ant-lion below to be on the alert. In order to secure the prey, Réaumur, Bonnet, and others have observed the ingenious insect throw up showers of sand by jerking it from his head in quick succession, till the luckless ant is precipitated within reach of the jaws of its concealed enemy. It feeds only on the blood or juice of insects; and as soon as it has extracted these, it tosses the dry carcass out of its den. Its next care is to mount the sides of the pitfall and repair any damage it may have suffered; and when this is accomplished, it again buries itself among the sand at the bottom, leaving nothing but its jaws above the surface, ready to seize the next victim.

When it is about to change into a pupa, it proceeds in nearly the same manner as the caterpillar of the water-betony moth (Cucullia scrophularia). It first builds a case of sand, the particles of which are secured by threads of silk, and then tapestries the whole with a silken web. Within this it undergoes its transformation into a pupa, and in due time, it emerges in form of a four-winged fly, closely resembling the dragon-flies (Libellulæ), vulgarly and erroneously called horse-stingers.

The instance of the ant-lion naturally leads us to consider the design of the Author of Nature in so nicely adjusting, in all animals, the means of destruction and of escape. As the larger quadrupeds of prey are provided with a most ingenious machinery for preying on the weaker, so are these furnished with the most admirable powers of evading their destroyers. In the economy of insects, we constantly observe, that the means of defence, not only of the individual creatures, but of their larvæ and pupæ, against the attacks of other insects, and of birds, is proportioned, in the ingenuity of their arrangements, to the weakness of the insect employing them. Those species which multiply the quickest have the greatest

number of enemies. Bradley, an English naturalist, has calculated that two sparrows carry, in the course of a week, above three thousand caterpillars to the young in their nests. But though this is, probably, much beyond the truth, it is certain that there is a great and constant destruction of individuals going forward; and yet the species is never destroyed. In this way a balance is kept up, by which one portion of animated nature cannot usurp the means of life and enjoyment which the world offers to another portion. In all matters relating to reproduction, Nature is prodigal in her arrangements. Insects have more stages to pass through before they attain their perfect growth than other creatures. The continuation of the species is, therefore, in many cases, provided for by a much larger number of eggs being deposited than ever become fertile. How many larvæ are produced, in comparison with the number which pass into the pupa state; and how many pupa perish before they become perfect insects! Every garden is covered with caterpillars; and yet how few moths and butterflies, comparatively, are seen, even in the most sunny season! Insects which lay few eggs are, commonly, most remarkable in their contrivances for their preservation. The dangers to which insect life is exposed are manifold; and therefore are the contrivances for its preservation of the most perfect kind, and invariably adapted to the peculiar habits of each tribe. The same wisdom

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determines the food of every species of insect; and thus some are found to delight in the rose-tree, and some in the oak. Had it been otherwise, the balance of vegetable life would not have been preserved. It is for this reason that the contrivances which an insect employs for obtaining its food are curious, in proportion to the natural difficulties of its structure. The ant-lion is carnivorous, but he has not the quick

ness of the spider, nor can he spread a net over a large surface, and issue from his citadel to seize a victim which he has caught in his outworks. He is therefore taught to dig a trap, where he sits, like the unwieldy giants of fable, waiting for some feeble one to cross his path. How laborious and patient are his operations-how uncertain the chances of success! Yet he never shrinks from them, because his instinct tells him that by these contrivances alone can he preserve his own existence, and continue that of his species.

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CHAPTER XII.

Clothes-Moth, and other Tent-making Caterpillars.-Leaf and Bark-Miners.

THERE are at least five different species of moths similar in manners and economy, the caterpillars of which feed upon animal substances, such as furs, woollen cloths, silk, leather, and, what to the naturalist is no less vexing, upon the specimens of insects and other animals preserved in his cabinet. The moths in question are of the family named Tinea by entomologists, such as the tapestry-moth (Tinea tapetzella), the fur-moth (Tinea pellionella), the woolmoth (Tinea vestianella), the cabinet-moth (Tinea destructor, STEPHENS), &c.

The moths themselves are, in the winged state, small, and well fitted for making their way through the most minute hole or chink, so that it is scarcely possible to exclude them by the closeness of a wardrobe or a cabinet.* If they cannot effect an entrance when a drawer is out, or a door open, they will contrive to glide through the key-hole; and if they once get in, it is no easy matter to dislodge or destroy them, for they are exceedingly agile, and escape out of sight in a moment. Moufet is of opinion that the ancients possessed an effectual method of preserving stuffs from the moth, because the robes of Servius Tullius were preserved up to the death of Sejanus, a period of more than five hundred years. On turning to Pliny to learn this secret, we find him relating that stuff laid upon a coffin will be ever after safe from moths; in the same way as a person once stung by a *See fig. d. p. 221.

scorpion will never afterwards be stung by a bee, or a wasp, or a hornet! Rhasis again says, that cantharides suspended in a house drive away moths; and, he adds, that they will not touch anything wrapped in a lion's skin!—the poor little insects, says Réaumur sarcastically, being probably in bodily fear of so terrible an animal.* Such are the stories which fill the imagination even of philosophers, till real science entirely expels them.

The effluvium of camphor or turpentine, or fumigation by sulphur or chlorine may sometimes kill them, when in the winged state, but this will have no effect upon their eggs, and seldom upon the caterpillars; for they wrap themselves up too closely to be easily reached by any agent except heat. This, when it can be conveniently applied, will be certain either to dislodge or to kill them. When the effluvium of turpentine, however, reaches the caterpillar, Bonnet says it falls into convulsions, becomes covered with livid blotches, and dies.†

The mother insect takes care to deposit her eggs on or near such substances as she instinctively foreknows will be best adapted for the food of the young, taking care to distribute them so that there may be a plentiful supply and enough of room for each. We have found, for example, some of those caterpillars feeding upon the shreds of cloth used in training wall-fruit trees; but we never saw more than two caterpillars on one shred. This scattering of the eggs in many places renders the effects of the caterpillars more injurious, from their attacking many parts of a garment or a piece of stuff at the same time.‡

When one of the caterpillars of this family issues

*Réaumur, Mem. Hist. Insectes, iii. 70.

+ Contemplation de la Nature, part xii. chap. x. note.

J. R.