The genus called aranea, or spider, comprehends a great many species. The spider has eight feet, and. an equal number of immoveable eyes. The chief prey of the spider is flies, animals whose motions are extremely quick and desultory. To enable the spider to observe their movements in every direction, it is furnished with eight eyes, the position of which merits attention: two of them are placed on the top of the head, other two on the front, and two on each side. The mouth is armed with two hooks or fangs, by which it seizes and kills its prey. The spider is. also possessed of several muscular instruments, each of which contains about a thousand tubes or outlets for threads so extremely minute, that many hundreds of them must be united before they form one of those visible ropes of which its web is composed. The figure of the web varies according to the species or the situation which the animal chooses for its abode. After the web is completed, some species reside in the centre, and others occupy the extremity of their habitations, where they lie in ambush, with astonishing patience, till a fly is accidentally entangled. The spider, from the vibration of the threads, perceives his prey, rushes forth from his cell, instantly seizes it with his fangs, devours its vitals, and afterward rejects the exhausted carcase. Spiders prey upon all weaker insects, and even upon their own species:

But chief to heedless flies the window proves
A constant death; where, gloomily retired,
The villain spider lives, cunning, and fierce,
Mixture abhorred! Amid a mangled heap
Of carcases, in eager watch he sits,
O'erlooking all his waving snares around.

up to those of the gnat; as also, saith he, 'How much greater must have been the power and wisdom of HIM who formed a flea? And if such attributes are so clearly perceptible in the formation of the vilest and most insignificant insects, how much more are they apparent in the structure of the nobler animals?'

Near the dire cell the dreadless wanderer oft
Passes, as oft the ruffian shows his front:
The prey at last ensnared, he dreadful darts,
With rapid glide, along the leaning line;
And, fixing in the wretch his cruel fangs,

Strikes backward grimly pleased: the fluttering wing
And shriller sound declare extreme distress,
And ask the helping, hospitable hand.

THOMSON'.

The scorpion is a venomous insect, and a native of warmer climates than those of the north of Europe. It has eight feet, and two claws, the last of which are situate on the forepart of the head. Like the 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.

The two genera cancer and monoculus are crustaceous, or have a hard shelly covering. The crabs and lobsters cast their skins annually, the body shrinking before the change, and enabling them easily to draw out their limbs from the shell. The larger kind of crabs possess the extraordinary power of casting off at pleasure any limb which may be accidentally maimed or bruised, and a new limb is gradually formed. Like some of the crabs, lobsters are said to be attached to particular parts of the sea.

In shelly armour wrapt, the lobsters seek
Safe shelter in some bay, or winding creek;
To rocky chasms the dusky natives cleave,
Tenacious hold, nor will the dwelling leave.

Nought like their home the constant lobsters prize,
And foreign shores and seas unknown despise.

See a Sonnet to the Spider in Time's Telescope for 1817, p. 117; an account of the garden-spider and descriptive lines in pp. 301, 302; some curious particulars respecting spiders' webs in T.T. for 1816, pp. 305-307; and on the gossamer appearance in T. T. for 1814, p. 272, for 1817, pp. 298-301, and the present volume, pp. 263-264.

Though cruel hands the banished wretch expel,
And force the captive from his native cell,
He will, if freed, return with anxious care,
Find the known rock, and to his home repair;
No novel customs learns in different seas,

But wonted food and home-taught manners please.

Egg State and Transformation.

Insects are, in general, oviparous, producing eggs which are gradually quickened into life by the joint influence of the heat of the sun, and of those warm substances which constitute their nidus. Bonnet mentions some instances in the order diptera, in which the parent insect produces living young. The genus aphis exhibits a singular phænomenon also in this respect: during summer, being viviparous, but oviparous towards winter; the mode of birth being determined by the nature of the season.

The nide in which the eggs of insects are deposited is generally chosen with admirable skill; and adapted equally to the security, warmth, and subsistence of the larves that are to be reared in it. Some construct their nests in the earth with great labour; others deposit their eggs upon those plants, the leaves of which are to supply food for the nascent brood; a third kind, as various species of the musca, bury their eggs in the body of the chrysalids of other insects, upon the juices of which the young are nourished at the expense of the defenceless animal which they devour. The skin, the nostrils, viscera, &c. of quadrupeds, furnish a receptacle for other insects; and here nature directs the parent animal to deposit its eggs. Instinct is the sole guide, and almost always an unerring one.

In the Lapland Alps there is an insect called the rein-deer gad-fly (oestrus tarandi), the attacks of which are greatly dreaded by the rein-deer. It hovers all day over these animals, who betray every mark of fear; their legs tremble under them; they

prick up their ears, and rush to the mountains covered with ice and snow, to escape from the fly, but often in vain; for the insect follows, and generally finds means to lodge its egg in the back of the deer. The worm hatching penetrates the skin, and remains under it in security during the winter; in the year following it falls out, changed to a pupa, and becomes a winged insect. The astrus bovis is an equal terror to oxen; the hippobosca equina to horses; and œstrus ovis to sheep: the latter insinuates its eggs into the head of those useful animals, through the nasal organs.

The nest formed by the female of the hydrophilus piceus, for the preservation of their eggs, is altogether remarkable, and is described with much minuteness by Lyonnet. This nest is whitish, its figure an oblatespheroid, three-fourths of an inch in length, and its breadth two-thirds of its length; on the upper surface it is terminated by a lengthened horn-like process, an inch long, ending in a point, and of a brownish colour. In this nest the eggs are deposited, and left floating on the water till in due time they hatch, and the larvæ desert the little bark contrived for their preservation in the state preceding, committing themselves to the water. These coques generally float among reeds and duck-weed. The purpose of the conical projection is supposed to be that of sustaining the case in an upright position, when assailed by the wind: but this is mere conjecture; we may have yet to learn its actual destination. Another aquatic insect (one of the nepa genus) that inhabits the waters of China, exhibits a far more extraordinary instance of the parental care which the insect race evince for the preservation of their eggs. This diminutive creature, scarcely an inch long, and of a subrotund figure, with the upper and lower surfaces flattened, is seen at particular seasons bearing a large cluster of eggs on its back, which, though disposed as compactly as possible,

by being placed on one end, and having the sides touching each other, cover no inconsiderable portion of the whole surface of the disk. In this manner they are conveyed by the insect, wherever it goes, till the larvæ hatch, and drop instinctively into the water; when the parent insect casts off the exuvia of the nidus, and resumes its former appearance'.

Each, as reflecting on their primal state,

Or fraught with scientific craft innate,
With conscious skill their oval embryon shed,
Where native first their infancy was fed:

Or on some vegetating foliage glued;

Or o'er the flood they spread their future brood;,
A stender cord the floating jelly binds,

Eludes the wave, and mocks the warring winds;
O'er this their sperm in spiral order lies,
And pearls in living ranges greet our eyes.

In firmest oak they scoop a spacious tomb.

Some flow'rs, some fruit, some gems, or blossoms choose,
And confident their darling hopes infuse;
While some their eggs in ranker carnage lay,

And to their young adapt the future prey.

BROOKE2.

The different changes of form which many insects undergo, from their first appearance as eggs till they arrive at their perfect and winged state, constitute an important article in their history: these have been termed their metamorphoses, or transformations; and, from the very language employed to express

**Donovan's Insects of China.

Of all the productions of nature, insects are supposed to be the most numerous and fertile. With the exception of fishes and crustacea, they are apparently the most prolific. Lyonnet has offered a curious estimate of the increase of insects, taken from their eggs. From a brood of 350 eggs, which he obtained from a single moth, he selected 80. These, when arrived at their perfect state, produced 15 females; and hence he deduces the following conclusion: If 80 eggs give 15 females, the whole breed of 350 would have produced 65. These 65, if equally fertile, would have produced 22,750 caterpillars, among which there would have been 4265 females. These, in the third ge neration, by the same mode of calculation, must amount to 1,492,750 caterpillars.