INTESTINAL TEACT OF BIRDS. 275 



EXPLANATION OF THE PLATES. 

 PLATE 21. 



Evolution of the Intestinal Tract in the Pelargo-Colymbomorphine Brigade. 

 (For Colymbimorphine read Colymbomorphine.) 



PLATE 22. 



Evolution of the Intestinal Tract in the Alectoromorphine Legion. 



PLATE 23. 



Evolution of the Intestinal Tract in the Coraciomorphine Legion. 

 (For Coracimorphine read Coraciomorphine.) 



In these Plates the affinities of the conformations of the Intestinal Tracts and not of the birds are 

 indicated. The outline of the coils of the tract in the unfolded condition is given ; the Hue of attachment 

 of the mesentery to the body lies to the reader's right. The diverticulum is represented as a dark spot 

 on the left. The duodenum lies towards the upper end of the Plates, the rectum towards the lower end. 

 with the caeca, when present, as a pair of dark lines. 



I? 

 OFTH I 



UNIVERSITY 



