Insect Adventures 7

Insect Adventures 7

Let us open the Spider’s cabin. What luxury! We have read how the Princess in the fairy-tale was unable to rest, if there was a crumpled rose-leaf in her bed. The Clotho is quite as fastidious. Her couch is more delicate than swan’s-down and whiter than the fleece of clouds where brood the summer storms. It is the ideal blanket. Above is a canopy or tester of equal softness. Between the two nestles the Spider, short-legged, clad in somber garments, with five yellow favors on her back. Rest in this exquisite retreat demands that it be perfectly steady, especially on gusty days, when sharp draughts creep under the stone dwelling. By taking a careful look at her we can see how the Spider manages this. The arches that bear the weight of the building are fastened to the stone at each end. Moreover, where they touch, you may see a cluster of diverging threads that creep along the stone and cling to it throughout their length, which spreads afar. I have measured some that were fully nine feet long. These are so many cables; they are like the ropes and pegs that hold the Arab’s tent in position. Another detail attracts our attention: whereas the inside of the house is exquisitely clean, the outside is covered with dirt, bits of earth, chips of rotten wood, little pieces of gravel. Often there are worse things still: hung up or embedded are the dry carcasses of Beetles that favor under-rock shelters; parts of Thousand-legged Worms, bleached by the sun; snail-shells, chosen from among the smallest. These relics are plainly, for the most part, table-leavings, broken victuals. Unskilled in laying traps, the Clotho lives upon the insects who wander from one stone to another. Whoever ventures under the slab at night is strangled by the hostess; and the dried-up carcass, instead of being flung to a distance, is hung to the silken wall, as though the Spider wished to make a bogey-house of her home. But this cannot be her aim. To act like the ogre who hangs his victim from the castle battlements is the worst way to disarm suspicion in the passers-by whom you are lying in wait to capture. There are other reasons which increase our doubts. The shells hung up are most often empty; but there are also some occupied by the Snail, alive and untouched. What can the Spider do with these snail-shells wherein the animal retreats so far that she cannot reach it? The Spider cannot break the hard shell or get at the hermit through the opening. Then why should she collect these prizes, whose slimy flesh is probably not to her taste? We begin to suspect a simple question of ballast and balance. The House Spider prevents her web, spun in a corner of the wall, from losing its shape at the least breath of air, by loading it with crumbling plaster and allowing tiny fragments of mortar to accumulate. The Clotho Spider dumps down on her abode any more or less heavy object, mainly corpses of insects, because she need not look for these and finds them ready to hand after each meal. They are weights, not trophies; they take the place of materials that must otherwise be collected from a distance and lifted to the top. In this way, a breastwork is obtained that strengthens and steadies the house. Further balance is often given by tiny shells and other objects hanging a long way down. The Clotho knows the laws of balancing; by means of additional weights, she is able to lower the center of gravity and thus to give her dwelling the proper equilibrium and roominess. Now what does she do in her softly-wadded home? Nothing, that I know of. With a full stomach, her legs luxuriously stretched over the down carpet, she does nothing, thinks of nothing; she listens to the sound of the earth revolving on its axis. It is not sleep, still less is it waking; it is a middle state where the Spider is conscious of nothing except that she is happy. We ourselves, when comfortably in bed, enjoy, just before we fall asleep, a few moments of bliss, when we neither think nor worry; and those moments are among the sweetest in our lives. The Clotho Spider seems to know similar moments and to make the most of them. [Illustration] CHAPTER XXI THE SPIDER’S TELEGRAPH-WIRE Of the six Garden Spiders I have noticed, two only, the Banded and the Silky Spiders, stay constantly in their webs, even under the blinding rays of a fierce sun. The others, as a rule, do not show themselves until nightfall. At some distance from the net they have a rough and ready retreat in the brambles, a hiding-place made of a few leaves held together by stretched threads. It is here that they usually remain in the daytime, motionless and sunk in meditation. But the shrill light that vexes them is the joy of the fields. At such time, the Locust hops more nimbly than ever, more gayly skims the Dragon-fly. Besides, the sticky web, in spite of the rents suffered during the night, is still in fairly good condition. If some giddy-pated insect allow himself to be caught, will the Spider, at the distance whereto she has retired, be unable to take advantage of the windfall? Never fear. She arrives in a flash. How does she know what has happened? Let us explain the matter. It is the vibration of the web which tells her, rather than the sight of the captured object. To prove this, I laid upon several Spiders’ webs a dead Locust. I placed the Locust where the Spider might have plainly seen it. Sometimes the Spider was in her web, and sometimes she was outside, in her hiding-place. In both cases, nothing happened at first. The Spider remained motionless, even when the Locust was at a short distance in front of her. She did not seem to see the game at all. Then, with a long straw, I set the dead insect trembling. That was quite enough. The Banded Spider and the Silky Spider hastened to the central floor, the others, who were in hiding, came down from the branch; all went to the Locust, bound him with tape, treated him, in short, as they would treat a live prey captured under the usual conditions. It took the shaking of the web to decide them to attack. If we look carefully behind the web of any Spider with a daytime hiding-place, we shall see a thread that starts from the center of the web and reaches the place where the Spider lurks. It is joined to the web at the central point only. Its length is usually about twenty-two inches, but the Angular Spider, settled high up in the trees, has shown me some as long as eight or nine feet. [Illustration: “The slanting cord is a telegraph wire.”] This slanting line is a foot-bridge by which the Spider hurries to her web when there is something going on there, and then, when her errand is finished, returns to her hut. But that is not all it is. If it were, the foot-bridge would be fastened to the upper end of the web. The journey would then be shorter and the slope less steep. The line starts from the center of the net because that is the place where the spokes meet and therefore where the vibration from any part of the net is best felt. Anything that moves upon the web sets it shaking. All then that is needed is a thread going from this central point to carry to a distance the news of a prey struggling in some part or other of the net. The slanting cord is not only a foot-bridge: it is a signaling-apparatus, a telegraph-wire. In their youth, the Garden Spiders, who are then very wide-awake, know nothing of the art of telegraphy. Only the old Spiders, meditating or dozing in their green tent, are warned from afar, by telegraph, of what takes place on the net. To save herself from keeping a close watch that would be drudgery and to remain alive to events even when resting, with her back turned on the net, the hidden Spider always has her foot upon the telegraph-wire. Here is a true story to prove it. An Angular Spider has spun her web between two laurestine-shrubs, covering a width of nearly a yard. The sun beats upon the snare, which is abandoned long before dawn. The Spider is in her day house, a resort easily discovered by following the telegraph-wire. It is a vaulted chamber of dead leaves, joined together with a few bits of silk. The refuge is deep: the Spider disappears in it entirely, all but her rounded hind-quarters, which bar the entrance. With her front half plunged into the back of her hut, the Spider certainly cannot see her web; she could not even if she had good sight, instead of being half blind as she is. Does she give up hunting during this period of bright sunlight? Not at all. Look again. Wonderful! One of her hind-legs is stretched outside the leafy cabin; and the signaling-thread ends just at the tip of that leg. Whoever has not seen the Spider in this attitude, with her hand, so to speak, on the telegraph-receiver, knows nothing of one of the most curious examples of animal cleverness. Let any game appear upon the scene, and the slumberer, at once aroused by means of the leg receiving the vibrations, hastens up. A Locust whom I myself lay on the web gives her this agreeable shock, and what follows? If she is satisfied with her prey, I am still more satisfied with what I have learned. One word more. The web is often shaken by the wind. The signaling-cord must pass this vibration to the Spider. Nevertheless, she does not leave her hut and remains indifferent to the commotion prevailing in the net. Her line, therefore, is something better than a bell-rope; it is a telephone capable, like our own, of transmitting infinitesimal waves of sound. Clutching her telephone-wire with a toe, the Spider listens with her leg; she can tell the difference between the vibration proceeding from a prisoner and the mere shaking caused by the wind. [Illustration] CHAPTER XXII THE CRAB-SPIDER The Banded Spider, who works so hard to give her eggs a wonderfully perfect dwelling-house, becomes, after that, careless of her family. For what reasons? She lacks the time. She has to die when the first cold comes, whereas the eggs are to pass the winter in their cozy home. She cannot help deserting the nest. But, if the hatching were earlier and took place in the Spider’s life, I imagine that she would be as devoted to her family as a Bird is. So I gather from the behavior of a shapely Spider who weaves no webs, lies in wait for her prey, and walks sideways, like a Crab. This Spider with the Crab-like figure does not know how to make nets for catching game. Without springs or snares, she lies hidden among the flowers, and waits for the arrival of the prey, which she kills by a scientific stab in the neck. The particular species I have observed is passionately fond of the pursuit of the Domestic Bee. The Bee appears, seeking no quarrel, intent upon plunder. She tests the flowers with her tongue; she chooses a spot that will yield a good return. Soon she is wrapped up in her harvesting. While she is filling her baskets and distending her crop, the Crab-spider, that bandit lurking under cover of the flowers, comes out of her hiding-place, creeps round behind the bustling insect, steals up close, and, with a sudden rush, nabs her in the nape of the neck. In vain the Bee protests and darts her sting at random; the assailant does not let go. Besides, the bite in the neck is paralyzing, because the nerve-centers are affected. The poor thing’s legs stiffen; and all is over in a second. The murderess Spider now sucks the victim’s blood at her ease and, when she has done, scornfully flings the drained corpse aside. We shall see the cruel vampire become a model of devotion where her family is concerned. The ogre loved his children; he ate the children of others. Under the tyranny of hunger, we are all of us, beasts and men alike, ogres. After all, this cutter of Bees’ throats is a pretty, a very pretty creature, in spite of her unwieldy body fashioned like a squat pyramid and embossed on the base, on either side, with a pimple shaped like a camel’s hump. The skin, more pleasing to the eye than any satin, is milk-white in some, in others lemon-yellow. There are fine ladies among them who adorn their legs with a number of pink bracelets and their backs with crimson patterns. A narrow, pale-green ribbon sometimes edges the right and left of the breast. The costume is not so rich as that of the Banded Spider, but much more elegant because of its soberness, its daintiness, and the artistic blending of its colors. People who shrink from touching any other Spider do not fear to handle the beautiful Crab Spider, so gentle in appearance. [Illustration] THE CRAB-SPIDER’S NEST Skillful in the prompt despatch of her prey, the little Crab-spider is no less clever in the nesting art. I find her settled on a privet in the inclosure. Here, in the heart of a cluster of flowers, the luxurious creature plaits a little pocket of white satin, shaped like a wee thimble. It is the receptacle for the eggs. A round, flat lid, of a felted fabric, closes the mouth. Above this ceiling rises a dome of stretched threads and faded flowerets which have fallen from the cluster. This is the watcher’s conning-tower. An opening, which is always free, gives access to this post. Here the Spider remains on constant duty. She has thinned greatly since she laid her eggs, has almost lost her figure. At the least alarm, she sallies forth, waves a threatening limb at the passing stranger and invites him, with a gesture, to keep his distance. Having put the intruder to flight, she quickly returns indoors. And what does she do in there, under her arch of withered flowers and silk? Night and day, she shields the precious eggs with her poor body spread out flat. Eating is neglected. No more lying in wait, no more Bees drained to the last drop of blood. Motionless, rapt in meditation, the Spider is sitting on her eggs. The brooding Hen does likewise, but she is also a heating-apparatus and, with the gentle warmth of her body, awakens the germs to life. For the Spider, the heat of the sun is enough; and this alone keeps me from saying that she “broods.” For two or three weeks, the little Spider, more and more wrinkled by lack of food, never relaxes her position. What is the withered thing waiting for, before expiring? She is waiting for her children to emerge; the dying creature is still of use to them. When the Banded Spider’s little ones come out from their balloon, they have long been orphans. There is none to come to their assistance; and they have not the strength to free themselves without help. The balloon has to split automatically and to scatter the youngsters and their flossy mattress all mixed up together. The Crab-spider’s wallet, sheathed in leaves over the greater part of its surface, never bursts; nor does the lid rise, so carefully is it sealed down. Nevertheless, after the delivery of the brood, we see, at the edge of the lid, a small, gaping hole, an exit-window. Who contrived this window, which was not there at first? The fabric is too thick and tough to have yielded to the twitches of the feeble little prisoners. It was the mother, therefore, who, feeling her offspring shuffle impatiently under the silken ceiling, herself made a hole in the bag. She persists in living for five or six weeks, despite her shattered health, so as to give a last helping hand and open the door for her family. After performing this duty, she gently lets herself die, hugging her nest and turning into a shriveled relic. The Hen does not reach this height of unselfishness! [Illustration] THE YOUNG CRAB-SPIDERS It is in July that some little Crab-spiders that I have in my laboratory come out of their eggs. Knowing their acrobatic habits, I have placed a bundle of slender twigs at the top of the cage in which they were born. All of them pass through the wire gauze and form a group on the summit of the brushwood, where they swiftly weave a roomy lounge of criss-cross threads. Here they stay, pretty quietly, for a day or two; then foot-bridges begin to be flung from one object to the next. This is the fortunate moment. I put the bunch laden with beasties on a small table, in the shade, before the open window. Soon they begin to spin threads to carry them away, but slowly and unsteadily. They hesitate, go back, fall short at the end of a thread, climb up again. In short, much trouble for a poor result. As matters continue to drag, it occurs to me, at eleven o’clock, to take the bundle of brushwood swarming with the little Spiders, all eager to be off, and place it on the window-sill, in the glare of the sun. After a few minutes of heat and light, things move much faster. The little Spiders run to the top of the twigs, bustle about actively. I cannot see them manufacturing the ropes or sending them floating at the mercy of the air; but I guess their presence. Three or four Spiders start at a time, each going her own way. All are moving upwards, all are climbing some support, as can be told by the nimble motion of their legs. Moreover, you can see the thread behind them, where it is of double thickness. Then, at a certain height, individual movement ceases. The tiny animal soars in space and shines, lit up by the sun. Softly it sways, then suddenly takes flight. What has happened? There is a slight breeze outside. The floating cable has snapped and the creature has gone off, borne on its parachute. I see it drifting away, showing, like a spot of light, against the dark foliage of the near cypresses, some forty feet distant. It rises higher, it crosses over the cypress-screen, it disappears. Others follow, some higher, some lower, hither and thither. [Illustration: “Like the finish of a fireworks display.”] But the throng has finished its preparations; the hour has come to disperse in swarms. We now see, from the crest of the brushwood, a continuous spray of starters, who shoot up like tiny rockets and mount in a spreading cluster. In the end, it is like the bouquet at the finish of a fireworks display, the sheaf of rockets fired all at once. The comparison is correct down to the dazzling light itself. Flaming in the sun like so many gleaming points, the little Spiders are the sparks of that living fireworks. What a glorious send-off! What an entrance into the world! Sooner or later, nearer or farther, the fall comes. To live, we have to descend, often very low, alas! The Spiderling, therefore, touches land. The parachute tempers her fall. She is not hurt. The rest of her story escapes me. What infinitely tiny Midges does she capture before possessing the strength to stab her Bee? What are the methods, what the wiles of atom contending with atom? I know not. We shall find her again in spring, grown quite large and crouching among the flowers whence the Bee takes toll. [Illustration] CHAPTER XXIII THE LABYRINTH SPIDER While the Garden Spiders are incomparable weavers, many other Spiders have even more ingenious devices for catching game. Some of them are real celebrities, who are mentioned in all the books. Certain Bird Spiders, or American Tarantulas, live in a burrow like the Tarantula I have been telling you about, but their burrow is more perfect than hers. My Tarantula surrounds the mouth of her hole with a simple curb, a mere collection of tiny pebbles, sticks, and silk; the American ones fix a movable floor to theirs, a round shutter with a hinge, a groove, and a set of bolts. When one of these Tarantulas comes home, the lid drops into the groove and fits so exactly one cannot tell where it joins. If any one from outside tries to raise the trap-door, the Spider pushes the bolt,—that is to say, plants her claws into certain holes on the opposite side to the hinge,—props herself against the wall, and holds the door firmly. Another, the Water Spider, builds herself an elegant silken diving-bell, in which she stores air. She waits in it for the coming of game and keeps cool meanwhile. On scorching hot days, hers must be a real palace of luxury, such as men have sometimes ventured to build under water, with mighty blocks of stone and marble. Tiberius, the wicked Roman Emperor, had such a submarine palace; but his is only a hateful memory, whereas the Water Spider’s dainty tower still flourishes. If I had had the chance to observe these Spiders, I should gladly add a few unpublished facts to their life-history; but I must give up the idea. The Water Spider is not found in my district. The American Tarantula, the expert in hinged doors, I saw once only, by the side of a path. I was occupied with something else, and did not give it more than a passing glance. I have never seen it again. But it is not only the uncommon insects that are worth attention. The common ones, if carefully observed, can tell us things just as important. I am interested in the Labyrinth Spider, which I find oftener than any other in the fields. Several times a week, in July, I go to study my Spiders on the spot, early in the morning, before the sun beats fiercely on one’s neck. The children come with me, each provided with an orange in case they get thirsty. We soon discover high silk buildings, the threads beaded with dew and glittering in the sun. The children are wonderstruck at those glorious chandeliers, so that they even forget their oranges for a moment. I am not indifferent to them, either. Our Spider’s labyrinth is a splendid spectacle. That and the concert of the Thrushes are worth getting up for. Half an hour’s heat, and the magic jewels disappear with the dew. Now is the time to look at the webs. Here is one spreading its sheet over a large cluster of rock-roses; it is the size of a handkerchief. Many guy-ropes moor it to the brushwood. It covers the bush like a piece of white muslin. The web is flat at the edges and gradually hollows into a crater, not unlike the bell of a hunting-horn. At the center is a funnel whose neck, narrowing by degrees, is eight or nine inches deep and leads back into the leafy thicket. At the entrance to the tube sits the Spider, who looks at us and shows no great excitement at our presence. She is gray, modestly adorned on the thorax with two black ribbons and on the abdomen with two stripes in which white specks alternate with brown. She has a sort of double tail at the end of her body, a rather curious feature in a Spider. I expected to find, at the bottom of the Spider’s funnel, a wadded cell where she might rest in her hours of leisure. On the contrary, there is only a sort of door, which stands always ajar so that the Spider may escape at any time through the grass and gain the open. Above, in the Spider’s web, there is a forest of ropes. It might be the rigging of a ship disabled by a storm. They run from every twig of the supporting boughs, they are fastened to the tip of every branch. There are long ropes and short ropes, upright and slanting, straight and bent, taut and slack, all criss-cross and a-tangle, to the height of three feet or so. The whole makes a chaos of netting, a real labyrinth which none but the very strongest insects can break through. There is nothing like the sticky snare of the Garden Spiders here. The threads are not sticky, but they are very bewildering. See this small Locust who has lighted on the rigging. He is unable to get a steady foothold on that shaky support; he flounders about; and the more he struggles, the more he is entangled. The Spider, looking at him from her funnel, lets him have his way. She does not run up the ropes; she waits until the desperate prisoner in his struggles falls on the main part of the web. Then she comes, flings herself upon her prey, and slowly drains his blood. The Locust is lifeless at the first bite; the Spider’s poison has settled him. When laying-time is at hand, the Spider changes her residence; she leaves her web, which is still in excellent condition; she does not come back to it. The time has come to make the nest. But where? The Spider knows well; I am in the dark. I spend whole mornings ransacking the bushes, until at last I learn the secret. The nest is some distance away from the web, in a low, thick cluster of bushes; it is a clumsy bundle of dead leaves, roughly drawn together with silk threads. Under this rude covering is a pouch of fine texture containing the egg-casket. [Illustration] I am disappointed in the appearance of this Spider’s nest, until I remember that she probably cannot do better in the places where she builds. In the midst of a dense thicket, among a tangle of dead leaves and twigs, there is no room for an elegant piece of work. By way of experiment, I carry half a dozen Labyrinth Spiders into my laboratory near the laying-time, place them in large wire-gauze cages, standing in earthen pans filled with sand, with a sprig of thyme planted in the center to give a support for each nest. Now they will show what they can do. The experiment works perfectly. By the end of August I have six nests, magnificent in shape and of a dazzling whiteness. The Spiders have had elbow-room, and they have done their best. The nests are ovals of exquisite white muslin, nearly as large as a Hen’s egg. They are open at either end. The front-entrance broadens into a gallery; the back-entrance tapers into a funnel-neck. It is somewhat the same construction as that of the Labyrinth web. Even the labyrinth is repeated, for in front of the bell-shaped mouth is a tangle of threads. The Spider has her pattern by heart, and uses it on all occasions. This palace of silk is a guard-house. Behind the soft, milky, partly transparent wall glimmers the egg-casket, its shape vaguely suggesting the star of some order of knighthood. It is a large pocket, of a splendid dead-white, with pillars on every side which keep it motionless in the center of the nest. There are about ten of these pillars; they are slender in the middle and wider at both ends. They form corridors around the central room. The mother walks gravely to and fro under the arches of these corridors, which are like the cloisters of a nunnery; she stops first here, then there; she listens to all that happens inside the satin wrapper of her egg-wallet. I would not disturb her for anything; but I find, from nests I have picked up in the fields, that the purse contains about a hundred eggs, very pale amber-yellow beads. When I remove the outer white-satin wall, I come upon a kernel of earthy matter, grains of sand mixed with the silk. However did they get there? Did they soak through the rain-water? No, the wrapper is spotless white outside. They have been put there by the mother herself. She has built around her eggs, to protect them from parasites, a wall composed of a great deal of sand and a little silk. Inside this is still another silken wrapper, and then come the little Spiders, already hatched out and moving about in their nursery. But, to go back—why does the mother leave her fine web when laying-time comes, and make her nest so far away? She has her reason, you may depend upon it. Her large net, like a sheet, with the labyrinth stretched above, is very conspicuous; parasites will not fail to come running at this signal, showing up against the green; if her nest is near, they will certainly find it; and a strange grub, feasting on a hundred new-laid eggs, will ruin her home. So the wise Labyrinth Spider shifts her quarters, and goes off at night to explore the neighborhood for a less dangerous retreat for her coming family. The low brambles dragging along the ground, keeping their leaves through the winter, and catching the dead leaves from the oaks hard by, or rosemary tufts, low and bushy, suit her perfectly. In such spots I usually find her nest. Many Spiders leave their nests after they have laid the eggs, but the Labyrinth, like the Crab-spider, remains to watch over hers. She does not become thin and wither away, like the Crab-spider. She keeps her appetite, she is on the lookout for Locusts; and so she builds a hunting-box, a tangle of threads, on the outside of her nest. When she is not hunting, as we have seen, she walks the corridors around her eggs, she listens to find out if all is well. If I shake the nest at any point with a straw, she quickly runs up to inquire what is happening. Probably she keeps off parasites in this way. The Spider’s appetite for Locusts shows that she must have more to do. Insects, unlike some human beings, eat only that they may work. When I watch her, I find out what this work is. For nearly another month, I see her adding layer upon layer to the walls of her nest. These were at first semi-transparent; they become thick and opaque. This is why the Spider eats, so that she may fill her silk-glands and make a thick wrapper for her nest. About the middle of September the little Spiders come out of their eggs, but they do not leave their house, where they are to spend the winter packed in soft wadding. The mother continues to watch and spin, but she grows less active from day to day. She eats fewer Locusts; she sometimes scorns those whom I myself entangle in her trap. But for four or five months longer she keeps on making her inspection-rounds of her egg-casket, happy at hearing the new-born Spiders swarming inside. At last, when October ends, she clutches her children’s nursery and dies. She has done all that a mother’s devotion can do; the special Providence that watches over tiny animals will do the rest. When spring comes, the youngsters will come out of their snug homes and scatter all over the neighborhood on their floating threads, like the little Crab-spiders you have read about. [Illustration] CHAPTER XXIV THE BUILDING OF A SPIDER’S WEB The smallest garden contains the Garden Spiders, all clever weavers. Let us go every evening, step by step, from one border of tall rosemaries to the next. Should things move too slowly, we will sit down at the foot of the shrubs, where the light falls favorably, and watch with unwearying attention. Let us give ourselves a title, “Inspector of Spiders’ Webs!” There are not many people in that profession, and we shan’t make any money by it; but never mind, we shall learn some very interesting things. The Spiders I watch are young ones, much slenderer than they will be in the late autumn. They work by day, work even in the sun, whereas the old ones weave only at night. Work starts in July, a couple of hours before sunset. The spinstresses of my inclosures then leave their daytime hiding-places, choose their posts and begin to spin, one here, another there. There are many of them; we can choose where we please. Let us stop in front of this one, whom we surprise in the act of laying the foundations of her web. She runs about the rosemary hedge, from the tip of one branch to another, within the limits of some eighteen inches. Gradually, she puts a thread in position, drawing it from her body with the combs attached to her hind-legs. She comes and goes impetuously, as though at random; she goes up, comes down, goes up again, dives down again and each time strengthens the points of contact with threads distributed here and there. The result is a sort of frame. The shapeless structure is what she wishes; it marks out a flat, free, and perpendicular space. This is all that is necessary. A special thread, the foundation of the stronger net which will be built later, is stretched across the area of the other. It can be told from the others by its isolation, its position at a distance from any twig that might interfere with its swaying length. It never fails to have, in the middle, a thick white point, formed of a little silk cushion. The time has come to weave the hunting-snare. The Spider starts from the center, which bears the white signpost, and, running along the cross-thread, hurriedly reaches the circumference, that is to say, the irregular frame inclosing the free space. Still with the same sudden movement, she rushes from the outside to the center; she starts again backwards and forwards, makes for the right, the left, the top, the bottom; she hoists herself up, dives down, climbs up again, runs down and always returns to the central landmark by roads that slant in the most unexpected manner. Each time a radius or spoke is laid, here, there, or elsewhere, in what looks like mad disorder. [Illustration] Any one looking at the finished web, so neat and regular in appearance, would think that the Spider laid the spokes in an orderly fashion, one after the other. She does nothing of the sort, but she knows what she is about, all the same. After setting a few spokes in one direction, the Spider runs across to the other side to draw some in the opposite direction. These sudden changes have a reason; they show us how clever the Spider is in her business. If she began by laying all the spokes on one side, she would pull the web out of shape or even destroy it. She must put some on the other side to balance. She is a past mistress of the secrets of rope-building, without serving an apprenticeship. One would think that this interrupted and apparently disordered labor must result in a confused piece of work. Wrong: the rays are equidistant and form a beautifully regular circle. Their number is a characteristic mark of the different species. The Angular Epeira places twenty-one in her web, the Banded Epeira thirty-two, the Silky Epeira forty-two. These numbers are not absolutely fixed; but the variation is very slight. Now which of us would undertake, offhand, without much preliminary experiment and without measuring-instruments, to divide a circle into a given quantity of sectors or parts of equal width? The Garden Spider, though weighted with a wallet and tottering on threads shaken by the wind, performs the delicate division without stopping to think. She achieves it by a method which seems mad according to our notions of geometry. Out of disorder she brings order. We are amazed at the result obtained. How does this Spider come to succeed with her difficult problem, so strangely managed? I am still asking myself the question. The laying of the radii or spokes is finished. The Spider takes her place in the center, on the little cushion. Stationed on this support, she slowly turns round and round. She is engaged on a delicate piece of work. With an extremely thin thread, she describes from spoke to spoke, starting from the center, a spiral line with very close coils. This is the center of the web. I will call it the “resting-floor.” The thread now becomes thicker. The first could hardly be seen; the second is plainly visible. The Spider shifts her position with great slanting strides, turns a few times, moving farther and farther from the center, fixes her line each time to the spoke which she crosses, and at last comes to a stop at the lower edge of the frame. She has described a spiral with coils of rapidly-increasing width. The average distance between the coils, even in the webs of the young Spiders, is about one third of an inch. This spiral is not a curved line. All curves are banished from the Spiders’ work; nothing is used but the straight line and its combinations. This line forms the cross-bars, or supporting rungs, connecting the spokes, or radii. All this is but a support for the snaring-web. Clinging on the one hand to the radii, on the other to the cross-bars, the Spider covers the same ground as when laying the first spiral, but in the opposite direction: formerly, she moved away from the center; now she moves towards it and with closer and more numerous circles. She starts from the end of the first spiral, near the outside of the web. What follows is hard to observe, for the movements are very quick and jerky, consisting of a series of sudden little rushes, sways, and bends that bewilder the eye. The two hind-legs, the weaving implements, keep going constantly. One draws out the thread from the spinneret, and passes it to the other, which lays it on the radius. As soon as the radius is touched, the thread sticks to it by its own glue. [Illustration] The Spider, without a stop of any kind, turns and turns and turns, drawing nearer to the center and always fixing her thread at each spoke which she crosses. At last, at some distance from the center, on the edge of what I have called the resting-floor, the Spider suddenly ends her spiral. She next eats the little cushion in the center, which is a mat of ends of saved silk. She does this to economize silk, for after she has eaten it the cushion will be turned into silk for the next web she spins. Two Spiders, the Banded and the Silky, sign their work by laying a broad white ribbon in a thick zigzag from the center to the lower edge of the web. Sometimes they put a second band of the same shape, but a little shorter, opposite the first, on the upper part of the web. [Illustration] THE STICKY SNARE The spiral part of the Garden Spider’s web is a wonderful contrivance. The thread that forms it may be seen with the naked eye to be different from that of the framework and the spokes. It glitters in the sun, and looks as though it were knotted. I cannot examine it through the microscope outdoors because the web shakes so, but by passing a sheet of glass under the web and lifting it I can take away a few pieces of thread to study. The microscope now shows me an astounding sight. Those threads, so slender as to be almost invisible, are very closely twisted twine, something like the gold cord of officers’ sword-knots. Moreover, they are hollow. They contain a sticky moisture resembling a strong solution of gum arabic. I can see it trickling from the broken ends. This moisture must ooze through the threads, making them sticky. Indeed, they are sticky. When I lay a straw flat upon them, it adheres at once. We see now that the Garden Spider hunts, not with springs, but with sticky snares that catch everything, down to the dandelion-plume that barely brushes against the web. Nevertheless, the Spider herself is not caught in her own snare. Why? For one thing, she spends most of her time on her resting-floor in the middle of the web, which the spiral does not enter. The resting-floor is not at all sticky, as I find when I pass a straw against it. But sometimes when a victim is caught, perhaps right at the end of the web, the Spider has to rush up quickly to bind it and overcome its attempts to free itself. She seems to be able to walk upon her network perfectly well then. Has she something on her feet which makes them slip over the glue? Has she perhaps oiled them? Oil, you know, is the best thing to prevent surfaces from sticking. I pull out the leg of a live Spider and put it to soak for an hour in disulphide of carbon, which dissolves fat. I wash it carefully with a brush dipped in the same fluid. When the washing is finished, the leg sticks to the spiral of the web! We see now that the Spider varnishes herself with a special sweat so that she can go on any part of her web without difficulty. However, she does not wish to remain on the spiral too long, or the oil might wear away, so most of the time she stays on her safe resting-floor. This spiral thread of the Spider’s is very quick to absorb moisture, as I find out by experiment. For this reason the Garden Spiders, when they weave their webs in the early morning, leave that part of the work unfinished, if the air turns misty. They build the general framework, they lay the spokes, they make the resting-floor, for all these parts are not affected by excess moisture; but they are very careful not to work at the sticky spiral, which, if soaked by the fog, would dissolve into sticky threads and lose its usefulness by being wet. The net that was started will be finished to-morrow, if the weather is right. But on hot days this property of the spiral is a fine thing; it does not dry up, but absorbs all the moisture in the atmosphere and remains, at the most scorching times of day, supple, elastic, and more and more sticky. What bird-catcher could compete with the Garden Spider in the art of laying snares? And all this industry and cunning for the capture of a Moth! Then, too, what a passion the Spider has for production. I calculated that, in one sitting, each time that she remakes her web, the Angular Spider produces some twenty yards of gummy thread. The more skillful Silky Spider produces thirty. Well, during two months, the Angular Spider, my neighbor, renewed her snare nearly every evening. During that time she manufactured something like three quarters of a mile of this tubular thread, rolled into a tight twist and bulging with glue. We cannot but wonder how she ever carries so much in her little body, how she manages to twist her silk into this tube, how she fills it with glue! And how does she first turn out plain threads, then russet foam, for her nest, then black stripes to adorn the nest? I see the results, but I cannot understand the working of her factory. [Illustration] CHAPTER XXV THE GEOMETRY OF THE SPIDER’S WEB [This chapter, one of the most wonderful in Fabre’s books, is included in a simplified form in this volume, on account of its interest to such younger readers as have studied geometry.] When we look at the webs of the Garden Spiders, especially those of the Silky Spider and the Banded Spider, we notice first that the spokes or radii are equally spaced; the angles formed by each consecutive pair are of the same value; and this in spite of their number, which in the webs of the Silky Spider sometimes exceeds forty. We know in what a strange way the Spider weaves her web and divides the area of the web into a large number of equal parts or sectors, a number which is almost always the same in the work of each species of Spider. The Spider darts here and there when laying her spokes as if she had no plan, and this irresponsible way of working produces a beautiful web like the rose-window in a church, a web which no designer could have drawn better with compasses. We shall also notice that, in each sector, the various chords, parts of the angular spiral, are parallel to one another and gradually draw closer together as they near the center. With the two radiating lines that frame them they form obtuse angles on one side and acute angles on the other; and these angles remain constant in the same sector, because the chords are parallel. There is more than this: these same angles, the obtuse as well as the acute, do not alter in value, from one sector to another, as far as the eye can judge. Taken as a whole, therefore, the spiral consists of a series of cross-bars intersecting the several radiating lines obliquely at angles of equal value. By this characteristic we recognize what geometricians have named the “logarithmic spiral.” It is famous in science. The logarithmic spiral describes an endless number of circuits around its pole, to which it constantly draws nearer without ever being able to reach it. We could not see such a line, the whole of it, even with our best philosophical instruments. It exists only in the imagination of scientists. But the Spider knows it, and winds her spiral in the same way, and very accurately at that. Another property of this spiral is that if one in imagination winds a flexible thread around it, then unwinds the thread, keeping it taut the while, its free end will describe a spiral similar at all points to the original. The curve will merely have changed places. Jacques Bernouilli, the professor of mathematics who discovered this magnificent theorem, had engraved on his tomb, as one of his proudest titles to fame, the spiral and its double, made by the unwinding of the thread. Written underneath it was the sentence: _Eadem mutata resurgo._ “I rise again like unto myself.” It was a splendid flight of fancy which showed his belief in immortality. Now is this logarithmic spiral, with its curious properties, merely an idea of the geometricians? Is it a mere dream, an abstract riddle?