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



at all as a free fold or as attached to the colon. This is an 

 exaggeration of the characters to which Klaatsch has called 

 attention in Mus and Myoxus. The splenic omentum (ligamentuni 

 recto-lienale) is attached to the colon direct as in Mus, and not to 

 the mesorectum as is often the case in Mammals. 



Although the loops of the colon in the Beaver have been figured 

 by Tullberg, I do not find myself entirely in agreement with that 

 figure. My own observations refer to the parts of the intestine 

 to be dealt with as seen from the ventral surface — the surface 

 exposed on dissection. I gather that the same view has been 

 taken by Dr. Tullberg, since he represents the i-ectum as lying 

 dorsally to those folds. If this be the case, the Beaver is another 

 example of a Rodent showing some variation from specimen to 

 specimen as is shown in the Yizcacha. The colon where it leaves 

 the cascum bends to the left and runs forward in close proximity 

 to itself, being bound here by a mesentery. It then curves round 

 and passes back again parallel to the beginning of the caecum and 

 large intestine, but on the opposite, i. e. the right, side, being here 

 also attached closely to the gut in question by mesentery. The 

 tube then bends upon itself and runs again parallel to itself foi- 

 a little distance, being still attached by mesentery. The colon 

 diverges to the right and forms the fii\st of two ansae coli like 

 those of S'cnirus &c. The first of these is attached by its left- 

 hand limb to the ascending portion of the colon. This loop is 

 slightly twisted to the left, and is indeed a rudimentary spiral 

 like that of the Oapybara &c. Immediately after the end of this 

 loop the colon is modified into a similar loop of about equal length. 

 Thereafter the colon runs in a broad curve to the rectum. It 

 will be observed that the direction of the colon according to my 

 observations is at first in the opposite direction as described by 

 Tullberg. 



The duodenum has varied attachments to the neighbouring- 

 regions of the colon and to the parietes, the latter of which I am 

 not able to describe accurately. It is, however, important to note 

 that the duodenum follows the curve of the first ansa coli and is 

 attached to it by mesentery ; there is also the usual ligatnentum 

 cavoduodenale. 



(3) Coils of /Small Intestine. — -As a general rule the festooned 

 coils of the small intestine are not at all permanent coils ; the 

 intestine can be passed through the fingers in a perfectly straight 

 line without tearing or in any way distorting the mesenteron. 

 At the same time of course the entire gut cannot be laid out in a 

 circle or a portion of a circle owing to the shortness of its sup- 

 porting mesentery. One portion can thus be freed from the rest, 

 which in correspondence become closer and denser elsewhere. 

 There are, however, exceptions to this general rule which I have 

 observed among the Marsupials. In a specimen of Pseudochini,s 

 peregriniis it was impossible to straighten out the coils of the 

 small intestine which were quite fixed. This characteristic, 



