Micrographia - or some physiological descriptions of minute bodies made by magnifying glasses with observations and inquiries thereupon/Chapter 48
Observ. XLVIII. Of the hunting Spider, and several other sorts of Spiders.
The hunting Spider is a small grey Spider, prettily bespeck'd with black spots all over its body, which the Microscope discovers to be a kind of feathers like those on Butterflies wings, or the body of the white Moth I lately describ'd. Its gate is very nimble by fits, sometimes running, and sometimes leaping, like a Grashopper almost, then standing still, and setting it self on its hinder leggs, it will very nimbly turn its body, and look round it self every way: It has six very conspicuous eyes, two looking directly forwards, plac'd just before; two other, on either side of those, looking forward and side-ways; and two other about the middle of the top of its back or head, which look backwards and side-wards; these seem'd to be the biggest. The surface of them all was very black, sphærical, purely polish'd, reflecting a very cleer and distinct Image of all the ambient objects, such as a window, a man's hand, a white Paper, or the like. Some other properties of this Spider, observ'd by the most accomplish'd Mr. Evelyn, in his travels in Italy, are most emphatically set forth in the History hereunto annexed, which he was pleas'd upon my desire to send me in writing.
Of all the sorts of Insects, there is none has afforded me more divertisements then the Venatores, which are a sort of Lupi, that have their Denns in the rugged walls, and crevices of our houses; a small brown and delicately spotted kind of Spiders, whose hinder leggs are longer then the rest.
Such I did frequently observe at Rome, which espying a Fly at three or four yards distance, upon the Balcony (where I stood) would not make directly to her, but craul under the Rail, till being arriv'd to the Antipodes, it would steal up, seldom missing its aim; but if it chanced to want any thing of being perfectly opposite, would at first peep, immediatly slide down again, till taking better notice, it would come the next time exactly upon the Fly's back: But, if this hapn'd not to be within a competent leap, then would this Insect move so softly, as the very shadow of the Gnomon seem'd not to be more imperceptible, unless the Fly mov'd; and then would the Spider move also in the same proportion, keeping that just time with her motion, as if the same Soul had animated both those little bodies; and whether it were forwards, backwards, or to either side, without at all turning her body, like a well mannag'd Horse: But, if the capricious Fly took wing, and pitch'd upon another place behind our Huntress, then would the Spider whirle its body so nimbly about, as nothing could be imagin'd more swift; by which means, she always kept the head towards her prey, though to appearance, as immovable, as if it had been a Nail driven into the Wood, till by that indiscernable progress (being arriv'd within the sphere of her reach) she made a fatal leap (swift as Lightning) upon the Fly, catching him in the pole, where she never quitted hold till her belly was full, and then carried the remainder home. I have beheld them instructing their young ones, how to hunt, which they would sometimes discipline for not well observing; but, when any of the old ones did (as sometimes) miss a leap, they would run out of the field, and hide them in their crannies, as asham'd, and haply not be seen abroad for four or five hours after; for so long have I watched the nature of this strange Insect, the contemplation of whose so wonderfull sagacity and address has amaz'd me; nor do I find in any chase whatsoever, more cunning and Stratagem observ'd: I have found some of these Spiders in my Garden, when the weather (towards the Spring) is very hot, but they are nothing so eager of hunting as they are in Italy.
There are multitudes of other sorts of Spiders, whose eyes, and most other parts and properties, are so exceedingly different both from those I have describ'd, and from one another, that it would be almost endless, at least too long for my present Essay, to describe them, as some with six eyes, plac'd in quite another order; others with eight eyes; others with fewer, and some with more. They all seem to be creatures of prey, and to feed on other small Insects, but their ways of catching them seem very differing: the Shepherd Spider by running on his prey; the Hunting Spider by leaping on it, other sorts weave Nets, or Cobwebs, whereby they ensnare them, Nature having both fitted them with materials and tools, and taught them how to work and weave their Nets, and to lie perdue, and to watch diligently to run on any Fly, as soon as ever entangled.
Their thread or web seems to be spun out of some viscous kind of excrement, lying in their belly, which, though soft when drawn out, is, presently by reason of its smallness, hardned and dried by the ambient Air. Examining several of which with my Microscope, I found them to appear much like white Hors-hair, or some such transparent horny substance, and to be of very differing magnitudes; some appearing as bigg as a Pigg's brisle, others equal to a Horss-hair; other no bigger then a man's hair; others yet smaller and finer. I observ'd further, that the radiating chords of the web were much bigger, and smoother then those that were woven round, which seem'd smaller, and all over knotted or pearl'd, with small transparent Globules, not unlike small Crystal Beads or seed Pearls, thin strung on a Clew of Silk; which, whether they were so spun by the Spider, or by the adventitious moisture of a fogg (which I have observ'd to cover all these filaments with such Crystalline Beads) I will not now dispute.
These threads were some of them so small, that I could very plainly, with the Microscope, discover the same consecutions of colours as in a Prisme, and they seem'd to proceed from the same cause with those colours which I have already describ'd in thin plated bodies.
Much resembling a Cobweb, or a confus'd lock of these Cylinders, is a certain white substance which, after a fogg, may be observ'd to fly up and down the Air; catching several of these, and examining them with my Microscope, I found them to be much of the same form, looking most like to a flake of Worsted prepar'd to be spun, though by what means they should be generated, or produc'd, is not easily imagined: they were of the same weight, or very little heavier then the Air; and 'tis not unlikely, but that those great white clouds, that appear all the Summer time, may be of the same substance.