According to the same excellent authority, the Stag Beetle (Lucanus cervus) has been known to gnaw a hole an inch in diameter through the side of an iron canister in which it was confined, and on which the marks of its jaws were distinctly visible, as proved by Mr Stephens, who exhibited the canister at one of the meetings of the Entomological Society.

Let us look at the powers of Insects exercised in the act of flying. The House-flies (Musca domestica), that wheel and play beneath the ceiling for hours together, ordinarily move at the rate of about five feet per second; but if excited to speed, they can dart along through thirtyfive feet in the same brief space of time Now in this period, as Kirby and Spence observe, "a race-horse could clear only ninety feet, which is at the rate of more than a mile in a minute. Our little fly, in her swiftest flight, will in the same space of time, go more than one-third of a mile. Now compare the immense difference of the size of the two animals (ten millions of the fly would hardly counterpoise one racer), and how wonderful will the velocity of this minute creature appear! Did the fly equal the race-horse in size, and retain its present powers in the ratio of its magnitude, it would traverse the globe with the rapidity of lightning."* Some of the flies that haunt our gardens shoot along so rapidly that the eye cannot follow them in flight.

Nor are these tiny creatures less masters of the arts of running and leaping. De Lisle mentions a fly so minute as almost to be invisible, which ran nearly six inches in a second, and in that space was calculated to have made

* Introd. to Entomology.

one thousand and eighty steps! This, according to the calculation of Kirby and Spence, is as if a man whose steps measured only two feet, should run at the incredible rate of twenty miles in a minute.

Every one has had occasion to observe, not always without an emotion of anger, the leaping powers of the Flea (Pulex irritans). A bound of two hundred times its own length is a common feat; as if a man should jump twelve hundred feet, or a quarter of a mile! What a pity that Insects were not allowed to be competitors in the athletic games of old!

With regard to their organisation, all Insects in the mature state are armed with three pairs of legs; which are divided into several parts, as, the hip, the thigh, the shank, and the foot, by distinct hinge-joints: the foot itself (tarsus) consists of several jointed pieces, and is usually terminated by two hooks, and often furnished with adhesive pads, or other organs accessory to locomotion. In most of the tribes there are also wings, two pairs in general (but in one extensive Order the hinder pair is obliterated); each of these organs consists of two films of highly elastic membrane, stretched over a frame-work of strong tubes, as the silk of an umbrella is expanded over its ribs. In the Order Coleoptera (Beetles), the fore pair are thick, leathery, and opaque, chiefly serving as shields to protect the hind pair in repose; and in some other Orders they are somewhat coriaceous; while in the beautiful Lepidoptera (Butterflies), the transparency of both pairs is concealed by a covering of minute feather-like scales, overlapping each other, reflecting various colours, and arranged in a mosaic of inimitable beauty.

The power of these organs, so delicate and filmy in appearance, we have before alluded to, but it may be illustrated by another anecdote. Leeuwenhoek has recorded a remarkable instance, in which he was an eyewitness of the comparative capabilities of the Dragon-fly and the Swallow, as relates to the perfection of their flight. The bird and the insect were both confined in a menagerie about a hundred feet long; and apparently their powers were fairly tested. The swallow was in full pursuit, but the insect flew with such astonishing velocity, that this bird of rapid flight and ready evolution was unable to overtake and entrap it; the insect eluding every attempt, and being generally six feet before it.

The organs of the mouth vary much in form and function in different insects. In a Beetle they consist of two pairs of jaws, generally hooked and toothed, working horizontally, and an upper and an under lip, closing the mouth above and below. Each lower jaw bears one or two filaments, consisting of several joints; and a similar pair is affixed to the lower lip. These filaments are called palpi, and are supposed to be highly endowed organs of touch. They greatly resemble the antennæ, or horns of many joints, which project from the front of the head; but these latter are considered to be organs of hearing.

If we look at a Gnat piercing our hand with its bloodsucking tube, or a Butterfly pumping up the nectar of a flower through its spiral tongue, or a Fly dissolving grains of sugar with the fleshy lips of its proboscis, we shall not very readily allow them any analogy with the apparatus of jaws and lips which we have just described. Yet great as is the dissimilarity, it is now established, that all these

forms of mouth are but modifications of the same model, adapting it to different functions. The sheath, horny and tubular in the Gnat, soft and muscular in the Fly, is the lower lip; the piercing lancets in the former are the jaws, which are inconspicuous in the latter. The elegant coiled spire of the Butterfly consists of two tubes, which are the lower jaws, greatly lengthened; and the labial palpi, stout and hairy, stand up on each side of them: the other essential parts can be detected only by the skill of the anatomist.

Some of the most interesting of the phenomena which occur in the economy of Insects, are the transformations which they exhibit in their progress of growth; the changes of their form being frequently so great, that it would be impossible, but for the testimony of experience, to avoid the conclusion that the same insect, in infancy, youth, and adult age, belonged to widely distinct and remote orders of existence. We shall enter into some details of this interesting subject in our next chapter.

CHAPTER XVII.

INSECTA (Insects).

Continued.

How delightful is the season, when the Butterflies begin to spangle the fields and woodlands! Welcome visitants they always are, in their airy grace and beauty; not less welcome than the flowers on which they alight, and whose brilliant hues and delicate petals are rivalled by their painted and filmy wings.

"The Butterflies are come !" Yes, it sends a thrill of pleasure through the heart, after the long dreary winter, to see the first Butterfly of the season sailing on its broad sylphic pinions in the warm beams of a calm April morning. Perhaps it is the pretty little Orange-tip (Mancipium cardamines), that attendant on early spring, coursing along some rural lane; or the Brimstone (Gonepteryx rhamni), hovering over a perfumed cluster of primroses, itself scarcely to be distinguished from one of them. Perhaps it is the Admiral (Vanessa Atalanta), whose fine scarlet bands afford so rich a contrast to its black velvet wings; or the Peacock ( V. Io), with its gorgeous violet eyes; or the Tortoise-shell (V. urtica), clouded with yel