(LECUMS IN BIRDS. 189 



same structure prevails at the commencement of the caecums, 

 and in a portion of the rectum. In the other portion of the 

 rectum there are only detached foliaceous papilla?,, which be- 

 come rounded quite at the extremity. The same rounded and 

 conical form of the papillae is all that exists in the caecums, 

 where there is seen besides a remarkable fatty network. 



In the cock of the wood (Tetrao urogallus) the duodenal 

 curvature is of moderate extent. The middle intestine is not 

 so long as in the other gallinaceous birds, yet disposed in the 

 same manner. The caecums are so long that each of them is 

 longer than the whole intestine above the point of insertion. 

 Their rectum is short. 



In birds generally there are two caecums (intestina cceca), a 

 few of the aquatic kind excepted. The caeca are inserted at 

 the sides of the termination of the ilium. They are generally 

 smaller at the base, and enlarge towards their shut extremi- 

 ties. They lie parallel to the small intestines, and contain the 

 same kind of aliment with them. In carnivorous and omnivor- 

 ous birds they are commonly long and of considerable diameter. 

 In nocturnal birds of prey they are in general very large ; but 

 in diurnal birds of prey they are absent, or of inconsiderable 

 size. From the end of the ilium, and also from the caecum, the 

 colon is sent off; it is proportionately short, and differs in 

 this respect from its ordinary condition in mammals, that it is 

 not formed into cells. 



The intestines are fixed to the body by the mesentery, which 

 arises from the spine opposite to the anterior mesenteric artery. 

 Where the mesentery supports the small intestine it is pretty 

 broad, but that part which surrounds the colon is narrow, that 

 intestine being more firmly fixed than the rest. 



The rectum, before terminating in the anus, undergoes a dila- 

 tation termed cloaca, which is suspended under the os coccygis, 

 and receives the terminations of the ureters or ducts from the 



