horny. The other legs, termed pro-legs, or tem- | it begins to bend its back, bringing the head near the porary legs, are soft, short, and conical; they vary in number in different species; the larva or caterpillar of the common cabbage butterfly has five pairs: these feet are furnished with a set of minute, slender, horny hooks, alternately longer and shorter, by means of which the animal is enabled to lay a very firm hold on the leaves of plants or other objects, and also to move along with tolerable dispatch. It is to be observed, that when five pairs of these limbs are present, none are found on the fourth, fifth, tenth, or eleventh segments, but a pair respectively on the sixth, seventh, eighth, ninth, and twelfth seginents. In some caterpillars there are only two pairs of these limbs-one pair on the last segment, one on the ninth; such are the geometrical larvæ.

Many caterpillars are covered with long stiff hairs, others with short harsh fur or bristles; some are furnished with tufts; other are naked.

attached feet; and, after continuing for some time in this attitude, it straightens itself, and repeats the same action. In about twenty-four hours the outer skin begins to split down the back, and the fissure is enlarged by the swelling and pressure of the chrysalis. till at length the head and lower portion of the suspended being become disengaged, the skin shrivelling up into a bundle surrounding the tail. This, however, has to be thrown off, and at the same time the chrysalis has to avoid disengaging itself from its mooring of silken threads from which it hangs: for, be it remembered, it was by its hind-legs that it attached itself To effect this, instinct-guided, it seizes on a portion of this shrivelled skin between two segments of its body holding it as with a pair of pincers, and thus, destitute of limbs, supports itself, till it withdraws the tail from the old useless skin which sheathed it; it then, still clinging, elongates the rings of its tail as much as A very important organ possessed by the larvae of possible, and scizes a higher portion of the skin, and butterflies and moths is the spinneret for the produc-in this manner, climbing backwards as it were upon tion of silken threads, by means of which some merely its exuvia, it repeats the manoeuvre till the extremity of suspend themselves during the pupa stage, while the tail presses the silk, to which it immediately adheres others envelop themselves as in a shroud. Many by means of a number of hooks provided for the purpose. caterpillars, moreover, weave tents of network or houses Still these exuviæ encumber it, and hang in contact for themselves in hawthorn, apple, and pear trees, in with it; curving its tail in such a manner as partly to which, on returning from their foraging excursions, embrace the shrivelled skin, it whirls rapidly round, they cluster by hundreds. The spinneret is seated jerking violently, and at length succeeds in disengaging beneath the horny lower lip, or labium, as entomologists it from its fastenings and throwing it to the ground. term it, and the two first legs; and appears in the form Other caterpillars attach themselves closely to the wall of a conical protuberance, whence two long tortuous or other object by bands of silk round the body, as well tubes extend down the body of the larva: these tubes as by a little cone of silk at their extremity; and some separate the silk from the juices of the body in the envelop themselves completely. In a short time the form of a guminy fluid, which, as it is drawn through chrysalis hardens (for at first it is very soft), and shows the aperture of the spinneret, hardens into a thread: through the outer case the wings, antennæ, eyes, and such is the silk of the silkworm. legs of the perfect insect. It now passes into a sort of torpid state, till the time arrives for the exit of the perfect butterfly from its case.

ever,

On its exclusion from the egg the caterpillar is of very small size; its growth, however, soon commences, and is as rapid as its appetite is voracious. As, howit is clothed in an outer skin which is not extensible, this investment, like the armour of the lobster, must be repeatedly changed. Beneath the old outer skin, or epidermis, which soon begins to be loosened, a new one is formed; a rent takes place, from the swelling out of the animal, down the back of the old skin, and this rent gradually increases, till the animal, with a brighter epidermis, frees itself from its discarded weeds, and appears of larger dimensions. During this process, which is often repeated, the caterpillar is sluggish and inactive, and refuses food; but when the process is over, it recovers its former voracity. During all this time the caterpillar is laying up an accumulation of fat to serve the wants of the system during the time of its torpid pupa state, which it is now preparing for. Beneath the last cuticle assumed, the vital energies of the system have developed wings, antenna, a slender proboscis, and all the parts of the perfect butterfly, or noth, that is to be. This last cuticle, or epidermis, is, however, yet to be cast off, and another is formed to clothe the pupa (or chrysalis, as the pupa of the butterfly is often termed, which in its turn is to be broken open for the exit of the perfect insect. Previously, however, to the pupa stage being assumed, it secures itself by means of its silk in a position varying according to the species. Suppose it merely suspends itself by the tail: in this case the first care of the caterpillar is to cover the spot to which it is about to suspend itself with successive layers of silken threads, which readily adhere, till at last a little silken cone is produced, into which the caterpillar pushes its hinder pair of pro-legs (those on the last segment), which become entangled, and so fixed, amidst the threads; it then permits itself to hang down with the head lowest. In a short time

The duration of the pupa or chrysalis stage of existence varies in different species, and even in the same, being retarded by cold and abbreviated by warmth-a wise provision, as it respects the safety of the matured insect. The butterfly, when ready for exclusion, bursts the skin of the chrysalis, now to be thrown off, which covers the thorax, and emerges, feeble and languid, with wings crumpled up into small bundles. Soon, however, the body acquires strength; the fluids circulate through the nervures of the wings: these gradually unfold, and the creature quivers them, as it feels its growing powers: at length, in the perfection of strength and beauty, it leaves its sordid mummy-case behind,-soars aloft, seeks the flowers of the garden, and commences a new existence.

Such is a sketch of the progress of the caterpillar from the egg to the butterfly; from

"The worm, a thing that crept

On the bare earth, then,wrought a tomb and slept," to the hovering "Psyche."

The rest of the story is soon told; bright things must fade: the butterfly enjoys a brief summer, deposits its eggs on the plants which instinct teaches it are the appropriate nourishment of the future caterpillar, and passes out of existence.

The group of butterflies before us consists of-a, the orange-tip butterfly (Pontia Cardamines); b, the blackveined white or hawthorn butterfly (Pieris Crategi); c, the small white butterfly (Pontia Rapa); d, the green-veined white butterfly (Pontia Napi); e, the common cabbage butterfly (Pontia Brassica); f, the brimstone butterfly (Gonopteryx Rhamni); g, the pale clouded yellow butterfly (Colias Hyale).

The orange-tip butterfly is tolerably common in our island, frequenting the borders of woods and lanes

| by means of a fine ovipositor deposits its eggs within the caterpillar's body, where they soon hatch, the larvæ feeding upon their victim, yet directed by instinct to avoid the vital organs. In due time the caterpillar crawls to some wall, as if about to undergo its pupa stage; but at this period the larva of the ichneumon are ready, and gnawing their way out, destroy the miserable being on whose substance they have fed, and, clustering together near the withering body of their supporter, enfold themselves in tiny cocoons of a golden yellow. The walls of our garden bear ample testimony to the parasitic habits of this ichneumon, and to the multitude of caterpillars that perish in the manner described.

winding through a woodland but cultivated district. of ichneumon (Ichneumon glomeratus, Linn.), which It usually appears about the end of May; seldom in April. The sexes are very dissimilar. The caterpillar is green, with a white streak along each side: it feeds upon various cruciferous plants, especially those of the genus Cardamine. The large or primary wings of the butterfly are white, dusky at the base, with a small black crescent-mark in the centre, and a black tip. In the male, the outer half of the wing is tinged with orange. In both, the hinder wings are marbled beneath with pale green; above they present faint tracings of the same. Extent of wing averaging an inch and a half. The black-veined white or hawthorn butterfly is very partially distributed in our island, occurring principally in the southern counties: it has been taken in the New Forest, near Chelsea, in Coombe Wood, and in various places in Berkshire. It is by no means uncommon on the Continent. In size it equals the common cabbage butterfly; but the wings are semi-transparent, with black nervures, and a black list round the outer edge. The caterpillars of this species are gregarious, feeding on the leaves of the hawthorn, and weaving a network of silk as a temporary residence, into which they crowd. They are partially hairy, black, and striped with reddish brown on each side.

Pallas once saw such vast flights of this butterfly in the vicinity of Winofka, that he at first mistook them for flakes of snow.

The small white butterfly bears, excepting in size, a close resemblance to the common cabbage species, from which, however, it is very distinct, as is proved by their respective caterpillars. It is a very common species, appearing about the beginning of May: a second flight takes place in August. This species is one of the pests of the garden, laying its eggs on cabbages, cauliflowers, &c. The larva, or caterpillars, are of a light bluish green, with a pale line above the back, and a whitish streak, somewhat speckled with yellow, along each side of the abdomen. It buries itself deeply between the leaves of the plants, and in the very heart of the cauliflower. The small white butterfly is rather variable in its markings. The colour of the wings above is white, with a slight tinge of yellow; the primary wings have a dusky spot at the tip; and there are two spots in the female-one in the male. in the centre: the hinder wings have a black nark on their anterior border. The anterior wings beneath have two black spots and a yellow tip; the hinder wings beneath are rather of a bright yellow, powdered with black, with a narrow streak of orangeyellow on the anterior edge at the base.

The green-veined white butterfly is extremely common, appearing first in May, a second flight occurring also in July. It frequents gardens, laying its eggs on cabbages and other culinary vegetables. In colouring it is subject to some differences; the general tinge is white inclining to yellow; the tip of the primary wing is dusky, and there are two central black dots in the female, one in the male; a smail black dot on the hinder wings near the anterior edge. Under surface of hinder wings and tip of primaries sulphur yellow, the nervures being strongly marked with green; two black spots on the upper wings near the hinder margin. The caterpillar is dull green, paler along the sides, with yellow stiginata, and covered with white warts, which are tufted with short hairs: chrysalis greenish yellow.

The common cabbage butterfly scarcely needs description, so well is it known, as is also its caterpillar, the ravages of which in the kitchen-garden are most annoying. Brocoli, cauliflower, cabbage, turnip, are all infested by it; at the same time it is itself destroyed in abundance by birds which feed upon it or carry it to their young; and it is the favourite victim of a species

The cabbage butterfly appears in April and May: the wings are white above, with a large patch of black on the tip of the anterior pair: in the male, a black spot near the middle of the anterior edge of the secondary wings; the female, besides this, has two others about the middle of the upper wings, and a patch at their hinder margin. The under surface of the wings inclines to yellow, the lower being finely powdered with black; the upper wings have two conspicuous black spots. The caterpillar is green, with a narrow line of yellow along the back, and another on each side of the abdomen; the body is thickly covered with tuberculous points of a black colour, each having a hair in the centre.

The brimstone butterfly is one of the earliest that make their appearance, and may be seen on the wing flitting along the lanes and copses in the month of March, when a bright sunny morning gives hope of the "year confirmed." As the spring advances, it becomes more common, and a second flight comes forth in August. This species is far more abundant in the southern than the northern counties of our island, although in certain localities of the north it is tolerably common. On the Continent it is very generally spread.

The male is of a pure sulphur yellow above, and in both sexes a small spot of orange occupies the centre of each wing. The female is greenish yellow above; the under side is paler than the upper.

The caterpillar is elongated, naked, and of a light green colour, with numerous black scaly dots on the back, and a pale line along each side of the abdomen. It feeds on the buckthorn and the berry-bearing alder, two species of Rhamnus: the chrysalis is short and angular.

The pale clouded yellow butterfly is rare, and found chiefly on the sea-coast in the counties of Kent, Sussex, and Suffolk. A pale variety occurs in the vicinity of Dover. Seldom has it been found far from the sea. It is a fine species: the male is usually of a rich sulphur yellow, the female nearly white: the upper wings are marked near the middle with a black spot, and at their extremity have a deep black border, almost divided by a series of yellow spots into two. The under wings have a large orange spot in the centre: beneath, the upper wings are whitish yellow, orange-stained at the tip, with a black ring-spot enclosing a yellow centre near the middle, and with a row of small dusky marks at some distance from the outer margin. The lower wings beneath are dull orange with a large and a small silvery spot in the centre surrounded with rust-red, and a curved row of small black spots. Fringe of the wings roseate. The caterpillar is green with two white lines on both sides; each segment is marked with two irregular transverse series of black spots. Its food is not precisely ascertained.

[Perugino.-The figures from a picture in the Museum at Bologna.]

In almost every collection on the Continent there are works of Perugino, for he was so popular in his lifetime, that his pictures were as merchandise, and sold all over Italy. His scholars were very numerous, but the fame of all the rest is swallowed up in that of his great disciple RAPHAEL. Bernardino di Perugia, called PINTURICCHIO, was rather an assistant than a pupil: he has left some excellent works.

ELASTIC CEMENT.

Perugino, in the very beginning of the sixteenth century, was certainly the most popular painter of his time; a circumstance which, considering that Raphael, Francia, and Leonardo da Vinci were all working at Pietro Perugino died in 1524. He survived Raphae. the same time, would surprise us did we not know that four years, and he may be said, during the last twentycontemporary popularity is not generally the recom-five years of liis life, to have survived himself. pense of the most distinguished genius: in fact Perugino has produced some of the weakest and worst, as well as some of the most exquisite pictures in the world. He undertook an immense number of works, and employed his scholars and assistants to execute them from his designs. A passion, of which perhaps the seeds were sown in his early days of poverty and misery, had taken possession of his soul. He was no longer excited to labour by a spirit of piety or the generous ambition to excel, but by a base and insatiable thirst for gain: all his late pictures, from the year 1505 to his death, betray the influence of this mean passion. He aimed at nothing beyond mechanical dexterity, and to earn his money with as little expense of time and trouble as possible; he became more and more feeble, mannered, and monotonous, continually repeating the same figures, actions, and heads, till his very admirers were wearied; and on his last visit to Florence, Michael Angelo, who had never done him justice, pronounced him, with contempt, "Goffo nell' arte," that is, a mere bungler; for which affront Pietro summoned him before the magistrates, but came off with little honour. He was no longer what he had been. Such was his love of money, or such his mistrust of his family, that when moving from place to place he carried his beloved gold with him; and being on one occasion robbed of a large sum, he fell ill, and was like to die of grief. It seems, however, hardly consistent with the mean and avaricious spirit imputed to him, that having married a beautiful girl of Perugia, he took great delight in seeing her arrayed, at home and abroad, in the most costly garments, and sometimes dressed her with his own hands. To the reproach of avaricetoo well founded-some writers have added that of irreligion nay, two centuries after his death they showed the spot where he was buried in unconsecrated ground under a few trees, near Fontignano, he having refused to receive the last sacraments: this accusation has been refuted; and in truth there is such a divine beauty in some of the best pictures of Perugino, such exquisite purity and tenderness in his Madonnas, such an expression of enthusiastic faith and devotion in some of the heads, that it would be painful to believe that there was no corresponding feeling in his heart. In one or two of his pictures he has reached a degree of sublimity worthy of him who was the master of Raphael, but the instances are few.

THERE have been within the last few years many attempts made to produce a glue or cement which shall be more coherent than even woody fibres in their natural state. The subject is a curious one, and shows that our current ideas, respecting the cohesion or strength of wood, require a little modification. However solid a piece of wood may appear to the eye, it is nevertheless a mere bundle of minute fibres and vessels, each one complete and independent in itself, yet all combined into a solid mass. The power which holds them side by side, or in intimate contact, is great; but we are wrong in supposing it greater than that which an artificial cement between two surfaces would exert. If a piece of lead, such as a bullet, be cut in two, and the two cut surfaces be rubbed against each other, they will shortly become so smooth that they will cohere, and each piece will support the other without further assistance. In this case the friction works out all the air from between the surfaces, and smooths down all the asperities, so that the cohesive attraction, which forms one of the mechanical properties of matter, has opportunity to exert itself, and to reunite the severed pieces. The same might, perhaps, be the case with a piece of wood severed into two, were it not that the fibrous nature of the wood prevents the complete expulsion of air, and also prevents the two surfaces from being rubbed to so homogeneous a state as the two surfaces of lead. If, however, a very thin layer of some other substance be introduced, so as to expel air and to adhere to each surface separately, the two surfaces will themselves unite; and it remains to be seen whether or not this artificial joining is as retentive and strong as the natural coherence of the woody fibre.

Such a cement as we here allude to is glue; and there has been proof given recently that a glue or cement so used may exceed in cohering power the woody fibres themselves. It is generally from some kind of animal substance that cement for wood is prepared; differing in this respect, as in others, from the cement used for stone.

Before speaking further of the new retentive cement, to which allusion was just made, we will briefly notice the nature and preparation of common glue, the general representatives of this class of cements.

In our National Gallery there is a little Madonna and Child by Perugino. The Virgin is seen half-length holding the infant Christ, who is standing in front and Glue may be obtained from the hides, hoofs, and grasps in his little hand one of the tresses of her long horns of animals; the ears of oxen, calves, and sheep; fair hair; the young St. John is seen half-length on the the parings of parchment; the refuse scrapings of left, looking up with joined hands. It is an early pic-leather-yards; and indeed from almost any kind of ture painted before his first residence at Florence, and animal matter containing gelatine. However diffebefore he had made his first essays in oil: it is very rent "calves-foot jelly" and "isinglass" may seem to feeble and finical in the execution, but very sweet and be from coarse glue, yet they are at one end of the simple in the expression. same scale of substances which has glue at the other: they are all varieties more or less pure of gelatine. Although glue can, however, be prepared from a variety of different sources, it is in practice procured almost entirely from the refuse of leather and parchment dressing; for horns and hoofs are more profitably sold by the tanner to others than glue-makers. Of all

In the Louvre at Paris there is a curious allegorical picture by Perugino, representing the Combat of Love and Chastity; many figures in a landscape. It seems a late production-feeble and tasteless; and the subject is precisely one least adapted to the painter's style and powers.