguloidea, Tylopoda, and Pecora. 



I have examined the intestinal tracts of several mammals 

 belonging to these three closely related sub-orders, since I 

 formerly gave an account of the patterns displayed in the 

 va,rious families concerned (Mitchell, 1905), but as I have little 

 of general interest to add, I shall review the group as a whole. 



The duodenal region is usually well separated, forming a long 

 distinct loop in nearly all, but rather less marked in the 

 Traguloidea and Tylopoda.. Meckel's tract is invariably enor- 

 mously long, of even calibre, and thrown itjto a very large number 

 of minor loops closely set round the periphery of the usual 



