54 MR. F. E. BEDDARB OX THE 



examole, the tract of tlie small intestine consists of two loops 

 only, which are approximately equisized and aie both rather 

 wide. Furthermore, the two oval loops of gut are attached to 

 each other along their whole length. It will be noted, therefore, 

 that these two loops agree in all their characteristics with those 

 of other Passerine and many Picarian Birds. But if this be so, it 

 follows that the jejunal loop in this Passerine is reduced to the 

 verge of disappearance. In any case, whatever be the interpre- 

 tation of the several regions of the small intestine in Ixocincla 

 crassirostris, it seems to me to be beyond all question that there is 

 a very close likeness between its gut and that of Rhea, whether 

 the likeness be superficial and due to parallelism of develojDment 

 or not. 



Moreover, there is no bird known to me in which the jejunal 

 loop has any intimate relations through ligaments with the ileic 

 loop — at any rate, to anything like the degree which is exhibited 

 in the case of Cryptiirus tataupa, on the view, of course, that the 

 jejunal loop is represented. Finally — though naturally it is not 

 attempted to lay any very great stress upon this piece of evidence 

 — a particular relationship between the Tinamou and Rhea is by 

 no means an unreasonable suggestion. 



There is, however, an alternative view to be ta,ken of the intes- 

 tinal tract of Rhea americana. It will be observed that Meckel's 

 diverticulum lies at about the middle of the lower limb of the 

 loop which has been provisionally regarded as the ileic loop ; the 

 diverticulum lies nearer to the duodenum, i. e. above the ends of 

 the two cseca. This fact would appear perhaps to militate against 

 the view that has just been set forth with regard to the intestinal 

 tract. For generally, at any rate, Meckel's diverticulum lies on 

 the jejunal portion of the intestine and, in fact, at about the middle 

 of the length of the entire small intestine. 



But although this may be generally the case in birds, it is by no 

 means universally so. In Dendrocygna discolor, for example, I 

 find Meckel's diverticulum to be very much nearer to the ileic loop 

 than to the duodenal, i. e. to be not by any means in the centre 

 of the jejunal region. This is a,lso clearly the case with Gar2Jo- 

 coccyx radiatus as shown in Dr. Mitchell's figure *. There is thus 

 no absolutely fixed position for Meckel's diverticulum within the 

 jejunal region of the gut, though there are no positive facts which 

 lead to the inference that this diverticulum may lie within the 

 ileic area. If it be held that the existence of the diverticulum 

 fixes the jejvinal region of the gut, then the intestinal tract of Rhea 

 is simply a slightly further development of that of Casuarius in the 

 direction of the Gallinaceous birds and many Picopasseres w^hen 

 there is no actual loop formed in the ileic region, but merely an 

 attachment by ligament to the duodenal loop. 



The gut of the Ostrich has been described by Dr. Mitchell, as 

 well as by othei'S, I have only some small matters to add to the 



* Trans. Linn. Soc. t. c. p. 243, fig. 60. 



