The eyes of eagles are celebrated for their brilliancy and strength, which has given rise to the popular opinion that they can gaze on the sun without shrinking: though this, from the overhanging eyebrow of the Eagle, would be an extremely difficult feat for the bird to perform. The eyes of all birds are curiously constructed, so as to enable them to see both distant objects and near ones with equal facility; and for this purpose they are furnished with a membrane placed near the edge of the crystalline lens of the eye, by which it can be moved at pleasure. The orbit of the eye is formed of about twelve or sixteen bony plates, which slide over each other when necessary. Birds are also furnished with an additional eyelid, of extremely thin texture, with which they occasionally appear to shade their eyes. THE VULTURE. (_Vultur Monachus._) THE first rank in the description of birds has been given to the eagle, not on account of its size, but because it is nobler in its habits and more delicate in its appetites. But it belongs to the falcon tribe, and should be placed after the Vultures. The eagle, unless pressed by famine, will not stoop to carrion; and generally devours only what he has earned by his own pursuit. The Vulture, on the contrary, is disgustingly voracious; and seldom attacks living animals when it can be supplied with dead. The eagle meets and singly opposes his enemy: the Vulture, if he expects resistance, calls in the aid of its kind, and overpowers its prey by combination. Putrefaction, instead of deterring, only serves to allure it. The Vulture seems among birds what the jackal and hyæna are among quadrupeds, who prey upon carcases, and root up the dead. Vultures may be easily distinguished from eagles by the nakedness of their heads and necks, which are without feathers, and only covered with a very slight down, or a few scattered hairs; their eyes are more prominent; those of the eagle being buried more in the socket, and shaded by an overhanging eyebrow. Their claws are shorter and less hooked. The inside of the wing is covered with a thick down, which is different in them from all other birds of prey. Their attitude is not so upright as that of the eagle, and their flight is more difficult and heavy. In this description we may include the Golden, the Ash-coloured, and the Brown Vulture, which are inhabitants of Europe; the Spotted and the Black Vulture of Egypt; the Bearded Vulture, the Brazilian Vulture and the King of the Vultures, of South America. They all agree in their nature, being equally indolent, rapacious, and unclean. The Condor also belongs to the Vulture tribe. [Illustration: THE KING VULTURE. (_Vultur_, or _Sarcorhamphus papa_.)]