great distance; but this, from recent observation, seems doubtful. The tongue in birds, is supported by a production of the hyoid bone. The taste is not very delicate. Digestion in birds is in proportion to the activity of their life, and the quantity of their respiration. The stomach is composed first of the crop, which is a dilatation of the œsophagus at the base of the neck. The food remains in this duct for some time, and there imbibes a fluid analogous to the saliva, which is secreted from the inside of the canal. When softened by the action of heat and moisture, it passes little by little into a muscular bag, called the gizzard, where the food is triturated the more easily, that many species swallow little stones to increase the effect. The gizzard, it has been remarked, is strongest in the birds which have slender bills, and which are of course unable to break down their food; in those which feed on fish or flesh, the muscles are much weaker, and the stomach is almost membranous. By the outlet of this stomach, the food, reduced to a species of chyme, flows through the remainder of the intestinal canal, where the nutritious parts are absorbed, and the remainder expelled by a cloaca, an orifice common to the urinary and genital organs. Birds, such as the partridge and common fowl, whose young are able to walk and feed themselves on their departure from the egg, do not generally live in pairs. One male serves many females, and the young are entirely trusted to the maternal care. The greater part of birds, however, are blind and helpless at their birth, and their parents are therefore under the necessity of providing for their subsistence. Pigeons disgorge half digested grains, to feed their young; and linnets bring them larvæ of insects, or the soft parts of other animals. These live always in pairs, construct their nest with great care, and constantly in the same manner; and each species appropriates for this purpose certain materials. All possess a kind of instinct which leads them to choose the most convenient places for their nests, such as best afford concealment, or which render them inaccessible to their enemies. In birds the ova exist already formed in the mother before fecundation; and it is not a rare occurrence to see eggs laid without impregnation, similar in every respect to those which produce young. Fecundation, in most of the species, is accomplished by mere juxtaposition. The eggs of birds differ much in the color of their calcareous covering. They have generally the form of an elongated ball, and one of their extremities is thicker than the other. The fecundated eggs require a certain heat, to be hatched; and the observation of this fact has led to the practice in Egypt, and elsewhere, of hatching large broods of chickens by artificial heat. The class of birds, though not apparently so useful to man as Mammalia, serve important purposes in the general economy of nature. Those whose food is chiefly insects, check the excessive reproduction of insect races, and for this purpose migrate at certain seasons to places where their food abounds. The indiscriminate destruction of crows and sparrows, in some districts, has accordingly been found to give rise to an infinitely more prejudicial multiplication of creatures, still more destructive. Some families of birds destroy field mice, snakes, frogs, and lizards; and others again, are led by choice to feed on carrion, or dead animal matter. Birds, besides, are extensive agents in the spread of vegetables and even animals. It is well ascertained that wild ducks, in their emigrations, carry impregnated spawn into remote ponds, and thus stock them with fish; and many by swallowing seeds whole, and subsequently expelling them, are the means of spreading vegetation over an extent of surface which scarcely any other means could accomplish. A great portion of this class and their eggs may be used as food; and the feathers of many, form an object of commerce. Nothing is more singular in the history of birds, than their periodical migrations. That these are connected in some measure with the necessity of a supply of food, and the impulse of reproduction, is almost demonstrated; but the instinctive feeling which guides them, without compass, across seas and continents, and enables them to migrate at certain periods, corresponding with the production of their food in distant countries, can only be referred to one Great Source. Who bade the stork, Columbus-like, explore Heavens not his own, and worlds unknown before? Who forms the phalanx, and who points the way? The flights of migratory birds have been noticed from the earliest periods; "the stork in the heaven knoweth her appointed times, and the turtle, and the crane, and the swallow observe the time of their coming." And, as if their passage through the air, or the structure of their bodies made them sooner perceive the incipient changes of the weather, the appearance and cries of birds have long been considered to afford presages of the coming storm, or the cessation of the tempest. The institution of a college of Augurs, at Rome, may therefore be conceived to have reference to something better than mere superstition; and though the flight of particular species might, in the hands of interested individuals, be made to presage the wished for result of a battle, or direct a march already determined on, yet, in the absence of the barometer and thermometer, the appearance or disappearance and cries of birds, were the signals for the husbandman to sow his fields, or to secure his crop. Jam veris prænuncia venit hirundo. - Ovid. Tum cornix plena plurium vocat improba voce.-Virg. The crow with clamorous cries the shower demands. - Dryd. In this country, the great migrations of birds take place in spring and autumn. Those which arrive in spring, come from warmer climates, and, after incubation, leave us in autumn; and another host, chiefly palmipedes, from the arctic regions, arrive in autumn, pass the winter on our lakes and shores, and depart again in spring. Each species has a particular mode of flight, in these annual journeys, and a certain period of arrival and departure. Assembled in large flocks, the cranes cleave the air in the form of a long triangle; wild geese fly in angular lines; and the smaller birds associate in less numerous families, and reach their destination in less continued flights. One of the most curious particulars connected with the annual migrations of birds, is the circumstance of individuals returning for a series of years to the same nestling places. Spallanzani having tied a thread of red silk round the leg of a swallow, which built its nest in his window, saw for three seasons the same stranger, with its progeny, annually appear. Ekmark remarked a lame starling, which occupied the same nest in the hole of an old alder, for a period of eight years; and similar instances are on record, concerning many other species of migratory birds. This wonderful direction of instinct, which divides the innumerable flocks of birds in their progress northward, and leads particular families to seek the protection of the same roof, or the same chimney top, which formerly sheltered them, affords a subject not the least worthy of contemplation, among the thousand instances of wisdom and beneficence which arrest the student of nature, at every step of his progress. The flight of birds is very rapid. Birds of prey have been observed to fly at the rate of about twenty leagues in an hour. A falcon belonging to Henry II. of France, escaping from Fontainbleau, was found next day at Malta, a distance of thirteen hundred and fifty miles, and recognized from the ring on its leg. Sir Hans Sloane mentions that, at Barbadoes, the gulls came to feed, and returned two hundred miles the same day. And Mr Audubon relates of the migratory pigeons of America, that they have been killed in the neighborhood of New York with rice in their crops, collected in the fields of Georgia and Carolina, the nearest points at which this supply could have been obtained. Reasoning from the fact, that the food of pigeons is entirely digested in twelve hours, Mr Audubon concludes that they must have travelled between three and four hundred miles in six hours. Birds in general live long, considering how early they arrive at maturity. Swans are said to live for a hundred years; and the pelican arrives at a similar age. Carnivorous birds, particularly the eagle, live to a very great age, perhaps beyond a century; the raven for a still longer period; and parrots have been known to live from sixty to eighty years. The life of gallinaceous birds, such as the domestic fowl, the pheasant, and the partridge, seldom exceeds twelve or twenty years. ORDER I.-RAPACES. BIRDS of this order have the bill short and strong; upper mandible covered at its base by a membrane or cere, compressed on the sides and hooked towards its extremity; nostrils open; legs strong, muscular, short or medium length, feathered to the knee or toes; toes three before and one behind, divided, or united at the base by a membrane, rough below, armed with powerful claws, sharp, retractile, and hooked. Nearly all these birds live on animal food; the females are always larger than the males. The number of their eggs seldom exceeds four. THE FULVOUS, OR GRIFFON VULTURE.1 THIS noble species of vulture, which is one of the largest birds of prey of the Old Continent, measuring from three feet and a half to four feet in length, and more than twice as much in the expanse of its wings, is found on the lofty mountain chains of Europe, Asia, and Africa. It is not uncommon during the summer, in the Alps and Pyrenees; but it is said to retreat in winter, to the north of Africa, extending itself, according to Le Vaillant, to the Cape of Good Hope. The nest of the griffon vulture, is formed in the clefts of rocks. It lays from two to four eggs, which are of a grayish white, with numerous spots 1 Vultur fulvus, LIN. The genus Vultur has the bill thick and short, deeper than broad; its base covered by a cere; upper mandible straight, bent towards the point; under mandible straight, rounded, and inclined at the point; head naked, or covered with a short down; nostrils naked, lateral, opening diagonally towards the edge of the cere; legs strong, furnished with slightly bent claws; the middle toe largest, and united with the exterior one at the base. Of the characters the most obvious, is the absence of feathers to a greater or less extent on the head and neck, a mark of distinction which, like all the rest, is closely connected with the habits of the birds. Thus a falling off, or thinning of the feathers, is the frequent result of feeding upon flesh, especially when in a state of decay. The barrenness of these parts in the vultures, enables them, moreover, to burrow in the putrid carcasses on which they prey, without risk of soiling their plumage. Their largely extended nostrils, and the great internal developement of these organs, would seem to be of manifest use in guiding the vultures to their prey, which they are generally believed to scent from a great distance. It has, however, been lately maintained by a most acute observer of the habits of birds, Mr Audubon, that this belief, which has been entertained from the earliest antiquity, is founded in error, and that the vultures are directed to their prey by sight alone; the lofty pitch at which they fly, and the surpassing excellence of their vision, enabling them to detect it at an almost inconceivable distance. Several of the experiments brought forward by that gentleman, in support of his hypothesis, appear at first sight almost decisive of the question. But we cannot consent to abandon the received opinion, corroborated as it is to the fullest extent, by the anatomical structure of the organs of smell, until repeated experiments shall have placed the fact beyond the possibility of doubt. It is almost unnecessary to point out the great utility of the strong, deep curved bill of most of the vultures in tearing to pieces the carcasses on which they feed and consigning them in large masses to their maws. The nakedness of their legs may be regarded as dependent on the same causes, and serving the same purposes as that of their heads and necks. of a very light and diluted red. Like all the other birds of its tribe, it feeds principally upon dead carcasses, to which it is frequently attracted in very considerable numbers. When it has once made a lodgment upon its prey, it rarely quits the banquet while a morsel of flesh remains; so that it is not uncommon to see it perched upon a putrefying corpse for several successive days. It never attempts to carry off a portion, even to satisfy its young; but feeds them by discharging the half digested morsel from its maw. Sometimes, but very rarely, it makes its prey of living victims; and even then of such only as are incapable of offering the smallest resistance; for in a contest for superiority, it has not that advantage which is possessed by the falcon tribes, of lacerating its enemy with its talons, and must therefore rely upon the force of its beak alone. It is only, however, when no other mode of satiating its appetite presents itself, that it has recourse to the destruction of other animals for its subsistence. After feeding, it is seen fixed for hours in one unvaried posture, patiently waiting until the work of digestion is completed, and the stimulus of hunger is renewed, to enable and to urge it to mount again into the upper regions of the air, and fly abroad in quest of its necessary food. If violently disturbed after a full meal, it is incapable of flight until it has disgorged the contents of its stomach; lightened of which, and freed from their debilitat |