The learned Mr. Boyle remarked that "his wonder dwelt not so much on nature's clocks as on her watches." The insect world combines the sublime and the beautiful—the interesting and the useful. The wisdom and power of the Creator are often most displayed where they are least manifest to the common eye. Diminutiveness is associated with insignificance only by those who estimate importance by bulk. The elephant, the boa, and the eagle may compel our wonder; but conceive a sentient being twenty-seven million times smaller than a mite, endowed with the principles of thought and action, and nicely adjusted mechanism, and we could no longer stigmatize the Great Architect as reigning over an imperfect creation. Flora cannot show such prototypes of beauty and symmetry. The touch and finish of nature's pencil has given to this despised portion of God's handiwork, an apparel unparalleled by the ornaments of man. Moreover, the endless variety of objects, and the novelty of the science open a wide field of discovery, and cannot cease to alluie every truly observing mind —every lover of knowledge. As to the economy or cuibono of Entomology time would fail us to speak of the advantages derived from the light thrown upon these sources of good and evil, of their practical utility in a medical and chemical point of view, of their physiology as a help-meet to the science of all organic functions, and the hints they give us for the improvement of our arts and manufactures—for, in fact, these Liliputians are the best mechanics in the world, having their files and saws, augers, and lancets,scissors and forceps, always in order, and working them with wonderful dexterity and precision. They are evidently in dignity and importance above the mineral and vegetable worlds—being nearly allied to ourselves ; indeed, if number determine the rank, they form the pre-eminent branch of Zoology, for they can claim 400,000 species, while all other animals together barely amount to 30,000. And yet after all, how many millions skim over the surface of the ocean of truth—never dreaming of or caring for these myriad shells below. May American intellect ever plow deep in every field of inquiry—but never slight these miniatures of nature. An insect is an oviparous, articulate animal, divided into three distinct parts—head, corslet, and abdomen ; having 6 legs, and 2 or 4 wings attached to the thorax ; and pores for respiration leading to tracheae along the sides. Some undergo metamorphoses or a series of developments, like the three states of human personality. The want of an organization of brain is made up by the medullary thread which gives them tenacity of life. They have a great range of vision, and such a delicate sense of touch, it is probable they communicate by it. They are carnivorous, herbiverous, and omniverous. As to their geology with three exceptions, they are not found below the oolite. I. CoLEOPTERA— (Sheath winged.) This order includes those insects having ierustaceous membranes which shut and form S a suture along the back; covering the proper j wings beneath. Here belongs the Beetle I tribe, which in number and size holds the foremost rank, and of which the above represen-I tation is a type. We are acquainted with ? "bout 50,000 species, varying in color according to their habits ; having two autenuae, large protuberant eyes, two horny mandibles, ; and worm-like larvae, many of which are very destructive to the roots of plants. La- treill e classified them according to the divisions of the foot. Trimera (three-parted), are small, not common, and of great benefit to the horticulturist. The Coccinella, or lady-bird, is of this section. Tetramera (four-parted) are vegetable feeders. The weevil tribe number 4,000 species, among which are the diamond beetle of South America, and the well known corn-weevil. The family of wood-eaters make havoc in pine forests. The Lon-gicornes and Eupoda are injurious to the cultivator ; while the species of Cyclica Haltica attack turnips and vines. Pentemara (five-parted) includes the carnivorous tiger beetle, the bombardier beetle, which discharges a volatile, acrid, fetid fluid, the whirligig, which darts in tortuous paths on the surface of quiet waters, the devil's coach-horse, which emits a powerful odor in self-defence, the splendid Buprestis, having golden spots on an emerald ground, the skip-jack, the glow-worm, the death-watch, whose ticking is the call of the male for its mate, the burying beetle, which inters the carcasses of mice and moles, the sacred beetle of the Egyptians, the shard-borne, the cock-chafer, so destructive to vegetation, and for its size, six times its strong as a horse. Heteromcra (differently parted) feed on vegetables, and are very tenacious of life. Here belong the meal-worm, and the cantharis or Spanish fly, used as an epispastic in pharmacy. II. HOMOPIERA—(Eqal winged.) The insects of this order present curious anomalies, agreeing in very little except in the structure ot the mouth. The tongue is long and channelled, and begirt with lanceolate organs, with which the animal pierces vegetable tissues to pump out the juices. The anterior and posterior pairs of wings are both strong membranes. The females deposit their eggs in leaves and stems, which they saw with an ovipositor. The Monomerous or one-jointed tribe contains the cocci or scale-insects, whose transformations are wonderful, whose rapidity of propagation is incredible, and whose possession of a tree dooms it to certain death. They furnish, however, our richest dyes. Kermes (whence crimson) is the dried body of the female of the species ilicis, and has been known from time immemorial. From it was derived the imperishable red of the silks of India, of the robes of Greek and Roman patricians, and of the tapestries of Brussels. But it is nearly supplanted by the Cochineal of the New World. This is a semi-globose, gravid female of the species cacti, discovered in Mexico in 1518. It was considered a seed until the microscope of Leemoenhock, in 1704, proved its real origin. It is of the size of a tick, requiring 70,000 to weigh a pound. Soils unfit for the vine and potato yield the plant on which it feeds. The scarlet grain of Poland, found on the roots of the perrenial knawel, is employed only by the Turks, Armenians, Cossacks, and Polish peasantry, for dyeing silk, wool, morocco, manes and tails of horses, and fingernails of women. Lac-lake or lac-dye is the tinctorial matter of mammelated resin produced by the puncture of the species laca, of the Banyan-tree of India. The insect is as large as a louse ; red, round, flat, with a tal and six claws. Dirmra (two-jointed) includes the family of Aphides or plant-lice—the second greatest enemy to the vegetable world. They are oviparous and viviparous, and their lecundity is astonishing, there being twenty generations in a year, and one male the progenitor of 5,904,900,000 descendants in three months. They are from a twelfth to a quarter of an inch in length, green, brown, or yellow in color, and wingless in spring. With a proboscis they destroy wheat, oats, barley hops, pulse, apricot, and peach ; and from two horns in the posterior, drop an excrement called honey-dew,whichrivalssugar in sweetness, and which Pliny named the " Sweat of Heaven." Of the Trimera (three-jointed) the cicadidae and iulgoridae are most remarkable. The peculiar characteristic of the former con. sists in the musical powers of the male, which produces a monotonous, loud and shrill sound by an apparatus under the abdomen. If the voice of man were increased in the same ratio of his size he could be heard around the globe. The latter family are night-singers, and are distinguished by a curious projection of the forehead. The great lantern fly (represented last), called " scare-sleep " by the Dutch, sounds like a knife-grinder at work. From the secretion ol another species, the Chinese make a fine white wax, and another attacks the sugar cane of the West Indies. The frog-hopper of the family Cercopidae, leaps 250 times its own length. J. O. [This is the first of a series of articles which will be continued lor a number of weeks, prepared for the Scientific American by an accomplished correspondent and lover of science, Mr. J. Orton, of Lisle Broome Co., ?. Y.