I.

Threads Thrown Out By Spiders.

The first thing that I perceived, and that put me on the track of the rest, was, as I have just said, that the greater part of _aranéides_, especially certain varieties of _thomises lycoses_, etc., besides the thread that they always draw with them, have the power of darting one or more of extraordinary length, and of which they make use to accomplish distances, to fasten their webs from one point to another, and even, as we shall see further on, to raise themselves in the air and there to seek their prey. The spider always points his abdomen to the side where he wishes to go. The thread shoots like an arrow, fastens itself by the end to the place destined, and the spider passes as under a suspended bridge. If this thread is cut, it is immediately replaced by another; and the ejaculation is so prompt, so rapid, the thread so straight, so tenuous, so brilliant, that it might be taken, if I may so express myself, for the jet of an imperceptible ray of light. To perceive this clearly, the spider must be held on a level with the eyes, which should be shaded, and examined with one's back to the sun.

The best time for such an observation is in the morning or evening, when the sun is low in the horizon and the temperature is mild; for without this latter condition the torpid spider is more inclined to creep along the earth than to throw out new threads.

Sometimes, to excite them, they may be held by their ordinary thread and gently shaken or blown upon--just a few puffs of breath--which they detest.

I have thus been able to scan closely, while watching their development, this instantaneous jet of thread, which could not be less than five or six yards long, that is, fifteen hundred or two thousand times the length of the spider. What a tremendous apparatus must be necessary to these little animals for so rapid an ejaculation, and one so disproportioned to their size! And especially if we consider that this thread, inasmuch as it adheres to the animal, has not the appearance of an independent organ, but seems solely to obey its will. Thus I have seen spiders, who seemed to miss the end desired with the first stroke, continue to hold the thread in the same direction, and actually _palpitate_, if I may so say, while striving to make it adhere.

But a truly interesting sight, and one obtained at a very trifling expense, is that which the _thomises bufo_ offer, described by Walckenaer, in the first volume of his _History of Insects_, page 506. In truth, these araneides do not only throw out one thread, but an entire bundle of them, and are seemingly guided by the smaller threads, just as a peacock unfolds by degrees his splendid plumage.

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And even in one's own room this sight may be enjoyed. It is only necessary to collect these _thomises_ and keep them in separate boxes, and nourish them in winter with one fly or so a month. Then take the boxes out, put them on a table in a very warm room, and sit a little in the shade and watch them. Very soon from each box will appear a multitude of threads, of extreme freshness and fineness, which the spider throws into the air with inexhaustible profusion. At certain seasons of the year we can enjoy this spectacle again, and at even less expense.