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 t\vo 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 T 9 ^ in diameter. The 
intestine 66 inches long ; at the commencement it has a diameter 
of i 5 ^, but immediately enlarges to |>, and so continues for 12 
inches, when it gradually contracts, so as near the cosca to be only 
/ g across. The creca 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 they 
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 arid 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 j 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 prey 
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- 
