490 DR. P. CHALMERS MITCHELL ON THE 



and more or less of the colic loops of the hind-gut, according to the extent to which it 

 has taken place. The elongation of the hind-gut is in the form of two loops, which, in 

 most cases, although folded over the Meckelian mesentery have remained fairly free 

 from it. The rectum shows a tendency to be elongated in its proximal region. It is 

 interesting to notice that vestiges of an originally paired condition of the caeca appear 

 to be specially characteristic of the whole group, but particularly of the Duplicidentata : 

 in Ochotona two caeca actually occur ; in the Hare they are present, the second caecum 

 being less marked, whilst in the Rabbit the second csecum is reduced to a sacculus 

 rotundus. 



Order INSECTIVORA. 

 Division Menotyphla. 

 Family Tupajid^e. 



I have not been able to examine any example of this family myself. According to 

 Flower (5) in Tupaia tana the intestinal tract is short and simple and there is no trace 

 of a caecum. Flower, however, quotes Hunter's authority for the existence of a caecum 

 in one species of Tupaia. 



Family Macroscelidid^e. 



I have not examined any of these Shrews myself. Flower (5 ) states that the intestinal 

 tract is much more like that of the Lemurs than that of other Insectivora. It is 

 relatively long, and a capacious caecum marks the position where the anterior part of 

 the tract passes into a capacious hind-gut which is differentiated into a looped colon 

 and a rectum. 



Division Lypotyphla. 



Family Talpid^e. Talpa europcea. 



In the Mole the duodenum is not well separated from the proximal portion of 

 Meckel's tract. The latter is relatively very long, and consists of a number of regularly 

 arranged, closely packed minor loops, at the periphery of a long oval expanse^ of 

 mesentery, the recurrent portion of the tract being nearly straight. The hind-gut 

 consists of a narrow, slightly twisted colic loop and a long straight rectum. There is 

 no trace of a caecum. The anterior mesenteric vein curves round the mesentery of 

 Meckel's tract and is joined by a straight posterior mesenteric vein. 



Family Soricid^e. 



I have examined no example of this family. Hunter (10) and Flower ^5) have 

 described the shortness and simplicity of the intestinal tract of these animals, calling 

 attention to the absence of the csecum, and in particular to the Reptilian fashion in 



