580 MR. F. E. BEDDARD OX THE ANATOMY OF [May 26, 



than half grown, measuring not more than a foot in extreme 

 length. The alimentary tract of this animal has been described 

 at considerable length by Dr. Mitchell, but I find myself in 

 grave disagreement with him, the disagreement extending to 

 matters of fact as well as to interpretations of the value of 

 certain structures. I furthermore deal with certain points- 

 which are not dealt with by Dr. Mitchell. 



When the body- wall is cut and the halves reflected, the intestinal 

 tract is seen to be represented by the large cascum Avhich occupies 

 the greater portion of the left moiety, and by the paired cseca 

 and the immediately preceding and succeeding sections of the 

 colon which occupy the right moiety of the supei-ficial j^art of 

 the abdominal cavity thus disclosed. Above, a few coils of the 

 small intestine are Aasible, but very few. As Dr. Mitchell has 

 correctly stated, the duodenal loop is longer than he has re- 

 presented in his figure *. It extends in the very general fashion 

 down to about the middle of the lumbar region below the kidneys, 

 and is there attached by the usual ligamentum cavoduodenale. 

 This loop of the duodenimi shows on the opposite side another 

 remarkable mesenteric fold. When the single cjecum is turned 

 forwards, it is seen that a mesenteiy w^ith a free edge directed 

 forwards runs over the duodenal loop, being attached on the left 

 to the colon where it emerges from the single ctecum, and on the 

 right to the colon where it passes towards the paired cajca. As 

 this fold has a free edge, a pocket is formed which appears to 

 be imperforate at the bottom. I have no facts to offer for the 

 purposes of a comparison of this mesenteric recess with possibly 

 similar structures in other mammals. The coils of the small 

 intestine, with the exception of the duodenal loop, are, as usual, 

 temporary coils, and the intestine can be straightened bit by 

 bit as it is passed through the fingers. The ileum opens into 

 the single caecum, the resemblance of which to the cfecum of 

 the Perissodactyles is apparent fi-om the descrijDtions of others 

 and from an inspection of this portion of the gut which has been 

 somewhat confused by Dr. Mitchell's figure. He represents it as 

 a bilobed dilatation on the course of " Meckel's Intestine." It is, 

 in fact, almost a facsimile of the caecum of a Rhinoceros, the chief 

 difference being that it has a much blunter termination than in the 

 Perissodactyle. It is moreover sacculated, and the relations to it of 

 the small and large intestines respectively are exactly as in the 

 Ehinoceros' ctecum. Moreover, the large intestine which emerges 

 from it is of greater calibre than the small intestine which enters it. 

 Finally Dr. Mitchell has taken no account of certain mesenteries 

 related to this csecum which unquestionably suggest its homology 

 with the usual unpaired csecum of mammals. That the paired 

 appendages of the gut which arise further down may be the 

 equivalents of the Edentate paired caecum is quite possible. But 

 if so, it is only in my opinion further evidence that the latter are 

 not the equivalents of the usual unpaired cEecum of other 



* Trans. Z. S. 1905. xvii. p. 461, fig. 14. 



