Zoological Society. 457 



vorous birds to enable them to glut themselves with portions of 

 their prey when too bulky to be borne away entire, and thus to 

 carry off more than the true digestive cavity can contain. But in 

 birds which, like the Toucans, the Hornbills, the Parrots, and the 

 Touracos, live amidst abundance of nutriment, and that of easy 

 digestion, a superadded cavity to act as a reservoir, or to submit the 

 food to maceration previous to its entering upon the digestive pro- 

 cess, appears unnecessary. 



" The intestinal canal in the Touraco has a similar affinity to that 

 of the tribes of Birds above mentioned, being short, ample and 

 without ccpca. It measured twice the length of the bird from the 

 end of the bill to the vent. A small pyloric canal intervenes between 

 the gizzard and duodenum, and opens into the latter upon a valvular 

 prominence. The duodenum suddenly dilates, and has a diameter 

 of half an inch; but I am doubtful whether this is natural, as it 

 was, in the present instance, distended with Tceniae, which had per- 

 forated it in some places, and probably caused the death of the bird. 

 The fold of the duodenum is 3 inches long, including a narrow bi- 

 lobed pancreas. The intestine gradually diminishes in diameter to 

 within 5 inches of the cloaca, when it suddenly dilates, and this 

 portion has the usual disposition and course of the rectum in birds. 



" The liver was composed, as usual, of two lobes. There was a 

 gall-bladder, of an elongated form, with the cystic duct continued 

 from the end furthest from the intestine. The mode of termination 

 of the biliary and pancreatic ducts I was unable to determine, 

 owing to the morbid adhesions caused by the irritation of the 

 Tcenice. 



" The testes were small. The kidneys and supra-renal glands 

 were of the usual structure. 



" From the affinity pointed out by Cuvier between the Touraco 

 and the Curassows, I examined carefully the structure of the trachea, 

 so remarkable for its convolutions in the latter family of birds. It 

 was, however, continued straight to the inferior larynx, and was 

 connected to the Jurculum only by a slight aponeurosis: the 

 sterno-tracheal muscles, a single pair, were strong in proportion to 

 the size of the bird. The rings of the trachea were of a flattened 

 form, gradually diminishing in size towards the lower extremity of 

 the tube. The lungs were of the usual form and structure, and the 

 air-cells apparently not extending along the neck, or beyond the 

 abdominal cavity, except to penetrate the osseous system; but of 

 this I cannot speak with safety, as the bird was skinned before I dis.- 

 sected it. 



" The eye of the Trmraco is large, measuring 7 lines in lateral 

 diameter. The lens is very convex posteriorly, and its capsule is 

 attached to a narrow mari>upium. 



" The clavicles were united, forming an osjiircatorium ; but they 

 were extremely weak, and yielded with facility at the point of union. 

 The keel of the sternum was of moderate size, its greatest depth 

 being to the length of the sternum as 1 to 4. The posterior mar- 

 gin of the sternum has two notches on cither side of the keel, as in 



Third Series. Vol. 4. No. 24. June 1834. 3 N 



