Imatges de pàgina
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CHAP. II.

OF THE SHAPE AND STRUCTURE OF INSECTS,

LE

ET us begin with the fhape and fabric of their bodies which, although it be somewhat different from that of birds, being particularly, for the most part, not so sharp before, to cut and make way through the air, yet is better adapted to their manner of life. For, confidering that there is little neceffity of long flights, and that the strength and activity of their wings doth much furpafs the refiftance their bodies meet with from the air, there was no great occafion their bodies fhould be fo fharpened before. But the condition of their food, and the manner of gathering it, together with the great neceffity of accurate vifion, by that admirable provifion made for them by the reticulated cornea of their eyes; these things, I fay, as they required a larger room, fo were a good occafion for the largenefs

largeness of the head, and its amplitude before. But for the rest of their body, all is well made, and nicely poifed for their flight, and every other of their occafions.

AND as their fhape, fo the fabric and make of their bodies is no lefs accurate, admirable, and fingular; nor built throughout with bones, and covered with flesh and skin, as in moft other animals; but covered with a curious mail of a middle nature, ferving both as skin and bone too, for the fhape, as well as ftrength and guard, of the body; and as it were on purpose to fhew, that the great contriver of nature is not bound up to one way only.

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Infecta non videntur nervos habere, nec offa, nec fpinas, nec cartilaginem, nec pinguia, nec carnes, nec cruftam quidem fragilem, ut quædam marina, nec quæ jure dicatur cutis : fed • mediæ cujufdam inter omnia hæc naturæ corpus,' &c. Plin. Nat Hift. 1. 11 c. 4.

CHAP.

СНАР.

III.

OF THE EYES AND ANTENNE OF INSECTS.

T

this laft-mentioned guard, we may add that farther guard provided in the eyes and antennæ. The structure of the eye is, in all creatures, an admirable piece of mechanifm; but that obfervable in the eyes of infects fo peculiar, that it muft needs excite our admiration : fenced with its own hardness, yea, even its own accurate vifion, is a good guard against external injuries; and its cornea, or outward coat, all over befet with curious, tranfparent, lenticular inlets, enabling thofe creatures to fee, no doubt,

very

* The cornea of flies, wafps, &c. are fo common an entertainment with the microfcope, that every body knows it is a curious • piece of lattice-work. In which this is remarkable, that every foramen is of a lenticular nature; fo that we fee objects through them topfey-turvey, as through fo many convex glaifes: yea, they become a fmall telescope, when there is a due focal distance between them and the lens of the microfcope.

VOL. II.

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This

very accurately every way, without any interval of time or trouble to move the eye towards objects.

AND as for the other part, the antennæ, or feelers, whatever their ufe may be in cleaning the eyes, or other fuch like ufe; they are, in all probability, a good guard to the eyes and head, in their walk and flight, enabling them, by the fenfe of feeling, to discover fuch annoyances, which, by their proximity, may perhaps escape the reach of the eyes and fight'. Befides which,

they

This lenticular power of the cornea, fupplies, as I imagine, the place of the chryftalline, if not of the vitreous humour too, there being neither of those humours that I could ever find (although, for truth's fake, I confefs I have not been fo diligent as I might in this inquiry;) but instead of humours and tunics, I imagine that every lens of the cornea hath a diftinct branch of the optic nerve miniftering to it, and rendering it as fo many diftinct eyes. So that as most animals are binocular, fpiders, for the most part octonocular, and fome, (as Mr. Willoughby thought, Raii Hift. Infect. p. 12.) fenocular; fo flies, &c. are multocular, having as many eyes as there are perforations in their cornea. By which means, as other creatures are obliged to turn their eyes to objects, these have some or other of their eyes ready placed towards objects, nearly all round them thus particularly it is in the dragon-fly, libella, the greatest part of whofe head is poffeffed by its eyes: which is of excellent ufe to that predacious infect, for the ready feeing and darting at fmall flies all round it on which it preys.

It is manifeft, that infects clean their eyes with their fore legs, as well as antennæ. And confidering, that as they walk along, they are perpetually feeling, and fearching before them, with their

feelers,

they are a curious piece of workmanship, and in many, a very beautiful piece of m garniture to the body.

feelers, or antennæ; therefore I am apt to think, that besides wiping and cleaning the eyes, the ufes here named may be admitted. For as their eyes are immoveable, fo that no time is required for the turning their eyes to objects; so there is no neceffity of the retina, or optic nerve being brought nigher unto, or fet farther off from the cornea, which would require time, as it is in other animals: but their cornea and optic nerve, being always at one and the fame distance, are fitted only to fee diftantial objects, but not fuch as are very nigh: which inconvenience the feelers obviate, left it fhould be prejudicial, in occafioning the infect to run its head against any thing.

And that this, rather than the wiping the eyes, is the chief ufe of the feelers, is farther manifeft from the antennæ of the flesh-fly, and many other infects, which are short, and ftrait, and incapable of being bent unto, or extended over the eyes as also from others enormously long, fuch as those of the capricorni, or goat-chafers, the cadew-fly, and divers others, both beetles and flies.

The lamellated antennæ of fome, the clavellated of others, the neatly articulated of others, the feathered and divers other forms of others, of the fearab, papilionaceous gnat, and other kinds, are furprifingly beautiful, when viewed through a microfcope. And in fome, those antennæ diftinguish the fexes: as in the gnat-kind, all those with tufts, feathers, and brush-horns, are males; thofe with fingle-fhafted antennæ, are females.

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