PIGEONS. 253 



forced out by the pylorus, and in the duodenum is reduced to 

 a thin pulp. In this part of the intestine it seems to undergo 

 the process of digestion properly so called. Being then farther 

 diluted by the biliary and pancreatic fluids, it deposits the 

 chyle in the rest of its course, ^yhich is gradually absorbed, the 

 residuum becoming thicker, until in the rectum it assumes a 

 more or less concrete cylindrical form, in which state it is 

 voided along with the urine. The intestine is about double 

 the length of that of a rapacious bird of the same size, a circum- 

 stance probably owing to the greater difficulty of assimilating 

 vegetable matter. It is also much longer than that of a Gal- 

 linaceous bird ; but in the latter the difference is made up by 

 the great develoi^ment of the coeca, which in the Pigeons are 

 merely rudimentary, that is, extremely small, and secreting a 

 mucous fluid only. 



A great difference between Pigeons and Gallinaceous birds 

 therefore is found in the structure of the intestine. The oeso- 

 phagus, crop, and gizzard, are similar in the two orders, as 

 well as to a certain extent in the thick-billed granivorous birds. 



Although their legs are short. Pigeons walk with great ease, 

 and even celerity. Their flight is very unlike that of the Gal- 

 linaceous birds, being strong, rapid, and protracted. Their 

 nests are generally placed on the branches of trees or bushes, 

 sometimes in holes, and even on the ground. They are formed 

 of a broad basis of twigs, often without any lining, but also 

 often lined with various soft substances, and for the most part 

 flat. The eggs are generally two, elliptical, and pure white ; 

 but some of the species that reside chiefly on the ground are 

 said to lay several or numerous eggs. The young are at first 

 scantily covered with soft down, and are fed with farinaceous 

 or pulpy substances which have undergone some degree of 

 maceration in the crop of the parent bird, from the m.outh of 

 which they receive it by introducing their bill sidewise. In 

 this respect also the Pigeons differ greatly from the Gallinaceous 

 birds. In their mode of drinking also a remarkable difference 

 is observed ; for while they immerse their bill to the base in 

 the water and drink continuously, the Gallinaceous birds take 

 a mouthful, elevate their head to enable them to swallow it 

 with ease, and repeat the action until satisfied. The young 



