Ephemeral Flies.—This species of insect is named ephemeral, because of its very short existence in the fly state. It is one of the most beautiful species of flies, and undergoes five changes. At first, the egg contains its vital principle; it comes forth a small caterpillar, which is transformed into a chrysalis, then into a nympha, and lastly, into a fly, which deposits its eggs upon the surface of water, where the sun’s rays bring them to life. Each egg produces a little red worm, which moves in a serpentine manner. They are found in abundance during the summer, in ponds and marshes; and as soon as cold weather sets in, the little worm makes for itself a shell or lodging, where it passes the winter; at the end of which it ceases to be a worm, and enters into its third state, that of a chrysalis. It then sleeps till spring, and gradually becomes a beautiful nympha, or a sort of mummy, something in the form of a fish. At the time of its metamorphosis, the nympha at first seems inactive and lifeless; in six days, the head appears, raising itself gradually above the surface of the water; the body next disengages itself slowly and by degrees, till at length the whole animal comes out of its shell. The new-born fly remains for some minutes motionless upon the water, then gradually revives, and feebly shakes its wings, then moves them quicker, and attempts first to walk, then to fly. As these insects are all hatched nearly at the same time, they are seen in swarms for a few hours flitting and playing upon the surface of the water; they then lay their eggs, and soon after die. Thus they terminate their short life in the space of a few hours, and the same day that saw them born, witnesses their death.
The Butterfly.
Behold, ye pilgrims of this earth, behold!
See all but man with unearn’d pleasure gay
See her bright robes the butterfly unfold,
Broke from her wintry tomb in prime of May!
What youthful bride can equal her array?
Who can with her for easy pleasure vie?
From mead to mead with gentle wing to stray,
From flower to flower on balmy gales to fly,
Is all she has to do beneath the radiant sky.
Thomson.
The first thing which fixes our attention on beholding these aërial inhabitants, is, the clothing with which they are adorned. Yet some of them have nothing in this respect to engage our notice, their vestment is simple and uniform; others have a few ornaments on the wings; but with some, those ornaments amount to profusion, and they are covered with them all over. This last species will occupy us for a short interval. How beautiful are the gradations of colour which decorate them! what harmony in those spots which relieve the other parts of their attire! with what delicacy has nature pencilled them! But, whatever may be my admiration when I consider this insect by the naked eye, how greatly is it augmented, when I behold this beautiful object through the medium of the microscope! Would any one ever have imagined, that the wings of butterflies were furnished with feathers? Nothing, however, is more true; and what we commonly call dust, is found in reality to be feathers. Their structure and arrangement are adjusted to as perfect symmetry, as their colours are soft and brilliant. The parts which form the centre of these little feathers, and which immediately touch the wing, are the strongest; those, on the contrary, which compose the exterior circumference, are much more delicate, and of an extraordinary fineness. All these feathers have a quill at their base, but the superior part is more transparent than the quill from which it proceeds. If we lay hold of the wing too rudely, we destroy the most delicate part of the feathers; but if we remove all that we term dust, there remains only a thin transparent skin, where may be distinguished the little orifices in which the quill of each feather was lodged. This skin, from the nature of its texture, may be as easily discerned from the rest of the wing, as a fine gauze from the cloth on which it is fastened; it is more porous, more delicate, and seems as if embroidered by the needle; to complete its beauty, its extremity finishes by a fringe, whose minute threads succeed each other with the utmost regularity.
What are our most laboured dresses, what is all their boasted ornament, in comparison of that refined tissue with which nature has invested this simple insect? Our finest laces are only like coarse cloth, when brought to vie with that luxurious clothing which covers the wings of the butterfly; and our smallest thread, by their infinitely delicate fibres, swells into hempen cord. Such is the wonderful difference to be observed between the works of nature and those of art, when viewed through a microscope. The former are finished to all imaginable perfection; the others, even the most beautiful of their kind, appear incomplete and coarsely wrought. How fine a piece of delicate cambric appears to us! nothing more slender than the threads, nothing more uniform than the texture: and yet in the microscope these threads resemble hempen strings, and we should rather be tempted to believe that they had been interlaced by the hand of a basket-maker, than wrought on the loom of a skilful weaver.
What is most astonishing in this brilliant insect, is, that it proceeds from a worm, than which nothing has a more abject and vile appearance. Behold how the butterfly displays to the sun his splendid wings, how he sports in his rays, how he rejoices in his existence, and, in respiring the vernal airs, how he flutters in the meadow from flower to flower. His rich wings present to us the magnificence of the rainbow. How beautiful is he now, who but a little while ago crept a worm in the dust, in perpetual danger of being crushed to death! Who has raised him above the earth? Who has given to him the faculty of inhabiting the ethereal regions? Who has furnished him with his painted wings? It is God.
In down of ev’ry variegated dye,
Shines, flutt’ring soft, the gaudy butterfly;
That powder, which thy spoiling hand distains,
The form of quills and painted plumes contains:
Not courts can more magnificence express,
In all their blaze of gems and pomp of dress.
Browne.
Their wings, all glorious to behold,
Bedropt with azure, jet, and gold,
Wide they display; the spangled dew
Reflects their eyes and various hue.
Gay.
We shall now briefly describe The Metamorphoses of Insects. And first, The Butterfly:
From form to form they pass in wondrous change.
Virgil.
At the first exclusion from the egg, and for some months of its existence afterwards, the creature which is to become a butterfly, is a worm-like caterpillar, crawling upon sixteen short legs, greedily devouring leaves with two jaws, and seeing by means of twelve eyes, so minute, as to be nearly imperceptible without the aid of a microscope. We now view it furnished with wings capable of rapid and extensive flights; of its sixteen feet, ten have disappeared, and the remaining six are in most respects wholly unlike those to which they have succeeded; its jaws having vanished, are replaced by a curled-up proboscis, suited only for sipping liquid sweets; the form of its head is entirely changed, two long horns projecting from its upper surface; and, instead of twelve invisible eyes, you behold two, very large, and composed of at least twenty thousand convex lenses, each supposed to be a distinct and effective eye!