The Book of Nature laid Open. (Continued from page 171.) "But who the various nations can declare BIRDS. THE OSTRICH, the EMU, and the CASSOWARY, are not only remarkable by reason of their superiority of size, but seem to claim our first attention among the feathery tribes on account of their constituting some of those apparent links, by which the winged is united to the order of Quadrupeds. For although these animals resemble birds in the outline, and in several parts of their conformation, they certainly cannot be classed among the more perfect orders of the species, in as much as they do not make use of their wings for the purpose of flying; and as to internal formation, the Ostrich is said to have as great a resemblance to the four-footed as to the volatile order. The structure of these creatures, as well as their appetites, is however well adapted for the situations in which they are severally placed, and they appear to know well how to supply the defect of some of their members by the use which they make of others. Of all animals that move on their legs, the Ostrich is by far the swiftest; and although the Arabians train their fleetest horses for the chace, it is not likely they would be successful in the pursuit of this animal, were it not for his circling manner of running: Nor is this surprising, when we consider, that this lofty mass of light materials is not only carried forward by his long springing legs, but is im pelled L pelled along by his wings, which he keeps in constant metion, and apparently serve the purpose of oars. The EMU, or Ostrich of the new continent, is also a remarkably swift runner, but its manner of assisting its legs is somewhat different from the former; besides making use of something behind, like a heel, heel, to push it forward, this animal uses a kind of action peculiar to itself, first lifting up one wing and keeping it elevated for some time in form of a sail, then leting it drop and elevating the other; by this means it moves along with such rapidity, that even the Greyhound can seldom overtake it. The favourite climate of the CASSAWARY seems to begin, where that of the Ostrich terminates, in the old world; and although its wings are so very small, that being covered with the hair on the back they are scarcely perceptible, it kicks up behind with the one leg, and then making a bound forward with the other, proceeds with such amazing speed, that the swiftest racer would be unable to maintain the pursuit ! IN THE STRUCTURE OF BIRDS OF THE MORE PERFECT ORDER, A FEW THINGS DEMAND OUR MOST SERIOUS atTENTION. The whole body is shaped in the most convenient manner for making their way through the air; being, as Mr RAY observes, constructed very near Sir ISAAC NEWTON'S form of least resistence. According to BAR, in his continuation of BUFFON: "It is neither extremely massive nor equally substantial in all its parts; but being designed to rise in the air, is capable of expanding a large surface without solidity. The body is sharp before, to pierce and make its way through that element; it then gradually increases in bulk, till it has acquired its just dimensions, and falls off in an expansive tail." The motion of this order being two-fold, walking and ying, they are provided with legs at once wonderfully contrived contrived to walk with, and raise them like a spring for their flight; wings to buoy them up and waft them along ; and a tail to keep them steady in the air, assist them in their evolutions, and to direct their course. Although their feathery covering is admirably constructed for lightness and buoyancy, their wings are fur nished with a strength that is amazing*; and by these they are enabled to impel themselves forward with an inconceivable rapidity. To fit them the better for their flight, the feathers are disposed in the most perfect order, lying one way; and that they may glide more smoothly along, they are furnished with a gland situated on the ramp, from which they occasionally press out oil with the bill, and anoint the feathers. The beak, or bill of birds, is a curious piece of art, formed of a hard horny substance, constructed in the most commodious manner for piercing the air, Their cars stand not out from their head to retard their flight, while their eyes are placed in such situations as to take in nearly a hemisphere on either side. Birds have no teeth to chew their food; but those of the granivorous kind are provided with two stomachs; in one of which the victuals are softened and macerated be *We refer our readers to p. 445 of our first volume, for the wonderful construction and properties of a feather.-The wings of birds are so remarkably strong, that the flap of a Swan's wing has been known to break a man's leg; and a similar blow from an Eagle has produced instant death. They glide through the air with a velocity superior to that of the fleetest quadruped, and can for a length of time continue their motion. If we suppose a bird to proceed at the rate of no more than a mile in two minutes for the space of twenty-four hours, it will, in that time, have passed over an extent of more than seven hundred miles What animal could continue its space over an extent of ground like this? In water-fowl this oil is so plentiful that by it their plumage is rendered completely water-proof. fore they enter the other to be completely digested. Being often employed in traversing the upper regions, where they behoved to be much incommoded did they bring forth their young in the manner of quadrupeds, their manner of generating is wisely made to differ, and their offspring are produced by means of eggs*. In the speedy growth of young birds, by which they acquire a degree of strength and size so as to be able so soon to provide for themselves, we have also an instance of the tender care of providence. What power unseen inspires these little creatures with "the passion of the groves," at the most fit season for form. ing their alliances!--when the genial temper of the weather covers the trees with leaves, the fields with grass, and produces such swarms of insects for the support of their future progeny? And, how comes it to pass, that no sooner is the connubial league formed than those little warbiers, (a pattern to new-married couples in humble life, who have nothing but their own industry to depend on) immediately set about building their nests, and making preparation for their tender offspring? In the building of their nests, what art and ingenuity are displayed! Whether they are constructed from the collected portions of clay and mortar, or from the more light materials of moss and straw, these little creatures contrive to mould them into the most convenient forms, and *What wisdom do we discover in the formation of an egg! The crustaceous coat serves to preserve the embryo from external injury while it is nourished. for some time by part of the substance (the white) from whence it is formed, and on its exclusion, as the parent has not the means of giving suck, it is nourished for some time by part of the yolk taken up into the belly by a channel peculiarly adapted for the purpose. See also "the Chick in the Egg," p. 108, Vol. I. and to give them a durability proportionate to their wants* Nor is the wonder less, that birds of the same kind, how ever widely separated, should all follow the same order of architecture in the construction of their habitationst; that each should make choice of the situation most suitable to its kind, and that all should agree in laying as many eggs as to be sufficient to keep up their species, yet no more than they can conveniently hatch and bring up. In the incubation, with what patience do these creatures sit on their eggs when necessary, till the young are ready to be hatched, and then how officious in assisting the little prisoners to escape!-With what inimitable care do they afterwards watch over and provide for the brood until it is capable of doing so for itself; and with what scrupul ous exactness during this period do they distribute to each his allotted portion of food. 1 "What is this Mighty Breath! ye sages say, And unremitting Energy pervades, S 3 -It wins my admiration, To view the structure of that little work, No glue to join! his little beak was all t These † Hatch a crow under a hen, and never let it see any of the works, of its own kind; the nest it makes will be the same, to the laying of a stick, with all the other nests of the same species! "Some to the rude protection of the thorn Commit their feeble offspring; the cleft tree Their food its insects, and its moss their nest. But most in woodland solitudes delight." In general it may be observed, that every bird resorts to hatch in that situation where it can do so with the greatest safety, and where its sustenance can be most readily found. |