The thing is obvious: the Spider did on that rent what she did every elsewhere, neither more nor less. Far from squandering silk upon it, she saved her silk so as to have enough for the whole web. The gap will be better mended, little by little, afterwards, as the sheet is strengthened all over with new layers. And this will take long. Two months later, the window—my work—still shows through and makes a dark stain against the dead-white of the fabric.
Neither weavers nor spinners, therefore, know how to repair their work. Those wonderful manufacturers of silk-stuffs lack the least glimmer of that sacred lamp, reason, which enables the stupidest of darning-women to mend the heel of an old stocking. The office of inspector of Spiders’ webs would have its uses, even if it merely succeeded in ridding us of a mistaken and mischievous idea.
CHAPTER XI: THE GARDEN SPIDERS: THE LIME-SNARE
The spiral network of the Epeirae possesses contrivances of fearsome cunning. Let us give our attention by preference to that of the Banded Epeira or that of the Silky Epeira, both of which can be observed at early morning in all their freshness.
The thread that forms them is seen with the naked eye to differ from that of the framework and the spokes. It glitters in the sun, looks as though it were knotted and gives the impression of a chaplet of atoms. To examine it through the lens on the web itself is scarcely feasible, because of the shaking of the fabric, which trembles at the least breath. By passing a sheet of glass under the web and lifting it, I take away a few pieces of thread to study, pieces that remain fixed to the glass in parallel lines. Lens and microscope can now play their part.
The sight is perfectly astounding. Those threads, on the borderland between the visible and the invisible, are very closely twisted twine, similar to the gold cord of our officers’ sword-knots. Moreover, they are hollow. The infinitely slender is a tube, a channel full of a viscous moisture resembling a strong solution of gum arabic. I can see a diaphanous trail of this moisture trickling through the broken ends. Under the pressure of the thin glass slide that covers them on the stage of the microscope, the twists lengthen out, become crinkled ribbons, traversed from end to end, through the middle, by a dark streak, which is the empty container.
The fluid contents must ooze slowly through the side of those tubular threads, rolled into twisted strings, and thus render the network sticky. It is sticky, in fact, and in such a way as to provoke surprise. I bring a fine straw flat down upon three or four rungs of a sector. However gentle the contact, adhesion is at once established. When I lift the straw, the threads come with it and stretch to twice or three times their length, like a thread of India-rubber. At last, when over-taut, they loosen without breaking and resume their original form. They lengthen by unrolling their twist, they shorten by rolling it again; lastly, they become adhesive by taking the glaze of the gummy moisture wherewith they are filled.
In short, the spiral thread is a capillary tube finer than any that our physics will ever know. It is rolled into a twist so as to possess an elasticity that allows it, without breaking, to yield to the tugs of the captured prey; it holds a supply of sticky matter in reserve in its tube, so as to renew the adhesive properties of the surface by incessant exudation, as they become impaired by exposure to the air. It is simply marvellous.
The Epeira hunts not with springs, but with lime-snares. And such lime-snares! Everything is caught in them, down to the dandelion-plume that barely brushes against them. Nevertheless, the Epeira, who is in constant touch with her web, is not caught in them. Why?
Let us first of all remember that the Spider has contrived for herself, in the middle of her trap, a floor in whose construction the sticky spiral thread plays no part. We saw how this thread stops suddenly at some distance from the centre. There is here, covering a space which, in the larger webs, is about equal to the palm of one’s hand, a fabric formed of spokes and of the commencement of the auxiliary spiral, a neutral fabric in which the exploring straw finds no adhesiveness anywhere.