the palmated or web-foot of the aquatic tortoises, and of numerous oceanic birds, in which the toes are united by a common skin. In the paddle the leg and toes together form the natatory organ; in the palmated, or lobed foot, the toes. Thus from fins we seem to have arrived at digitated legs. Wings. Turning from the denser medium of water, we must next inquire what organs have been given to animals by their Creator, to enable them to traverse the rarer medium of air, to have their hold upon what to the sight appears a nonentity, and to withstand the fluctuating waves of the atmospheric sea, and the rush of the fierce winds which occasionally sweep through space over the earth. The name of wings has by general consent been given, not only to the feathered arm of the bird, but also to those filmy organs extended, and often reticulated, by bony vessels-the longitudinal ones in some degree analogous to the rays of the fins of the fishes, especially of the flying fishes-which so beautifully distinguish the insect races; as well as to the rib-supported membrane forming the flying organs of the dragon; and those hand-wings by which the bats with so much tact and such nice perception steer without the aid of their eyes through the shrubs, and between the branches of trees; those also of other mammiferous animals, such as the flying squirrel and flying opossum use in their leaps from tree to tree. Savigny is of opinion that certain dorsal scales, in pairs, observable in two of the genera1 of his first family of Nerëideans,' are analogous to the elytra and wings of insects: this he infers from characters connected with their insertion, dorsal position, substance and structure, but not with their uses and functions; for, as he also states, they are evidently a species of vesicle, communicating by a pedicle with the interior of the body, which, in the laying season, is filled with eggs, a circumstance in which they agree with the egg-pouches of the Entomostracans; and therefore Baron Cuvier's opinion, that there is little foundation for the application of this term to these organs seems to me correct. Wings may be divided into organs of flight and organs of suspension. The first are found in insects, in which they are distinct from the legs; in birds, in which the anterior leg of 1 Halithea and Polynoe. See Aphrodita Clava. Montague in Linn. Trans. ix. 108, t. vii. f. 3. 2 Aphrodite. 4 Regn. Anim. iii. 206. 3 Syst. des Annel. 27. quadrupeds becomes a wing; and in bats and vampyres, in which both the anterior and posterior legs support a wing. She second kind of wings is found in the flying cat, the flying squirrel, and the flying opossum; and, under a different form, in the flying dragon of modern zoologists. The wings of insects differ materially from those of birds, and of certain Mammalians: for instance, the bats and vampyres, since in them they are not formed by skin or membrane, attached to the fore-leg, or both legs, but are distinct organs implanted in the trunk, usually leaving the animal its classical number of legs, for its locomotions on terra firma. These organs are composed of two membranes, closely applied to each other, and attached to elastic nervures issuing from the trunk, and accompanied by a spiral trachea or air-vessel. These nervures vary in their number and distribution: in some insects the wing has none except that which forms its anterior margin,' and in others the whole wing is reticulated by them;" the longitudinal ones often give an inequality to the surface, and form it into folds, which probably, in flight, it can relax or contract according to circumstances, in some genera3 the wing is folded longitudinally in repose, and in others also transversely. In the higher animals the wings never exceed a single pair; but in insects the typical number is four; and though some are called Dipterous, or two-winged, yet even a large proportion of these have, in the winglets, the rudiment of another pair. The anterior pair, called elytra, &c., in the beetles, and some others, are principally useful to cover and protect the wings when unemployed, still they produce some effect in flight, and they partake, in a reduced degree of the motion of the wings, those of the cock-chaffer describing an are equal to only a fourth part of that of the latter organs. M. Jurine, in which he is followed by M. Chabrier, has regarded the primary wing of insects as analogous to the wing of birds; but though this may hold good in some respects, it does not in its main feature. If we consider that the wing of birds is really the analogue of the fore-leg of quadrupeds, and replaces it; and also that insects have a representative of that leg fixed to the anterior segment of the trunk, thence called the Manitrunk, in contradistinction to the Alitrunk, which bears the wings; it seems not probable that the anterior leg, and the anterior wing which belong to different segments, should 1 Psilus, &c, See Jurine Hymenopt. t. v. and xiii. G. 48. 2 Libellulina. 5 Alule, 3 Vespida. 4 Cleoptera. be analogues of the same organ. The first pair of wings or their representatives, the elytra, are connected with the hipjoint, by an intermediate piece called the scapular; and the posterior wings are connected with the same joint of the posterior legs by the parapleura, so that, in some sort, the wings of insects may be regarded as appendages,-not of the fore-legs, or arms, which are the real analogues of the fore-leg of quadrupeds, and wing of birds,-but the first pair of the mid-legs, and the second of the hind-legs. Some winged insects, especially the dragon-flies, like the crabs and spiders, can retrograde in their flight, and also move laterally, without turning; thus they can more readily pursue their prey, or escape from their enemies. The situation of their wings is usually so regulated in the majority with respect to their centre of gravity, as to enable them to maintain nearly a horizontal position in flight; but in some, as the stag-beetles, the elytra and wings have their attachment in advance of that point, so that the head, prothorax, and mandibles do not fully counterpoise the weight of the posterior part of their body, occasioning this animal to assume a nearly vertical position when on the wing. The apparatus and conditions of flight in birds and insects are very different, varying according to the functions and structure of the animal. In birds a longer and more acute anterior extremity distinguishes the wing, by which their Creator enables them to pass with more ease through the air; but in insects that extremity is not a trenchant point that can win its own way, but usually is very blunt, opposing either the portion of a circle, or a very obtuse angle to it; hence perhaps it is that the common dung-beetle, which is a short obtuse animal, "wheels its droning flight" in a zig-zag line, like a vessel steering against the wind, and thus it flies, as every one knows, with great velocity as well as noise. This also may be one reason why insects have usually a greater volume of wing than birds, and that a very large number are fitted and adorned with four of these organs, which can sometimes hook to each other, by a beautiful contrivance," and so form a single ample van to sail on the aerial waves, and bear forward the bluff-headed vessel. The motions, in the air, of numerous insects are an alternate rising and falling, or a zig-zag onward flight, in a direction up and down, as all know who have ob Cora, Sce Introd. to Ent. iii. 661. 3 Ibid. 575 5 Geotrupes stercorarius, &c. 2 Scapulare, Ibid. 561, 4 Lucanus. 6 Mon, Ap. Angl. i, 108, served the flight of a butterfly, or a kind of hovering in the air, or a progress from flower to flower, or backwards and forwards and every way in pursuit of prey,-how admirably has their Creator furnished them to accomplish all these motions with the greatest facility and grace. And though their wings are usually naked, without any representative of those plumes which so ornament the wings of birds, and give them as it were more prise upon the air, yet in one numerous tribe,1 the moths and butterflies, they rival the birds, and even exceed them, both in the brilliancy of the little plumes, or rather scales, which clothe the wings, and the variety of the pattern figured upon them, and likewise of their forms and arrangement. So that every one, who minutely examines them in this respect with an unbiassed mind, can hardly help exclaiming,-I trace the hand and pencil of an Almighty Artist, and of one whose understanding is infinite, and who is in himself the architype of all symmetry, beauty, and grace! The wings of a variety of insects, though few, save the Lepidoptera, are ornamented with scales, are planted with little bristles, more or less numerous or dispersed; these Chabrier thinks, as well as the scales now alluded to, amongst other uses, are means of fixing the air in flight, as well as augmenting the surfaces, and points of arrest, in each wing. They also strengthen the wing and add to its weight, and doubtless have other uses not so easily ascertained. Hair, in scripture, is denominated power, and probably those fluids, which we can neither weigh nor coerce, find their passage into the body of the animal, or out of it, by these little conductors; and thus the various piligerous, plumigerous, pennigerous, and squamigerous ani nals, may offer points and paths not only to the air, but to more subtile fluids, either going or coming, whose influences introduced into the system, may add a momentum to all the animal forces, or, which having executed their commission and become neutralized, may thus pass off into the atmosphere. But of all the winged animals which God has created and given it in charge to traverse the atmosphere, there is none comparable to the great and interesting Class of birds, which emulating the insects on one side by their diminutive size and dazzling splendours, on the other vie with some of the Mammalians in magnitude and other characters. Here we have the humming-birds of America, scarcely bigger than the humble-bee; and there the savage condor of the same country, I Lepidoptera, 2 Sur le Vol des Ins. 24, whose outstretched wings would serve to measure the length of the giant elephant or rhinoceros. Though we cannot mount into the air ourselves, yet every one, from the peasant to the prince, that is able to follow the flight of the birds with his eyes, is delighted with the spectacle of life that they exhibit in the aërial regions, and we should scarcely miss the beasts of the earth and all the creatures that are moving in all directions and paces over its surface, than we should the disappearance of the birds of every wing from the atmosphere. And therefore the prophet in his sublime description of the desolation of Judah, makes the disappearance of the birds of heaven the most striking feature of his picture. I beheld the earth, says he, and lo, it was without form and void: and the heavens, and they had no light; I beheld the mountains, and lo, they trembled, and all the hills moved lightly. I beheld, and lo, there was no man, and all the birds of the heavens were fled.1 2 The wing of these animals, in many cases, so powerful to bear them on through the thin air, and counteract the gravity of their bodies; to take strong hold of that element which man cannot subdue like water, to move through himself, and so to push themselves on, often with the swiftness of an arrow, through its rushing winds or almost motionless breath: the wing of birds is in fact the fore-leg or arm adapted and clothed by Supreme Intelligence, for the action it has to maintain, and for the medium in which that action is to take place, and consists of nearly the same parts as the fore-leg in Mammalians, for there is the shoulder, fore-arm, and the hand, with the analogue of a thumb, called the winglet, and of a finger. The ten primary quill feathers are planted in the hand, and the secondaries, varying in number, on the fore-arm, these quillfeathers, being very principal instruments of the wing in flight, are also named the remiges or rowers of the vessel. The primary feathers usually vary in length, the external ones being the longest, so as to cause the wing to terminate in a point; those that cover the shoulder are called scapulars; and those short ones that cover the base of the wings above and below are called coverts. Wings usually curve somewhat inwards, are convex above and concave below, and are acted upon by very powerful muscles. Wonderful is the structure of the feathers that compose them, and each is a master-piece of the Divine Artificer. In general it is evident that each has been measured and weighed with reference to its station and func |
