FOOTNOTES:
[a] The Cornea of Flies, Wasps, &c. are so common an Entertainment with the Microscope, 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; so that we see Objects through them topsey-turvey, as through so many convex Glasses: Yea, they become a small Telescope, when there is a due focal Distance between them and the Lens of the Microscope.
This lenticular Power of the Cornea, supplies, (as I imagine,) the Place of the Crystalline, if not of the vitreous Humour too, there being neither of those Humours that I could ever find, (although for Truth Sake, I confess I have not been so diligent as I might in this Enquiry;) but instead of Humours and Tunicks, I imagine that every Lens of the Cornea, hath a distinct Branch of the optick Nerve ministring to it, and rendring it as so many distinct Eyes. So that as most Animals are binocular, Spiders for the most Part octonocular, and some, (as Mr. Willughby thought, Raii Hist. Insect. p. 12.) senocular; so Flies, &c. are multocular, having as many Eyes as there are Perforations in their Cornea. By which Means, as other Creatures are oblig’d to turn their Eyes to Objects, these have some or other of their Eyes ready plac’d towards Objects, nearly all round them: Thus particularly it is in the Dragon-Fly, (Libella,) the greatest Part of whose Head is possess’d by its Eyes: Which is of excellent Use to that predatious Insect, for the ready seeing and darting at small Flies all round it, on which it preys.
[] It is manifest, that Insects clean their Eyes with their Fore-legs, as well as Antennæ. And considering, that as they walk along, they are perpetually feeling, and searching before them, with their Feelers, or Antennæ; therefore I am apt to think, that besides wiping and cleaning the Eyes, the Uses here nam’d may be admitted. For as their Eyes are immoveable, so that no Time is requir’d for the turning their Eyes to Objects; so there is no Necessity of the Retina, or optick Nerve being brought nigher unto, or set farther off from the Cornea, (which would require Time,) as it is in other Animals: But their Cornea and optick Nerve, being always at one and the same Distance, are fitted only to see distantial Objects, but not such as are very nigh: Which Inconvenience the Feelers obviate, lest it should be prejudicial, in occasioning the Insect to run its Head against any Thing.
And that this, rather than the wiping the Eyes, is the chief Use of the Feelers, is farther manifest from the Antennæ of the Flesh-Fly, and many other Insects, which are short, and strait, and incapable of being bent unto, or extended over the Eyes: As also from others enormously long, such as those of the Capricorni, or Goat-chasers, the Cadew-Fly, and divers others, both Beetles and Flies.
[c] The lamellated Antennæ of some, the clavellated of others, the neatly articulated of others, the feather’d and divers other Forms of others, of the Scarab, Papilionaceous Gnat, and other Kinds; are surprizingly beautiful, when view’d through a Microscope. And in some, those Antennæ distinguish the Sexes: As in the Gnat-kind, all those with Tufts, Feathers, and Brush-horns, are Males; those with short, single shafted Antennæ, are Females.
CHAP. IV.
Of the Parts and Motion of Insects.
From the Head, pass we to the Members, concern’d in their Motion. And here we have a copious Subject, if I was minded to expatiate. I might take Notice of the admirable Mechanism in those that creep; the curious Oars in those amphibious Insects that swim and walk[a]; the incomparable Provision made in the Feet of such as walk, or hang upon smooth Surfaces[]; the great Strength and Spring in the Legs of such as leap[c]; the strong and well-made Feet and Talons of such as dig[d]: And to name no more, the admirable Faculty of such as cannot fly, to convey themselves with Speed and Safety, by the Help of their Webs[e], or some other Artifice to make their Bodies lighter than the Air[f]: These, and a Multitude of other such like Things as these, I might, I say, take Notice of, as great Evidences of the infinite Creator’s Wisdom: But lest I should be too tedious, I will confine my Observations to the Legs and Wings only. And these, at first View, we find to be incomparably fitted up for their intended Service, not to over-load the body, not in the least to retard it; but to give it the most proper and convenient Motion. What, for Example, can be better contriv’d, and made for this Service, than the Wings? Distended and strengthen’d by the finest Bones, and these cover’d with the finest and lightest Membranes, some of them adorn’d with neat and beautiful Feathers[g]; and many of them provided with the finest Articulations, and Foldings, for the Wings to be withdrawn, and neatly laid up in their Vaginæ, and Cases, and again readily extended for Flight[h].
And then for the Poising of the Body, and keeping it upright, and steady in Flight, it is an admirable Artifice and Provision for this Purpose; in some, by four Wings[]; and in such as have but two, by Pointels, and Poises plac’d under the Wings, on each Side the Body.
And lastly, It is an amazing Thing to reflect upon the surprizing Minuteness, Art, and Curiosity of the[k] Joynts, the Muscles, the Tendons, the Nerves, necessary to perform all the Motions of the Legs, the Wings, and every other Part. I have already mention’d this in the larger Animals; but to consider, that all these Things concur in minute Animals, even in the smallest Mite; yea, the Animalcules, that, (without good Microscopes,) escape our Sight; to consider, I say, that those minutest Animals have all the Joynts, Bones, Muscles, Tendons and Nerves, necessary to that brisk and swift Motion that many of them have, is so stupendous a Piece of curious Art[l], as plainly manifesteth the Power and Wisdom of the infinite Contriver of those inimitable Fineries. But having nam’d those minute Animals, Why should I mention only any one Part of their Bodies, when we have, in that little Compass, a whole and compleat Body, as exquisitely form’d, and, (as far as our Scrutiny can possibly reach,) as neatly adorn’d as the largest Animal? Let us consider, that there we have Eyes, a Brain, a Mouth, a Stomach, Entrails, and every other Part of an animal Body, as well as Legs and Feet; and that all those Parts have each of them their necessary Apparatus of Nerves, of various Muscles, and every other Part that other Insects have; and that all is cover’d and guarded with a well-made Tegument, beset with Bristles, adorn’d with neat Imbrications, and many other Fineries. And lastly, Let us consider in how little Compass all Art and Curiosity may lie, even in a Body many Times less than a small Grain of Sand[m]; so that the least Drop of Water can contain many of them, and afford them also sufficient Room to dance and frisk about in[n].
Having survey’d as many of the Parts of Insects as I care to take Notice of; I shall in the next Place say somewhat of their State, and Circumstances of Life. And here I shall take Notice only of two Things, which have been only hinted at before; but will deserve more particular Consideration here, as being Acts of a wonderful Instinct; namely, Their Security of themselves against Winter; and their special Care of preserving their Species.