Why did Linnæus call the small tortoiseshell-butterfly "the deceptive herald of spring"?

Because there often appear, on fine days, individuals which have survived the winter.

Why is the atlas-moth so called? Because of its immense wings, larger than those of a common bat; the body is, however, remarkably

small.

In a Madras Journal, date 1829, we read of a person at Arracan who caught a moth which measured from the tip of one wing to the tip of the other, ten inches. Both wings are beautifully variegated with the brightest colours. The editor thinks this the largest moth on record, exceeding in dimensions the largest in the British Museum, which measures about nine inches from tip to tip.

Why is the goat-moth so called?

Because it emits a peculiarly subtle smell, which has been thought to resemble that of the goat. The object and seat of this odour seem not well understood. Some have conjectured it to proceed from the mouth, and discharged to soften the wood in which it burrows: the latter opinion is not, however, tenable, as many other insects that perforate timber, are not so supplied, and the microscope does not manifest the exudation of any fluid.

Why is the gamma-moth so called?

Because it has imprinted on its dark wings a white character, something like the letter Y, but more like the small Greek gamma.

Why is the large white-moth used by anglers callea the miller's fly?

Because of the mealy substance about its wings and body.

Why is the death's-head moth so called?

Because of the markings of its back being superstitiously associated with the head of a skeleton, with the limb-bones crossed beneath. In German-Poland, this moth is called the death's-head phantom, the wandering death-bird, &c. Its cry, produced by scratching its mandible against its horny chest, there becomes the voice of anguish, the moaning of a child, the signal of grief; it is regarded as the device of evil spirits, and the very shining of its eyes is thought to represent the fiery element whence it is supposed to have proceeded. Flying into the apartments of weak persons, in the evening, it at times extinguishes the light, foretelling war, pestilence, hunger, death-to man and beast.

Why is the ghost-moth so called?

Because of its singular flight in the twilight hour, haunting, as it were, one particular spot-wherefore the fancy of some collector probably considered it a spectre-like action. Knapp.

Why is the ghost-moth distinguishable from all others by its continued flight over one spot?

Because it thus wocs its mate, lying concealed in the herbage over which it sports. Knapp.

Why is the male ghost-moth supposed to be destroyed in such numbers by nocturnal birds?

Because his white satiny wings are easily discerned in the twilight, and these wings are frequently found scattered about in our morning walks.

Why are the caterpillars of the swallow-tailed-moth called surveyors, loopers, and geometers?

Because of their peculiar peculiari manner of moving, which may readily be conceived by those who have not seen them, when we mention, that at the commencement of each step their bodies present a pretty exact figure of the Greek letter 2. In this position, laying hold with their hinder prolegs, they stretch out their heads to the full extent of their body, laying hold with their forelegs while they again bring forward their body into the shape 2 again.

THE SILKWORM.

Why does the silkworm spin a silky cocoon?

Because it may therein change from the caterpillar to the pupa state in greater safety. This cocoon it prepares from a gum or tenacious fluid contained in two pouches, placed along the back, beneath the stomach; which fluid it spins into very fine threads, by means of a particular tube placed behind the mouth. It is the middle portion of the cocoon, after removing the floss or loose silk on the exterior, which is used in our manufactories.

Why is the first preparation of silk to throw the cocoons into warm water?

Because it may dissolve any slight adhesions which may have occurred when the caterpillar was spinning. Why is it evident that the insect spins the whole without interruption?

Because the cocoons may be generally unwound without breaking the thread. It is popularly supposed, however, that if the insect be disturbed during the operation by any sort of noise, it will take alarm, and break its thread; but Latreille says this is a vulgar error. The length of the unbroken thread in a cocoon varies from 600 to 1,000 feet; and as it is all spun double by the insect, it will amount to nearly two thousand feet of silk, the whole of which does not weigh above three grains and a half. Five pounds of silk from ten thousand cocoons is considerably above the usual average. When we consider, therefore, the enormous quantity of silk which is used at present, the number of worms in producing it will almost exceed our comprehension.

Why is it requisite to devote whole plantations of mulberry-trees to the culture of silkworms? Because of the voracity of the animal, a single caterpillar weighing, when first hatched, only the hundredth part of a grain-consuming, in thirty days, above an ounce of leaves; that is to say, it devours in vegetable substance about 60,000 times its primitive

weight.

Count Dandolo, in his recent Treatise on Silkworms,

thus estimates their progressive increase in weight:

400

1,628

9,500

After the third moulting

After the fourth moulting

On attaining their greatest size and weight

They have, therefore, in thirty days, increased 9,500 times their primitive weight. The length of the silkworm also increases about forty times in twenty-eight days. Again, the Count calculates that the quantity of leaves drawn from the tree employed for each ounce of eggs, amounts to 1,609 lb. 8 oz.

In France, the scorzonera, or salsifis, has been advantageously substituted for the mulberry in rearing silkworms. The silk produced is equal to that of the worms fed upon mulberry leaves, and surpasses that obtained from worms fed upon lettuce-leaves; in the latter case, the quantity has been doubled.

To prevent the jaundice common among silkworms, the Abbé Esseric, of Carpentras, used to powder them with quick-lime by means of a silk sieve; he then gave them mulberry-leaves moistened with a few drops of wine. It was at first supposed that the cocoons of silk were injured by this process; this, however is not the case, and his method is now adopted generally in the department of Vaucluse in the south of France.

Why has it been inferred that silk is a vegetable, not an animal product?

Because part of the interior of the white mulberry, upon which silkworms thrive best, is composed of a tissue of beautiful white silky fibres, much resembling China silk: hence, the basis of the material, in its proximate form, is derived from the vegetable kingdom, though the spinning of its substance into a lengthened thread is entirely due to the mechanical functions of the silkworm.

The growth of the silkworm has been tried, but with no great success, in this country. Evelyn computed that one mulberry-tree would feed as many silkworms annually as would produce seven pounds of silk. "According to that estimate," says Barham, (dated 1719,) "the two thousand trees already planted in Chelsea Park, (which take up one-third of it) will make 14,000 lb. weight of silk; to be commonly worth twenty-shillings a pound, those trees must make £14,000 per annum."

Why do silkworms in warm climates consume a rather less quantity of leaves?

Because the leaves are supposed to be more nutritive; but, in that case, the silk produced is not so delicate and fine.

Of the kind and size of the silkworm also is the Sustillo, a caterpillar bred in the pacae, a tree well known in Peru. When completely satiated with the leaves, it spins a fine silk paper, which has been gathered measuring a yard and a half in length. In proportion to the vigour and majestic growth of this tree is the number of insects it nourishes.

Why is silk manufacture one of the most important of commercial resources ?

Because the labour in preparing new silk affords much more employment to the country producing it, than any other raw material. The fact has been established before a committee of both Houses of Parliament. We may add, that the raw silk imported into England, from all parts of the world, in 1814, amounted to one million six hundred and thirty-four thousand, five hundred and one pounds; and in 1824, to three millions, three hundred and eighty-two thousand, three hundred and fifty-seven. The official values of these imports are £703,009, and £1,464,994.