INTESTINAL TEACT OF BIRDS. 



219 



In association with the growth of the posterior portion of Meckel's tract, the visceral 

 ganglionated chain forms a curious elongated loop, which, on comparison of figs. 38 

 and 39, will be seen to be obviously connected with the distal growth of the tract. In 

 two other species of Crax and in two species of Penelope the conformation of the gut 

 with its blood-vessels and nerve was identical in all main points with the condition just 

 described. 



Fig. 39 



m 



Intestinal Tract of Crax Daubentoni. Lettering as before. 



GALLID^E. I have examined a considerable number of these, including species of 

 Argus, Caccabis, Callipepla, Coturnix, Francolinus, Gallus, Lophophorus, Pavo, 

 Phasianm, Perdix, and Tetrao, and in all the conformation closely resembles that 

 shown in the figure of Pavo cristatus (fig. 40). Meckel's tract is more elongated in 

 the axial line than in the Cracidse, and the middle mesenteric vein runs obviously from 

 the remains of the diverticulum. There is a similar distal prolongation of the tract 

 drained by a large recurrent vein, and to the straight distal portion of this the very 



