The fact is now established, that all insects come from eggs, as plants do from seeds.

Why is the life of insects the briefest of all existence?

Because the males rarely survive the inclemency of the first winter, and the females die after having deposited their eggs.

Why may the ephemeral nature of many tribes of insects be considered rather apparent than real?

Because the wonderful metamorphoses to which they are subjected, conceal their identity from the eye of the uninitiated, and greatly interfere with a continuous tracing of the same individual, from the egg to the perfect form. For example-many aquatic flies, such as the Ephemera and others, whose declared and more obvious existence, does not exceed a few hours, have, previous to their assuming the winged state, spent months or even years in the banks of rivers, and beneath the surface of the stream.

Why is the Linnaan arrangement of insects considered superior to others?

Because the primary divisions of Linnæus are taken from circumstances connected with the condition of the wings. The simplicity of this method, and the obviousness of the characters which have been employed, have secured for this system a decided preference among the entomologists of Britain.-Fleming.

Why is the first Linnæan order of insects called Coleoptera?

Because they have wings in sheaths: (koleos, a sheath-pteron, a wing ;) as the common black-beetle: -4,087 species.

Why is the second order called Hemiptera?

Because they have half of one wing overlaid by the other: (hemisu, half-pteron, a wing;) as the common cockroach:-1,427 species.

Why is the third order called Lepidoptera?

Because they have wings covered with very fine scales: (lepis, a scale-pteron, a wing ;) as the butterfly:-2,570 species.

Why is the fourth order called Neuroptera?

Because they have reticulated or nerved wings: (neuron, a nerve-pteron, a wing ;) as the dragon-fly: -174 species.

Why is the fifth called Hymenoptera ?

Because they have membraneous wings: (hymen, a film-pteron, a wing;) as the bee:-1,265 species. Why is the sixth order called Diptera ? Because they are two-winged: (dis, twice-pteron, a wing;) as the common gnat:-692 species.

Why is the seventh order called Aptura?

Because they have no wings: (a, privative—pteron, a wing ;) as the spider and the centipede:-679 species.

About thirty years ago, the recorded number of insects amounted to about eleven thousand; but a great additional number has since been discovered and described: Humboldt says 44,000.

Why is it evident that the nourishment in insects is not merely calculated for the preservation of the individual, but more particularly for the purpose of consuming organized matter?

Because insects must eat,-not solely to satisfy hunger, but also to destroy carrion, to annihilate other insects, to extirpate weeds, &c.; an admirable provision, to the execution of which, besides the almost incalculable number of species, the extremely rapid multiplication of many, the unexampled voracity of others, and the quickness with which digestion is carried on in their very short intestinal canal, all tend to contribute. Thus, it is known, that a caterpillar will, in twenty-four hours, consume more than three times its own weight.-Blumenbach.

Why may the abode of insects on and under the sur face of the earth, be considered as much less limited than that of the other classes of animals?

Because they are found on almost all warm-blooded animals; and even the larger insects, as bees, chaffers, &c. are infested by peculiar kinds of lice. There are but few plants, also, (such as, perhaps, the yew, savine, and most tree-mosses,) which do not serve for the abode and support of known insects. Many again, as the oak, are frequented and inhabited by more than a hundred distinct species. Generally, however, as insects are diffused over the earth, the residence of individual species is not less frequently limited to a very small number of animals and plants, or even particular parts of them.

Why are insects so serviceable in the general economy of nature?

Because some destroy numerous kinds of weeds in the bud, or extirpate them when full grown. Others feed on carrion, live in dung, &c., and thus destroy, disperse, and change noxious animal substances; on the one hand, obviating the infection of the air; and on the other, promoting the fertilization of the earth. It is in this way, for instance, that flies are so serviceable in warm climates. So again, innumerable insects effect the impregnation of plants in a very remarkable

manner.

Why are insects important in the arts?

Because of the ready adaptation of their labours to many of the conveniences of life. Thus, mead is prepared in many parts of Europe from the honey of bees; silk is employed for clothing: several insects, as cochineal, afford excellent dyes. Galls are employed for ink; wax, for lights, and other purposes. Lac, employed to make varnish, sealing-wax, &c. is produced by a certain Indian species of coccus. As medicines, we have Spanish flies, ants; and, adds Blu

menbach, the oil-beetle, recommended for hydrophobia, and many beetles for relieving tooth-ache.

Why are the eyes of certain insects termed compound? Because they consist of an aggregation of smaller eyes, or those which are termed simple; for their general convexity is divided into one immense number of small hexagonal or six-sided convex surfaces, which may be considered cornea. Simple eyes are formed in the larvæ of many winged insects, which upon their last or complete metamorphosis, at the same time that they receive their wings, gain the large compound eyes. The late Mr. T. Carpenter, the optician, of Regent-street, paid more attention to this branch of entomology than any man of his time. By aid of a powerful microscope, he experimented upon upwards of 200 insects; the most familiar of which were the boat-fly, dragon-fly, ant, gnat, bee, wasp, ichneumon, cockchaffer, peach-fly, earwig, grasshopper, locust, cricket, and cockroach. His results were a conviction that the whole of these insects did really possess numerous and distinct eyes, varying in number according to the species of insect; in some, upwards of 40-in others, 1,000; and upwards of 30,000 in some species! The eyes of the libellula, or dragon-fly, Mr. Carpenter says, are, on account of their size, peculiarly well adapted for examination under the microscope. They are a couple of protuberances immovably fixed in the head, and divided into a number of hexagonal cells, each of which contains a complete eye. The external parts of these eyes are so perfectly smooth, and so well polished, that when viewed as opaque objects, they will, like so many mirrors, reflect the images of all surrounding objects: each of these protuberances, in its natural state, is a body cut into a number of facets, like an artificial multiplying glass-but with this superiority in the workmanship, that as in that glass every facet is plain, here every one is convex; they are also much more numerous, and contained in a much

smaller space. Each of the eyes is an hexagon, vary ing in size, according to its situation in the head; and each of them is a distinct convex lens, and has a similar effect of forming the image of an object placed before it.

Blumenbach observes, compound eyes seem calculated for seeing at a distance; simple eyes, for looking at near objects; at least it may be supposed so, as we find that butterflies, in their perfect winged state, have such large compound, telescopic eyes; whilst, as caterpillars, they have small simple ones. Only a few insects can move their eyes, and from this fact has been deduced a probable explanation of at least one object of the numerous facets or surfaces of which the compound eyes of insects are composed.

Leuwenhoeck has counted 17,235 facets in the cornea of a butterfly.

Why have insects antennæ or feelers?

Because the organ of touch is not generally distributed over the body, and the antennæ are considered as appropriated to this sense. These organs are two or more in number, and are present in all the crustacea and insects, but wanting in the arachnidæ, or spider genus. They are situated on the head, usually between the eyes and the mouth. They consist of a number of joints, in general capable, by their flexibility of examining the surface of a body.-Fleming.

Why are these antennæ particularly necessary to insects?

Because of the insensibility of their outward coat, which is generally of a horny consistence; and also from their eyes being destitute, in most instances, of the power of motion.

The feelers of insects are better adapted for exploring the condition of the surfaces of bodies than any organ which we possess. But their sensibility of touch is limited to particular qualities, or confined within