Diurnal Rapacious Birds. 133 



that of the rectum is furnished at its anterior part with numerous 

 mucous crypts. On the elevated ring or kind of valve which sepa- 

 rates the rectum from the cloaca, open the two ureters, g, g ; and 

 behind it is the entrance to the bursa Fabricii, a large oval bag ly- 

 over or behind the end of the rectum, and of which the inner sur- 

 face is coarsely rugous, with rounded prominences, and numerous 

 irregular cellular cavities, secreting a mucous fluid. The inner 

 surface of the cloaca is smooth, and it is closed by a strong sphincter. 



The above description is taken from a male bird shot in Locha- 

 ber in the winter of 1835. In a female, which had been kept in a 

 state of captivity for several years, the dimensions of the intestinal 

 canal were as follows : 



(Esophagus 12| long, dilated on the neck into a crop 5^ long, 

 and 3 in diameter, then contracted to 1^ ; the proventriculus 1^ in 

 diameter. The stomach, 2| long, its tendons ^ in diameter. The 

 intestine 66 inches long ; at the commencement it has a diameter 

 of j^ , but immediately enlarges to \^, and so continues for 12 

 inches, when it gradually contracts, so as near the cceca to be only 

 ^ across. The cceca are -^ long. The rectum is 7 inches in length, 

 its dilated part 2 in diameter. 



The crop and the stomach may present different appearances in 

 individuals, according as they are more or less full or empty when 

 the bird is killed. When empty and contracted, they can scarcely 

 be inflated to so large a size as that which they present when the}' 

 have been stuffed with food by the bird. In the latter case, they 

 retain^ when emptied after death, the form given to them. Persons 

 therefore, measuring their dimensions in these different conditions, 

 would differ greatly in their statements. The measurements given 

 above and in the sequel, are taken from the parts inflated with air. 



I shall now offer a few remarks on the digestive process. By 

 means of the sharp-edged, strong mandibles, and the pointed de- 

 curved tip of the upper, the eagle tears up fragments of flesh from 

 the quadrupeds or birds which it has captured with the aid of its 

 powerful wings and feet, and killed by thrusting into them its long, 

 curved, tapering, very acute claws, or from animals which it may 

 have found dead. If the supply be plentiful, it fills the stomach, 

 and afterwards the crop ; for I have found them both completely 

 crammed, both in this species and in other birds of the family. It 

 is not nice in selecting its morsels, but swallows along with them 

 bones, hair, and feathers, in considerable quantity, when the pre}' 

 is small. The crop or dilatation of the oesophagus is merely a reci- 

 pient of the food, which is found in it quite unaltered, and it is en- 



