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F we look across the grass some warm sunny morning
or evening of early fall, we see threads of
spider silk clinging everywhere; these are not
regular webs for trapping insects, but are single
threads spun from grass stalk to grass stalk until
the fields are carpeted with glistening silk. We
have a photograph of a plowed field, taken in
autumn, which looks likes the waves of a lake;
so completely is the ground covered with spider
threads that it shows the "path of the sun" like
water.
When we see so many of these random threads, it is a sign that the young spiders have started on their travels, and it is not difficult then to find one in the act. The spiderling climbs up some tall object, like a twig or a blade of grass, and sends out its thread of silk upon the air. If the thread becomes entangled, the spiderling sometimes walks off on it, using it as a bridge, or sometimes it begins again. If the thread does not become entangled with any object, there is soon enough given off, so that the friction of the air current upon it supports the weight of the body of the little creature, which promptly lets go its hold of earth as soon as it feels safely buoyed up, and off it floats to lands unknown. Spiders thus sailing through the air have been discovered in mid-ocean.
Thus we see that the spiders have the same way of distributing their species over the globe, as have the thistles and dandelions. It has been asked what the spiders live upon while they are making these long journeys, especially those that have drifted out to sea. The spider has very convenient habits of eating. When it finds plenty of food it eats a great deal; but in time of famine it lives on, apparently comfortably, without eating. One of our captive spiders was mislaid for six months and when we found her she was as full of "grit" as ever, and she did not seem to be abnormally hungry when food was offered her.
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"A noiseless, patient spider, I mark'd where, on a little promontory, it stood isolated: Mark'd how to explore the vacant, vast surrounding. It launched forth filament out of itself Ever unreeling them—ever tirelessly speeding them. "And you, my soul, where you stand, Surrounded, surrounded, in measureless oceans of space. Ceaselessly, musing, venturing, throwing, seeking the spheres to connect them; Till the bridge you will need be form'd— till the ductile anchor hold; Till the gossamer thread you fling catch somewhere, O my soul." —Walt Whitman. |
Leading thought—The young of many species of spiders scatter themselves like thistle seeds in balloons which they make of silk.
Method—These observations should be made out of doors during some warm sunny day in October. Read Nature's Craftsmen, McCook, p. 182.
Observations—
1. Look across the grass some warm sunny morning or evening of early fall, and note the threads of spider silk gleaming everywhere, not regular webs, but single threads spun from grass stalk to grass stalk, or from one object to another, until the ground seems glistening with silk threads.
2. Find a small spider on a bush, fence post, or at the top of some tall grass stalk; watch it until it begins to spin out its thread.
3. What happens to the thread as it is spun out?
4. If the thread does not become entangled in any surrounding object what happens? If the thread does become entangled, what happens?
5. How far do you suppose a spider can travel on this silken aeroplane? Why should the young spider wish to travel?