CHAPTER XIV. Arachnida Embolobranchiata (_continued_)—Araneae (_continued_)

ARACHNIDA EMBOLOBRANCHIATA (CONTINUED)—ARANEAE (CONTINUED)

HABITS—ECDYSIS—TREATMENT OF YOUNG—MIGRATION—WEBS—NESTS—EGG-COCOONS— POISON—FERTILITY—ENEMIES—PROTECTIVE COLORATION—MIMICRY—SENSES— INTELLIGENCE—MATING HABITS—FOSSIL SPIDERS

EARLY LIFE OF SPIDERS.

=Ecdysis or Moulting.=—Spiders undergo no metamorphosis—that is to say, no marked change of form takes place, as is so often the case among Insects, in the period subsequent to the hatching of the egg. This fact, by the by, is a great trouble to collectors, as it is generally extremely difficult, and sometimes quite impossible, to identify immature specimens with certainty.

But although unmistakably a spider as soon as it leaves the egg, the animal is, at first, in many respects incomplete, and it is only after a series of moults, usually about nine in number, that it attains its full perfection of form.

Until the occurrence of its first moult it is incapable of feeding or spinning, mouth and spinning tubes being clogged by the membrane it then throws off. It is at first pale-coloured and less thickly clothed with hairs and spines than it eventually becomes, and the general proportions of the body and the arrangement of the eyes are by no means those of the adult in miniature, but will be greatly modified by unequal growth in various directions. It speedily, however, attains its characteristic shape and markings, and after one or two ecdyses little alteration is to be noticed, except increase in size, until the final moult, when the spider at length becomes sexually mature.

The first moult takes place while the newly-hatched spider is still with the rest of the brood either in or close to the “cocoon” or egg-bag. M‘Cook thus describes the conclusion of the operation in the case of Agelena naevia:—

“While it held on to the flossy nest with the two front and third pairs of legs, the hind pair was drawn up and forward, and the feet grasped the upper margin of the sac-like shell, which, when first seen, was about half-way removed from the abdomen. The feet pushed downwards, and at the same time the abdomen appeared to be pulled upward until the white pouch was gradually worked off.”

The later moults are generally accomplished by the spider collecting all its legs together and attaching them with silk to the web above, while the body, also attached, hangs below. The old skin then splits along the sides of the body, and the animal, by a series of violent efforts, wriggles itself free, leaving a complete cast of itself, including the legs, suspended above it. For a day or two before the operation the spider eats nothing, and immediately upon its completion it hangs in a limp and helpless condition for a quarter of an hour or so, until the new integument has had time to harden. It is not unlikely that the reader has mistaken these casts for the shrivelled forms of unlucky spiders, and has had his sympathies aroused, or has experienced a grim satisfaction, in consequence—an expenditure of emotion which this account may enable him to economise in future.

Limbs which the animal has accidentally lost are renewed at the time of moulting, though their substitutes are at first smaller than those they replace. On the other hand, the struggle to get rid of the old skin sometimes results in the loss of a limb, and the spider is doomed to remain short-handed until the next ecdysis.

Until the last moult the generative apertures, which are situated under the anterior part of the abdomen, are completely sealed up. Their disclosure is accompanied, in the case of the male, by a remarkable development of the last joint of each pedipalp, which becomes swollen and often extremely complicated with bulbs, spines, and bristles. A mature male spider may at once be distinguished by the consequent knobbed appearance of its palps; and the particular form they assume is highly characteristic of the species to which the spider belongs.

The number of moults, and the intervals at which they occur, no doubt vary with different species. In the case of Argiope aurelia, Pollock has found that the female moults nine times after leaving the cocoon, the first ecdysis occurring after an interval of from one to two months, according to the abundance or scarcity of food. The subsequent intervals gradually increase from about a fortnight to something over three weeks.

=Behaviour of the Newly-hatched Spider.=—The mode of life of a spider just freed from the cocoon will of course vary greatly according to the Family to which it belongs.

The EPEIRIDAE are the builders of the familiar wheel or orb-web. Spiders of this Family usually remain together on friendly terms for a week or more after leaving the nest. Most of the time they are congregated in a ball-like mass, perhaps for the sake of warmth, but upon being touched or shaken they immediately disperse along the multitudinous fine lines which they have spun in all directions, to reassemble as soon as the panic has subsided. Such a ball of the yellow and black offspring of the large Garden-spider, Epeira diademata, is no uncommon sight in the early autumn, and the shower of “golden rain” that results from their disturbance is not likely to be forgotten if it has ever been observed by the reader. This harmonious family life only continues as long as the young spiders are unable to feed—a period which, in some of the larger species, is said to extend to ten days or a fortnight.

Individual life then commences, and each member of the dispersed group sets up housekeeping on its own account, constructing at the first attempt a snare in all respects similar, except in size, to those of its parent.

Of course the young Spiders have not migrated far, and a bush may frequently be seen covered by the often contiguous nets of the members of a single brood. This, as Dr. M‘Cook thinks, is the true explanation of some of the cases of “gregarious spiders” which Darwin and other naturalists have occasionally described, though social spiders exist (see Uloborus, p. 411).

Very similar habits obtain among the THERIDIIDAE, or line-weaving spiders, a familiar example of which is the pretty little Theridion sisyphium, whose highly-irregular snare may be found on any holly bush during the summer months.

FIG. 188.—=A=, Pardosa sp. ♀, with young on the abdomen; =B=, young Pardosa detached; =C=, outline of the Spider with young removed. (From the living specimen.) ]

The LYCOSIDAE, or Wolf-spiders, which chase their prey instead of lying quietly in ambush to ensnare it, are exceedingly interesting in their treatment of their young. The cocoon, or bag of eggs, is carried about on all their expeditions, attached beneath the abdomen, or held by the jaws, and the young spiders, on escaping from it, mount on the mother’s back, and indulge vicariously in the pleasures of the chase from this point of vantage. The empty egg-bag is soon discarded, but the brood continues to ride on the mother’s back for about a week, dismounting only to follow her as she enters her little silk-lined retreat in the ground.

During this time they appear to require no food, but they at length begin to disperse, the mother gently but firmly removing such individuals as are disposed to trespass upon her maternal solicitude longer than she considers desirable.

Many young spiders of various Families proceed immediately to seek new hunting-grounds by the aid of the wind, and become for the time being diminutive aeronauts. This habit was observed by the earliest British araneologist, Martin Lister, as long ago as 1670, and has been alluded to by many writers since his time.

The topmost bar of an iron railing in spring or early autumn will generally be found peopled with minute spiders, and if the day be fair and the wind light, the patient observer may be rewarded by a curious and interesting sight.

The spider seeks the highest spot available, faces the wind, and straightens its legs and body, standing, so to speak, upon its toes, its abdomen with its spinning tubes being elevated as much as possible. Streamers of silk presently appear from the spinnerets and float gently to leeward on the light current of air. The spider has no power to shoot out a thread of silk to a distance, but it accomplishes the same result indirectly by spinning a little sheet or flocculent mass which is borne away by the breeze.

FIG. 189.—Young Spider preparing for an aerial voyage. (After Emerton.) ]

When the streaming threads pull with sufficient force the animal casts off, seizes them with its legs, and entrusts itself to the air, whose currents determine the height to which it is carried and the direction of its journey. The duration, however, is not quite beyond the spider’s control, at all events in calm weather, for it can furl its sail at will, hauling in the threads “hand-over-hand,” and rolling them up into a ball with jaws and palps.

This curious ballooning habit of young Spiders is independent of the particular family to which they belong, and it is remarkable that newly-hatched Lycosidae and Aviculariidae, whose adult existence is spent entirely on or under the ground, should manifest a disposition to climb any elevated object which is at hand.

The “Gossamer,” which so puzzled our forefathers, is probably no mystery to the reader. It is, of course, entirely the product of Spider industry, though not altogether attributable to the habit of ballooning above described. Only a small proportion of gossamer flakes are found to contain spiders, though minute insects are constantly to be seen entangled in them. They are not formed in the air, as was supposed long after their true origin was known, but the threads emitted by multitudes of spiders in their various spinning operations have been intermingled and carried away by light currents of air, and on a still, warm day in spring or autumn, when the newly-hatched spider-broods swarm, the atmosphere is often full of them.

They rise to great heights, and may be carried to immense distances. Martin Lister relates how he one day ascended to the highest accessible point of York Minster, when the October air teemed with gossamer flakes, and “could thence discern them yet exceeding high” above him. Gilbert White describes a shower, at least eight miles in length, in which “on every side, as the observer turned his eyes, he might behold a continual succession of fresh flakes falling into his sight, and twinkling like stars as they turned their sides toward the sun.” The ascent of a hill 300 feet in height did not in the least enable him to escape the shower, which showed no sign of diminution.

The mortality among very young spiders must be exceedingly great; indeed, this is indicated by the large number of eggs laid by many species, an unfailing sign of a small proportion of ultimate survivors. We shall have, by and by, to speak of some of their natural enemies, but apart from these their numbers are sadly reduced by the rigours of the weather, and appreciably also by their tendency to cannibalism. A thunderstorm will often destroy a whole brood, or they may perish from hunger in the absence of an adequate supply of insects minute enough for their small snares and feeble jaws. In the latter case they sometimes feed for a time on one another, and it is even said that two or three of a brood may be reared on no other food than their unfortunate companions.

The large and handsome Garden-spider, Epeira diademata, has been known, when well fed, to construct six cocoons, each containing some hundreds of eggs, and some species are even more fertile, while their adult representatives remain stationary, or even diminish in number.

=Spider-Webs.=—Some account has already been given of the external and internal spinning organs of Spiders. Within the body of the animal the silk is in the form of a gummy fluid; and this, being emitted in exceedingly fine streams, solidifies as it meets the air. It cannot be shot out to any distance, but the animal usually draws it out by its hind legs, or attaches it to a spot, and moves away by walking or allowing itself to drop. It has some power of checking the output, and can stop at will at any point of its descent; but the sphincter muscles of the apertures are but weak, and by steady winding the writer has reeled out a hundred yards of the silk, the flow of which was only then interrupted by the spider rubbing its spinnerets together and breaking the thread.

There is, of course, no true spinning or interweaving of threads in the process, but parallel silken lines are produced, varying in number according to the special purpose for which they are designed, and sometimes adhering more or less to one another on account of their viscidity and closeness.

The silk is utilised in many ways, serving for the construction of snares, nests, and cocoons, as well as for enwrapping the captured prey, and for anchoring the spider to a spot to which it may wish to return.

Spiders may be roughly distinguished as sedentary or vagabond, the former constructing snares, and the latter chasing their prey in the open. We will first consider the various forms of snare, beginning with that characteristic of the Epeiridae.

=The Circular Snare.=—This familiar object, sometimes spoken of as the orb-web or wheel-web, is always the work of some spider of the Family Epeiridae.

The accuracy and regularity of form exhibited by these snares has caused their architects to be sometimes called the geometric spiders. The ingenuity displayed by them has always excited the admiration of the naturalist, and this is increased on closer observation, for the snares are in reality even more complex than they appear at first sight.

The first care of the spider is to lay down the foundation threads which are to form the boundary lines of its net. If the animal can reach the necessary points of attachment by walking along intervening surfaces the matter is comparatively simple. The spinnerets are separated and rubbed against one of the points selected, and the spider walks away, trailing behind it a thread which it keeps free from neighbouring objects by the action of one of its hind legs. On reaching another desirable point of attachment the line is made taut and fixed by again rubbing the spinnerets against it. By a repetition of this proceeding a framework is presently constructed, within which the wheel or orb will ultimately be formed.

The process of fixing and drawing out a line can be conveniently watched in the case of a Spider imprisoned in a glass vessel, and it will be seen, by the aid of a lens, that a large number of very fine lines starting from the point of attachment seem to merge into a single line as the Spider moves away. This has given rise to the prevalent and very natural idea that the ordinary spider’s line is formed or “woven” of many strands. This, however, is not the case, for the fine attachment-lines are not continued into the main thread, but only serve to anchor it to the starting-point.

As has been said, the spider can throw into play a varying number of spinning tubes at will, and in point of fact those used in laying down these foundation-lines are either two or four in number. The spider, however, often finds it necessary to strengthen such a line by going over it afresh.

Every one must have noticed that orb-webs frequently bridge over gulfs that are clearly quite impassable to the spider in the ordinary way. They often span streams—and Epeirid spiders cannot swim—or they are stretched between objects unattainable from each other on foot except by a very long and roundabout journey. When this is the case, the animal has had recourse to the aid of the wind. A spider of this family placed on a stick standing upright in a vessel of water is helpless to escape if the experiment be tried in a room free from draughts. With air-currents to aid it, silken streamers will at length find their way across the water and become accidentally entangled in some neighbouring object. When this has happened, the spider hauls the new line taut, and tests its strength by gently pulling at it, and if the result is satisfactory, it proceeds to walk across, hand-over-hand, in an inverted position, carrying with it a second line to strengthen the first. This is exactly what happens in nature when a snare is constructed across chasms otherwise impassable, and it may be imagined that the spider regards as very valuable landed property the foundation lines of such a web, for, if destroyed, the direction or absence of the wind might prevent their renewal for days. They are accordingly made strong by repeated journeys, and are used as the framework of successive snares, till accident at length destroys them.

A single line which finds anchorage in this way is sufficient for the purposes of the spider. It has only to cross over to the new object, attach a thread to some other point of it, and carry it back across the bridge to fix it at a convenient spot on the surface which formed the base of its operations. Between two such bridge-lines the circular snare is constructed in a manner to be presently described. Sometimes the tentative threads emitted by the spider travel far before finding attachment. In the case of the English Epeira diademata the writer has measured bridge-lines of eleven feet in length; and with the great Orb-weavers of tropical countries they frequently span streams several yards in width.

Two stout bridge-lines thus constructed will form the upper and lower boundaries of the net. The lateral limits are easily formed by cross lines between them at a convenient distance apart. The spider chooses a point, say, on the upper bridge-line, fixes its thread there, and carries it round to the lower line, where it is hauled taut and firmly attached. Two such cross lines give, with the bridge-lines, an irregular four-sided figure within which to stretch the snare, and now the work is perfectly straightforward, and can proceed without interruption.

Attention is first paid to the radii of the circular web. The first radii are formed by drawing cross lines within the framework in the same manner as before, but the spider carefully attaches these where they intersect by a small flossy mass of silk, and this central point or hub becomes the basis of its subsequent operations. It is a simple matter to add new radial lines by walking from the centre along one of those already formed and fixing the thread to some new point of the circumference. They are not laid down in any invariable order, but with a kind of alternation which has the general effect of keeping the strain on every side fairly equal. Almost every time the spider reaches the centre it slowly revolves, uniting the radii afresh at their point of junction, and increasing the strength and complexity of the hub. It also occasionally digresses so far as to stretch the whole structure by bracing the framework at additional points, so that it loses its four-sided form and becomes polygonal. We have now a number of spokes connecting a central hub with an irregular circumference.

The hub is next surrounded by what Dr. M‘Cook calls a “notched zone,” consisting of a few turns of spiral thread which serve to bind more firmly the spokes of the wheel. The most important part of the work is still to be performed. The lines hitherto laid down are perfectly dry and free from viscidity, so that an entangled insect would easily be able to free itself. A viscid spiral line remains to be spun, and the snare will be complete. The precise method of laying this down will vary somewhat according to the species, but, to refer again to the large Garden-spider, the proceeding is as follows:—Commencing at a point somewhat outside the notched zone, the creature rapidly works in a spiral thread of ordinary silk with the successive turns rather far apart. This forms a kind of scaffolding, by clinging to which the spider can put in the viscid spiral, which it commences at the circumference.

Its action now becomes exceedingly careful and deliberate, though by no means slow, and so great is its absorption in the work that it may be observed quite closely with a hand-lens without fear of interrupting it. The proceeding consists in drawing out from its spinnerets with one (or both) of its hind legs successive lengths of a highly elastic line, which it stretches just at the moment of fixing it to a radius, and then lets go with a snap. There is no hesitation or pause for consideration, but there is a peculiar deliberateness in drawing out each length of the thread which, together with stretching and sudden release, require explanation. Now, it has already been mentioned that the framework and radii of the snare are not at all moist or adhesive. This, however, is not the case with the spiral, upon which the spider chiefly relies in capturing its prey. A close examination of it—even with the naked eye— will show it to be beaded over with little viscid globules which, under a low magnifying power, are seen to be arranged with remarkable regularity.

FIG. 190.—=A=, =B=, =C=, =D=, Stages in the formation of the viscid globules of the web. ]

A very convenient method of investigation is to carry off a newly-constructed web—or, better still, one not quite finished—on a piece of plate glass, to which it will adhere by reason of the viscid spiral, and on which it may be examined at leisure. Immersion in a staining fluid will colour the viscid spiral, and show its structure in a striking manner. It will appear to consist of a thread strung with beads of two sizes, occurring with pretty uniform alternation, though two of the larger beads are often separated by two or more of the smaller.

Until recently it was supposed that the deposition of these beads upon the spiral line was a subsequent operation, and, in view of their vast numbers and regularity, the circumstance naturally excited great wonder and admiration. Blackwall estimated that, in a fourteen-inch net of Epeira cornuta, there were at least 120,000 viscid globules, and yet he found that its construction occupied only about forty minutes! The feat, from his point of view, must be allowed to be rather startling.

As a matter of fact, the thread, on being slowly drawn out, is uniformly coated with viscid matter which afterwards arranges itself into beads, the change being assisted by the sudden liberation of the stretched line.

Boys has shown their formation to be quite mechanical, and has obtained an exact imitation of them by smearing with oil a fine thread ingeniously drawn out from molten quartz. The oil arranged itself into globules exactly resembling the viscid “beads” on the spider’s line. If the web be carried bodily away on a sheet of glass, as above described, while the spider is engaged upon the spiral line, the experimenter will have permanent evidence of the manner in which the globules are formed. The last part of the line will be quite free from them, but uniformly viscid. Tracing it backwards, however, the beads are soon found, at first irregularly, but soon with their usual uniformity. The thread which the spider has thus “limed” for the capture of prey is really two-stranded—the strands not being twisted, but lying side by side, and glued together by their viscid envelope.

The snare is now practically complete, and the proprietor takes up her position either in the centre thereof, or in some retreat close at hand, and connected with the hub by special lines diverging somewhat from the plane of the web. Notwithstanding the possession of eight eyes—which, in sedentary spiders, are by no means sharp-sighted—it is mainly by the sense of touch that the spider presently becomes aware that an insect is struggling in the net. She immediately rushes to the spot, and suits her action to the emergency.

If the intruder is small, it is at once seized, enveloped in a band of silken threads drawn out from the spinnerets, and carried off to the retreat, to be feasted on at leisure. If it seems formidable it is approached carefully—especially if armed with a sting—and silk is deftly thrown over it from a safe distance till it is thoroughly entangled, and can be seized in safety by the venomous jaws of its captor. Sometimes the insect is so powerful, or the spider so sated with food, that the latter hastens to set free the intruder by biting away the threads which entangle it before much havoc has been wrought with the net.

The viscid matter on the spiral line dries up after some hours, so that, even if the web has not been destroyed by insects and stress of weather, this portion of it must be frequently renewed. Commencing a new web is, as has been seen, a troublesome matter, and it will readily be understood that the spider prefers, where practicable, to patch up the old one. This is done by biting away torn and ragged portions and inserting new lines in their place.

The part played by the various spinning glands in the construction of the orb-web may be briefly stated. The ampullaceal glands furnish the silk for the foundation lines and radii. The spiral has a double ground-line proceeding from the middle spinnerets, but it is not quite certain whether it proceeds from the ampullaceal or the tubuliform glands. The chief function of the latter, in the female, is to furnish silk for the egg-cocoon. The viscid globules are the products of the aggregate glands. The aciniform and piriform glands provide the multitudinous threads by which the spider anchors its various lines and enwraps its prey.

Some Orb-weavers always decorate their snares with patches or tufts of flossy silk. In the snare of the North American Argiope cophinaria the hub is sheeted, and from it extends downwards a zigzag ribbon of silk stretched between two consecutive radii. Vinson discovered a remarkable use for similar zigzag bands in the web of the Mauritian spider, Epeira mauritia. It furnished a reserve supply of silk for enveloping partly entangled insects whose struggles were too vigorous to succumb to the rather feeble threads which the spider was able to emit at the moment of capture. The spider was able to overcome a grasshopper much more powerful than itself by dexterously throwing over it with one of its hind legs a portion of the ribbon of silk which it had thus stored up for emergencies.

FIG. 191.—=A=, Snare of Hyptiotes cavatus; =B=, enlarged view of the Spider, showing the “slack” of the hauled-in line. (After Emerton.) ]

Many orb-webs are defective, a sector of the circle being uniformly omitted in the structure. The genus Hyptiotes does not belong to the Epeiridae but to the cribellate Uloboridae, but its defective orb-web is so curious that it deserves a special mention. A single foundation-line is laid down, and from it four radii are drawn and are connected with cross lines, the snare constituting about one-sixth of a circle. From the centre of the incomplete circle a thread proceeds to some more or less distant object, and on this the spider takes up its position, inverted, and hauls in the line till the snare is taut. When the trembling of the line shows the spider that an insect has struck the net, it lets go with its fore-legs, and the web, springing back to its normal position, entangles the intruder more thoroughly by its vibrations. When large insects are in question the spider has been observed to “spring” the net several times in succession. H. cavatus is common in the pine woods of Pennsylvania, but the only English species, H. paradoxus, is extremely rare.

A remarkable spider has been discovered in Texas by M‘Cook, which, after building a horizontal orb-web, converts it subsequently into a dome (Fig. 192) of exceedingly perfect form. It is named Epeira basilica, and has been the object of careful study by Dr. Marx, who observed the whole process of web-construction. Threads are attached at various points on the upper surface of the horizontal wheel, the central portion of which is gradually pulled up until the height of the dome is nearly equal to the diameter of its base. But the snare of this spider does not consist of the dome alone. A sheet of irregular lines is stretched below, while above there is a maze of threads in the form of a pyramid. Several other Orb-weavers, as, for instance, E. labyrinthea and E. triaranea, supplement their typical webs by an irregular structure of silk, and thus form connecting links, as regards habit, between the group of which we have been speaking and the Theridiidae or Line-weavers, which may now briefly be dealt with.

FIG. 192.—Snare of Epeira basilica. (After M‘Cook.) ]

=The Irregular Snare.=—The great majority of British Spiders belong to the family of the Theridiidae, or Line-weavers. Some of these are among the handsomest of our native species, and are in other respects highly interesting, but their snares lack the definiteness of structure exhibited by the orb-web, and little need be said about them.

For the most part they consist of fine irregular lines running in all directions between the twigs of bushes or among the stems of grass and herbage. One large and important genus, Linyphia, always constructs a horizontal sheet of irregular threads with a maze of silk above it. Such snares may be seen in myriads in the wayside hedges during the summer, and they are especially notable objects when heavily laden with dew. Insects impeded in their flight by the maze of threads drop into the underlying sheet, and are soon completely entangled. The spider usually runs beneath the sheet in an inverted position.

The sheet or hammock of silk is absent in the case of most of the other genera of this family, their snares being innocent of any definite method in their structure. They are frequently quite contiguous, and it is no uncommon thing to find a holly bush completely covered with a continuous network of threads, the work of a whole colony of the pretty little spider Theridion sisyphium.

As might be imagined from the simplicity or absence of design in the structure of the net, there appears to be very little complexity in the nature of the silk used. It is interesting, however, to find that viscid globules, not unlike those which stud the “spiral line” of the Epeiridae, are sometimes present in the snares of the Line-weavers, and in these, too, aggregate glands are present. There is a large spider of this family, Theridion tepidariorum, which may be found to a certainty in almost any hothouse in this country. In its snare, which is of the ordinary irregular type, F. Pickard-Cambridge has observed little patches of flocculent silk, calculated to render more certain the entanglement of prey, and he has further described a curious comb-like structure on the hind leg of the animal which is probably used in the production of this phenomenon. It is by no means unlikely that a more careful study of these apparently simple snares will lead to the discovery of further complexity of structure.

FIG. 193.—Snare of Uloborus sp., some of the lines being thickened with threads from the cribellum. (After M‘Cook.) ]

Uloborus, a cribellate genus which has an Epeirid-like, orbicular snare, decorates some of the lines with the produce of the cribellate glands, but viscid globules are absent.

=Sheet-Webs.=—The webs which are such familiar—and, by association, unpleasant—objects in unused rooms and outhouses are usually the work of spiders belonging to the Agelenidae and the Dictynidae. To the first belongs the common House-spider, Tegenaria civilis, and its larger congener, T. parietina. These spiders are not attractive in appearance, and the last-named species especially, with the four-inch span of its outstretched legs, is a formidable object, and a terror to domestic servants. An obscure tradition connecting it with Cardinal Wolsey and Hampton Court has caused it to be known as the Cardinal Spider. An out-door example of the Agelenidae is the very abundant Agelena labyrinthica, whose sheet-web, with its tubular retreat, is to be sought on the banks of ditches, or in the hedges of our country lanes.

The snares of these spiders are exceedingly closely woven of very fine silk, and take a long time to complete. The process of their construction may be watched by keeping an Agelena labyrinthica confined in a box with a glass front, and the web, kept free from dust, is a beautiful object, as its fine texture gradually becomes visible as a delicate transparent film which develops by imperceptible stages into an opaque white sheet. The excessive fineness of the silk makes it difficult at first to see what is taking place. The animal is seen to be busily moving about, but the result of its labours only gradually becomes visible. A few delicate foundation-lines are first stretched across the compartment in which it is confined, and upon these the spider walks to and fro incessantly with a serpentine motion, and by and by a muslin-like floor of silk comes into view.

An examination of the spinnerets throws some light upon the operation. The posterior pair are very long and mobile, and the hair-like spinning-tubes are distributed on their under surface. The cephalothorax and abdomen are far more rigidly connected in Agelena than in the Orb-weavers, but its length of leg and the length and mobility of its posterior spinnerets enable it to give a wide lateral sweep as it walks along, strewing fine silken threads upon the foundation-lines already laid down. Some hours elapse before even a moderately stout web is constructed, and for long afterwards the spider devotes odd moments of leisure in going over the ground again and strewing new silk upon the gradually thickening web. At one corner a silken tube of similar structure is formed, and in this the spider awaits the advent of any insect which may alight upon the sheet, when it immediately rushes forth and seizes it.

The webs of the Dictynidae are very similar in general appearance to those of the Agelenidae, consisting of a closely-woven sheet with a tubular nest. They are to be found, moreover, in similar situations, stretching across the angles of walls in cellars or outhouses, though some species prefer an out-door existence. Crannies in rock form convenient sites for such snares, but the family is not without its representatives in still more open situations. The web, though so similar to that of Agelena, is, however, constructed in a different manner. In the Dictynidae neither the legs nor the spinnerets are unusually long, and they do not strew the foundation-lines by a swinging motion of the body, but the operation is effected by a special apparatus. These spiders are cribellate, and in front of the six ordinary spinnerets there are a pair of perforated plates connected with a large number of additional minute spinning glands (see Fig. 182, p. 326). In conjunction with this, the female possesses on the last joint but one of each hind leg a curious comb-like arrangement of spines, the “calamistrum.” The animal constructs a sort of skeleton web by means of its ordinary spinnerets, and when this is completed it combs out silk from the cribellum by means of the calamistrum, using each hind leg alternately, and distributes it with a curling motion upon the scaffolding prepared for it, a nearly opaque web being the result. The silk from the cribellum is of an adhesive nature, and renders escape from the web very difficult.

=Spiders’ Nests and Retreats.=—All Spiders construct some description of nest, and often display great ingenuity in building them. Perhaps none are more curious than those of the burrowing Aviculariidae, a family which includes the interesting “Trap-door Spiders.” They are nocturnal in their habits, about which, consequently, little is known, but their nests have been carefully studied, especially by Moggridge, who found them in considerable abundance in various districts of the Riviera.

The jaws of these spiders are especially adapted for digging, and with them a hole is excavated in the ground to the depth of several inches, and wide enough to allow the animal to turn. This is carefully lined with silk which the spider throws against the sides from its long and upturned posterior spinnerets. But the chef d’œuvre of the whole structure is a lid or door which protects the entrance to the tube. There are two types of door which find favour with different species—the wafer and the cork type, as Moggridge has named them. The former consists of a thin circular or oval sheet of silk which flaps down loosely over the tube-entrance, with which it is connected by a hinge-like attachment. A trap-door of the cork type is a more complicated structure, being of considerable thickness and having a bevelled edge, so that it fits into the tube like a plug. Like the wafer door, it possesses a silken hinge.

To form the wafer door, the spider covers the entrance to the tube with a closely-woven layer of silk, which it afterwards bites away at the edge, except at the point where the hinge is to be. Doors of the cork type consist of alternate layers of silk and earth. After weaving a covering of silk, the creature brings earth in its jaws and lays it on the top, binding it down with a second layer of silk, and the process is repeated until the requisite thickness is attained.

The nests are exceedingly difficult to detect, as the spiders take the precaution of attaching leaves, moss, or small twigs to the outer surface of the doors. This does not appear to be the result of intelligence, but a mere instinctive habit; for if a door be removed and the surrounding earth denuded of moss, the spider will render the new door conspicuous by bringing moss from a distance, and thus making a green spot in the bare patch of earth.

The cork doors fit with great exactness, and there is always to be found on their under surface a notch by which they are held down by the fore-legs of the spider against any attempt to open them from without.

Many nests with trap-doors of the wafer type are found to have a second and more solid door within the tube. This serves to shut off the lower part of the nest as a still more secure retreat. This second door opens downwards, and the Spider, getting beneath it, is effectually shielded from an enemy which may have mastered the secret of the outer barrier. The nests of some species present still further complications in the way of lateral branches from the main tube. In one case (Nemesia congener) the burrow becomes =Y=-shaped, and the second door hangs at the fork of the =Y= in such a manner as to connect the bottom chamber either with the entrance or with the branch, which does not reach the surface, but ends blindly.

Trap-door Spiders are greatly attached to their tubes, which they enlarge and repair at need. They begin burrowing very early in life, and their tiny tubes resemble in all respects those of their parents. Their habits are nocturnal, and little is known of them; an observation, however, on a species inhabiting the island of Tinos in the Grecian Archipelago (Cteniza ariana), by Erber, must not be omitted. This spider leaves its tube at night and spins a web near at hand and close to the ground. It carries captured insects into its tube, and in the morning clears away the net, adding the material of it, M. Erber believes, to the trap-door.

No true trap-door Spider has as yet been found in this country, but the allied Atypidae are represented by at least one species, Atypus affinis, which has been discovered in colonies in some localities in the south of England, notably near Ventnor in the Isle of Wight, and on Bloxworth Heath in Dorsetshire. This spider, like its continental cousins, excavates a hole in the earth, generally near the edge of a heathery bank, and lines it with a tube of silk of such firm texture that it may be removed intact from the earth in which it is embedded. The silken tube projects some two inches above the ground, either erect among the roots of the heather, or lying loosely upon the surface. Its extremity is always found to be closed, whether from its own elasticity or by the deliberate act of the proprietor is uncertain, and it seems probable that the animal spends almost the whole of its existence in the tube. Simon believes that it feeds almost entirely upon earth-worms which burrow into its vicinity, and which it, therefore, need not leave its nest to catch; but the remains of beetles and earwigs have been found in the tubes at Ventnor.

FIG. 194.—Funnel of Cyrtauchenius elongatus. (After M‘Cook.) ]

This description of nest seems common to all species of the genus Atypus. The American “Purse-web Spider,” A. abboti, burrows at the foot of a tree, against the trunk of which it rears the projecting portion of its silken tube. At the bottom of the nest the cavity is enlarged, and blind processes project in different directions.

Another burrowing spider, Cyrtauchenius elongatus, surmounts its silk-lined burrow by a funnel-shaped structure of pure white silk, about three inches in height and two or three inches in width. There is no attempt at concealment, and the white funnels are conspicuous among the thin grass, presenting the appearance of fungi.

The burrowing habit is also common to the Wolf-spiders or Lycosidae, but beyond a very slight lining of silk there is usually little spinning work about their nests. Occasionally there is a certain amount of superstructure in the shape of a silken funnel (Lycosa tigrina, M‘Cook), or of an agglomeration of twigs and pebbles, as in the case of the “Turret-spider” (Lycosa arenicola, Scudder).

FIG. 195.—Turret of Lycosa carolinensis. (After M‘Cook.) ]

A colony of our handsome species, Lycosa picta, is an interesting sight to watch. Their favourite habitat is a sandy soil, variegated with many-coloured patches of moss and lichen, among which their own markings are calculated to render them inconspicuous. The observer, by lying perfectly still, may see them silently stealing forth from their burrows in the bright sunshine, and hunting diligently in the neighbourhood, ready to dart back on the faintest alarm, or if the sun should be temporarily obscured by a passing cloud. So closely do they resemble their surroundings, that it is only when in motion that they can readily be detected. It is very curious to see them popping out their heads to ascertain that the coast is clear before venturing forth, and the utter silence of their operations adds to the eeriness of the effect. The tubes of these spiders, though without a trap-door, and only slightly lined with silk, are =Y=-shaped like those of Nemesia congener, the main tunnel giving off a blind branch about half-way down.

The nest of the Water-spider, Argyroneta aquatica, must not be passed over without mention. This spider, though strictly an air-breathing animal, spends almost the whole of its existence beneath the water. That it can live in such a medium is due to the fact that the long hairs which clothe its abdomen retain a bubble of air as it swims beneath the water, so that it carries with it its own atmosphere. The air-bubble which invests its body gives it a strong resemblance to a globule of quicksilver, and renders it a pretty object in an aquarium as it swims about in search of food or in prosecution of its spinning operations.

Of these the most interesting is the building of its nest. Working upon a water plant some distance below the surface, it forms a silken dome of closely-woven threads, which it next proceeds to fill with air. To do this the spider rises in the water, raises its abdomen above the surface, and jerks it down again quickly, so as to carry with it a bubble of air which it helps to retain with its hind legs. With this it swims back to its tent, into which it allows the imprisoned air-globules to escape. By degrees the dome or bell is filled, and the creature has a dry and snug retreat beneath the water. In this it passes the winter in a torpid condition. The young of this species appear to be fond of utilising the empty shells of water-snails, which they float by filling them with air, and thus save themselves the trouble of nest-construction.

FIG. 196.—Egg-cocoons. =A=, Epeira diademata, nat. size. =B=, Theridion pallens × 4, attached to a leaf. =C=, Agroeca brunnea, nat. size, attached to a weed, and not yet coated with mud. =D=, Ero furcata × 4, attached to a log. ]

=Cocoon.=—The last important spinning operation which remains to be described is the building of the so-called cocoon. This must be distinguished from the cocoon of insects, which is a protective covering of silk within which the larva assumes the pupa form. In the case of the Spider, the term is applied to the structure which serves to protect and conceal the eggs. It is often of considerable complexity, and is highly characteristic of the particular species which constructs it.

All egg-bags are commenced in very much the same way. A small sheet of silk is woven, and against this, sometimes upon the upper and sometimes on the under surface, the eggs are deposited, and then covered in with a second silken layer. The compact silk-covered ball of eggs is then, in many cases, enclosed in a small compartment which the spider builds with infinite care and unfailing uniformity, after the pattern peculiar to its kind. A considerable number of the Orb-weavers are content with a simple silken case closely investing the eggs, and by its thickness and the non-conducting quality of the material, sufficient protection is afforded against inclement weather.

The egg-bag of the large Garden-spider (E. diademata) may be recognised by its great size and its yellow colour, which is deepened by the still more yellow tint of the eggs within. Those of Zilla x-notata and of many other English Epeirids are of similar structure, but of white silk. The mother generally avails herself of some natural shelter, hiding her cocoon beneath loose bark, in the crannies of masonry, or under the copings of walls.

Many species, on the contrary, boldly expose their cocoons in their snares, sometimes as many as fourteen being constructed in succession and strung in a chain. The American species Epeira caudata and E. bifurca are good examples of this habit, stringing a chain of characteristic cocoons upon the line connecting the retreat with the web.

The sedentary Theridiid spiders usually suspend their cocoons in the neighbourhood of their irregular snares. The green cocoon of Theridion sisyphium is generally more or less concealed by an accumulation of débris. The minute species T. pallens constructs a cocoon of peculiar shape on the under surface of a leaf (Fig. 196, B). It is a conical structure of white silk, considerably larger than the spider itself, attached at its broad end, and having several curious lateral projections near the middle.

Among the Lycosidae or “Wolf-spiders” the prevailing habit of the mother is to carry the egg-bag attached beneath her abdomen upon all her hunting excursions. It is spheroidal in shape, made up of an upper and a lower half, with a seam-like junction at the equator, so to speak. The lower half is first woven, and the eggs are deposited within it. The upper hemisphere is then spun, and the edges gathered in and finished off, the seam or suture being always discernible. The bag is now attached by silken threads to the spinnerets, and bumps merrily over the ground as the animal hurries along in search of prey. If deprived of it she evinces the greatest distress, and frequently will not try to escape without it.

=Attempts to utilise Spider Silk.=—It is long since the web of the House-spider, taken internally, was considered a specific for the ague, though its value as a styptic has been recognised in quite recent times. It is, however, with other uses of Spider silk that we are here concerned.

Spider silk has been extensively used in the micrometer eyepieces of telescopes where very fine intersecting lines are required. For this purpose the radial or scaffolding lines of the circular snare were selected, the spiral being unsuited on account of its row of viscid beads. Professor C. V. Boys has, however, discovered in his quartz fibres a material better adapted for this purpose.

Several attempts have been made to weave the silk of Spiders as a substitute for that of the silk-worm. Web silk is, of course, far too fine to furnish a durable material, but the cocoons are usually formed of coarser silk, and it is with them that the experiment has been tried. About the beginning of the eighteenth century certain stockings and mittens made of Spider silk from the cocoons of Epeira diademata, by M. Bon of Languedoc, attracted so much attention that the Academy desired M. Réaumur to investigate the matter. His report was unfavourable to the commercial utility of Spider silk. The cocoon threads, though eighteen times stronger than those of the web, were but one-fifth of the strength of those obtained from the silk-worm, and the lustre was inferior. A still more fatal objection, however, was founded upon the cannibalistic habits of the spider, and the difficulty of furnishing it with acceptable food.

M. Vinson has recorded that some of the spiders of Madagascar, especially Epeira madagascarensis, are far better adapted than any of our English species to a commercial use. They furnish silk of a beautiful clear yellow colour; they are accustomed to live harmoniously together in families; and the range of climate in which they can thrive is very considerable. The Creole ladies of this island, under the administration of General Decaen, wove a magnificent pair of gloves from spider silk, with their own hands, for presentation to the French Empress.

=Poison of Spiders.=—All spiders possess poison-glands, which have their openings on the fangs of the chelicerae. The action of the chelicera in striking does not express the venom, but the poison-bag itself is covered with a muscular coat by which the contained fluid is expelled. It is highly probable, therefore, that the venom is under the control of the animal’s will, and is economised when the simple wound is sufficient for the purpose—a supposition which may partially explain the very divergent opinions held with regard to the effect of the spider’s bite. The reputation of the “Tarantula” Spider is well known, but what particular species, if any, was intended by the name is quite uncertain. The name is derived from the town Tarentum, and was certainly applied to a Lycosid spider. Probably the common south European species, Lycosa narbonensis, has as good a claim to the honour as any. The confusion has been increased by extending the name to spiders of quite a different family. Eurypelma hentzii, one of the Aviculariidae, is commonly known as the Tarantula in America.

The superstition of the tarantula dance is well known. The bite of the spider was supposed to induce a species of madness which found its expression—and its cure—in frantic and extravagant contortions of the body. If the dance was not sufficiently frenzied, death ensued. In the case of survivors, the symptoms were said to recur on the anniversary of the bite. Particular descriptions of music were supposed to incite the patient to the excessive exertion necessary for his relief; hence the “Tarantella.”

In the Middle Ages epidemics of “tarantism” were of frequent occurrence, and spread with alarming rapidity. They were seizures of an hysterical character, analogous to the ancient Bacchic dances, and quite unconnected with the venom of the spider from which they took their name. The condition of exaltation and frenzy was contagious, and would run through whole districts, with its subsequent relapse to a state of utter prostration and exhaustion. The evil reputation of the Tarantula appears to have exceedingly little basis in fact.

Baglivi relates how the country people capture the Tarantula by imitating the buzzing of an insect at the mouth of its hole. “Quo audito, ferox exit Tarentula ut muscas, quorum murmur esse putat, captet; captatur tamen a rustico insidiatore.”

Fabre acted the part of the “insidious rustic” with slight success; but by other stratagems he enticed the creatures from their holes, and made some interesting observations upon the effects of their bite. He found that bees and wasps were instantaneously killed by them. This immediately fatal effect he found to be due to the fact that the spider invariably struck the insect in a particular spot, at the junction of the head with the thorax. Bees must often wander into Tarantula’s holes, and a prolonged contest, though it might end in the death of the insect, would be certain also to result fatally for the spider. It has, therefore, acquired the habit of striking its foe in the one spot which causes instant death. When Fabre presented a bee to a Tarantula in such a manner that it was bitten in some other region, the insect survived several hours.

A young sparrow, just ready to leave the nest, was bitten in the leg. The wound became inflamed, and the limb appeared to be paralysed, but the victim did not at first suffer in general health, and fed heartily; death resulted, however, on the third day. A mole died in thirty-six hours after the bite.

From these experiments, Fabre came to the conclusion that the venom of the Tarantula was at all events too powerful to be entirely negligible by man.

FIG. 197.—Latrodectus mactans, ♂, natural size. ]

Trifling causes may have a fatal effect upon a man in ill health, and it is quite possible that death has sometimes resulted from the Tarantula’s bite. Its effect upon a healthy subject, however, is certainly not serious. Goldsmith, in his Animated Nature, entirely discredits the current stories about this animal, saying that the Italian peasants impose upon credulous travellers by allowing themselves, for money, to be bitten by the Tarantula, and then feigning all the symptoms which are traditionally supposed to ensue.

There is a genus of the Theridiidae, by name Latrodectus, whose poisonous reputation almost rivals that of the Tarantula. It is remarkable, moreover, that it is regarded as particularly dangerous in such widely separated portions of the world as Madagascar, New Zealand, Algeria, the West Indies, and North America. These spiders, strangely enough, are by no means particularly large or formidable in appearance.

There are two species in Madagascar, known to the natives by the names of Mena-vodi and Vancoho. Vinson describes the terror which is locally inspired by the first-named species, whose bite is believed to be fatal unless measures are promptly taken to counteract the poison. They sometimes cauterise the wound, but the usual treatment consists in inducing profuse perspiration—a method of cure which recalls the Tarantula dance of Southern Europe. Flacourt mentions the Vancoho as the most dangerous animal of Madagascar, and more formidable than the scorpion. He relates cases among his own negroes where the bite was followed by a condition of syncope which lasted two days.

A New Zealand species is known by the natives as the Katipo. It is of about the size of a pea, and almost black in colour. Mr. Meek of Waiwera gives a most circumstantial account of the effect of its bite upon his son. During the four days which followed the bite he suffered excruciating pain, which spread from his leg to the spine, arms, and chest, and he lost twelve pounds in weight. Relief was obtained by frequent doses of brandy and the use of a liniment.

The natives of New Zealand have a great horror of this spider, but hold the curious belief that its death will ensure the cure of any one it may have bitten. If unable to find it, they will burn the house down rather than allow it to escape. Their dread, however, is confined to a variety which lives among the sedge of the sea-beach, and they carefully avoid sleeping in such places.

Two of the best authenticated cases of serious results ensuing from the bite of a spider of this genus come from North Carolina.

A farm labourer in the employ of Mr. John Dick of Greensborough was bitten by Latrodectus mactans about half-past eight in the morning, and died between ten and eleven o’clock at night. Small pimples were raised in the neighbourhood of the bite, but no puncture was discernible. Intermittent pains and spasms ended in a comatose condition from which he did not rally. The man appeared previously to be in perfect health.

Another man on Mr. Dick’s farm was bitten by the same species of spider. He resumed work, but a spasm of pain caused him to mount his horse and endeavour to ride home, but he fell off, and lay in a state of unconsciousness. He was found in this condition by a fellow-workman, and taken home. Large quantities of whisky were administered without any intoxicating effect, and this afforded some relief from the constantly-recurring spasms. The paroxysms continued for three weeks, and two months elapsed before he was able to resume work. On the ankle where he was bitten pimples appeared as in the previous case, and these broke out again, long after the occurrence, whenever he became overheated in his work.

These accounts are sufficiently circumstantial and well authenticated, but the fact of the actual bite depends upon the statement of the victims alone, and they may possibly have mistaken the cause of their trouble.

Southern Europe possesses a congener of this spider in Latrodectus 13–guttatus, the well-known “Malmignatte,” which is also considered extremely poisonous. The Royal Academy of Medicine and Surgery at Barcelona appointed Dr. Graells, in 1833, to inquire into the effects of the bite of this spider, cases of which had become exceedingly frequent. He found a curious correspondence between the frequency of these cases and the advent of migratory locusts, which the spider successfully attacked. In his report he details the symptoms in certain unquestionably authentic cases. There was a double puncture, surrounded by red circles, the region of the wound afterwards swelling greatly. The pain and swelling extended over the whole limb, and often to the body, and convulsions occurred, followed by great prostration and collapse. All the patients eventually recovered, their cure being heralded by profuse perspiration.

It must be mentioned, however, that the eminent Arachnologist M. Lucas states that he has several times allowed himself to be bitten by this identical spider without any ill effects.

The testimony is thus conflicting in this case also. It is impossible, however, to believe that there is no basis in fact for the poisonous reputation of a comparatively insignificant-looking spider in so many widely separated parts of the world, supported as it is by certain well-substantiated cases. The variable effects of its bite may find a partial explanation in a variation in the strength of its venom at different seasons, and it has already been mentioned that the injection of poison into its victim is a voluntary act, and does not necessarily accompany its bite. Among the species regarded as especially venomous must be mentioned Phidippus morsitans, one of the larger of the Attidae.

It is exceedingly likely that the bite of the large tropical Aviculariidae is really formidable. They appear, however, more anxious to escape than to show fight, and we possess little reliable information with regard to them. Doleschall shut up small birds with two West Indian species, and death followed their bite almost immediately. Ten days’ starvation appeared to weaken the venom, for a bird bitten by a spider fasting for that period recovered after an indisposition of six hours.

Most Arachnologists have recorded experiments with regard to the venom of the commoner European species, with equally conflicting results. Blackwall came to the conclusion that loss of blood, and not poison, caused the death of spider-bitten insects. He could not himself distinguish a spider bite from the prick of a needle inflicted upon his hand at the same time. Bees, wasps, and grasshoppers survived the bite about as long as other insects of the same species outlived a needle-prick in the same part of the body. Walckenaer’s experience was of the same nature. Bertkau, however, when bitten in the hand, felt clear indications of an irritant poison in the wound. The hairs of some of the large hairy species of the Aviculariidae possess poisonous properties. They are readily parted with, and when the animal is touched by the hand considerable irritation is set up.

=Fertility of Spiders.=—Spiders vary greatly in the average number of eggs laid by different species, and within the limits of each species there is a very considerable variation in fertility. As a rule it appears that the large and vigorous spiders are more prolific than the smaller and weaker members of the order. Were all the facts before us, however, we should no doubt find that the number of eggs laid bore a direct proportion, not to the size of the species, but to the dangers to which the young of that species are exposed. Where the total numerical strength of a species is fairly stationary, such a proportion must of course exist. Some species, no doubt, are tending to become extinct, while others are increasing in numerical importance. As a general rule, however, it is safe to infer that, if a species is especially prolific, special dangers attend the rearing of the young. The largest of North American Epeirids, Argiope cophinaria, constructs a cocoon containing, on an average, 1150 eggs. As many as 2200 have been counted in exceptional cases. Even this number is exceeded in the case of some of the great Aviculariidae. Theraphosa leblondi deposits as many as 3000 eggs. The large European Epeirids, E. quadrata and E. diademata, lay about 600 eggs, those of Lycosa narbonensis reaching about the same number. Those American spiders which have been described as stringing up a series of cocoons in their webs usually attain about the same aggregate, the eggs being less numerous in each cocoon.

These are examples of fairly large and fertile spiders. In the case of other species the number of eggs laid is exceedingly small. Ero furcata makes a single cocoon containing six eggs. Synageles picata, an ant-like Attid, lays only three. Oonops pulcher constructs several cocoons, but each contains only two eggs. The eggs of Cave-spiders, and such as live in dark and damp places, are generally few in number. Anthrobia mammouthia, for example, an inhabitant of the great American caves, deposits only from two to five eggs.

Our knowledge of the special perils which beset particular species is so incomplete that we are often at a loss for the reason of this great inequality in fertility. For instance, how does Synageles picata maintain its numerical strength by laying only three eggs, when, as M‘Cook points out, its resemblance to the ant, though advantageous to the adult spider, affords no protection to the egg? Our knowledge must be greatly extended before we are able to account for particular cases. Many influences hostile to spiders as a group are, however, well known, and we may here enumerate them.

=Natural Enemies.=—The precautions taken by the mother in constructing the cocoon render the inclemency of the weather very much less destructive to the eggs than to the newly-hatched young. Nevertheless, among spiders inhabiting swampy regions great havoc is wrought by the occasional wholesale swamping of the cocoons by floods. Professor Wilder considers the great fertility of Nephila plumipes necessary to counterbalance the immense destruction worked by the heavy rains upon their cocoons, which are washed in great numbers from the trees, to the leaves of which they are attached. But such exposed situations are avoided by many species, and their eggs, enclosed in their silken envelope, are well protected against the severities of the weather.

A more universal enemy to the egg is found in Ichneumon flies. On examining the cocoons of almost any species of spider, a large proportion are almost certain to be found to contain Ichneumon larvae. Mr. F. Smith, in the Transactions of the Entomological Society for 1860, describes two species, Hemeteles fasciatus and H. formosus, which are parasitic on the eggs of Agelena brunnea. They are figured in Mr. Blackwall’s book on British Spiders. Pezomachus gracilis attacks the cocoons of many kinds of American spiders, appearing to have no special preference for any particular species, while Acoloides saitidis seems to pay special attention to the eggs of certain of the Jumping-spiders, and particularly of Saitis pulex.

The Ichneumons which thus regard the Spider’s eggs as convenient food for their own larvae are probably very numerous. Nor are they themselves always free from parasites. Occasionally the larvae of minute Hymenopterous insects are found to be parasitic upon the eggs of an Ichneumon which have been laid in a Spider’s cocoon.

It sometimes happens that the development of the young spiders has so far advanced at the time of the Ichneumon’s intrusion that the latter’s intention is frustrated, and its offspring, instead of devouring, are themselves devoured. Again, some few of the eggs in an infested cocoon occasionally escape the general destruction and reach the adult condition, but there can be no doubt that Ichneumons are largely instrumental in keeping down the numbers of most species of spiders. The perils which attend the Spider after leaving the cocoon are no less formidable, and much more numerous. The whole newly-hatched brood may be destroyed by a heavy rain-storm. If there is not a sufficient supply of food suitable to their feeble digestive powers they perish of inanition, or eat one another. This cannibalistic propensity is a considerable factor in the mortality among young spiders, and the adult animals frequently prey upon one another.

Argyrodes piraticum, in California, invades the webs of larger spiders of the family Epeiridae, which it seizes and devours. A. trigonum, common in the eastern states of North America, has the same habit. Hentz found in Alabama a spider, which he named Mimetus interfector, of still more ferocious and piratical habits. Its special quarry is Theridion tepidariorum. Sometimes the Theridion overcomes the invader, and one case was observed in which a second Mimetus was devouring a Theridion beside the dead body of its predecessor, who had come off the worse in the combat.

The eggs of Theridion tepidariorum are also sometimes devoured by this spider, and a similar propensity has been observed in some English species, for Staveley states that it is common to see certain spiders of the genus Clubiona feeding upon the eggs which have been laid by their neighbours. The larvae of some Hymenopterous insects are parasitic upon Spiders themselves, and not upon their eggs. Blackwall found this to be the case with the larvae of Polysphincta carbonaria, an Ichneumon which selects spiders of the genera Epeira and Linyphia on which to deposit its eggs. The spider thus infested does not moult, and is soon destroyed by the parasite which it is unable to dislodge from its back. Menge, in his Preussische Spinnen, enumerates several cases of parasitism in which the larva, as soon as it has developed from the egg, enters the spider’s body, there to continue its growth. Spiders are also subject to the attack of a parasitic worm, Gordius (cf. vol. ii. p. 173).

Some of the most deadly foes of Spiders are the Solitary Wasps. There are many species of Pompilus (vol. vi. p. 101), which, having excavated holes in clay banks, store them with spiders or other creatures which they have paralysed by their sting. They then deposit an egg in the hole, and immediately seal up the orifice. This habit is found to characterise the solitary wasps of all parts of the world. Belt relates the capture of a large Australian spider by a wasp. While dragging its victim along, it was much annoyed by the persistent presence of two minute flies, which it repeatedly left its prey to attempt to drive away. When the burrow was reached and the spider dragged into it, the two flies took up a position on either side of the entrance, doubtless with the intention of descending and laying their own eggs as soon as the wasp went away in search of a new victim. Fabre gives an interesting account of one of the largest European Pompilidae, Calicurgus annulatus, which he observed dragging a “Tarentula” to a hole in a wall. Having with great difficulty introduced its burden into the cavity, the wasp deposited an egg, sealed up the orifice, and flew away. Fabre opened the cell and removed the spider, which, though completely paralysed, lived for seven weeks.

The same indefatigable observer describes the method adopted by the comparatively small Pompilus apicalis in attacking the formidable Wall-spider, Segestria perfida. The combatants are well matched, and the issue of the battle would be doubtful if the wasp did not have recourse to stratagem. Its whole energies are directed towards forcing the spider away from its web. At home, it is confident and dangerous; when once dislodged, it appears bewildered and demoralised. The wasp darts suddenly towards the spider and seizes it by a leg, with a rapid effort to jerk it forth, releasing its hold before the enemy has had time to retaliate. The spider, however, as well as being anchored by a thread from its spinnerets, is clinging to its web with its hind legs, and if the jerk is not sufficiently energetic, it hastily scrambles back and resumes its defensive position. Before renewing the attack the wasp gives the spider time to recover from the excitement of the first onset, seeking, meanwhile, the retreats of other victims. Returning, it succeeds, by a more skilful effort, in drawing the spider from its retreat and hurling it to the ground, where, terrified and helpless, it falls an easy prey. Should the insect bungle in its first attack and become entangled in the web, it would itself become the victim. Certain wasps thus appear to seek out particular species of spiders as food for their larvae. Others are less discriminate in their tastes. Again, some, as in the cases cited above, store their egg-nest with a single spider, while others collect many for the purpose.

The American “blue digger wasp” (Chlorion caeruleum) excavates its nest in the ground, and inserts a single large spider of any species. Another wasp, of the genus Elis, selects the Wolf-spiders, and especially Lycosa tigrina, for the use of its larvae, while Priocnemus pomilius shows a preference for the Crab-spiders, or Thomisidae.

One of the most remarkable instances is that of Pepsis formosa, which preys upon the gigantic spider Eurypelma hentzii, wrongly styled in America the “tarantula,” but really belonging to an entirely different family, the Aviculariidae.

Fabre’s most interesting researches have established the fact that the instinct of the wasp leads it to sting the spider in a particular spot, so as to pierce the nerve-ganglion in the thorax. The precision with which this is effected is absolutely necessary for the purpose of the insect. If stung elsewhere, the spider is either incompletely paralysed, or it is killed outright, and thus rendered useless as food for the future larvae of the wasp. On the one hand, therefore, the Tarantula has acquired the habit of striking the wasp in the only point where its blow is instantaneously fatal, while on the other the wasp, with a different object in view, has been led to select the precise spot where its sting will disable without immediately destroying the spider. The latter case is, if anything, the more extraordinary, as the insect can hardly have any recollection of its larval tastes, and yet it stores up for progeny, which it will never see, food which is entirely abhorrent to itself in its imago state.

Spiders taken from the egg-nests of wasps by M‘Cook survived, on the average, about a fortnight, during which period they remained entirely motionless, and would retain any attitude in which they were placed.

There are many animals which either habitually or occasionally feed upon spiders. They are the staple food of some hummingbirds, and many other birds appear to find in them a pleasing variation on their customary insect diet. These creatures, moreover, are destructive to spiders in another way, by stealing the material of their webs, and especially the more closely textured silk of their egg-cocoons, to aid in the construction of their nests. M‘Cook has observed this habit in the case of Vireo noveborocensis, and he states, on the authority of others, that the “Plover” and the “Wren” are addicted to it. The smaller species of monkeys are extremely fond of spiders, and devour large numbers of them. They are said, moreover, to take a mischievous delight in pulling them in pieces. Armadillos, ant-eaters, snakes, lizards, and indeed all animals of insectivorous habit, draw no distinction between Insecta and Arachnida, but feed upon both indiscriminately. The army ants, so destructive to insect life in tropical countries, include spiders among their victims. These formidable insects march along in vast hordes, swarming over and tearing in pieces any small animal which lies in their path. They climb over intervening obstacles, searching every cranny, and stripping them bare of animal life. Insects which attempt to save themselves by flight are preyed upon by the birds, which are always to be seen hovering above the advancing army. The spider’s only resource is to hang from its thread in mid-air beneath the branch over which the ants are swarming, for the spider line is impracticable to the ant. Belt has observed a spider escape the general destruction by this means.

=Protective Coloration.=—Examples are numerous in which the spider relies upon the inconspicuousness not of its nest, but of itself, to escape its natural foes. Its general hues and markings are either such as to render it not readily distinguishable among its ordinary surroundings, or the principle has been carried still further, and a special object has been “mimicked” with more or less fidelity.

This country is not rich in the more striking mimetic forms, but the observer cannot fail to notice a very general correspondence in hue between the spiders of various habits of life and their environment. Those which run on the ground are usually dull-coloured; tree-living species affect grey and green tints, and those which hunt their food amongst sand and stones are frequently so mottled with yellow, red, and grey, that they can scarcely be recognised except when in motion.

A few of our indigenous species may be mentioned as especially protected by their colour and conformation. Tibellus oblongus is a straw-coloured spider with an elongated body, which lives among dry grass and rushes. When alarmed it clings closely to a dry stem, remains motionless, and escapes observation by its peculiarity of colour and shape. Misumena vatia, another of the Thomisidae or Crab-spiders, approximates in colour to the flowers in which it is accustomed to lurk on the watch for prey. It is of a variable hue, generally yellow or pink, and some observers believe that they have seen it gently waving its anterior legs in a way which made them easily mistaken for the stamens of the flower stirred by the breeze. Its purpose appears to be to deceive, not its enemies, but its victims. It seems to be partial to the blooms of the great mullein (Verbascum thapsus), and Pickard-Cambridge has more than once seen it seize and overcome a bee which had visited the flower in search of honey. He has also observed it in the blossoms of rose and furze bushes.

An Epeirid (Tetragnatha extensa) resembles Tibellus in its method of concealing itself when alarmed. It also possesses an elongated abdomen, of a grey-green tint, which it closely applies to one of the twigs among which it has stretched its net, at the same time extending its four long anterior legs straight before it, and in this position it lies perdu, and is very easily overlooked. Another Orb-weaver, Epeira cucurbitina, is of an apple-green colour, which is admirably calculated to conceal it among the leaves which surround its snare.

Most of our English Attidae, or Jumping-spiders, imitate closely the prevailing tone of the surfaces on which they are accustomed to hunt. This will be recognised in the familiar striped Wall-spider, Salticus scenicus, and we may also mention the grey Attus pubescens, which affects stone walls, and the speckled Attus saltator, which is hardly distinguishable from the sand which it searches for food.

Examples may also be found among the Lycosidae or Wolf-spiders. Of the prettily variegated Lycosa picta, Pickard-Cambridge says: “Much variation exists in the extent of the different portions of the pattern and in their depth of colouring, these often taking their prevailing tint from the colour of the soil in which the spider is found. The best marked, richest coloured, and largest examples are found on sandy and gravelly heaths, where there is considerable depth and variety of colouring.... But on the uniformly tinted greyish-yellow sandhills between Poole and Christchurch I have found a dwarf, pale yellow-brown variety, with scarcely any dark markings on it at all, the legs being of a uniform hue, and wholly destitute of dark annuli.”

=Mimicry.=—In the island of Portland, a locality remarkable for the number of species peculiar to itself, there is found a spider, Micaria scintillans, very closely resembling a large blackish ant which frequents the same neighbourhood. Its movements, moreover, are exceedingly ant-like, as it hurries along in a zigzag course, frequently running up and down grass stems after the manner of those insects. It is a great lover of sunshine, and disappears as soon as the sun is obscured by a passing cloud.

Such resemblances, obvious enough in nature, and heightened by the behaviour of the mimetic form, are often by no means striking in the cabinet. In some American species of spiders, however, imitation of the ant has passed beyond the stage of a general resemblance as regards size and colour and method of progression. The head of the ant is well marked off from the body, and the thorax is frequently divided into distinct regions. These peculiarities are imitated by constrictions in the cephalothorax of mimetic spiders. The resemblance, moreover, is much increased by their habit of using but six legs for locomotion, and carrying the second pair as ants do their antennae. The best known examples of these spiders are Synageles picata and Synemosyna formica (see Fig. 215, C, p. 420), and even more striking resemblances have been observed among some undescribed South American species.

The object of such mimicry seems to vary in different cases. Sometimes the spider preys upon the ant which it resembles. Sometimes, again, by its disguise, it escapes the notice of the ant which would otherwise feed upon it. More often spider and ant are neutral as regards each other, but, under cover of its resemblance, the Arachnid is enabled to approach an unsuspecting victim to which the ant is not a terror. Again, the unpleasantly acid taste of ants is unpalatable to most birds, though not to all, and the increased danger from specially ant-eating birds may be more than counterbalanced by the immunity they acquire from other birds.

There is quite a large class of Spiders of nocturnal habits, whose only precaution by day is to sit perfectly still and be mistaken for something else. We have referred to the adaptation in colour of our English species, Misumena vatia, to the flowers in which it lies in wait for prey. Bates mentions exotic examples of the same family which mimic flower-buds in the axils of leaves. Herbert Smith says of a spider which sits upon a leaf waiting for prey: “The pink three-lobed body appears just like a withered flower that might have fallen from the tree above; to the flies, no doubt, the deception is increased by the strong sweet odour, like jasmine.”

Trimen describes a Cape Town species which is of the exact rose-red of the flower of the oleander. “To more effectually conceal it, the palpi, top of the cephalothorax, and four lateral stripes on the abdomen are white, according remarkably with the irregular white markings so frequent on the petals of Nerium.”

The same observer, approaching a bush of the yellow-flowered Senecio pubigera, noticed that two of the numerous butterflies settled upon it did not fly away with their companions. Each of these he found to be in the clutches of a spider, whose remarkable resemblance to the flower lay not only in its colour, but in the attitude it assumed. “Holding on to the flower-stalk by the two hinder pairs of legs, it extended the two long front pairs upward and laterally. In this position it was scarcely possible to believe that it was not a flower seen in profile, the rounded abdomen representing the central mass of florets, and the extended legs the ray florets; while, to complete the illusion, the femora of the front pair of legs, adpressed to the thorax, have each a longitudinal red stripe which represents the ferruginous stripe on the sepals of the flower.”

Cambridge found in Palestine some species of Thomisidae which, when at rest, were indistinguishable from bits of coarse fleecy wool, or the rough seeds of some plant.

There is perhaps no more curious case of mimicry than that of a spider, Phrynarachne (= Ornithoscatoides) decipiens, which Forbes discovered in Java while butterfly-hunting. It appears that butterflies of the Family Hesperidae have a custom of settling, for reasons best known to themselves, upon the excreta of birds, dropped upon a leaf. Forbes noticed one in this position. Creeping up, he seized the butterfly, but found it mysteriously glued by the feet. On further investigation the “excreta” proved to be a spider. So accurate was the mimicry that he was again completely deceived by the same species in Sumatra. Its habit is to weave upon a leaf a small white patch of web, of a shape which greatly assists the deception, and in the midst of this it lies on its back, holding on by the spines with which its legs are furnished. It then folds its legs over its thorax, and waits for some insect to settle upon it.

In rare cases spiders have come to resemble their enemies the Ichneumon flies. A frequent habit of these insects is to deposit their eggs in the newly-formed cocoon of the spider. The Ichneumon eggs are the first to hatch, and the larvae have a convenient food-supply at hand. Sometimes, however, they adopt another method, and insert their eggs into the body of the spider itself. It is probably in order to avoid this unpleasant contingency that the spider has evinced towards the Ichneumon the sincerest form of flattery.

=The Senses of Spiders.=

SIGHT.—Though, as has been shown, spiders are well provided with eyes, their power of vision, in most cases, is by no means remarkable. As might be expected, it is less developed in those of sedentary than in those of nomadic habit.

It is noticeable that, in most spiders, some of the eyes are of a pearly grey colour, and others of a much darker hue. Simon designates the former nocturnal and the latter diurnal eyes, according to the special use which he believes them to subserve.

This view of the matter cannot be regarded as at all established, and has not found general acceptation. Moreover, Pillai has shown that certain Attid spiders can change the colour of their eyes by a movement of the internal mechanism. The Epeiridae, spinners of the round web, are certainly, as a rule, very dim-sighted creatures. A fly may be held within an inch of them, but, unless it buzz, it will excite no notice whatever. A careful observation of the performances of the large Garden-spider in securing her prey will soon convince the onlooker that she is guided almost entirely by appeals to her sense of touch communicated along the tremulous lines of her snare. Interpreting these too hastily, she will sometimes rush straight past the entangled fly, and wait for it to renew its struggles before making sure of its whereabouts. Keen sight would be of little utility to such spiders, as they are concerned with nothing beyond the limits of their snare, and within its range they are furnished with the equivalent of complete telegraphic communication.

That most of the vagabond spiders can see well within the range of several inches there is no doubt, though some observers have been misled by the result of certain experiments on the Lycosidae, or “Wolf-spiders.” It will be remembered that the female Lycosid carries her egg-bag about with her, attached usually to her spinnerets. If it be removed and placed close at hand, the spider experiences the greatest difficulty in finding it again. Lubbock attributed this to defective sight, whereas it merely arises from unfamiliarity with the appearance of the egg-bag, which, since its construction, has been so situated as to be out of the view of the spider. Peckham found that spiders of the genus Theridion, accustomed to the sight of their cocoons, readily recognised them by that sense when removed to a distance.

The most keen-sighted of the spider tribe are undoubtedly the Attidae, or Leaping-spiders. The little black and white striped Wall-spider, Salticus scenicus, is probably a familiar object to most of our readers, and a very little observation of its movements, like those of a cat stalking a bird, will convince the observer that its visual powers are wonderfully keen and accurate. Its attitude of “attention” on sighting its prey, its stealthy manœuvring to approach it unobserved, and the unerring certainty of its final leap, are very interesting to witness.

It is somewhat noticeable that both in the Epeiridae and in the Attidae the two portions of the body, cephalothorax and abdomen, have more than the usual freedom of independent motion. In the Orb-weavers this gives play to the spinnerets in binding up a captured insect, but in the Leaping-spiders it allows of the rapid directing of the large anterior eyes towards the quarry, as it continually alters its position.

Professor and Mrs. Peckham of Wisconsin performed some interesting experiments to ascertain the sensitiveness of the spider’s eye to colour. Freely communicating compartments of differently coloured glass were constructed, and spiders were confined in them, when it was found that red was the most and blue the least attractive hue. This agrees well with what Lubbock found to be the case with ants, but those insects displayed a greater antipathy for blue and not so marked a preference for red.

HEARING.—Most of our knowledge about the auditory sense of spiders is due to experiments performed by C. V. Boys, and repeated by Professor and Mrs. Peckham.

The spider usually responds to the stimulus in one of two ways; it either raises its front legs, extending them in the direction of the sound, or it allows itself to drop suddenly, as though in alarm. It was only in the case of the Epeiridae that any results were obtained, and these spiders were more sensitive to low than to high notes. Now, as M‘Cook points out, it is exceedingly strange that the nomadic and hunting spiders, to which the sense of hearing might be expected to be extremely useful, should be deficient in this faculty, while the sedentary spiders, to which it would appear comparatively unimportant, should possess it in a tolerably developed form. That writer may possibly be correct in supposing that the sense, as possessed by spiders, is hardly differentiated from that of ordinary touch, and that the web-making species are only aware of sounds by the vibrations communicated to their feet by the medium of the web. However this may be, we must reluctantly but sternly reject the numerous and seemingly authentic stories, often connected with historic personages, which credit the spider with a cultivated taste for music.

We have seen that among the spiders which possess a stridulating apparatus it is confined, in certain groups, to the male, or if present in the female it exists only in a rudimentary form. If in these cases stridulation has been rightly interpreted as a sexual call, the power of hearing, at least in the female, is of course connoted. The spiders in question are members of the Theridiidae, a family closely allied to the Epeiridae, and therefore more likely than most groups to possess the power of hearing.

Theraphosid spiders show no response to the stimulus of sound, and among them stridulation is not confined to one sex. If, as is generally believed, the organ is used to warn off enemies, it is not necessary that the sound produced should be audible to the spider itself. If there be any true hearing organ in spiders its location is quite uncertain. Some have supposed the so-called lyriform organs in the legs to have an auditory function, while others have supposed the power of hearing to reside in certain hairs, of which there are several different types distributed over the body and limbs of the animal.

=Spider Intelligence.=—The experiments performed by the Peckhams clearly proved that spiders have short memories—a sure indication of a low state of intelligence. Members of the Lycosid or “Wolf-spider” group, when deprived of their cocoons, recognised them again after a few hours, but in most instances they refused to resume them after a lapse of twenty-four hours, and in every case an absence of two days sufficed to prevent any sign of recognition on their restoration. Moreover, when, after a shorter interval, the cocoons of other spiders, even of different genera, were offered to them, they appeared equally satisfied, and attached them in the orthodox manner, beneath the abdomen. The same treatment was even accorded to pith balls, which, if of the right size, seemed to be a perfectly satisfactory substitute. The contents of one cocoon were replaced by a shot three or four times their weight, but the spider accepted it with alacrity, spending half an hour in refixing it, when its weight caused it to fall from its attachment.

The habit of “feigning death,” which seems to be especially characteristic of the Epeiridae or orb-weaving spiders, probably arises from no desire to deceive its adversary as to its condition, but from an instinct to remain motionless, and therefore inconspicuous. Where a nomadic spider seeks safety in flight, a sedentary species finds a greater chance of escape in dropping a certain distance, and, while still attached by its silken line, giving as little evidence of its whereabouts as possible—trusting, in many cases, to its protective colouring. This method, moreover, has the advantage of facilitating its return to the web when the danger is past—a feat of which it would be quite incapable were it once to relinquish its clue.

All the remarkable and apparently intelligent actions of these creatures seem to be done in obedience to a blind instinct, which is obeyed even when there is no longer any object to be served. We have seen how the Trap-door spiders decorate the lids of their nests with moss even when the surrounding ground is bare, and Agelena labyrinthica has been observed to go through the whole lengthy and laborious operation of constructing its egg-cocoon though all its eggs were removed immediately on being laid.

=Mating Habits.=—The sex of a mature spider can readily be recognised by the palpus which, as we have seen, is furnished in the male with a “palpal organ.” After the last moult but one the palp appears tumid, but it is only at the last moult that the organ is fully formed, and that the genital orifice is visible under the anterior part of the abdomen.

No alteration takes place in the female palp at maturity, but it is only after the last moult that the “epigyne” is distinguishable.

FIG. 198.—Argiope aurelia, ♂ and ♀, natural size. ]

That the palpal organs are used in the fertilisation of the female has long been established. How they came to contain the sperm matured in the abdomen was a problem which has only been solved comparatively recently. No direct connection could be found by way of the palpus with the abdominal organs, which, indeed, were seen to have an orifice between the lung-sacs. It is now known that some spiders at all events spin a slight web upon which they deposit a drop of spermatic fluid, which they afterwards absorb into their palpal organs for transference to the female. Secondary sexual differences are often very marked, the male being almost invariably the smaller in body, though its legs are frequently longer and more powerful than those of the female.

Among some of the sedentary spiders the disparity in size is excessive. The most striking examples are furnished by the Epeirid genera Argiope and Nephila, the male in some instances not attaining more than the thousandth part of the mass of the female. The coloration of the sexes is frequently quite dissimilar, the male being usually the darker, though in the Attidae he is in many cases the more strikingly ornamented.

In the minute Theridiid spiders of the group Erigoninae (see p. 404), the male cephalothorax often presents remarkable and characteristic excrescences not observable in the female. Some curious examples of this phenomenon may be seen in Fig. 209.

To the ordinary observer male spiders will appear to be comparatively rare, and to be greatly outnumbered by the females. This is probably to some degree true, but the unsettled habits of the males and the shorter duration of their life are calculated to give an exaggerated impression of their rarity. They only appear in considerable numbers at the mating season, shortly after which the males, in the case of many species, may be sought for in vain, as, after performing their functions, they quickly die. The snares they spin are often rudimentary, their capabilities in this direction appearing to deteriorate after the adult form is attained. Young spiders of indistinguishable sex make perfect snares on a small scale, while such as eventually develop male organs will often thereafter be content with a few straggling lines made with very slight regard to symmetry. They become nomadic in their habits, wandering off in search of the females, and pitching a hasty tent by the way.

The relations between the sexes in the Spider tribe present points of extreme interest, but in this connexion the various groups must be separately treated on account of their very different habits of life.

In no group are these relations more curious than in the Epeiridae, the constructors of the familiar wheel-like web. Love-making is no trifling matter here. If the female is not in the mood for the advances of the male she will probably regard him as a desirable addition to her larder. Even if his wooing is accepted, he has to beat a precipitate retreat after effecting his purpose, or he may fall a victim to his partner’s hunger.

This strange peril braved by the male in courting the female, which has, as far as is known, no parallel in any other department of the animal kingdom, is frequently mentioned as universal among spiders. It unquestionably exists, and may be verified by any patient observer in the case of the large Garden-spider Epeira diademata, but it has only been observed among certain species of the Epeiridae and Attidae. It will be remembered that in the Epeiridae the males are sometimes absurdly small in comparison with the females, and this diminution of size is thought to have a direct connection with the danger undergone at the mating season. Small active males stand a better chance of escape from ferocious females, so that natural selection has acted in the direction of reducing their size as far as is compatible with the performance of their functions.

Pickard-Cambridge cites an extreme case. He says: “The female of Nephila chrysogaster, Walck. (an almost universally distributed tropical Epeirid), measures 2 inches in the length of its body, while that of the male scarcely exceeds ⅒th of an inch, and is less than ¹⁄₁₃₀₀th part of her weight.”

During the mating season the males may be looked for on the borders of the snares of the females. Their action is hesitating and irresolute, as it well may be, and for hours they will linger on the confines of the web, feeling it cautiously with their legs, and apparently trying to ascertain the nature of the welcome likely to be extended to them. If accepted, they accomplish their purpose by applying their palps alternately to the epigyne of their mate. If repulsed, they do their best to make their escape, and wait for a more auspicious moment. Emerton says: “In these encounters the males are often injured; they frequently lose some of their legs; and I have seen one, that had only four out of his eight left, still standing up to his work.”

Among the other groups of sedentary spiders the relations between the sexes seem to be more pacific, and there is even some approach to domesticity. Males and females of Linyphia may be found during the mating season living happily together in their irregular snares. The same harmony seems to exist among the Tube-weavers, and Agelena labyrinthica lingers for days unmolested about the web of the female, though it is perhaps hardly correct to say that they have their home in common.

Among the wandering spiders the male usually seeks out the female and leaps on her back, from which position his sperm-laden palps can reach their destination. This is the habit of the Thomisidae or Crab-spiders, and of the quick-running Wolf-spiders, or Lycosidae.

FIG. 199.—Male Astia vittata dancing before the female. (After Peckham.) ]

The sexual relations of the Leaping-spiders, or Attidae, are so remarkable as to deserve a longer notice. This Family includes the most beautiful and highly ornamented examples of spider life. Their headquarters are the tropics, and their brilliant colouring led Wallace to speak of those he saw in the Malay Archipelago as “perfect gems of beauty.”

Now among these spiders the male is almost always more highly decorated than the female, and Peckham’s observations would lead to the conclusion that the female is influenced by the display of these decorations in the selection of her mate.

The so-called “love-dances” of certain tropical birds are known to all readers of natural history, but it was hardly to be expected that their counterpart would exist among spiders. Yet the antics by which male Attidae endeavour to attract the attention of the females afford an almost exact parallel.

The following extract from the account of Professor and Mrs. Peckham of their observations on Saitis pulex will make this abundantly clear: “When some four inches from her he stood still, and then began the most remarkable performances that an amorous male could offer to an admiring female. She eyed him eagerly, changing her position from time to time, so that he might be always in view. He, raising his whole body on one side by straightening out the legs, and lowering it on the other by folding the first two pairs of legs up and under, leaned so far over as to be in danger of losing his balance, which he only maintained by sidling rapidly towards the lowered side.... Again and again he circles from side to side, she gazing towards him in a softer mood, evidently admiring the grace of his antics. This is repeated until we have counted a hundred and eleven circles made by the ardent little male. Now he approaches nearer and nearer, and when almost within reach whirls madly around and around her, she joining with him in a giddy maze. Again he falls back and resumes his semicircular motions, with his body tilted over; she, all excitement, lowers her head and raises her body so that it is almost vertical; both draw nearer; she moves slowly under him, he crawling over her head, and the mating is accomplished.”

FIG. 200.—Dancing attitude of male Icius mitratus. (After Peckham.) ]

A similar but not exactly identical performance was gone through by the male of several different species, but it was noteworthy that the particular attitudes he adopted were always such as to display to the best advantage his special beauties, whether they consisted in crested head, fringed palpi and fore-legs, or iridescent abdomen. Sometimes even such exertions failed to captivate the female, and she would savagely attack the male, occasionally with fatal effect.

In the case of some species, when the male had won the consent of his mate, he would weave a small nuptial tent or web, into which he would partly lead and partly drive the female, who no longer offered serious resistance.

=Fossil Spiders.=

About 250 species of fossil spiders have been discovered. Of these about 180 are embedded in amber, a fossil resinous substance which exuded from ancient coniferous trees, and quantities of which are annually washed up from the Baltic upon the shores of northern Prussia.

The most ancient fossil spider known was obtained from the argillaceous slate of Kattowitz in Silesia, and belongs, therefore, to the Carboniferous strata of the Palaeozoic epoch. It has been named Protolycosa anthrocophila. There is some doubt as to the affinities of this spider. Roemer, who described it, placed it among the Citigradae, while others have thought it to belong rather to the Territelariae. Thorell, on account of its agreement in certain important points with the very curious recent Malay spider Liphistius, has placed them both in a separate sub-family, Liphistioidae. To the same epoch belongs the American fossil spider Arthrolycosa antiqua, which was found in the Coal measures of Illinois.

The other localities from which fossil spiders have been obtained are the Swiss Miocene at Oeningen, the Oligocene deposits at Aix, the Oligocene of Florissant, Colorado, Green River, Wyoming, and Quesnel, British Columbia.

Many of the spiders from the rocks are so fragmentary that it is impossible to decide with certainty on their systematic position, but a considerable number of them—more than half—have been assigned to recent genera.

The amber spiders are mostly well preserved, and can be classified with more certainty. Many of them are surprisingly like existing forms, though others, like Archaea paradoxa, differ greatly from most spiders now extant, though they show some affinities with one or two remarkable and aberrant forms.