572 MR. F. E. BEDDARD ON THE ANATOMY OF [May 26,, 



the contrary direction. Tlie conditions obtaining in the Oarnivora, 

 and as it would appear in the whole of that group, cannot be 

 looked upon as a reduction due to small size. For it will have 

 been noted that the large Bear is quite on a level with the small 

 Cercoleptes or Ictonyx. It is not only the Oarnivora which show 

 this simplification of the gut. For I have already remarked that 

 the same state of the intestine and its mesenteiy is to be seen 

 alternatively in Centetes. Even among the Primates it exists ; 

 for in Chrysothrix scvai-eus, as I point out later {^. 577), the 

 intestine can equally well be laid out along a compai-atively 

 straight mesentery to either right or left side. It must be noted, 

 however, that in this animal and in the Oarnivora the colon is 

 very short. It is, in the specimen which I dissected, only 6| 

 inches in length, a measurement which agrees exactly with that 

 of Martin *. 



Although the above facts concerning the Oai'nivora are I 

 believe correct, and indeed quite bear out Klaatsch's figure t of 

 the intestinal tract of the Oat, where the mesentery attached 

 to the duodenum and to the middle line is figured and termed 

 " ligamentum cavoduodenale," and his statements concerning other 

 genera. Max Weber has, however, described and figured a 

 diflerent state of affairs in the Bear J. The species examined 

 was Ursus arctos, and the gut is figured as turned over to right 

 and left without a trace of this ligament, and described in the 

 following words : — " Der ganze iibrige Darm an einer einfachen 

 Mesenterialplatte (Mesenterium commune) die mit einfacher 

 radix mesenterii an der Wirbelsalile wurzelt aufgehiingt ist." 

 There may of course be this diiference between the two species 

 of Ursus, or the case may be analogous to that which I have 

 described above in Centetes ecccudatus. In any case it is clear 

 that the majority of the Oarnivora (whether Arctoid or ^luroid) 

 do not bear out the statement of Max "Weber with reference 

 to Ursus arctos. 



In more difierentiated forms a f urthei complexity is introduced 

 in the existence of a special ligament joining the commencing 

 duodenum with the proximal end of the colon. For this Klaatsch 

 adopts Krause's term ligamentum colicodiwdenale . It is figured 

 by Klaatsch in several forms, in Myoxus, Stenops, and human 

 embryo. IS'or has Tullbei'g neglected this connection between 

 the small and large intestine in his figures of certain Rodents. 

 This structure is so persistent in the Rodents that it even occui's 

 in the case of the small Arvicanthis, where the colic coils are 

 reduced to a minimum ; as indeed they are according to Klaatsch's 

 figures in Myoxas. It is very important to note that even the 

 Marsupials with their little specialised gut show traces of the 

 sanae ; in Trichosiirus vidpecula and Pseudochirus peregrinus 



* P. Z. S. 1833, p. 89. 



t " Zuv Morphologie der Mesenterialbildungen, &c. ii Theil," Morpli. Jahrb. xvii 

 1892, p. 646, fig. 4. 



X Die Saugetliiere, p. 212. 



