Various - The Atlantic Monthly, Volume 18, No. 106, August, 1866
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- Название:The Atlantic Monthly, Volume 18, No. 106, August, 1866
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The Atlantic Monthly, Volume 18, No. 106, August, 1866: краткое содержание, описание и аннотация
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For some time they seemed to eat nothing at all; but within a few days all had shed their skins, and now the abdomen was smaller, while the cephalothorax and legs were larger and darker; but they showed no desire to leave their cocoons. Still they grew perceptibly; and coincident with this was a less pleasing fact: their numbers were decreasing in the same proportion, and occasionally one was seen eating another. It was some time before I could reconcile the good temper and quiet behavior of the parents with this instinctive and habitual fratricide on the part of their children. But look at it in this way: here were several hundred active little creatures in a space just large enough to contain them; presently they were hungry, and as no two could be of exactly the same size, the smaller and weaker naturally fell a prey to their larger brethren, or rather sisters, for either very few males are hatched, or else they are particularly good eating, and a very small proportion survive the perils of infancy. It is evidently an established and well-understood thing among them: all seem to be aware of their destiny, to eat or be eaten . What else can they do? Human beings would do the same under the same circumstances; and I have never seen the least sign of personal spite or malignity in the spider. There is no pursuit, for there is no escape; and we can only conclude that, as the new-born fish's first nourishment is the contents of the yolk-sac, partly outside, though still a portion of its body, so the first food of the young spiders is, if not themselves, the next best thing,—each other. Thus it is provided that the smaller and less vigorous shall furnish food for the larger until the latter are strong enough to venture forth in search of other means of support.
In consequence of this mutual destruction, aided materially by the depredations of birds and of other insects, and by exposure to the weather, only about one per cent of those hatched reach maturity. If properly protected, however, a far larger proportion may be saved; and as their multiplication is so rapid, no fear need be entertained of a limit to the supply.
By keeping these little spiders in glass jars, inverted, and with a wet sponge at the bottom, they were easily watched and cared for. At first only about one twentieth of an inch long and nearly as wide, they increased in length as they grew, but for many weeks lived in common on an irregular web, feeding together on the crushed flies or bugs thrown to them. But when one fourth of an inch in length, they showed a disposition to separate, and to spin each for herself a regular web, out of which all intruders were kept. And now it was found that all these webs were inclined at nearly the same angle, and were never exactly vertical ; that, like the spider in the first web she made in the Botanical Garden, the insect took a position much nearer the upper than the lower border; and also that, instead of a web of perfect circles laid upon regular radii , as used to be described and is still figured in our books, or even one of a spiral line , as is now more correctly described of ordinary geometrical spiders (Fig. 6), these never made a circle, nor even a spiral, but a series of concentric loops or arcs of circles, the lines turning back upon themselves before reaching a point over the spider, and leaving the larger portion of the web below her; and more than this, that the lines, though quite regular, were by no means perfectly so, as may be seen in Fig. 7, copied from a photograph.
Fig. 6. Web of common Garden Spider.
Fig. 7. Web of Nephila plumipes.
As usual, the radii , or spokes , of the wheel-shaped structure are first made; then the spider begins a little way from the centre, and, passing from one radius to another, spins a series of loops at considerable distances from each other till she reaches the circumference. These first loops, like the radii, are of white, dry , and inelastic silk, and may be recognized by the little notches at their junction with the radii. The notches are made by the spider's drawing her body a little inward toward the centre of the web at the time of attaching them to the radii, and so they always point in the direction in which the spider is moving at that time, and in opposite directions on any two successive lines (Fig. 8). Having reached what is to be the border of her web, and thus constructed a firm framework or scaffolding, she begins to retrace her steps, moving more slowly and spinning now in the intervals of the dry loops two or three similar loops, but much nearer together and made of the elastic and viscid silk, till she has again reached her starting-point near the middle of the web, where, on its under side, she takes a position, head downward, hanging by her claws, and thus keeping her body from direct contact with the web.
Fig. 8. Section of Web.
Here she will remain quiet for hours as if asleep; but no sooner does a fly or other insect strike the web, than she darts in the direction whence the vibrations proceed, and usually seizes her prey; but, strangely enough, if the insect have ceased its struggles before she reaches it, she stops, and if she cannot renew them by shaking the web with her claws, will slowly and disconsolately return to the centre of the web, there to await fresh vibrations. These and many other facts, even more conclusive, have satisfied me that, although this spider has eight eyes (Fig. 9), it is as blind as a man with his eyelids shut, and can only distinguish light from darkness, nothing more. This seems to be the case with other geometrical species, but not at all with the field and hunting spiders, some of which will boldly turn upon you and look right in your eyes; they alone, of all insects, seeming to recognize the face of man as different from his body.

Fig. 9. Face and Jaws, magnified (eyes dimly seen).
The hearing and touch of this spider are very acute. The latter is exercised by the palpi and the tips of the legs, especially the first pair, but no ear has yet been discovered; neither is anything known of the organs of taste and smell, or even whether the insect possesses these senses at all.
I ought before this to have anticipated and answered a question which nine out of ten, perhaps, of my readers have already asked themselves, "Do not spiders bite? and is not their bite poisonous, nay, at times, deadly even to man?" The answer is, in brief, Yes, spiders do bite, probably all of them, if provoked and so confined that they cannot escape; though only a few tropical species can be said to seek of their own accord an opportunity for attacking man, or any creature larger than the insects that form their natural prey. Even the Nephila plumipes , which, it has been intimated, is "Christian in its disposition, and well-behaved beyond most of its kind," will readily bite, if it is held in the fingers and anything is put to its jaws. But that is nothing. So would you, most gentle reader, if a great giant pinched you between his thumb and finger, and held your hands and feet and head; and if, too, like our spider, you could not see enough to distinguish friends from foes. Spiders, then, will bite. But to the second part of the inquiry our answer must be less positive. They have a very bad name; but much of this is due to their grim and forbidding aspect, and their bloody trade of trapping and eating poor little insects. It is to be remembered that there are very few, if any, medical reports of injuries from the bites of spiders, and that the accounts of such cases occurring in the newspapers consist in great measure of inference, and either make no mention of the offender at all, or merely speak of a little black or gray spider being found in the vicinity. A number of experiments have been made in England to ascertain the effect of the bite of the larger geometrical spiders upon the experimenter himself, upon other spiders, and upon common insects; and the conclusion was, that it produces no greater effect than the prick of a pin, or any other injury of equal extent and severity; while the speedy death of its victim is ascribed to the spider's sucking its juices, rather than to any poison instilled into the wound. But these experiments, though somewhat reassuring, are not conclusive; for they were tried only on one person, and people vary much in their susceptibility to poison of all kinds; moreover, the spiders employed were of the geometrical kinds, which have never been so much feared as the larger field and hunting spiders. Indeed, it may be found that among spiders there is as great a difference in respect to venom as among serpents, and that those which depend upon their jaws for taking and holding their prey, such as the field and hunting spiders, are poisonous, while the web-builders which ensnare their victims are not so. In regard to our spiders, I have caused a large one to bite, so as to draw blood, a kitten three days old, and the kitten has not appeared to suffer in the least on that account.
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