Chapter VI: Spiders and Scorpions

_Emotions._

THE emotional life of spiders, so far as we can observe it as expressed in their actions, seems to be divided between sexual passion (including maternal affection) and the sterner feelings incidental to their fiercely predatory habits. But the emotions, although apparently few and simple in character, are exceedingly strong in force. In many species the male spider in conducting his courtship has to incur an amount of personal danger at the hands (and jaws) of his terrific spouse, which might well daunt the courage of a Leander. Ridiculously small and weak in build, the males of these species can only conduct the rites of marriage with their enormous and voracious brides by a process of active manoeuvring, which if unsuccessful is certain to cost them their lives. Yet their sexual emotions are so strong that, as proved by the continuance of the species, no amount of personal risk is sufficient to deter them from giving these emotions full play. There is no other case in the animal kingdom where courtship is attended with any approach to the gravity of danger that is here observable. Among many animals the males have to meet a certain amount of inconvenience from the coquetry or disinclination of the females; but here the coquetry and disinclination has passed into the hungry determination of a ferocious giantess. The case, therefore, because unique, is of interest from an evolutionary point of view. We can see a direct advantage to species from the danger incurred by males on account of mutual jealousy; for this, giving rise to what Mr. Darwin has called 'the law of battle,' must obviously be a constant source of the creation and the maintenance of specific proficiency; the law of battle determines that only the strongest and most courageous males shall breed. But the benefit to species is not so obvious where the danger of courtship arises from the side of the female. Still, that there must be some benefit is obvious, seeing that the whole structure of the male, if we take that of the female as the original type, has been greatly modified with reference to this danger: had the latter been wholly useless, either it would not have been allowed to arise, or the species must have become extinct. The only suggestion I can make to meet this aberrant case is that the courage and determination required of the male, besides being no doubt of use to him in other relations in life, may be of benefit to the species by instilling these qualities into the psychology both of his male and female descendants.

The courage and rapacity of spiders as a class are too well and generally known to require special illustration. One instance, however, may be quoted to show the strength of their maternal emotions. Bonnet threw a spider with her bag of eggs into the pit of an ant-lion. The latter seized the eggs and tore them away from the spider; but although Bonnet forced her out of the pit, she returned, and chose to be dragged in and buried alive rather than leave her charge.

The only other point that occurs to me with reference to the emotions of spiders is the somewhat remarkable one concerning their apparent fondness of music. The testimony is so varied and abundant on this matter that we can scarcely doubt the truth of the facts. These simply are that spiders--or at any rate some species or individuals--approach a sounding musical instrument, 'especially when the music is tender and not too loud.' They usually approach as near as possible, often letting themselves down from the ceiling of the room by a line of web, and remain suspended above the instrument. Should the music become loud, they often again retreat. Professor C. Reclain, during a concert at Leipsic, saw a spider descend in this way from one of the chandeliers while a violin solo was being played; but as soon as the orchestra began to sound it quickly ran back again.[75] Similar observations have been published by Rabigot, Simonius, von Hartmann, and others.

A highly probable explanation of these facts has recently been given by Mr. C. V. Boys, which relieves us of the necessity of imputing to animals so low in the scale any rudiment of æsthetic emotion as aroused by musical tones. As the observation is an interesting one, I shall quote it _in extenso_:--

Having made some observations on the garden spider
which are I believe new, I send a short account of
them, in the hope that they may be of interest to the
readers of _Nature_.

Last autumn, while watching some spiders spinning
their beautiful geometrical webs, it occurred to me to
try what effect a tuning-fork would have upon them. On
sounding an A fork, and lightly touching with it any
leaf or other support of the web, or any portion of
the web itself, I found that the spider, if at the
centre of the web, rapidly slues round so as to face
the direction of the fork, feeling with its fore-feet
along which radial thread the vibration travels.
Having become satisfied on this point, it next darts
along that thread till it reaches either the fork
itself or a junction of two or more threads, the right
one of which it instantly determines as before. If the
fork is not removed when the spider has arrived it
seems to have the same charm as any fly; for the
spider seizes it, embraces it, and runs about on the
legs of the fork as often as it is made to sound,
never seeming to learn by experience that other things
may buzz besides its natural food.

If the spider is not at the centre of the web at the
time that the fork is applied, it cannot tell which
way to go until it has been to the centre to ascertain
which radial thread is vibrating, unless of course it
should happen to be on that particular thread, or on a
stretched supporting thread in contact with the fork.

If, when a spider has been enticed to the edge of the
web the fork is withdrawn, and then gradually brought
near, the spider is aware of its presence and of its
direction, and reaches out as far as possible in the
direction of the fork; but if a sounding fork is
gradually brought near a spider that has not been
disturbed, but which is waiting as usual in the middle
of the web, then, instead of reaching out towards the
fork, the spider instantly drops--at the end of a
thread, of course. If under these conditions the fork
is made to touch any part of the web, the spider is
aware of the fact, and climbs the thread and reaches
the fork with marvellous rapidity. The spider never
leaves the centre of the web without a thread along
which to travel back. If after enticing a spider out
we cut this thread with a pair of scissors, the spider
seems to be unable to get back without doing
considerable damage to the web, generally gumming
together the sticky parallel threads in groups of
three and four.

By means of a tuning-fork a spider may be made to eat
what it would otherwise avoid. I took a fly that had
been drowned in paraffin and put it into a spider's
web, and then attracted the spider by touching the fly
with a fork. When the spider had come to the
conclusion that it was not suitable food, and was
leaving it, I touched the fly again. This had the same
effect as before, and as often as the spider began to
leave the fly I again touched it, and by this means
compelled the spider to eat a large portion of the
fly.

The few house-spiders that I have found do not seem to
appreciate the tuning-fork, but retreat into their
hiding-places as when frightened; yet the supposed
fondness of spiders for music must surely have some
connection with these observations; and when they come
out to listen, is it not that they cannot tell which
way to proceed?

The few observations that I have made are necessarily
imperfect, but I send them, as they afford a method
which might lead a naturalist to notice habits
otherwise difficult to observe, and so to arrive at
conclusions which I in my ignorance of natural history
must leave to others.[76]

_General Habits._

Coming now to general habits, our attention is claimed by the only general habit that is of interest--namely, that of web-building. The instinct of constructing nets for the capture of prey occurs in no other class of animals, while in spiders it not only attains to an extraordinary degree of perfection (so that, in the opinion of some geometers, the instinct is not less wonderful in this respect than is that displayed by the hive-bee in the construction of its cells), but also ramifies into a number of diverse directions. Thus we have, in different species, wide open networks spread between the branches of bushes, &c., closely woven textures in the corners of buildings, earth tubes lined with silk, the strong muslin-like snare of the Mygale, which, as first noticed by Madame Merian,[77] and since confirmed by Bates,[78] is able to retain a struggling humming-bird while this most beautiful animal in creation is being devoured by the most repulsive; and many other varieties might be mentioned. It may at first sight appear somewhat remarkable that this instinct of spreading snares should on the one hand occur only in one class of the animal kingdom, while on the other hand, in the class where it does occur, it should attain such extreme perfection, and run into so much variety. But we must here remember that the development of the instinct obviously depends upon the presence of a web-secreting apparatus, which is a comparatively rare anatomical feature. In caterpillars, which are not predaceous, the web is used only for the purposes of protection and locomotion; and it is easy to see that the spreading of snares would here be of no use to the animals. But in spiders, of course, the case is otherwise. Once granting the power of forming a web, and it is evident that there is much potential service to which this power may be put with reference to the voracious habits of the animal; and therefore it is not to be wondered that both the anatomical structures and their correlated instincts should attain to extreme perfection in sundry lines of development. The origin of the web-building structure was probably due to the use of the web for purposes of locomotion or of cocoon-spinning, as we see it still so used in the same way that it is used by caterpillars for descending from heights, and in the case of the gossamer spider for travelling immense distances through the air. As the anatomical structures in question differ very greatly in the case of spiders and in that of caterpillars, we may wonder why analogous if not homologous structures should never have been developed in the case of any other animal having predaceous habits--especially, perhaps, in that of the imago form of predaceous insects. It is easy to see how, if there were any original tendency to secrete a viscid substance in the neighbourhood of the anus, this might be utilised in descending from low elevations (as certain kinds of slugs use their viscid slime as threads whereby to let themselves down from low branches to the ground); and so we can understand how natural selection might thus have the material supplied out of which to develop such highly specialised organs as the spinnerets of a spider. But if we are inclined to wonder why this should not have happened among other animals, we must remember that any expectation that it should rests on negative grounds; we have no reason to suppose that in any other case the initial tendency to secrete a viscid substance was present. One inference, however, in the case of spiders seems perfectly valid. As this comparatively rare faculty of web-spinning occurs so generally throughout the class, it must have had its earliest origin very far back in the history of that class, though probably not so far back as to include the common progenitors of the spiders and the scorpions, seeing that the latter do not spin webs.

I shall now give a few details on the manner in which spiders' webs are made. Without going into the anatomy of the subject further than to observe that a spider's 'thread' is a composite structure made up of a number of finer threads, which leave their respective spinneret-holes in an almost fluid condition, and immediately harden by exposure to the air, I shall begin at once to describe the method of construction.

The so-called 'geometric spider' constructs her web by first laying down the radiating and unadhesive rays, and then, beginning from the centre, spins a spiral line of unadhesive web, like that of the rays which it intersects. This line, in being woven through the radii in a spiral from centre to circumference, serves as a scaffolding for the spider to walk over, and also keeps the rays properly stretched. She next spins another spiral line, but this time from the circumference to near the centre, and formed of web, covered with a viscid secretion to retain prey. Lastly, she constructs her lair to bide and watch for prey, at some distance from the web but connected with it by means of a line of communication or telegraph, the vibrations of which inform her of the struggling of an insect in the net.[79]

According to Thompson,--

The web of the garden spider--the most ingenious and
perfect contrivance that can be imagined--is usually
fixed in a perpendicular or somewhat oblique direction
in an opening between the leaves of some plant or
shrub; and as it is obvious that round its whole
extent lines will be required to which those ends of
radii that are farthest from the centre can be
attached, the construction of those exterior lines is
the spider's first operation. It seems careless about
the shape of the area they are to enclose, well aware
that it can as readily inscribe a circle in a triangle
as a square; and in this respect it is guided by the
distance or proximity of the points to which it can
attach them. It spares no pains, however, to
strengthen and keep them in a proper degree of
tension. With the former view it composes each line of
five or six or even of more threads glued together;
and with the latter it fixes to them from different
points a numerous and intricate apparatus of smaller
threads; and having thus completed the foundation of
its snare, it proceeds to fill up the outline.
Attaching a thread to one of the main lines, it walks
along it, guiding it with one of its hind legs, that
it may not touch in any part and be prematurely glued,
and crosses over to the opposite side, where, by
applying its spinners, it firmly fixes it. To the
middle of this diagonal thread, which is to form the
centre of its net, it fixes a second, which in like
manner it conveys and fastens to another part of the
lines including the area. The work now proceeds
rapidly. During the preliminary operations it
sometimes rests, as though its plan required
meditation; but no sooner are the marginal lines of
the net firmly stretched, and two or three radii spun
from its centre, than it continues its labour so
quickly and unremittingly that the eye can scarcely
follow its progress. The radii, to the number of about
twenty, giving the net the appearance of a wheel, are
speedily finished. It then proceeds to the centre,
quickly turns itself round, pulls each thread with its
feet to ascertain its strength, breaking any one that
seems defective, and replacing it by another. Next it
glues, immediately round the centre, five or six small
concentric circles, distant about half a line from
each other, and then four or five larger ones, each
separated by the space of half an inch or more. These
last serve as a sort of temporary scaffolding to walk
over, and to keep the radii properly stretched while
it glues to them the concentric circles that are to
remain, which it now proceeds to construct. Placing
itself at the circumference, and fastening its thread
to the end of one of the radii, it walks up that one,
towards the centre, to such a distance as to draw the
thread from its body of a sufficient length to meet
the next. Then stepping across and conducting the
thread with one of its hind legs, it glues it with its
spinners to the point in the adjoining radius to which
it is to be fixed. This process it repeats until it
has filled up nearly the whole space from the
circumference to the centre with concentric circles,
distant from each other about two lines. It always,
however, leaves a vacant interval around the smallest
first spun circles that are nearest to the centre, and
bites away the small cotton-like tuft that united all
the radii, which being held now together by the
circular threads have thus probably their elasticity
increased; and in the circular opening, resulting from
this procedure, it takes its station and watches for
its prey, or occasionally retires to a little
apartment formed under some leaf, which it also uses
as a slaughter-house.[80]

According to Büchner,--

The long main threads, with the help of which the
spider begins and attaches its web, are always the
thickest and strongest; while the others, forming the
web itself, are considerably weaker. Injuries to the
web at any spot the spider very quickly repairs, but
without keeping to the original plan, and without
taking more trouble than is absolutely necessary. Most
spiders' webs, therefore, if closely looked into, are
found to be somewhat irregular. When a storm
threatens, the spider, which is very economical with
its valuable spinning material, spins no web, for it
knows that the storm will tear it in pieces and waste
its pains, and it also does not mend a web which has
been torn. If it is seen spinning or mending, on the
other hand, fine weather may be generally reckoned
on. . . . The emerged young at first spin a very
irregular web, and only gradually learn to make a
larger and finer one, so that here, as everywhere
else, practice and experience play a great part. . . .
The position must also offer favourable opposite
points for the attachment of the web itself. People
have often puzzled their brains, wondering how
spiders, without being able to fly, had managed first
to stretch their web through the air between two
opposite points. But the little creature succeeds in
accomplishing this difficult task in the most various
and ingenious ways. It either, when the distance is
not too great, throws a moist viscid pellet, joined to
a thread, which will stick where it touches; or hangs
itself by a thread in the air and lets itself be
driven by the wind to the spot; or crawls there,
letting out a thread as it goes, and then pulls it
taut when arrived at the desired place; or floats a
number of threads in the air and waits till the wind
has thrown them here or there. The main or radial
threads which fasten the web possess such a high
degree of elasticity, that they tighten themselves
between two distant points to which the spider has
crawled, without it being necessary for the latter to
pull them towards itself. When the little artist has
once got a single thread at its disposition, it
strengthens this until it is sufficiently strong for
it to run backwards and forwards thereupon, and to
spin therefrom the web.[81]

_Special Habits._

_Water-spider._--The water-spider (_Argyroneta aquatica_), as is well known, displays the curious instinct of building her nest below the surface of water, and constructing it on the principle of a diving-bell. The animal usually selects still waters for this purpose, and makes her nest in the form of an oval hollow, lined with web, and held secure by a number of threads passing in various directions and fastened to the surrounding plants. In this oval bell, which is open below, she watches for prey, and, according to Kirby,[82] passes the winter after having closed the opening. The air needful for respiration the spider carries from the surface of the water. To do this she swims upon her back in order to entangle an air-bubble upon the hairy surface of her abdomen. With this bubble she descends, 'like a globe of quicksilver,' to the opening of her nest, where she liberates it and returns for more.

_The Vagrant or Wolf Spider._--This insect catches its prey by stealthily stalking it until within distance near enough to admit of a sudden dart being successful in effecting capture. Some species, before making the final dart (_e.g. Salticus scenicus_), fix a line of web upon the surface over which they are creeping, so that whether their station is vertical or horizontal with reference to the prey, they can leap fearlessly, the thread in any case preventing their fall. Dr. H. F. Hutchinson says that he has seen this spider crawling over a looking-glass stalking its own reflection.[83]

The following is quoted from Büchner:--

Less idyllic than the water-spider is our native
hunting-spider (_Dolomedes fimbriata_), which belongs
to those species which spin no web, but hunt their
victims like animals of prey. As the _Argyroneta_ is
the discoverer of the diving-bell, so may this be
regarded as the discoverer or first builder of a
floating raft. It is not content with hunting insects
on land, but follows them on the water, on the surface
of which it runs about with ease. It, however, needs a
place to rest on, and makes it by rolling together dry
leaves and such like bodies, binding them into a firm
whole with its silken threads. On this raft-like
vessel it floats at the mercy of wind and waves; and
if an unlucky water-insect comes for an instant to the
surface of the water to breathe, the spider darts at
it with lightning speed, and carries it back to its
raft to devour at its ease. Thus everywhere in nature
are battle, craft, and ingenuity, all following the
merciless law of egoism, in order to maintain their
own lives and to destroy those of others!

_Trap-door Spiders._--These display the curious instinct of providing their nests with trap-doors. The nest consists of a tube excavated in the earth to the depth of half a foot or more. In all save one species the tube is unbranched; it is always lined with silk, which is continuous with the lining of the trap-door or doors, of which it forms the hinge. In the species which constructs a branching tube, the branch is always single, more or less straight, takes origin at a point situated a few inches from the orifice of the main tube, is directed upwards at an acute angle with that tube, and terminates blindly just below the surface of the soil. At its point of junction with or departure from the main tube it is provided with a trap-door resembling that which closes the orifice of the main tube, and of such a size and arrangement that when closed against the opening of the branch tube it just fills that opening; while when turned outwards, so as to uncork this opening, it just fills the diameter of the main tube: the latter, therefore, is in this species provided with two trap-doors, one at the surface of the soil, and the other at the fork of the branched tube.

Each species of trap-door spider is very constant in building a particular kind of trap-door; but among the different species there are four several kinds of trap-doors to be distinguished. 1st. The single-door cork nest, wherein the trap-door is a thick structure, and fits into the tube like a cork into a bottle. 2nd. The single-door wafer nest, wherein the trap-door is as thin as a piece of paper. 3rd. The double-door unbranched nest, wherein there is a second trap-door situated a few inches below the first one. And 4th, the double-door branched nest already described. In all cases the trap-doors open outwards, and when the nest is placed, as it usually is, on a sloping bank, the trap-door opens upwards; hence there is no fear of its gaping, for gravity is on the side of holding it shut.

The object of the trap-door is to conceal the nest, and for this purpose it is always made so closely to resemble the general surface of the ground on which it occurs, that even a practised eye finds it difficult to detect the structure when closed. In order to make the resemblance to the surrounding objects as perfect as possible, the spider either constructs the surface of its door of a portion of leaf, or weaves moss, grass, &c., into the texture. Moggridge says,[84]--

Thus, for example, in one case where I had cut out a
little clod of mossy earth, about two inches thick and
three square on the surface, containing the top of the
tube and the moss-covered cork door of _N.
cæmentaria_, I found, on revisiting the place six
days later, that a new door had been made, and that
the spider had mounted up to fetch moss from the
undisturbed bank above, planting it in the earth which
formed the crown of the door. Here the moss actually
called the eye to the trap, which lay in the little
plain of brown earth made by my digging.

If an enemy should detect the trap-door and endeavour to open it, the spider frequently seizes hold of its internal surface, and, applying her legs to the walls of the tube, forcibly holds the trap-door shut. In the double trap-door species it is surmised that the second trap-door serves as an inner barrier of defence, behind which the spider retires when obliged to abandon the first one. In the branched tube species (which, so far as at present known, only occurs in the south of Europe) it is surmised that the spider, when it finds that an enemy is about to gain entrance at the first trap-door, runs into the branch tube and draws up behind it the second trap-door. The surface of this trap-door, being overlaid with silk like the walls of the tube, is then invisible; so that the enemy no doubt passes down the main tube to find it empty, without observing the lateral branch in which the spider is concealed behind the closed door.

As showing that these animals are to no small extent able to adapt their dwellings to unusual circumstances, I shall here quote the following from Moggridge (_loc. cit._, p. 122):--

Certain nests which were furnished with two doors of
the cork type were observed by Mr. S. S. Saunders in
the Ionian Islands. The door at the surface of these
nests was normal in position and structure, but the
lower one was placed at the very bottom of the nest,
and inverted, so that, though apparently intended to
open downwards, it was permanently closed by the
surrounding earth. The presence of a carefully
constructed door in a situation which forbade the
possibility of its ever being opened seemed, indeed,
something difficult to account for. However, it
occurred to Mr. Saunders that, as these nests were
found in the cultivated ground round the roots of
olive trees, they may occasionally have got turned
topsy-turvy when the soil was broken up. The spider
then, finding her door buried below in the ground and
the bottom of the tube at the surface, would have
either to seek new quarters or to adapt the nest to
its altered position, and make an opening and door at
the exposed end. In order to try whether one of these
spiders would do this, Mr. Saunders placed a nest,
with its occupant inside, upside down in a flower-pot.
After the lapse of ten days a new door was made,
exactly as he had conjectured it would be, and the
nest presented two doors like those which he had found
at first.

The most remarkable fact connected with these animals, if we regard their peculiar instinct from the standpoint of the descent theory, is the wide range of their geographical distribution. In all quarters of the globe species of trap-door spiders are found occurring in more or less localised areas; and as it is improbable that so peculiar an instinct should have arisen independently in more than one line of descent, we can only conclude that the wide dispersion of the species presenting it has been subsequent to the origin and perfecting of the instinct. This conclusion of course necessitates the supposition that the instinct must be one of enormous antiquity; and in this connection it is worthy of remark that we seem to have independent evidence to show that such is the case. It is a principle of evolution that the earlier any structure or instinct appears in the development of the race, the sooner will it appear in the development of the individual; and read by the light of this principle we should conclude, quite apart from all considerations as to the wide geographical distribution of trap-door spiders, that their instincts--as, indeed, is the case with the characteristic instincts of many other species of spiders--must be of immense age. Thus, again to quote Moggridge,--

It seems to be the rule with spiders generally that
the offspring should leave the nest and construct
dwellings for themselves when very young.

Mr. Blackwall, speaking of British spiders,
says:--'Complicated as the processes are by which
these symmetrical nets are produced, nevertheless
young spiders, acting under the influence of
instinctive impulse, display, even in their first
attempts to fabricate them, as consummate skill as the
most experienced individuals.'

Again, Mr. F. Pollock[85] relates of the young of
_Epeira aurelia_, which he observed in Madeira, that
when seven weeks old they made a web the size of a
penny, and that these nets have the same beautiful
symmetry as those of the full-grown spider.

And, speaking of trap-door spiders, Moggridge says,--

I cannot help thinking that these very small nests,
built as they are by minute spiders probably not very
long hatched from the egg, must rank among the most
marvellous structures of this kind with which we are
acquainted. That so young and weak a creature should
be able to excavate a tube in the earth many times its
own length, and know how to make a perfect miniature
of the nest of its parents, seems to be a fact which
has scarcely a parallel in nature.[86]

Regarding the steps whereby the instinct of building trap-doors probably arose, Büchner quotes Moggridge thus:--

To show, lastly, how various are the transitional
forms and gradations so important in deciding upon the
gradual origin of the forms of nests, Moggridge also
alludes to the similar buildings made by other genera
of spiders. _Lycosa Narbonensis_, a spider of Southern
France much resembling the Apuleian tarantula, and
belonging to the family of the wolf spiders, makes
cylindrical holes in the earth, about one inch wide
and three or four inches deep, in a perpendicular
direction; when they have attained this depth they run
further horizontally, and end in a three cornered
room, from one to two inches broad, the floor of which
is covered with the remnants of dead insects. The
whole nest is lined within with a thick silken
material, and has at its opening--closed by no
door--an above-ground chimney-shaped extension, made
of leaves, needles, moss, wood, &c., woven together
with spider threads. These chimneys show various
differences in their manner of building, and are
intended chiefly, according to Moggridge, to prevent
the sand blown about by the violent sea-winds from
penetrating into the nests. During winter the opening
is wholly and continuously woven over, and it is very
well possible, or probable, that the process of
reopening such a warm covering in the spring, after
this opening was three-quarters completed, and was
large enough to let the spider pass out, may have long
ago awaked in the brain of some species of spider the
idea of making a permanent and moveable door. But from
this to the practical construction of so perfect a
door as we have learned to know, and even to the
building of the exceedingly complicated nest of the
_N. Manderstjernæ_, through all the gradations which
we already know, and which doubtless exist in far
greater number, is no great or impossible step.

_General Intelligence._

Coming now to the general intelligence of spiders, I think there can be no reasonable doubt, from the force of concurrent testimony, that they are able to distinguish between persons, and approach those whom they have found to be friendly, while shunning strangers. This power of discrimination, it will be remembered, also occurs among bees and wasps, and therefore its presence in spiders is not antecedently improbable. I myself know a lady who has 'tamed' spiders to recognise her, so that they come out to be fed when she enters the room where they are kept; and stories of the taming of spiders by prisoners are abundant. The following anecdote recorded by Büchner is in this connection worth quoting:--

Dr. Moschkau, of Gohlis, near Leipsic, writes as
follows to the author, on August 28, 1876:--'In
Oderwitz(?), where I lived in 1873 and 1874, I noticed
one day in a half-dark corner of the anteroom a
tolerably respectable spider's web, in which a
well-fed cross-spider had made its home, and sat at
the nest-opening early and late, watching for some
flying or creeping food. I was accidentally several
times a witness of the craft with which it caught its
victim and rendered it harmless, and it soon became a
regular duty to carry it flies several times during a
day, which I laid down before its door with a pair of
pincers. At first this feeding seemed to arouse small
confidence, the pincers perhaps being in fault, for it
let many of the flies escape again, or only seized
them when it knew that they were within reach of its
abode. After a while, however, the spider came each
time and took the flies out of the pincers and spun
them over. The latter business was sometimes done so
superficially, when I gave flies very quickly one
after the other, that some of the already ensnared
flies found time and opportunity to escape. This game
was carried on by me for some weeks, as it seemed to
me curious. But one day when the spider seemed very
ravenous, and regularly flew at each fly offered to
it, I began teasing it. As soon as it had got hold of
the fly I pulled it back again with the pincers. It
took this exceedingly ill. The first time, as I
finally left the fly with it, it managed to forgive
me, but when I later took a fly right away, our
friendship was destroyed for ever. On the following
day it treated my offered flies with contempt, and
would not move, and on the third day it had
disappeared.[87]

Jesse relates the following anecdote, which seems to display on the part of a spider somewhat remote adaptation of means to novel circumstances. He confined a spider with her eggs under a glass upon a marble mantelpiece. Having surrounded the eggs with web,--

She next proceeded to fix one of her threads to the
upper part of the glass which confined her, and
carried it to the further end of the piece of grass,
and in a short time had succeeded in raising it up and
fixing it perpendicularly, working her threads from
the sides of the glass to the top and sides of the
piece of grass. Her motive in doing this was obvious.
She not only rendered the object of her care more
secure than it would have been had it remained flat on
the marble, but she was probably aware that the cold
from the marble would chill her eggs, and prevent
their arriving at maturity: she therefore raised them
from it in the manner I have described.[88]

Mr. Belt gives the following account of the intelligence which certain species of South American spiders display in escaping from the terrible hosts of the Eciton ants:--

Many of the spiders would escape by hanging suspended
by a thread of silk from the branches, safe from the
foes that swarmed both above and below.

I noticed that spiders generally were most intelligent
in escaping, and did not, like the cockroaches and
other insects, take shelter in the first hiding-place
they found, only to be driven out again, or perhaps
caught by the advancing army of ants. I have often
seen large spiders making off many yards in advance,
and apparently determined to put a good distance
between themselves and the foe. I once saw one of the
false spiders, or harvest-men (_Phalangidæ_), standing
in the midst of an army of ants, and with the greatest
circumspection and coolness lifting, one after the
other, its long legs, which supported its body above
their reach. Sometimes as many as five out of its
eight legs would be lifted at once, and whenever an
ant approached one of those on which it stood, there
was always a clear space within reach to put down
another, so as to be able to hold up the threatened
one out of danger.[89]

Mr. L. A. Morgan, writing to 'Nature' (Jan. 22, 1880), gives an account of a spider conveying a large insect from the part of the web where it was caught to the 'larder,' by the following means. The spider first went two or three times backwards and forwards between the head of the insect and the main strand of the web. After this he went about cutting all the threads around the insect till the latter hung by the head strands alone. The spider then fixed a thread to the tail end, and by this dragged the carcass as far on its way to the larder as the head strands would permit. As soon as these were taut, he made the tail rope fast, went back to the head rope and cut it; then he attached himself to the head and pulled the body towards the larder, until the tail rope was taut. In this way, by alternately cutting the head and tail ropes and dragging the insect bit by bit, he conveyed it safely to the larder.

But the practical acquaintance with mechanical principles which this observation displays is perhaps not so remarkable as that which is sometimes shown by spiders when they find that a widely spread web is not tightly enough stretched, and as a consequence is to an inconvenient extent swayed about by the wind. Under such circumstances these animals have been observed to suspend to their webs small stones or other heavy objects, the weight of which serves to steady the whole system. Gleditsch saw a spider so circumstanced let itself down to the ground by means of a thread, seize a small stone, remount, and fasten the stone to the lower part of its web, at a height sufficient to enable animals and men to walk beneath it. After alluding to this case, Büchner observes (_loc. cit._, p. 318),--

But a similar observation was made by Professor E. H.
Weber, the famous anatomist and physiologist, and was
published many years ago in Müller's Journal. A spider
had stretched its web between two posts standing
opposite each other, and had fastened it to a plant
below for the third point. But as the attachment below
was often broken by the garden work, by passers-by,
and in other ways, the little animal extricated itself
from the difficulty by spinning its web round a little
stone, and fastened this to the lower part of its web,
swinging freely, and so to draw the web down by its
weight instead of fastening it in this direction by a
connecting thread. Carus ('Vergl. Psycho.,' 1866, p.
76) also made a similar observation. But the most
interesting observation on this head is related by J.
G. Wood ('Glimpses into Petland'), and repeated by
Watson (_loc. cit._, p. 455). One of my friends, says
Wood, was accustomed to grant shelter to a number of
garden spiders under a large verandah, and to watch
their habits. One day a sharp storm broke out, and the
wind raged so furiously through the garden that the
spiders suffered damage from it, although sheltered by
the verandah. The mainyards of one of these webs, as
the sailors would call them, were broken, so that the
web was blown hither and thither, like a slack sail in
a storm. The spider made no fresh threads, but tried
to help itself in another way. It let itself down to
the ground by a thread, and crawled to a place where
lay some splintered pieces of a wooden fence thrown
down by the storm. It fastened a thread to one of the
bits of wood, turned back with it, and hung it with a
strong thread to the lower part of its nest, about
five feet from the ground. The performance was a
wonderful one, for the weight of the wood sufficed to
keep the nest tolerably firm, while it was yet light
enough to yield to the wind, and so prevent further
injury. The piece of wood was about two and a half
inches long, and as thick as a goose-quill. On the
following day a careless servant knocked her head
against the wood, and it fell down. But in the course
of a few hours the spider had found it and brought it
back to its place. When the storm ceased, the spider
mended her web, broke the supporting thread in two,
and let the wood fall to the ground!

If so well-observed a fact requires any further confirmation, I may adduce the following account, which is of the more value as corroborative evidence from the writer not appearing to be aware that the fact had been observed before. This writer is Dr. John Topham, whom the late Dr. Sharpey, F.R.S., assured me is a competent observer, and who publishes the account in 'Nature' (xi. 18):--

A spider constructed its web in an angle of my garden,
the sides of which were attached by long threads to
shrubs at the height of nearly three feet from the
gravel path beneath. Being much exposed to the wind,
the equinoctial gales of this autumn destroyed the web
several times.

The ingenious spider now adopted the contrivance here
represented. It secured a conical fragment of gravel
with its larger end upwards by two cords, one attached
to each of its opposite sides, to the apex of its
wedge-shaped web, and left it suspended as a moveable
weight to be opposed to the effect of such gusts of
air as had destroyed the webs previously occupying the
same situation.

The spider must have descended to the gravel path for
this special object, and having attached threads to a
stone suited to its purpose, must have afterwards
raised this by fixing itself upon the web, and pulling
the weight up to a height of more than two feet from
the ground, where it hung suspended by elastic cords.
The excellence of the contrivance is too evident to
require further comment.

An almost precisely analogous case, with a sketch, is published by another observer in 'Land and Water,' Dec. 12, 1877.

_Scorpions._

Before quitting the Arachnida I must allude to some recent correspondence on the alleged tendency of the scorpion to commit suicide when surrounded by fire. This alleged tendency has long been recognised in popular fables, and has been used by Byron as a poetical metaphor in certain well-known lines. But until the publication of the correspondence to which I allude, no one supposed the tendency in question to have any existence in fact. This correspondence took place in 'Nature' (vol. xi.), and as the subject is an interesting one, I shall reproduce the more important contributions to it _in extenso_. It was opened by Mr. W. G. Biddie as follows:--

I shall feel obliged if you will record in 'Nature' a
fact with reference to the common black scorpion of
Southern India, which was observed by me some years
ago in Madras.

One morning a servant brought to me a large specimen
of this scorpion, which, having stayed out too long in
its nocturnal rambles, had apparently got bewildered
at daybreak, and been unable to find its way home. To
keep it safe the creature was at once put into a
glazed entomological case. Having a few leisure
minutes in the course of the forenoon I thought I
would see how my prisoner was getting on, and to have
a better view of it the case was placed in a window in
the rays of the hot sun. The light and heat seemed to
irritate it very much, and this recalled to my mind a
story which I had read somewhere that a scorpion, on
being surrounded with fire, had committed suicide. I
hesitated about subjecting my pet to such a terrible
ordeal, but taking a common botanical lens, I focussed
the rays of the sun on its back. The moment this was
done it began to run hurriedly about the case, hissing
and spitting in a very fierce way. This experiment was
repeated some four or five times with like results,
but on trying it once again, the scorpion turned up
its tail and plunged the sting, quick as lightning,
into its own back. The infliction of the wound was
followed by a sudden escape of fluid, and a friend
standing by me called out, 'See, it has stung itself:
it is dead;' and sure enough in less than half a
minute life was quite extinct. I have written this
brief note to show (1) that animals may commit
suicide; (2) that the poison of certain animals may be
destructive to themselves.

The following corroborative evidence on the subject was then supplied by Dr. Allen Thomson, F.R.S. ('Nature,' vol. xx., p. 577):--

Doubts having been expressed at various times, even by
learned naturalists, as to the reality of the suicide
or self-destruction of the scorpion by means of its
own poison, and these doubts having been again stated
in 'Nature,' vol. xx., p. 553, by Mr. B. F.
Hutchinson, of Peshawur, as the result of his own
observations, I think it may be useful to give an
articulate account of the phenomenon as it has been
related to me by an eye-witness, which removes all
possible doubt as to its occurrence under certain
circumstances.

While residing many years ago, during the summer
months, at the baths of Sulla in Italy, in a somewhat
damp locality, my informant together with the rest of
the family was much annoyed by the frequent intrusion
of small black scorpions into the house, and their
being secreted among the bedclothes, in shoes, and
other articles of dress. It thus became necessary to
be constantly on the watch for these troublesome
creatures, and to take means for their removal and
destruction. Having been informed by the natives of
the place that the scorpion would destroy itself if
exposed to a sudden light, my informant and her
friends soon became adepts in catching the scorpions
and disposing of them in the manner suggested. This
consisted in confining the animal under an inverted
drinking-glass or tumbler, below which a card was
inserted when the capture was made, and then, waiting
till dark, suddenly bringing the light of a candle
near to the glass in which the animal was confined. No
sooner was this done than the scorpion invariably
showed signs of great excitement, running round and
round the interior of the tumbler with reckless
velocity for a number of times. This state having
lasted for a minute or more, the animal suddenly
became quiet, and turning its tail on the hinder part
of its body over its back, brought its recurved sting
down upon the middle of the head, and piercing it
forcibly, in a few seconds became quite motionless,
and in fact quite dead. This observation was repeated
very frequently; in truth, it was adopted as the best
plan of getting rid of the animals. The young people
were in the habit of handling the scorpions with
impunity immediately after they were so killed, and of
preserving many of them as curiosities.

In this narrative the following circumstances are
worthy of attention:--

(1) The effect of light in producing the excitement
amounting to despair, which causes the animal to
commit self-destruction;

(2) The suddenness of the operation of the poison,
which is probably inserted by the puncture of the head
into the upper cerebral ganglion; and

(3) The completeness of the fatal symptoms at once
induced.

I am aware that the phenomena now described have been
observed by others, and they appear to have been
familiarly known to the inhabitants of the district in
which the animals are found. Sufficient confirmation
of the facts is also to be found in the narratives of
'G. Biddie' and 'M. L.' contained in 'Nature,' vol.
ix., pp. 29-47, and it will be observed that the
circumstances leading the animal to self-destruction
in these instances were somewhat similar to those
narrated by my informant. It is abundantly clear,
therefore, that the view taken by Mr. Hutchinson,
viz., that the 'popular idea regarding scorpionic
suicide is a delusion based on an impossibility,' is
wholly untenable; indeed, the recurved direction of
the sting, which he refers to as creating the
impossibility of the animal destroying itself,
actually facilitates the operation of inflicting the
wound. I suppose Mr. Hutchinson, arguing from the
analogy of bees or wasps, imagined that the sting
would be bent forwards upon the body, whereas the
wound of the scorpion is invariably inflicted by a
recurvation of the tail over the back of the animal.

It will be perceived that these observations were not made by Dr. Allen Thomson himself, and that there are certain inherent discrepancies in the account which he has published--such, for instance, as the reason given for trying and repeating the experiment, the method being clearly a cumbersome one to employ if the only object were that of 'disposing of' the animals. Nevertheless, as Dr. Thomson is a high authority, and as I learn from him that he is satisfied regarding the capability and veracity of his informant, I have not felt justified in suppressing his evidence. Still I think that so remarkable a fact unquestionably demands further corroboration before we should be justified in accepting it unreservedly. For if it is a fact, it stands as a unique case of an instinct detrimental alike to the individual and to the species.

FOOTNOTES:

[75] _Body and Mind_, p. 275.

[76] _Nature_, xxiii., pp. 149-50.

[77] _Naturalist on the Amazon_, p. 83.

[78] For many other confirmations see Sir E. Tennent, _Nat. Hist. Ceylon_, pp. 468-69.

[79] Kirby, vol. ii., p. 298.

[80] Thompson, _Passions of Animals_, p. 145.

[81] _Loc. cit._, p. 316 _et seq._

[82] _Hist. Habits and Inst. of Animals_, vol. ii. p. 296.

[83] _Nature_, vol. xx., p. 581.

[A] _Loc. cit._, p. 323.

[84] _Harvesting Ants and Trap-door Spiders_, p. 120.

[85] 'The History and Habits of _Epeira aurelia_,' in _Annals and Mag. of Nat. Hist._ for June 1865.

[86] _Harvesting Ants and Trap-door Spiders_, p. 126. This admirable work, with its appendix, contains a very full account of the whole economy of the interesting animals with which it is concerned.

[87] _Loc. cit._, p. 319.

[88] _Gleanings_, vol. i., p. 103.

[89] _Naturalist in Nicaragua_, p. 19.