226: 



DR. P. CHALMERS MITCHELL ON THE 



the Rallidse and Gruidse, the loops of Meckel's tract being long and straight, the first 

 and second being partly fused and the third having disappeared. 



OxiDiDyE. I have had the opportunity of examining only Otis tarda, the Great 

 Bustard. In it (fig. 45) the duodenum is a long narrow loop. Meckel's tract is thrown 

 only into two loops, of which the second is a very large supra-duodenal loop drained by 

 a pair of large bridging vessels, and has Jong and peculiar caeca closely applied to it. 

 The proximal loop 1 take to be the axial loop seen in the Rallidae ; it bears upon it, low 



Fig. 45. 



un 



S.DF 



PC ^ 



Intestinal Tract of Otis tarda. 



n.i?., nerves entering mesentery; v.ii.u:., ganglion iu duodenum from which nerves pass to eseca and supra- 

 duodenal loop; v.n.g., large gnngliou of visceral nerve; v.n., branch of visceral nerve in rectum. 



down on its distal limb, a Meckel's diverticulum. A pair of very small but quite 

 definite folds, marked "a" and "c" in the figure, I take to represent the similarly 

 designated large loops in the Rallidae and Gruidse. 



The intestinal tract of Otis is certainly markedly apocentric. The loops are all very 

 definite and the supra-duodenal loop in particular is highly specialized, being closely 

 applied to the duodenum, over which it lies in the unfolded condition, and from which 

 it receives not only a pair of bridging veins, but two branches of the autonomic visceral 



