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bably their elasticity increased; and, in the circular opening resulting from this procedure, she takes her station and watches for her prey.-You must not infer, that the toils of spiders are, in every part of the world, formed of such fragile materials, as those which we are accustomed to see, or that they are every where con

nted with small insects for their food. An author in the Philosophical Transactions asserts, that the spiders of Bermudas spin webs between trees seven or eight fathoms distant, which are strong enough to ensnarea bird as largeasathrush: and Sir G. Staunton informs us, that, in the forests of Java, spiders' webs are met with of so strong a texture, as to requirea sharp cutting instrument to make way through them. Kirby and Spence.

ON THE MEANS OF DISGUISE, &c. POSSESSED BY IN

SECTS FOR THEIR PROTECTION. With the insect tribes infinite hosts of enemies wage continual war, many of whom derive the whole of their subsistence from them; and, amongst these tribes themselves, there are numerous civil broils, the strong often preying upon the weak, and the cunning upon the simple; so that, unless a watchful Providence (which cares for all its creatures, even the most insignificant), had supplied them with some mode of resistance or escape, this innumerable race must soon be extirpated. These means of defence are of two kinds, passive, or such as are independent of any efforts of the insect,and active, or such as result from certain efforts of the insect, in the employment of those instincts and instruments, with which Providence has furnished it for this purpose.-Some of the principal passive means of defence, with which insects are provided, are derived from their colour and form, by which they deceive their enemies. Sometimes they so exactly resemble the soil which they inhabit, that it must be a practised eye which can distinguish them from it. Thus, one of our scarcest British weevils, by its gray colour spotted with black, so closely resembles the soil, consisting of white sand mixed with black earth, on which I have always found it, that its chance of escape,eventhough it be hunt. ed for by the sharp eye of an entomologist, is not small. Another insect of the same tribe abounds in pits of a loamy soil, of the same colour precisely with itself; a circumstance, that doubtless occasions many to escape from their pitiless foes. Several other weevils resemble chalk, and perhaps inhabit a chalky or white soil. Many insects, also, are like pebbles and stones, both rough and polished, and of various colours; a resemblance, which we may safely regard as given them to enable them to elude the vigilance of their enemies. A numerous host of our little animals escape from birds and other assailants, by their resemblance to the colour of the plants, or parts of them, which they inhabit, or the twigs of shrubs and trees, their foliage, flowers, and fruit. Many of the mottled moths, which take their station of diurnalrepose on the north side of the trunks of trees, are with difficulty distinguished from the gray and green lichens that cover them. There is one caterpillar, which, when it feeds on a yellow lichen, is always yellow; but, when upon a gray lichen, its hue becomes gray: this change is probably produced by the colour of its food. Å kind of Mayfly frequents the black flower-spikes of the common sedge, which fringes the banks of our rivers: I have often been unable to distinguish it from them, and the birds probably often make the same mistake and pass by it. The spectre tribe go still further in this resemblance, representing a small branch with its

I have one from Brazil eight inches long, that, unless it was seen to move, could scarcely be conceived to be any thing else ; the legs, as well as the head, having their little snugs and knobs, so that no imitation can be more accurate. Other insects of various tribes represent the leaves of plants, living, decayed, and dead; some in their colour, and some both in their colour and shape. The caterpillar of a moth that feeds upon the privet is so exactly of the colour of the underside of the leaf, upon which it usually sits in the daytime, that you may have the leaf in your hand and yet not discover it. There are several species that resemble dry leaves so exactly, by their opacity, colour, rigidity, and veins, that, were certain parts of the animal only visible, even after a close examination it would be generally affirmed to be nothing but a dry leaf. Some species are extremely like flowers and fruits. I recollect to have seen, in a collection made by Mr Masson at the Cape of Good Hope, a kind of insect, arranged by Linne with the grasshoppers, which, in certain positions, had very much the appearance of a fine flower of a rose or pink colour. A most beautiful and black brilliant beetle, found by Captain Hancock in Brazil, by the inequalities of its ruby-coloured surface strikingly resembles some kinds of fruit. Some singular larvæ live in the nests of humble-bees, and are the offspring of a particular genus of fily, many of the species of which strikingly resemble those bees in shape, clothing, and colour. Thus has the Author of Nature provided, that they may enter these nests, and deposit their eggs undiscovered. Did these intruders venture themselves amongst the humble-bees in a less kindred form, their lives would probably pay the forfeit of their presumption. The active means of defence, which tend to secure insects from injury or attack, are much more numerous and diversified than the passive; and also more interesting, since they depend, more or less, upon the efforts and industry of these creatures themselves. Of these, the attitudes which they assume, for the purpose of deceiving their enemies, are none of the least remarkable. Some beetles, by rolling themselves up in a particular manner, put on the appearance of pebbles. There is a species of wood-louse, which, when alarmed, rolls itself up into a little ball. In this attitude its legs, and the underside of the body, which are soft, are entirely covered and defended by the hard crust, that forms the upper surface of the animal. These balls are perfectly spherical, black and shining, and belted with narrow white bands, so as to resemble beautiful beads; and, could they be preserve ed in this form and strung, would make very ornamental necklaces and bracelets. At least so thought Swammerdam's maid, who, finding a number of those insects thus rolled

spray.

up in her master's garden, mistaking them for beads, employed herself in stringing them on a thread; when, to her great surprise, the poor animals beginning to move and struggle for their liberty, she, crying out and running away in the utmost alarm, threw down her prize. The golden-wasp tribe, also, roll themselves up, as I haveoften observed, intoalittle ball, when alarmed, and can thus secure themselves,—the upper surface of the body being remarkably hard and impenetrable to their weapons,—from the stings of those insects, whose nests they enter with the view of depositing their eggs in their offspring. Other insects endeavour to protect themselves from danger by simulating death. The common dungchaffer, when touched or in fear, sets out its legs as stiff, as if they were made of iron wire, which is their posture when dead; and, remaining perfectly motionless, thus deceives the rooks, which prey upon them, and, like the ant-lion, will eat them only when alive. A different attitude is assumed by one of the treechaffers, probably with the same view. It sometimes elevates its posterior legs into the air, so as to form a straight vertical line, at right angles with the upper surface of its body. Another genus of insects of the same order, the pill-beetles, have recourse to a method the reverse of this. They pack their legs, which are short and flat, so close to their body, and lie so entirely without motion when alarmed, that they look like a dead body, or rather the dung of some small animal. Amongst the weevil tribe, there is one species, which, when an entomological finger approaches them, as I have often experienced to my great disappointment, applying the rostrum and legs to the underside of their trunk, fall from the station on which you hope to entrap them, to the ground or among the grass ; where, lying without stirring a limb, they are scarcely to be distinguished from the soil around them. Thus also, doubtless, they often disappoint the birds, as well as the entomologist. A little timber-boring beetle has long been famous for a most pertinacious simulation of death. All that has been related of the heroic constancy of American savages, when taken and tortured by their enemies, scarcely comes up to that which these little creatures exhibit. You may maim them, pull them limb from limb, roast them alive over a slow fire, but you will not gain your end; not a joint will they move, nor show the least symptom that they suffer pain. Do not think, however, that I ever tried these experiments upon them myself, or that I recommend

you

to do the same. I am content to believe the fact, that I have here stated, upon the concurrent testimony of respectable witnesses, without feeling any temptation to put the constancy of the poor insect again to the test. A similar apathy is shown by some species of the saw-fly, and by spiders.

Kirby and Spence.

ON THE ADAPTATION OF PLANTS TO THEIR RESPECTIVE

COUNTRIES.

“ A HUNDRED thousand species of plants upon the surface of the earth!” you exclaim. Yes: and, what is more surprising still, every one of these species has its native country,--some particular region, or peculiar spot, on the surface of the globe, to which, in its constitution and formation, it is peculiarly adapted. Some are formed to spring up into luxuriance beneath the scorching raysof a tropical sun,-some are so constituted as to vegetate beneath the snow, and to withstand the severity of a polar winter,--some are made to deck the valley with their variegated beauties, and some are formed « to blush unseen, and give their sweetness to the desert air” amidst alpine solitudes: but there is not one of those numerous plants, which has not its particular place assigned it. It would be equally vain to attempt to make some of these vegetable forms change their places (without a corresponding change of temperature) with impunity, as it would be to make the experiment of removing the finny inhabitants of the ocean from their native element, in order to make them harmonize and live in comfort among the feathery tenants of the grove. The wisdom and goodness of the Deity are indeed no less manifested in the geographical distribution, than in the curious process observed in the vegetation, the wonderful structure, and other striking peculiarities of plants. We have not room to mula tiply instances. But where, it may be asked, could the dense woods, which constitute the Brazilian forest, be

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