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.

Animal Intelligence The International Scientific Series, Vol. XLIV. · 第 9 / 22 章