SUPPLEMENT TO TRAP-DOOR SPIDERS. (continued 2)

I have, unfortunately, but few details to give of the nocturnal habits of the trap-door spiders. It would appear, however, that they are more active by night than by day, and that it is more common to find their doors ajar at night, with the spiders posted on the look-out at the narrow opening. This is borne out by my observations on captive spiders, to which I shall allude shortly.

When at Hyères on the 11th of May, 1873, the evening being very warm and a bright moon shining, I went at 8:30 P.M. with my father and sister to see what the spiders would be doing on a hedge bank where we had previously marked five cork and eight wafer nests. The moonlight did not fall upon this spot, but I was provided with a lantern, and by its light the nests at first appeared to be tightly closed, but we soon perceived first one and then another with the door slightly raised, ready to close on the smallest alarm, whether from a footfall or from the flickering of the lamp. When the light of the lantern was steady it did not appear to frighten the spiders in the least, even when brought to within a few inches of the door,148 and this enabled me to watch them very closely. On either side of the raised door of one of the wafer nests I could see the feet of the spider projecting, and just at that moment I caught sight of a beetle close at hand, feeding on the topmost spray of some small plant below. Using every precaution, I contrived to gather the spray without shaking off the beetle, and gradually pushed it nearer and nearer to the nest. When it almost touched the lip of the nest the door flew open, and the spider snatched at the beetle and dragged it down below.

For a few seconds the door remained tightly closed, and then, to our great surprise, was suddenly opened again, and the beetle was cast alive and unharmed out of the nest. I immediately secured the insect, which proved to be the common Chrysomela Banksii.149

I cannot doubt that this beetle was distasteful in some way to the spider, for it was neither so large nor so powerful as many beetles the remains of which I have found in the spiders' nests, and, besides, it did not escape from the nest, but was distinctly rejected by its captor.

This shows that this spider does not know instinctively what insects to reject and what to take.

This little episode was scarcely ended when I espied a wood-louse (Oniscus) walking down the bank, not far from another of these wafer nests. By a little guidance I managed so to turn its course that this unsuspicious crustacean went straight to the very point I wished, and made as if it would walk over the spider's door; but no sooner was it well within reach than, quick as thought, the spider clutched it and dragged it in. No rejection followed on this capture, and, though I could not actually witness the conclusion of this adventure, I do not doubt that it ended in a tragedy and a supper.

In these two cases, as in all those previously noted, the spiders did not leave the nest nor allow the door to close behind them, but kept it propped up on the abdomen and hindmost pair of legs. In this way the act of seizing their prey, and that of withdrawing into the nest, were almost simultaneous.

In no case did we see any of these spiders out of their nests, and their behaviour by night appeared to be the same as by day, only that they were bolder and more on the alert.

The spiders in the cork nests (N. Moggridgii) resisted our attempts to raise their doors just as rigorously as in the daytime.

All the spiders which I have kept in captivity have shown themselves more active at night than during the day, and I imagine that experience has taught them that fewer of their enemies are then abroad, while ants, beetles, wood-lice, and other creatures upon which they prey are quite as nocturnal as themselves.

I brought back to England some young cork and wafer spiders from Hyères, and one adult cork (N. Moggridgii). The latter was placed in a small tin box, with moss and a little earth at the bottom, on the evening of May the 10th, 1873, and by next morning she had made a silk tube through the moss, carrying up earth from below for the purpose of strengthening its walls on the outside. On the 13th of May the tube was furnished with a perfect door.

I hoped that this spider might lay eggs in her prison,150 and therefore broke up her nest from time to time after my return to London in order to search for them. Between the 27th of May (when her nest had been transferred into a box of earth) and the 6th of October I destroyed her dwelling four times, and after each demolition she furnished the cylindrical hole which I bored for her with a lid, having thus made five doors since her capture. I got no eggs however, though the spider appeared in perfect health.

Neither this spider nor the true N. cæmentaria of Montpellier appears to have any idea of digging a hole when placed on soft earth if they are adult; and the same thing is true of N. Manderstjernæ and N. Eleanora, but the young of all these spiders readily excavate nests for themselves.

I have once seen a nearly full grown, and probably adult, Cteniza Moggridgii make a perfect tube and furnish it with a moveable door in a single night when confined under gauze on moist earth, but this is the only instance (except that of Cteniza Californica, recorded above) in which I have known an adult trap-door spider excavate or attempt to do so.

These Ctenizas seem to be peculiarly able to adapt themselves to circumstances, for two young ones, which I sent by post to M. Lucas at the Jardin des Plantes in Paris in little wide-mouthed, cylindrical, blue glass bottles, not only lined the bottles with silk but also closed them at the mouth with a door fitting accurately into a bevelled lip, in the manufacture of both of which fragments of moss, the only material at their disposal, were used in place of earth.151 It is curious to see how quickly the young trap-door spiders, both of the cork and wafer kinds, when taken from the nest of the mother, will make their own perfect little dwellings in captivity, and I have known them construct tube and door within fifteen hours.

I have watched the proceedings of the young spiders, when taken from the mother's nest, in the following species: Nemesia Manderstjernæ, N. Eleanora, N. congener, and N. Moggridgii, the three first constructing wafer, and the last a cork nest. All of these very young spiders will excavate their own tubes and bring out pellets of the earth, which closely resemble those carried out from their galleries by the ants.

As has been stated before, the young brood, while still in the mother's nest, will often comprise individuals of different sizes, and though the majority are no larger than the baby-spider represented at Fig. B 2, Pl. IX, Ants and Spiders, some may occasionally be found that are fully twice as large.

The little nests which they make in captivity vary accordingly in size. Thus, out of sixteen young taken from the mother's nest (N. Eleanora), eleven, three days after capture, had made nests in the earth of a flower-pot, and the wafer doors of six of these nests measured 2 lines across, of four 2¹/₂ lines, and of one 3 lines. The first nests of another similar lot of young Eleanora spiders had wafer doors measuring respectively 2, 2¹/₂, 2¹/₂, 3 and 3 lines. In another case when I captured fourteen young (the entire brood found in the nest of the mother, N. Manderstjernæ), after the lapse of five days every one of them had made a nest, but these were smaller and more uniform, ten of the wafer doors measuring 2 lines across, one 1¹/₂, and one 2¹/₂.

These little spiders need to be kept constantly supplied with flies, which should be killed and placed near their nests; they are often so greedy that they will attempt to drag a house-fly entire down their tubes for which it is much too large, when the door is pushed open, and the fly remains sticking in the entrance to the nest with its legs up in the air. One may even feed these spiders oneself by approaching carefully and, without causing any vibration, pushing the fly, placed on the end of a pencil, within reach of the spider.

I have given my reasons before (Ants and Spiders, p. 127) for believing that the trap-door spiders do not as a rule desert their nests, but enlarge them from time to time to meet their own requirements of growth; showing, by a comparison of the measurements of the doors of eight nests in April with those of the same nests in the following October, that all had increased in size.

Subsequent observations have confirmed this; I find that the young spiders taken from the mother's nest enlarge their nests in captivity in a precisely similar way.

Thus, for example, the wafer doors of three young Eleanora spiders, made within a few days after their removal from the mother's nest on February 20th, 1873, and first measured on February 28th, had increased between that date and Nov. 29th following from 2 to 4 lines, 2¹/₂ to 4 lines, and 2¹/₂ to 6 lines respectively.

It is unfortunate that the male and female spiders are undistinguishable when very young, as it would be interesting to know whether the males construct nests before they take to their adult life, during which they roam from place to place and hide under stones.

In one case fourteen young spiders, forming this entire family taken with a female N. Manderstjernæ, made nests; so that unless all of these were females, we have evidence here to prove that the males do commence life by building nests for themselves.

I kept the male Cteniza Moggridgii, for ten days on damp earth in captivity, but he made no attempt to excavate or spin, and wandered restlessly about, scarcely touching the flies152 with which I supplied him.

Seeing this I could not venture to prolong his captivity, as I feared to risk injuring a specimen which was quite unique and which there was little likelihood of my being able to replace. It is rather curious that M. Simon should also have found one male, and one only, of the closely-related Ct. fodiens of Corsica, and that his specimen should be, like mine, the only one known.

Bearing in mind the curious problems which arise as to the affinities of the flora and fauna of the Alpes Maritimes with that of Corsica, the fact that the species of Cteniza which is found at Mentone, though allied to, is yet distinct from the insular species, gains a new interest.

We ask ourselves whether the Corsican species sprang from that of the Alpes Maritimes, or vice versâ; or again, whether both diverged in remote times from a common ancestor. Questions such as these cannot be answered at present, but I hope the day may come when the geographical distribution of the various existing forms of life will be traced with sufficient accuracy to enable us to follow on the map the lines along which affinity travels; and thus point out at once the probable relationship between two given forms, and also the route by which they reached their present stations. Records of local varieties, and the careful discrimination between forms which have small but permanent points of difference, thus acquire an importance which they would not otherwise possess.

The geographical distribution of trap-door spiders is of peculiar interest on account of the sedentary habits maintained during life by the females. Most animals are capable of travelling long distances, or of being accidentally transported from place to place in such a way that colonies are frequently established far away from the parent settlement, and we are left in the dark as to whence they came and who are their nearest relations. But, in the case of spiders inhabiting true trap-door nests, this is not so; they begin life immediately on leaving the parent nest by making homes for themselves near at hand which they will not desert, and there is no likelihood of their being accidentally carried from place to place unless occasionally by running water. Thus it happens that whenever we find the same trap-door spider at two distant localities, we may feel tolerably sure that the species has travelled from one to the other by gradual extension, and that, either now or in times past, it occupied all the intervening country.

For instance, we find Nemesia Eleanora at Mentone, and again at Cannes, while it has not yet been detected at Nice, Antibes, nor any other intermediate point; but according to this hypothesis, this species either does actually live, or has done so formerly, along the whole intervening line. I will now enumerate the species alluded to in the preceding pages and indicate briefly the habitats which they are known with certainty to occupy.

I. Atypus piceus, Sulzer (ex Simon). The builder of the tubular nest the silk lining of which is figured at A in Pl. XIII It is stated by M. Simon153 to be common in all the centre, east, and west of France, but it remains doubtful whether this exact form is found in England or not, the true characters and habits of the English species being still uncertain.

II. Cyrtauchenius elongatus, Simon, constructing the funnel type of nest. It inhabits the neighbourhood of Fez in Morocco.

III. Cteniza Moggridgii, Cambridge (formerly described under the name of Ct. fodiens154), one of the many builders of a nest of the cork type; I have hitherto found this spider only at Mentone and San Remo. It will probably be discovered in shady valleys in the neighbourhood of Nice.

IV. Ct. fodiens, Camb. (Ct. Sauvagii, Rossi ex Simon): large nest of cork type; inhabits Corsica. It has been said that the species found near Pisa (Ct. Sauvagii) is the same as that which is so common in Corsica, but it is desirable to have further confirmation of this.

V. Ct. Californica, Camb.—Large nest of cork type. Found near Visalia, about 350 miles south of San Francisco, by Mr. G. Treadwell.

VI. Nemesia cæmentaria, Latr.—Nest of cork type. Only known with certainty to inhabit the neighbourhood of Montpellier.

VII. N. Moggridgii, Camb. (formerly described under the name of N. cæmentaria, Latr.155)—Nest of cork type; is found at San Remo, Mentone, Cannes, Hyères, and Marseilles. Its range probably extends some distance to the eastwards, but I doubt whether it does so towards the west, for there I think it likely that it will be found to be replaced by the typical cæmentaria.

VIII. N. Simoni, Camb.—Nest of the single-door unbranched wafer type, discovered at Bordeaux in May, 1874.

IX. N. suffusa, Camb.—Nest of single-door branched wafer type, discovered at Montpellier in May, 1873.

X. N. Eleanora, Camb.—Nest of double-door unbranched wafer type; is found at San Remo, Mentone, Cannes, Vaucluse near Avignon. M. Simon says156 he has also found it at Digne, in the Basses Alpes.

XI. N. congener, Camb.—Nest of double-door branched wafer type; discovered at Hyères in May, 1873.

XII. N. Manderstjernæ, Koch, in Ausserer (formerly described under the name of N. meridionalis, Costa).157—Nest of double-door, branched, cavity wafer type; is found at San Remo, Bordighera, Mentone, Nice, Cannes, and Hyères (apparently very rare at the last-named place).

XIII. N. meridionalis, Costa.—Structure of nest doubtful (see description in Ants and Spiders, p. 138). Found near Naples and in Ischia. M. Simon has discovered a spider in Corsica which he considers the same as that described by M. Costa under the name of meridionalis, but it seems desirable, in order thoroughly to establish this conclusion, that specimens of the spiders and their nests from these distant habitats should be compared together.

We can scarcely suppose that the real geographical distribution of the above-named twelve species is as restricted as it would appear to be from the above enumeration, and there is little doubt, I think, that many more habitats will be added in time. Indeed, our knowledge of the habits and distribution of these spiders can only as yet be said to be in its infancy, the whole subject being, for the most part, new and untrodden ground.

But, it may be asked, what are the chances in the future for the discovery of undescribed spiders and types of nests: and what reward of this kind may the travelling naturalist expect in order to compensate him for the time and pains which such a search demands, and which must divert him in a great measure from making other collections?

The reply is not doubtful.

Europe alone, most probably, contains many trap-door spiders the specific characters and habits of which are at present unknown; and as for the warmer regions of other parts of the globe, we only know enough to lead us to surmise that still stranger and more startling discoveries await us there.

Dr. L. Koch's description of the very remarkable branched-wafer nest from Australia, alluded to above (p. 217), and the fragmentary specimens of giant cork-nests from the same country exhibited at the British Museum, give us a hint of what the Antipodes will some day reveal to us; while a stray allusion to a trap-door nest found near Lake Dilolo, in Southern Africa, by Livingstone,158 affords an indication of their existence in another quarter of the globe. Hitherto but little importance has been attached by naturalists to the study of the nests of trap-door spiders, but a knowledge of their structure is often of the greatest assistance, and will, I venture to predict, be found to afford a clue leading to the discovery of many new species; for it not unfrequently happens that, while two spiders appear so much alike as to pass for representatives of the same species, their nests are totally dissimilar and proclaim them, as in fact they are, quite distinct from one another. For an example of this we have only to turn to the seven species of Nemesia, treated of in the foregoing pages, of which six construct dissimilar nests, and only two, building nests of the cork type, make them alike, though the general resemblance between the spiders themselves is extraordinarily close. Thus far, indeed, it will be seen that no two distinct species of European trap-door spider make wafer nests of the same type, each kind of wafer nest having its own peculiar spider.

This strikes me as a very curious fact, and I await with interest the discovery of new species of wafer-building spiders in order to learn whether this will continue to hold good or not.

That such discoveries will be made I entertain no doubt; indeed, I have reason to believe that, even at Mentone, where perhaps more pairs of eyes have been at work searching for trap-door spiders than anywhere else, new species still remain to be detected. In April, 1873, the surface door of a wafer-nest together with a very small portion of the tube was brought to me from the summit of the Aiguille mountain, near Mentone. I was greatly surprised to learn that a trap-door spider could live in such a situation, for the earth on that plateau, which has an elevation of 4032 feet above the sea, is always frozen hard for weeks and even months together during the winter, and snow frequently lingers there. The spider, therefore, which endures these conditions is scarcely likely to be of the same species as any one of those inhabiting the lower country. The trap-door spiders of these spurs of the Maritime Alps, are probably of distinct species from those of the plains, but they are absolutely unknown at present.

Then the males of several species, as, for example, those of Nemesia Simoni, N. suffusa, N. congener, and N. Moggridgii, have yet to be discovered; while of the habits of the males in general we know little or nothing.

Indeed, there is no one species with the habits of which we can say we are thoroughly acquainted, and we must admit that up to the present time these ingenious little architects have been at least as successful in concealing themselves from the intrusion of naturalists as from the attacks of their proper enemies.

Surely these trap-door spiders, which have lain quiet in the earth century after century, have hidden themselves long enough from our inquisitive admiration, and the time has now come for us to seek them out and learn their ways.