The Story-Book of Science Chapter 26


HERE Uncle Paul caught Claire looking at him thoughtfully. It was evident that some change was taking place in her mind: the spider was no longer a repulsive creature, unworthy of our regard. Uncle Paul continued:

“With its legs, armed with sharp-toothed little claws like combs, the spider draws the thread from its spinnerets as it has need. If it wishes to descend, like the one this morning that came down from the ceiling on to Mother Ambroisine’s shoulder, it glues the end of the thread to the point of departure and lets itself fall perpendicularly. The thread is drawn from the spinnerets by the weight of the spider, and the latter, softly suspended, descends to any depth it wishes, and as slowly as it pleases. In order to ascend again, it climbs up the thread by folding it gradually into a skein between its legs. For a second descent, the spider has only to let its skein of silk unwind little by little.

“To weave its web, each kind of spider has its own method of procedure, according to the kind of game it is going to hunt, the places it frequents, and according to its particular inclinations, tastes, and instincts. I will merely tell you a few words about the epeiræ, large spiders magnificently speckled with yellow, black, and silvery white.            They are hunters of big game,—of green or blue damsel-flies that frequent the water-courses, of butterflies, and large flies. They stretch their web vertically between two trees and even from one bank of a stream to the other. Let us examine this last case.

“An epeira has found a good place for hunting: the dragon-flies, or blue and green damsel-flies, come and go from one tuft of reeds to another, sometimes going up, sometimes down the stream. Along its course are butterflies also, and horse-flies, or large flies that suck blood from cattle. The site is a good one. Now, then, to work! The epeira climbs to the top of a willow at the water’s edge. There it matures its plan, an audacious one, the execution of which seems impossible. A suspension bridge, a cable which serves as support for the future web, must be stretched from one bank to the other. And observe, children, that the spider cannot cross the stream by swimming; it would perish by drowning if it ventured into the water. It must stretch its cable, its bridge, from the top of its branch without changing place. Never has an engineer found himself in such difficulties. What will the little creature do? Put your heads together, children; I am waiting for your ideas.”

“Build a bridge from one side to the other, without crossing the water or moving away from its place? If the spider can do that it is cleverer than I am.” Thus spoke Jules.

“Than I, too,” chimed in his brother.

“If I did not already know,” said Claire, “since you have just told us, that the spider does accomplish it, I should say that its bridge is impossible.”

Mother Ambroisine said nothing, but by the slackening of the tick-tack of her needles, every one could see that she was much interested in the spider’s bridge.

“Animals often have more intelligence than we,” continued Uncle Paul; “the epeira will prove it to us. With its hind legs it draws a thread from its spinnerets. The thread lengthens and lengthens; it floats from the top of the branch. The spider draws out more and more; finally, it stops. Is the thread long enough? Is it too short? That is what must be looked after. If too long, it would be wasting the precious silky liquid; if too short, it would not fulfil the given conditions. A glance is thrown at the distance to be crossed, an exact glance, you may be sure. The thread is found too short. The spider lengthens it by drawing out a little more. Now all goes well: the thread has the wished-for length, and the work is done. The epeira waits at the top of its branch: the rest will be accomplished without help. From time to time it bears with its legs on the thread to see if it resists. Ah! it resists; the bridge is fixed! The spider crosses the stream on its suspension bridge! What has happened, then? This: The thread floated from the top of the willow. A breath of air blew the free end of the thread into the branches on the opposite bank. This end got entangled there: behold the mystery. The epeira has only to draw the thread to itself, to stretch it properly and make a suspension bridge of it.”

“Oh, how simple!” cried Jules. “And yet not one of us would have thought of it.”

“Yes, my friend, it is very simple, but at the same time very ingenious. It is thus with all work: simplicity in the means employed is a sign of excellence. To simplify is to have knowledge; to complicate is to be ignorant. The epeira, in its kind of construction, is science perfected.”

“Where does it get that science, Uncle?” asked Claire. “Animals have not reason. Then who teaches the epeira to build its suspension bridges?”

“No one, my dear child; it is born with this knowledge. It has it by instinct, the infallible inspiration of the Father of all things, who creates in the least of His creatures, for their preservation, ways of acting before which our reason is often confounded. When the epeira, from the top of the willow, gets ready to spin its web, what inspires it with the audacious project of the bridge; what gives it patience to wait for the floating end of the thread to entwine in the branches of the other bank; what assures it of the success of a labor that it is performing perhaps for the first time, and has never seen done? It is the universal Reason that watches over creation, and takes among men the thrice-holy name of Providence.”

Uncle Paul had won his case: in the eyes of all, even of Mother Ambroisine, spiders were no longer frightful creatures

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