188 PHYSIOLOGY AT THE FARM. 



caecums, which appear to possess an important share in the 

 functions of chylification. Pigeons alone make an exception ; 

 these have either only rudimentary csecums, or else are alto- 

 gether destitute of them. 



The dimensions of the intestinal canal in gallinaceous birds 

 are great in diameter as well as in length. It is remarkable 

 that the length of the intestinal canal is in an inverse propor- 

 tion to that of the caecum. In the grouse tribe the caecum s 

 are of the greatest proportional length. This great length co- 

 incides with the existence of intestinal papillae which extend 

 almost to their termination, while these are not found in other 

 gallinaceous birds, except in a portion always small at their 

 commencement. These papillae are generally composed of 

 filaments variable in their dimensions. In pheasants the last 

 doubling of the intestine is attached to the duodenum ; the 

 caecuras are dilated into a club at their extremity, and give 

 entrance to feculent matters. In the domestic cock the pile 

 of the mucous membrane is formed of innumerable folds like 

 ruffles, without fringed borders but pressed close together. 

 Towards the extremity these folds become detached and form 

 a foliaceous pile, which is observed in the first third of the 

 caecums, while the remaining portion by degrees loses these 

 irregularities and becomes wholly uniform. As to the rectum, 

 it presents the same foliaceous pile as the caecums and the end 

 of the small intestine. 



In the golden pheasant the duodenum presents a network 

 with very distinct meshes. 



In the peacock the internal surface of the duodenum ex- 

 hibits a fine network with polygonal meshes, the borders of 

 which are fringed : this network is continued throughout the 

 whole extent of the small intestine, but the laminae of which 

 it is formed become thicker and nearer to each other, losing 

 their regularity, and no longer fringed in the border. The 



