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spider, the scorpion has eight eyes, three of which are placed on each side of the breast, and the other two on the back. The tail is long, jointed, and terminates in a sharp crooked sting. The venom of the scorpion is more destructive than that of any other insect; and is sometimes fatal in Africa and other hot regions.
Such are the divisions into which insects have been classed according to the Linnean system, and such is their structure and conformation. There are many other curious particulars concerning this wonderful part of the creation, which shall be the subject of future discussion. In the mean time, I shall conclude this paper, with a beautiful comparison from the moral Thomson:
Thick in yon stream of light, a thousand ways,
ON THE TRANSFORMATION OF INSECTS.
Where greatness is to Nature's works denied,
In a small space the more perfection's shown,
IN my two former papers I took a view of the divisions into which insects have been classed, according to the Linnean system. I am now to give a more particular account of what I have hitherto only incidentally mentioned-the various and wonderful transformations which they undergo.
All winged insects, without exception, and many of those which are destitute of wings, must pass through several changes before the animals arrive at the perfection of their natures. The appearance, the structure, and the organs of a caterpillar, a chrysalis, and a fly, are so different, that, to a person unacquainted with their transformations, au identical animal would be considered as three distinct species. Without the aid of experience, who could believe that a butterfly, adorned with four beautiful wings, furnished with a long spiral proboscis, instead of a mouth, and with six legs, proceeded from a disgusting caterpillar, provided with jaws and teeth,
and fourteen feet? Without experience, who could imagine that a long, white, smooth, soft worm, hid under the earth, should be transformed into a black crustaceous, beetle, having wings covered with horny cases?
Beside their final metamorphosis into flies, caterpillars undergo several intermediate changes. All caterpillars cast or change their skins more or less frequently according to the species. The silkworm, previous to its chrysalis state, casts its skin four times. The first skin is cast on the 10th, 11th, or 12th day, according to the nature of the season; the second in five or six days after; the third in five or six days more; and the fourth and last in six or seven days after the third. This changing of skin is not only common to all caterpillars, but to every insect whatever. Not one of them arrives at perfection without casting its skin at least once or twice. The skin, after it is cast, preserves so entirely the figure of the caterpillar in its head, teeth, legs, colour, hair, &c. that it is often mistaken for the animal itself. A day or two before this change happens, caterpillars take no food; they lose their former activity, attach themselves to a particular place, and bend their bodies in various directions, till, at last, they escape from the old skin, and leave it behind them. The intestinal canal of caterpil lars is composed of two principal tubes, the one inserted into the other: the external tube is compact and fleshy; but the internal one is thin and transparent. Some days before caterpillars change into the chrysalis state, they void, along with their excrement, the inner tube which lined their stomach and intestines. When about to pass into the chrysalis state, which is a state of imbecility, they select the most proper places and modes of concealing themselves from their enemies. Some, as the silkworm and many others, spin silken webs or cords
round their bodies, which completely disguise the animal form. Others leave the plants upon which they formerly fed, and hide themselves in little cells which they make in the earth. The rat-tailed worm abandons the water upon the approach of its metamorphosis, retires under the earth, where it is changed into a chrysalis, and, after a certain time, bursts from its seemingly inanimate condition, and appears in the form of a winged insect. Thus the same animals pass the first and longest period of their existence in the water, another under the earth, and the third and last in the air. Some caterpillars, when about to change into a chrysalis state, cover their bodies with a mixture of earth and of silk, and conceal themselves in the loose soil. Others incrust themselves with a silky or glutinous matter, which they push out from their mouths, without spinning it into threads. Others retire into the holes of walls or decayed trees. Others suspend themselves to the twigs of trees, or to other elevated bodies, with their heads undermost. Some attach themselves to walls, with their heads higher than their bodies, but in various inclinations: and others choose a horizontal position. Some fix themselves by a gluten, and spin a rope round their middle to prevent them from falling. Those which feed upon trees attach themselves to the branches, instead of the leaves, which are less durable, and subject to a greater variety of accidents. The colours of the caterpillars give no idea of those of the future flies.
In general, the figure of chrysales approaches to that of a cone, especially in their posterior part. When under this form, the insect seems to have neither legs nor wings. It is incapable either of walking or of crawling, It takes no nourishment, because it has no organs suited to that purpose; yet, in some species, life is continued for several
months before their last metamorphosis takes place. In a word, it seems to be a lifeless mass. But, upon a more attentive observation, it possesses the power of bending upward and downward the posterior part of its body. The skin, or exterior covering, of those which do not spin cods, seems to be of a cartilaginous nature. It is commonly smooth and shining; but in some species it is more or less covered with hair and other rugosities. Though chrysales differ both in figure and colour, their appearances are by no means so various as those of the caterpillars from which they are produced. The colour of some chrysales is that of pure gold, from which circumstance the whole have received their denomination. For the same reason they are called aurelie in Latin. Some are brown, others green; and, indeed, they are to be found of almost every colour and shade.
The life of winged insects consists of three principal periods, which present very different scenes to the student of Nature. In the first period, the insect appears under the form of a worm or caterpillar. Its body is long, cylindrical, and consists of a succession of rings, which are generally membraneous, and encased within each other. By the aid of its rings, or of crotchets, or of several pair of legs, it crawls about in quest of food; and its movements are, in some species, remarkably quick. Its head is armed with teeth, or pincers, by which it eats the leaves of plants or other kinds of food. In this state, it is absolutely deprived of sex, and, consequently, of the power of multiplication. Its blood moves from the tail toward the head. It respires either by small apertures placed on each side of its body, or by one or several tubes situate on its posterior part, which have the resemblance of so many tails. In the second period, the insect appears under the form of a nymph, or that of a chrysalis. When an insect,