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understanding of his words, and not the words them

GONVERSATIONS ON

selves, that are contradicted by the facts Geology has disclosed.

SERIES OF FAMILIAR CONVERSATIONS

ON THE ANIMAL KINGDOM.

CONVERSATION VI.

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CLASS ARTICULATA-SUB-CLASS INSECTS.

Insects in their Pupa State.
ANNA.Is it convenient to you, papa, to renew the
subject we were conversing on last evening ?
PAPA.—Yes, my dear; perfectly so.

We were
speaking, I recollect, of insects in their larva state.

ANNA.-Yes, papa.

PAPA.- We have taken a view of them then in that which is generally by far the longest, but by no means the most interesting part of their existence.

ANNA.--How long do they continue in that state?

PAPA.-The length of time varies considerably: some continue in it only a few days or weeks; others several months or years. When they are about to enter their third state they cease eating : some wrap themselves up in silken webs; others conceal themselves in decayed wood or in the earth; some take up their residence in the hollow stalks of plants; and many are concealed under leaves, or suspend themselves in dark places where they cannot easily be seen; and their skin, separating once more, discloses an oblong body, which Linnæus called a pupa, from its resemblance in miniature to a child trussed up like a mummy in swaddling clothes; as young infants used to be in this country, and still are in many parts of the Continent. Pupa, you know, is a Latin word for baby. In this state most insects eat no food, are incapable of changing their

place, and when touched shew no other signs of life but that of giving their abdomen violent contortions. If opened, they seem filled with a watery fluid, in which no distinct organs can be traced. The shape, however, of the pupæ of different tribes varies considerably; and as I have, I believe, told you, different names have been applied to them. “Those of the beetle and bee tribes are covered with a membranous skin, inclosing in separate and distinct sheaths the external organs, as the antennæ, legs and wings; which are consequently not closely applied to the body, but have their form for the most part clearly distinguishable: to these Aristotle originally gave the name of nymphe, which was continued by Swammerdam and other authors, and has been adopted by many English writers on insects. Butterflies, Moths, and some of the two-winged tribe are in their pupa state also inclosed in a similar membranous envelope; but their legs, antennæ, and wings, are closely folded over their breast and sides ; and the whole body inclosed in a common case or covering of a horny consistence, which admits a much less distinct view of the organs beneath it. As these pupæ are often tinged of a golden colour, they were called from this circumstance chrysalides by the Greeks, and aureliæ by the Romans: both which terms are in some measure become anglicized; and though not strictly applicable to ungilded papæ, are now given to those of all lepidopterous insects.”

ANNA.-What are lepidopterous insects, papa ?

PAPA.—Lepidopterous means scaly-winged: it is a name applied to those whose wings are covered with what

appears a fine powder, such as moths and butterflies. The pupæ of flies, and some other two-winged genera, which are not excluded from the skin of the larva, but remain concealed under it till the perfect insect bursts forth, are called cased-nymphs: those of grasshoppers, locusts, and others of that sort, that resemble the perfect insect except in having only the rudiments of wings, which are bound down under a skin that keeps them confined, are called semi-nymphs, these can eat and move as well while in the pupa state as when they have attained perfection: and those whicbe still more nearly resemble the perfect inseot, under going but slight changes either in their external or ine, ternal conformation, and retaining, throughout the course of their metamorphoses, the same power of moving and eating, are termed by Linnæus complete pupe. The pupæ of fleas, lice, and many other wingless insects, are of this kind.

ANNA.- Now, papa, let me try if I can repeat the names of the different species of pupæ; I think thene: are five: the chrysalis, the nymph, the cased-nymphe, the semi-nymph, and the complete pupa,

PAPA.-Good girl; you have repeated them very correctly. The larva, of the butterfly becomes a chrysa-. lis; that of the beetle and the bee, a nympht; that of the fly, a cased-nymph; that of the grasshopper, a semí-. nymph; and that of the fleą, a complete pupa. The envelope of cased-nymphs, which, as I said before, is. formed of the skin of the larva, considerably altered in form and texture, is called the pupanium ; while the. artificial coverings of different kinds, whether of silk, wood, or earth, which many insects fabrigate for theme. selves previously to assuming the pupa atate, is termedi the COCOon

ANNA.-Are there any other insects besides silk worms that form for themselves silken, coverings?

PAPA.--Yes, many do, both during their larva state and; previously to, assuming the pupa: there are none, however, whose production is so valuable to us. The Tinea, or clothes' moth, as soon as it comes into, existence, manufactures for itself a thick, warm coat of wool; or hair, curiously incorporated with silk drawn from its. own mouth: and another species of Tinea, which may often be found on the under surface of the leaves of the pear-tree in the spring, constructs its habitation entirely

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of silk; its little downy russet-coloured tents, which are about a quarter of an inch high, and not much thicker than a pin, resemble, at first sight, so many spines growing out of the leaf; but if you pull off one of them, and give it a gentle squeeze, you will see a little yellowish caterpillar, with a black head, emerge from the lower end of it. The strong, white webs too, that frequently disfigure the hedges and fruit trees, are a silken covering, produced by the joint labours of a species of caterpillars, the larvæ of the Bombyx Chrysorrhæa, and intended as their common residence, under which they may be securely sheltered during their various changes. Indeed the instances are numberless of insects that use silk, either wholly or in part, in the construction of their habitations: whatever other substances be employed in forming the fabric, silk is almost always the cement that fastens them together.

ANNA.—None, however, produce such beautiful Cocoons.

PAPA.-None, perhaps, enrich them with so much beautiful material : the silk worm, in the three days it employs in spinning, produces, at least, three hundred yards of silk : but there are several, even in our own country, that form very curious ones.

Did you never see those of a species of weevil, the curculio arator, which are frequently found attached to the common spurrey? They very much resemble fine gauze. Many of the saw flies too are remarkable for the cocoons they construct: they form an internal one of a soft, close, flexible texture ; which they surround with another composed of a strong kind of net work that effectually secures them from injury during their period of repose in the pupa state.

ANNA.-Do insects remain in the pupa state long?

Papa.--They vary very much in that respect. Some species continue in it only a few hours; others months; and others one or more years. The length of time depends, in some measure, on the warmth of the climate:

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the same insects will remain pupæ as long again in our country as they will in India. Your silk-worms, for instance, which you have probably observed to be about a month in escaping from their prisons, would become moths in fifteen days in their natural climate.

ANNA.-I always help them as much as I can by snipping open the cocoon when I have wound off the silk.

PAPA.—You need not do that; for the moth is provided with a solvent fluid which would enable it very readily to open a passage for itself.

When the insect is disclosed from the pupa it is in all respects different from what it had been before: it often requires no food at all, and scarcely ever more than a very small quantity; indeed its stomach is found to have been very much contracted, in some instances to a tenth of its former bulk: its almost sole objeet appears to be to make provision for the production of future generations, by depositing its eggs on that substance which is suited for the support of its infant offspring; and having done that, it generally dies. I have much, however, to tell you of its structure and habits during this short but interesting period of its existence. When I have a convenient opportunity, I will indulge you with a sight of my cabinet, and we will converse on the subject more at large.

ANNA. That will indeed be a great pleasure to me: I am more and more anxious to become acquainted with these interesting little beings.

PAPA.—The same creature is, you see, in fact, three different animals; and the modes of its existence are · often as distinct as those of animals the most distantly related of other tribes. The same insect often lives successively in three or four worlds: at one period it is an inhabitant of water ; at another of earth; at a third of air; and in each abode has a form and propensities that adapt it to the offices in the creation it is intended to fulfil.

Z. Z.

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