The Life of the Spider
by
J. Henri Fabre - translated by Alexander Teixeira de Mattos
Part 4 out of 4
Half an hour's heat; and the magic jewels disappear with the dew.
Now is the moment to inspect the webs. Here is one spreading its
sheet over a large cluster of rock-roses; it is the size of a
handkerchief. A profusion of guy-ropes, attached to any chance
projection, moor it to the brushwood. There is not a twig but
supplies a contact-point. Entwined on every side, surrounded and
surmounted, the bush disappears from view, veiled in white muslin.
The web is flat at the edges, as far as the unevenness of the
support permits, and gradually hollows into a crater, not unlike
the bell of a hunting-horn. The central portion is a cone-shaped
gulf, a funnel whose neck, narrowing by degrees, dives
perpendicularly into the leafy thicket to a depth of eight or nine
inches.
At the entrance to the tube, in the gloom of that murderous alley,
sits the Spider, who looks at us and betrays no great excitement at
our presence. She is grey, modestly adorned on the thorax with two
black ribbons and on the abdomen with two stripes in which white
specks alternate with brown. At the tip of the belly, two small,
mobile appendages form a sort of tail, a rather curious feature in
a Spider.
The crater-shaped web is not of the same structure throughout. At
the borders, it is a gossamer weft of sparse threads; nearer the
centre, the texture becomes first fine muslin and then satin; lower
still, on the narrower part of the opening, it is a network of
roughly lozenged meshes. Lastly, the neck of the funnel, the usual
resting-place, is formed of solid silk.
The Spider never ceases working at her carpet, which represents her
investigation-platform. Every night she goes to it, walks over it,
inspecting her snares, extending her domain and increasing it with
new threads. The work is done with the silk constantly hanging
from the spinnerets and constantly extracted as the animal moves
about. The neck of the funnel, being more often walked upon than
the rest of the dwelling, is therefore provided with a thicker
upholstery. Beyond it are the slopes of the crater, which are also
much-frequented regions. Spokes of some regularity fix the
diameter of the mouth; a swaying walk and the guiding aid of the
caudal appendages have laid lozengy meshes across these spokes.
This part has been strengthened by the nightly rounds of
inspection. Lastly come the less-visited expanses, which
consequently have a thinner carpet.
At the bottom of the passage dipping into the brushwood, we might
expect to find a secret cabin, a wadded cell where the Spider would
take refuge in her hours of leisure. The reality is something
entirely different. The long funnel-neck gapes at its lower end,
where a private door stands always ajar, allowing the animal, when
hard-pushed, to escape through the grass and gain the open.
It is well to know this arrangement of the home, if you wish to
capture the Spider without hurting her. When attacked from the
front, the fugitive runs down and slips through the postern-gate at
the bottom. To look for her by rummaging in the brushwood often
leads to nothing, so swift is her flight; besides, a blind search
entails a great risk of maiming her. Let us eschew violence, which
is but seldom successful, and resort to craft.
We catch sight of the Spider at the entrance to her tube. If
practicable, squeeze the bottom of the tuft, containing the neck of
the funnel, with both hands. That is enough; the animal is caught.
Feeling its retreat cut off, it readily darts into the paper bag
held out to it; if necessary, it can be stimulated with a bit of
straw. In this way, I fill my cages with subjects that have not
been demoralized by contusions.
The surface of the crater is not exactly a snare. It is just
possible for the casual pedestrian to catch his legs in the silky
carpets; but giddy-pates who come here for a walk must be very
rare. What is wanted is a trap capable of securing the game that
hops or flies. The Epeira has her treacherous limed net; the
Spider of the bushes has her no less treacherous labyrinth.
Look above the web. What a forest of ropes! It might be the
rigging of a ship disabled by a storm. They run from every twig of
the supporting shrubs, they are fastened to the tip of every
branch. There are long ropes and short ropes, upright and
slanting, straight and bent, taut and slack, all criss-cross and a-
tangle, to the height of three feet or so in inextricable disorder.
The whole forms a chaos of netting, a labyrinth which none can pass
through, unless he be endowed with wings of exceptional power.
We have here nothing similar to the lime-threads used by the Garden
Spiders. The threads are not sticky; they act only by their
confused multitude. Would you care to see the trap at work? Throw
a small Locust into the rigging. Unable to obtain a steady foot-
hold on that shaky support, he flounders about; and the more he
struggles the more he entangles his shackles. The Spider, spying
on the threshold of her abyss, lets him have his way. She does not
run up the shrouds of the mast-work to seize the desperate
prisoner; she waits until his bonds of threads, twisted backwards
and forwards, make him fall on the web.
He falls; the other comes and flings herself upon her prostrate
prey. The attack is not without danger. The Locust is demoralized
rather than tied up; it is merely bits of broken thread that he is
trailing from his legs. The bold assailant does not mind. Without
troubling, like the Epeirae, to bury her capture under a paralysing
winding-sheet, she feels it, to make sure of its quality, and then,
regardless of kicks, inserts her fangs.
The bite is usually given at the lower end of a haunch: not that
this place is more vulnerable than any other thin-skinned part, but
probably because it has a better flavour. The different webs which
I inspect to study the food in the larder show me, among other
joints, various Flies and small Butterflies and carcasses of
almost-untouched Locusts, all deprived of their hind-legs, or at
least of one. Locusts' legs often dangle, emptied of their
succulent contents, on the edges of the web, from the meat-hooks of
the butcher's shop. In my urchin-days, days free from prejudices
in regard to what one ate, I, like many others, was able to
appreciate that dainty. It is the equivalent, on a very small
scale, of the larger legs of the Crayfish.
The rigging-builder, therefore, to whom we have just thrown a
Locust attacks the prey at the lower end of a thigh. The bite is a
lingering one: once the Spider has planted her fangs, she does not
let go. She drinks, she sips, she sucks. When this first point is
drained, she passes on to others, to the second haunch in
particular, until the prey becomes an empty hulk without losing its
outline.
We have seen that Garden Spiders feed in a similar way, bleeding
their venison and drinking it instead of eating it. At last,
however, in the comfortable post-prandial hours, they take up the
drained morsel, chew it, rechew it and reduce it to a shapeless
ball. It is a dessert for the teeth to toy with. The Labyrinth
Spider knows nothing of the diversions of the table; she flings the
drained remnants out of her web, without chewing them. Although it
lasts long, the meal is eaten in perfect safety. From the first
bite, the Locust becomes a lifeless thing; the Spider's poison has
settled him.
The labyrinth is greatly inferior, as a work of art, to that
advanced geometrical contrivance, the Garden Spider's net; and, in
spite of its ingenuity, it does not give a favourable notion of its
constructor. It is hardly more than a shapeless scaffolding, run
up anyhow. And yet, like the others, the builder of this slovenly
edifice must have her own principles of beauty and accuracy. As it
is, the prettily-latticed mouth of the crater makes us suspect
this; the nest, the mother's usual masterpiece, will prove it to
the full.
When laying-time is at hand, the Spider changes her residence; she
abandons her web in excellent condition; she does not return to it.
Whoso will can take possession of the house. The hour has come to
found the family-establishment. But where? The Spider knows right
well; I am in the dark. Mornings are spent in fruitless searches.
In vain I ransack the bushes that carry the webs: I never find
aught that realizes my hopes.
I learn the secret at last. I chance upon a web which, though
deserted, is not yet dilapidated, proving that it has been but
lately quitted. Instead of hunting in the brushwood whereon it
rests, let us inspect the neighbourhood, to a distance of a few
paces. If these contain a low, thick cluster, the nest is there,
hidden from the eye. It carries an authentic certificate of its
origin, for the mother invariably occupies it.
By this method of investigation, far from the labyrinth-trap, I
become the owner of as many nests as are needed to satisfy my
curiosity. They do not by a long way come up to my idea of the
maternal talent. They are clumsy bundles of dead leaves, roughly
drawn together with silk threads. Under this rude covering is a
pouch of fine texture containing the egg-casket, all in very bad
condition, because of the inevitable tears incurred in its
extrication from the brushwood. No, I shall not be able to judge
of the artist's capacity by these rags and tatters.
The insect, in its buildings, has its own architectural rules,
rules as unchangeable as anatomical peculiarities. Each group
builds according to the same set of principles, conforming to the
laws of a very elementary system of aesthetics; but often
circumstances beyond the architect's control--the space at her
disposal, the unevenness of the site, the nature of the material
and other accidental causes--interfere with the worker's plans and
disturb the structure. Then virtual regularity is translated into
actual chaos; order degenerates into disorder.
We might discover an interesting subject of research in the type
adopted by each species when the work is accomplished without
hindrances. The Banded Epeira weaves the wallet of her eggs in the
open, on a slim branch that does not get in her way; and her work
is a superbly artistic jar. The Silky Epeira also has all the
elbow-room she needs; and her paraboloid is not without elegance.
Can the Labyrinth Spider, that other spinstress of accomplished
merit, be ignorant of the precepts of beauty when the time comes
for her to weave a tent for her offspring? As yet, what I have
seen of her work is but an unsightly bundle. Is that all she can
do?
I look for better things if circumstances favour her. Toiling in
the midst of a dense thicket, among a tangle of dead leaves and
twigs, she may well produce a very inaccurate piece of work; but
compel her to labour when free from all impediment: she will then-
-I am convinced of it beforehand--apply her talents without
constraint and show herself an adept in the building of graceful
nests.
As laying-time approaches, towards the middle of August, I instal
half-a-dozen Labyrinth Spiders in large wire-gauze cages, each
standing in an earthen pan filled with sand. A sprig of thyme,
planted in the centre, will furnish supports for the structure,
together with the trellis-work of the top and sides. There is no
other furniture, no dead leaves, which would spoil the shape of the
nest if the mother were minded to employ them as a covering. By
way of provision, Locusts, every day. They are readily accepted,
provided they be tender and not too large.
The experiment works perfectly. August is hardly over before I am
in possession of six nests, magnificent in shape and of a dazzling
whiteness. The latitude of the workshop has enabled the spinstress
to follow the inspiration of her instinct without serious
obstacles; and the result is a masterpiece of symmetry and
elegance, if we allow for a few angularities demanded by the
suspension-points.
It is an oval of exquisite white muslin, a diaphanous abode wherein
the mother must make a long stay to watch over the brood. The size
is nearly that of a Hen's egg. The cabin is open at either end.
The front-entrance broadens into a gallery; the back-entrance
tapers into a funnel-neck. I fail to see the object of this neck.
As for the opening in front, which is wider, this is, beyond a
doubt, a victualling-door. I see the Spider, at intervals,
standing here on the look-out for the Locust, whom she consumes
outside, taking care not to soil the spotless sanctuary with
corpses.
The structure of the nest is not without a certain similarity to
that of the home occupied during the hunting-season. The passage
at the back represents the funnel-neck, that ran almost down to the
ground and afforded an outlet for flight in case of grave danger.
The one in front, expanding into a mouth kept wide open by cords
stretched backwards and forwards, recalls the yawning gulf into
which the victims used to fall. Every part of the old dwelling is
repeated: even the labyrinth, though this, it is true, is on a
much smaller scale. In front of the bell-shaped mouth is a tangle
of threads wherein the passers-by are caught. Each species, in
this way, possesses a primary architectural model which is followed
as a whole, in spite of altered conditions. The animal knows its
trade thoroughly, but it does not know and will never know aught
else, being incapable of originality.
Now this palace of silk, when all is said, is nothing more than a
guard-house. Behind the soft, milky opalescence of the wall
glimmers the egg-tabernacle, with its form vaguely suggesting the
star of some order of knighthood. It is a large pocket, of a
splendid dead-white, isolated on every side by radiating pillars
which keep it motionless in the centre of the tapestry. These
pillars are about ten in number and are slender in the middle,
expanding at one end into a conical capital and at the other into a
base of the same shape. They face one another and mark the
position of the vaulted corridors which allow free movement in
every direction around the central chamber. The mother walks
gravely to and fro under the arches of her cloisters, she stops
first here, then there; she makes a lengthy auscultation of the
egg-wallet; she listens to all that happens inside the satin
wrapper. To disturb her would be barbarous.
For a closer examination, let us use the dilapidated nests which we
brought from the fields. Apart from its pillars, the egg-pocket is
an inverted conoid, reminding us of the work of the Silky Epeira.
Its material is rather stout; my pincers, pulling at it, do not
tear it without difficulty. Inside the bag there is nothing but an
extremely fine, white wadding and, lastly, the eggs, numbering
about a hundred and comparatively large, for they measure a
millimetre and a half. {37} They are very pale amber-yellow beads,
which do not stick together and which roll freely as soon as I
remove the swan's-down shroud. Let us put everything into a glass-
tube to study the hatching.
We will now retrace our steps a little. When laying-time comes,
the mother forsakes her dwelling, her crater into which her falling
victims dropped, her labyrinth in which the flight of the Midges
was cut short; she leaves intact the apparatus that enabled her to
live at her ease. Thoughtful of her natural duties, she goes to
found another establishment at a distance. Why at a distance?
She has still a few long months to live and she needs nourishment.
Were it not better, then, to lodge the eggs in the immediate
neighbourhood of the present home and to continue her hunting with
the excellent snare at her disposal? The watching of the nest and
the easy acquisition of provender would go hand in hand. The
Spider is of another opinion; and I suspect the reason.
The sheet-net and the labyrinth that surmounts it are objects
visible from afar, owing to their whiteness and the height whereat
they are placed. Their scintillation in the sun, in frequented
paths, attracts Mosquitoes and Butterflies, like the lamps in our
rooms and the fowler's looking-glass. Whoso comes to look at the
bright thing too closely dies the victim of his curiosity. There
is nothing better for playing upon the folly of the passer-by, but
also nothing more dangerous to the safety of the family.
Harpies will not fail to come running at this signal, showing up
against the green; guided by the position of the web, they will
assuredly find the precious purse; and a strange grub, feasting on
a hundred new-laid eggs, will ruin the establishment. I do not
know these enemies, not having sufficient materials at my disposal
for a register of the parasites; but, from indications gathered
elsewhere, I suspect them.
The Banded Epeira, trusting to the strength of her stuff, fixes her
nest in the sight of all, hangs it on the brushwood, taking no
precautions whatever to hide it. And a bad business it proves for
her. Her jar provides me with an Ichneumon {38} possessed of the
inoculating larding-pin: a Cryptus who, as a grub, had fed on
Spiders' eggs. Nothing but empty shells was left inside the
central keg; the germs were completely exterminated. There are
other Ichneumon-flies, moreover, addicted to robbing Spiders'
nests; a basket of fresh eggs is their offspring's regular food.
Like any other, the Labyrinth Spider dreads the scoundrelly advent
of the pickwallet; she provides for it and, to shield herself
against it as far as possible, chooses a hiding-place outside her
dwelling, far removed from the tell-tale web. When she feels her
ovaries ripen, she shifts her quarters; she goes off at night to
explore the neighbourhood and seek a less dangerous refuge. The
points selected are, by preference, the low brambles dragging along
the ground, keeping their dense verdure during the winter and
crammed with dead leaves from the oaks hard by. Rosemary-tufts,
which gain in thickness what they lose in height on the unfostering
rock, suit her particularly. This is where I usually find her
nest, not without long seeking, so well is it hidden.
So far, there is no departure from current usage. As the world is
full of creatures on the prowl for tender mouthfuls, every mother
has her apprehensions; she also has her natural wisdom, which
advises her to establish her family in secret places. Very few
neglect this precaution; each, in her own manner, conceals the eggs
she lays.
In the case of the Labyrinth Spider, the protection of the brood is
complicated by another condition. In the vast majority of
instances, the eggs, once lodged in a favourable spot, are
abandoned to themselves, left to the chances of good or ill
fortune. The Spider of the brush-wood, on the contrary, endowed
with greater maternal devotion, has, like the Crab Spider, to mount
guard over hers until they hatch.
With a few threads and some small leaves joined together, the Crab
Spider builds, above her lofty nest, a rudimentary watch-tower
where she stays permanently, greatly emaciated, flattened into a
sort of wrinkled shell through the emptying of her ovaries and the
total absence of food. And this mere shred, hardly more than a
skin that persists in living without eating, stoutly defends her
egg-sack, shows fight at the approach of any tramp. She does not
make up her mind to die until the little ones are gone.
The Labyrinth Spider is better treated. After laying her eggs, so
far from becoming thin, she preserves an excellent appearance and a
round belly. Moreover, she does not lose her appetite and is
always prepared to bleed a Locust. She therefore requires a
dwelling with a hunting-box close to the eggs watched over. We
know this dwelling, built in strict accordance with artistic canons
under the shelter of my cages.
Remember the magnificent oval guard-room, running into a vestibule
at either end; the egg-chamber slung in the centre and isolated on
every side by half a score of pillars; the front-hall expanding
into a wide mouth and surmounted by a network of taut threads
forming a trap. The semi-transparency of the walls allows us to
see the Spider engaged in her household affairs. Her cloister of
vaulted passages enables her to proceed to any point of the star-
shaped pouch containing the eggs. Indefatigable in her rounds, she
stops here and there; she fondly feels the satin, listens to the
secrets of the wallet. If I shake the net at any point with a
straw, she quickly runs up to enquire what is happening. Will this
vigilance frighten off the Ichneumon and other lovers of omelettes?
Perhaps so. But, though this danger be averted, others will come
when the mother is no longer there.
Her attentive watch does not make her overlook her meals. One of
the Locusts whereof I renew the supply at intervals in the cages is
caught in the cords of the great entrance-hall. The Spider arrives
hurriedly, snatches the giddy-pate and disjoints his shanks, which
she empties of their contents, the best part of the insect. The
remainder of the carcass is afterwards drained more or less,
according to her appetite at the time. The meal is taken outside
the guard-room, on the threshold, never indoors.
These are not capricious mouthfuls, serving to beguile the boredom
of the watch for a brief while; they are substantial repasts, which
require several sittings. Such an appetite astonishes me, after I
have seen the Crab Spider, that no less ardent watcher, refuse the
Bees whom I give her and allow herself to die of inanition. Can
this other mother have so great a need as that to eat? Yes,
certainly she has; and for an imperative reason.
At the beginning of her work, she spent a large amount of silk,
perhaps all that her reserves contained; for the double dwelling--
for herself and for her offspring--is a huge edifice, exceedingly
costly in materials; and yet, for nearly another month, I see her
adding layer upon layer both to the wall of the large cabin and to
that of the central chamber, so much so that the texture, which at
first was translucent gauze, becomes opaque satin. The walls never
seem thick enough; the Spider is always working at them. To
satisfy this lavish expenditure, she must incessantly, by means of
feeding, fill her silk-glands as and when she empties them by
spinning. Food is the means whereby she keeps the inexhaustible
factory going.
A month passes and, about the middle of September, the little ones
hatch, but without leaving their tabernacle, where they are to
spend the winter packed in soft wadding. The mother continues to
watch and spin, lessening her activity from day to day. She
recruits herself with a Locust at longer intervals; she sometimes
scorns those whom I myself entangle in her trap. This increasing
abstemiousness, a sign of decrepitude, slackens and at last stops
the work of the spinnerets.
For four or five weeks longer, the mother never ceases her
leisurely inspection-rounds, happy at hearing the new-born Spiders
swarming in the wallet. At length, when October ends, she clutches
her offspring's nursery and dies withered. She has done all that
maternal devotion can do; the special providence of tiny animals
will do the rest. When spring comes, the youngsters will emerge
from their snug habitation, disperse all over the neighbourhood by
the expedient of the floating thread and weave their first attempts
at a labyrinth on the tufts of thyme.
Accurate in structure and neat in silk-work though they be, the
nests of the caged captives do not tell us everything; we must go
back to what happens in the fields, with their complicated
conditions. Towards the end of December, I again set out in
search, aided by all my youthful collaborators. We inspect the
stunted rosemaries along the edge of a path sheltered by a rocky,
wooded slope; we lift the branches that spread over the ground.
Our zeal is rewarded with success. In a couple of hours, I am the
owner of some nests.
Pitiful pieces of work are they, injured beyond recognition by the
assaults of the weather! It needs the eyes of faith to see in
these ruins the equivalent of the edifices built inside my cages.
Fastened to the creeping branch, the unsightly bundle lies on the
sand heaped up by the rains. Oak-leaves, roughly joined by a few
threads, wrap it all round. One of these leaves, larger than the
others, roofs it in and serves as a scaffolding for the whole of
the ceiling. If we did not see the silky remnants of the two
vestibules projecting and feel a certain resistance when separating
the parts of the bundle, we might take the thing for a casual
accumulation, the work of the rain and the wind.
Let us examine our find and look more closely into its
shapelessness. Here is the large room, the maternal cabin, which
rips as the coating of leaves is removed; here are the circular
galleries of the guard-room; here are the central chamber and its
pillars, all in a fabric of immaculate white. The dirt from the
damp ground has not penetrated to this dwelling protected by its
wrapper of dead leaves.
Now open the habitation of the offspring. What is this? To my
utter astonishment, the contents of the chamber are a kernel of
earthy matters, as though the muddy rain-water had been allowed to
soak through. Put aside that idea, says the satin wall, which
itself is perfectly clean inside. It is most certainly the
mother's doing, a deliberate piece of work, executed with minute
care. The grains of sand are stuck together with a cement of silk;
and the whole resists the pressure of the fingers.
If we continue to unshell the kernel, we find, below this mineral
layer, a last silken tunic that forms a globe around the brood. No
sooner do we tear this final covering than the frightened little
ones run away and scatter with an agility that is singular at this
cold and torpid season.
To sum up, when working in the natural state, the Labyrinth Spider
builds around the eggs, between two sheets of satin, a wall
composed of a great deal of sand and a little silk. To stop the
Ichneumon's probe and the teeth of the other ravagers, the best
thing that occurred to her was this hoarding which combines the
hardness of flint with the softness of muslin.
This means of defence seems to be pretty frequent among Spiders.
Our own big House Spider, Tegenaria domestica, encloses her eggs in
a globule strengthened with a rind of silk and of crumbly wreckage
from the mortar of the walls. Other species, living in the open
under stones, work in the same way. They wrap their eggs in a
mineral shell held together with silk. The same fears have
inspired the same protective methods.
Then how comes it that, of the five mothers reared in my cages, not
one has had recourse to the clay rampart? After all, sand
abounded: the pans in which the wire-gauze covers stood were full
of it. On the other hand, under normal conditions, I have often
come across nests without any mineral casing. These incomplete
nests were placed at some height from the ground, in the thick of
the brushwood; the others, on the contrary, those supplied with a
coating of sand, lay on the ground.
The method of the work explains these differences. The concrete of
our buildings is obtained by the simultaneous manipulation of
gravel and mortar. In the same way, the Spider mixes the cement of
the silk with the grains of sand; the spinnerets never cease
working, while the legs fling under the adhesive spray the solid
materials collected in the immediate neighbourhood. The operation
would be impossible if, after cementing each grain of sand, it were
necessary to stop the work of the spinnerets and go to a distance
to fetch further stony elements. Those materials have to be right
under her legs; otherwise the Spider does without and continues her
work just the same.
In my cages, the sand is too far off. To obtain it, the Spider
would have to leave the top of the dome, where the nest is being
built on its trellis-work support; she would have to come down some
nine inches. The worker refuses to take this trouble, which, if
repeated in the case of each grain, would make the action of the
spinnerets too irksome. She also refuses to do so when, for
reasons which I have not fathomed, the site chosen is some way up
in the tuft of rosemary. But, when the nest touches the ground,
the clay rampart is never missing.
Are we to see in this fact proof of an instinct capable of
modification, either making for decadence and gradually neglecting
what was the ancestors' safeguard, or making for progress and
advancing, hesitatingly, towards perfection in the mason's art? No
inference is permissible in either direction. The Labyrinth Spider
has simply taught us that instinct possesses resources which are
employed or left latent according to the conditions of the moment.
Place sand under her legs and the spinstress will knead concrete;
refuse her that sand, or put it out of her reach, and the Spider
will remain a simple silk-worker, always ready, however, to turn
mason under favourable conditions. The aggregate of things that
come within the observer's scope proves that it were mad to expect
from her any further innovations, such as would utterly change her
methods of manufacture and cause her, for instance, to abandon her
cabin, with its two entrance-halls and its star-like tabernacle, in
favour of the Banded Epeira's pear-shaped gourd.
CHAPTER XVI: THE CLOTHO SPIDER
She is named Durand's Clotho (Clotho Durandi, LATR.), in memory of
him who first called attention to this particular Spider. To enter
on eternity under the safe-conduct of a diminutive animal which
saves us from speedy oblivion under the mallows and rockets is no
contemptible advantage. Most men disappear without leaving an echo
to repeat their name; they lie buried in forgetfulness, the worst
of graves.
Others, among the naturalists, benefit by the designation given to
this or that object in life's treasure-house: it is the skiff
wherein they keep afloat for a brief while. A patch of lichen on
the bark of an old tree, a blade of grass, a puny beastie: any one
of these hands down a man's name to posterity as effectively as a
new comet. For all its abuses, this manner of honouring the
departed is eminently respectable. If we would carve an epitaph of
some duration, what could we find better than a Beetle's wing-case,
a Snail's shell or a Spider's web? Granite is worth none of them.
Entrusted to the hard stone, an inscription becomes obliterated;
entrusted to a Butterfly's wing, it is indestructible. 'Durand,'
therefore, by all means.
But why drag in 'Clotho'? Is it the whim of a nomenclator, at a
loss for words to denote the ever-swelling tide of beasts that
require cataloguing? Not entirely. A mythological name came to
his mind, one which sounded well and which, moreover, was not out
of place in designating a spinstress. The Clotho of antiquity is
the youngest of the three Fates; she holds the distaff whence our
destinies are spun, a distaff wound with plenty of rough flocks,
just a few shreds of silk and, very rarely, a thin strand of gold.
Prettily shaped and clad, as far as a Spider can be, the Clotho of
the naturalists is, above all, a highly talented spinstress; and
this is the reason why she is called after the distaff-bearing
deity of the infernal regions. It is a pity that the analogy
extends no further. The mythological Clotho, niggardly with her
silk and lavish with her coarse flocks, spins us a harsh existence;
the eight-legged Clotho uses naught but exquisite silk. She works
for herself; the other works for us, who are hardly worth the
trouble.
Would we make her acquaintance? On the rocky slopes in the
oliveland, scorched and blistered by the sun, turn over the flat
stones, those of a fair size; search, above all, the piles which
the shepherds set up for a seat whence to watch the sheep browsing
amongst the lavender below. Do not be too easily disheartened:
the Clotho is rare; not every spot suits her. If fortune smile at
last upon our perseverance, we shall see, clinging to the lower
surface of the stone which we have lifted, an edifice of a weather-
beaten aspect, shaped like an over-turned cupola and about the size
of half a tangerine orange. The outside is encrusted or hung with
small shells, particles of earth and, especially, dried insects.
The edge of the cupola is scalloped into a dozen angular lobes, the
points of which spread and are fixed to the stone. In between
these straps is the same number of spacious inverted arches. The
whole represents the Ishmaelite's camel-hair tent, but upside down.
A flat roof, stretched between the straps, closes the top of the
dwelling.
Then where is the entrance? All the arches of the edge open upon
the roof; not one leads to the interior. The eye seeks in vain;
there is nothing to point to a passage between the inside and the
outside. Yet the owner of the house must go out from time to time,
were it only in search of food; on returning from her expedition,
she must go in again. How does she make her exits and her
entrances? A straw will tell us the secret.
Pass it over the threshold of the various arches. Everywhere, the
searching straw encounters resistance; everywhere, it finds the
place rigorously closed. But one of the scallops, differing in no
wise from the others in appearance, if cleverly coaxed, opens at
the edge into two lips and stands slightly ajar. This is the door,
which at once shuts again of its own elasticity. Nor is this all:
the Spider, when she returns home, often bolts herself in, that is
to say, she joins and fastens the two leaves of the door with a
little silk.
The Mason Mygale is no safer in her burrow, with its lid
undistinguishable from the soil and moving on a hinge, than is the
Clotho in her tent, which is inviolable by any enemy ignorant of
the device. The Clotho, when in danger, runs quickly home; she
opens the chink with a touch of her claw, enters and disappears.
The door closes of itself and is supplied, in case of need, with a
lock consisting of a few threads. No burglar, led astray by the
multiplicity of arches, one and all alike, will ever discover how
the fugitive vanished so suddenly.
While the Clotho displays a more simple ingenuity as regards her
defensive machinery, she is incomparably ahead of the Mygale in the
matter of domestic comfort. Let us open her cabin. What luxury!
We are taught how a Sybarite of old was unable to rest, owing to
the presence of a crumpled rose-leaf in his bed. The Clotho is
quite as fastidious. Her couch is more delicate than swan's-down
and whiter than the fleece of the clouds where brood the summer
storms. It is the ideal blanket. Above is a canopy or tester of
equal softness. Between the two nestles the Spider, short-legged,
clad in sombre garments, with five yellow favours on her back.
Rest in this exquisite retreat demands perfect stability,
especially on gusty days, when sharp draughts penetrate beneath the
stone. This condition is admirably fulfilled. Take a careful look
at the habitation. The arches that gird the roof with a balustrade
and bear the weight of the edifice are fixed to the slab by their
extremities. Moreover, from each point of contact, there issues a
cluster of diverging threads that creep along the stone and cling
to it throughout their length, which spreads afar. I have measured
some fully nine inches long. These are so many cables; they
represent the ropes and pegs that hold the Arab's tent in position.
With such supports as these, so numerous and so methodically
arranged, the hammock cannot be torn from its bearings save by the
intervention of brutal methods with which the Spider need not
concern herself, so seldom do they occur.
Another detail attracts our attention: whereas the interior of the
house is exquisitely clean, the outside is covered with dirt, bits
of earth, chips of rotten wood, little pieces of gravel. Often
there are worse things still: the exterior of the tent becomes a
charnel-house. Here, hung up or embedded, are the dry carcasses of
Opatra, Asidae and other Tenebrionidae {39} that favour underrock
shelters; segments of Iuli, {40} bleached by the sun; shells of
Pupae, {41} common among the stones; and, lastly, Snail-shells,
selected from among the smallest.
These relics are obviously, for the most part, table-leavings,
broken victuals. Unversed in the trapper's art, the Clotho courses
her game and lives upon the vagrants who wander from one stone to
another. Whoso ventures under the slab at night is strangled by
the hostess; and the dried-up carcass, instead of being flung to a
distance, is hung to the silken wall, as though the Spider wished
to make a bogey-house of her home. But this cannot be her aim. To
act like the ogre who hangs his victims from the castle battlements
is the worst way to disarm suspicion in the passers-by whom you are
lying in wait to capture.
There are other reasons which increase our doubts. The shells hung
up are most often empty; but there are also some occupied by the
Snail, alive and untouched. What can the Clotho do with a Pupa
cinerea, a Pupa quadridens and other narrow spirals wherein the
animal retreats to an inaccessible depth? The Spider is incapable
of breaking the calcareous shell or of getting at the hermit
through the opening. Then why should she collect those prizes,
whose slimy flesh is probably not to her taste? We begin to
suspect a simple question of ballast and balance. The House
Spider, or Tegenaria domestica, prevents her web, spun in a corner
of the wall, from losing its shape at the least breath of air, by
loading it with crumbling plaster and allowing tiny fragments of
mortar to accumulate. Are we face to face with a similar process?
Let us try experiment, which is preferable to any amount of
conjecture.
To rear the Clotho is not an arduous undertaking; we are not
obliged to take the heavy flagstone, on which the dwelling is
built, away with us. A very simple operation suffices. I loosen
the fastenings with my pocket-knife. The Spider has such stay-at-
home ways that she very rarely makes off. Besides, I use the
utmost discretion in my rape of the house. And so I carry away the
building, together with its owner, in a paper bag.
The flat stones, which are too heavy to move and which would occupy
too much room upon my table, are replaced either by deal disks,
which once formed part of cheese-boxes, or by round pieces of
cardboard. I arrange each silken hammock under one of these by
itself, fastening the angular projections, one by one, with strips
of gummed paper. The whole stands on three short pillars and gives
a very fair imitation of the underrock shelter in the form of a
small dolmen. Throughout this operation, if you are careful to
avoid shocks and jolts, the Spider remains indoors. Finally, each
apparatus is placed under a wire-gauze, bell-shaped cage, which
stands in a dish filled with sand.
We can have an answer by the next morning. If, among the cabins
swung from the ceilings of the deal or cardboard dolmens, there be
one that is all dilapidated, that was seriously knocked out of
shape at the time of removal, the Spider abandons it during the
night and instals herself elsewhere, sometimes even on the trellis-
work of the wire cage.
The new tent, the work of a few hours, attains hardly the diameter
of a two-franc piece. It is built, however, on the same principles
as the old manor-house and consists of two thin sheets laid one
above the other, the upper one flat and forming a tester, the lower
curved and pocket-shaped. The texture is extremely delicate: the
least trifle would deform it, to the detriment of the available
space, which is already much reduced and only just sufficient for
the recluse.
Well, what has the Spider done to keep the gossamer stretched, to
steady it and to make it retain its greatest capacity? Exactly
what our static treatises would advise her to do: she has
ballasted her structure, she has done her best to lower its centre
of gravity. From the convex surface of the pocket hang long
chaplets of grains of sand strung together with slender silken
cords. To these sandy stalactites, which form a bushy beard, are
added a few heavy lumps hung separately and lower down, at the end
of a thread. The whole is a piece of ballast-work, an apparatus
for ensuring equilibrium and tension.
The present edifice, hastily constructed in the space of a night,
is the frail rough sketch of what the home will afterwards become.
Successive layers will be added to it; and the partition-wall will
grow into a thick blanket capable of partly retaining, by its own
weight, the requisite curve and capacity. The Spider now abandons
the stalactites of sand, which were used to keep the original
pocket stretched, and confines herself to dumping down on her abode
any more or less heavy object, mainly corpses of insects, because
she need not look for these and finds them ready to hand after each
meal. They are weights, not trophies; they take the place of
materials that must otherwise be collected from a distance and
hoisted to the top. In this way, a breastwork is obtained that
strengthens and steadies the house. Additional equilibrium is
often supplied by tiny shells and other objects hanging a long way
down.
What would happen if one robbed an old dwelling, long since
completed, of its outer covering? In case of such a disaster,
would the Spider go back to the sandy stalactites, as a ready means
of restoring stability? This is easily ascertained. In my hamlets
under wire, I select a fair-sized cabin. I strip the exterior,
carefully removing any foreign body. The silk reappears in its
original whiteness. The tent looks magnificent, but seems to me
too limp.
This is also the Spider's opinion. She sets to work, next evening,
to put things right. And how? Once more with hanging strings of
sand. In a few nights, the silk bag bristles with a long, thick
beard of stalactites, a curious piece of work, excellently adapted
to maintain the web in an unvaried curve. Even so are the cables
of a suspension-bridge steadied by the weight of the
superstructure.
Later, as the Spider goes on feeding, the remains of the victuals
are embedded in the wall, the sand is shaken and gradually drops
away and the home resumes its charnel-house appearance. This
brings us to the same conclusion as before: the Clotho knows her
statics; by means of additional weights, she is able to lower the
centre of gravity and thus to give her dwelling the proper
equilibrium and capacity.
Now what does she do in her softly-wadded home? Nothing, that I
know of. With a full stomach, her legs luxuriously stretched over
the downy carpet, she does nothing, thinks of nothing; she listens
to the sound of earth revolving on its axis. It is not sleep,
still less is it waking; it is a middle state where naught prevails
save a dreamy consciousness of well-being. We ourselves, when
comfortably in bed, enjoy, just before we fall asleep, a few
moments of bliss, the prelude to cessation of thought and its train
of worries; and those moments are among the sweetest in our lives.
The Clotho seems to know similar moments and to make the most of
them.
If I push open the door of the cabin, invariably I find the Spider
lying motionless, as though in endless meditation. It needs the
teasing of a straw to rouse her from her apathy. It needs the
prick of hunger to bring her out of doors; and, as she is extremely
temperate, her appearances outside are few and far between. During
three years of assiduous observation, in the privacy of my study, I
have not once seen her explore the domain of the wire cage by day.
Not until a late hour at night does she venture forth in quest of
victuals; and it is hardly feasible to follow her on her
excursions.
Patience once enabled me to find her, at ten o'clock in the
evening, taking the air on the flat roof of her house, where she
was doubtless waiting for the game to pass. Startled by the light
of my candle, the lover of darkness at once returned indoors,
refusing to reveal any of her secrets. Only, next day, there was
one more corpse hanging from the wall of the cabin, a proof that
the chase was successfully resumed after my departure.
The Clotho, who is not only nocturnal, but also excessively shy,
conceals her habits from us; she shows us her works, those precious
historical documents, but hides her actions, especially the laying,
which I estimate approximately to take place in October. The sum
total of the eggs is divided into five or six small, flat,
lentiform pockets, which, taken together, occupy the greater part
of the maternal home. These capsules have each their own
partition-wall of superb white satin, but they are so closely
soldered, both together and to the floor of the house, that it is
impossible to part them without tearing them, impossible,
therefore, to obtain them separately. The eggs in all amount to
about a hundred.
The mother sits upon the heap of pockets with the same devotion as
a brooding hen. Maternity has not withered her. Although
decreased in bulk, she retains an excellent look of health; her
round belly and her well-stretched skin tell us from the first that
her part is not yet wholly played.
The hatching takes place early. November has not arrived before
the pockets contain the young: wee things clad in black, with five
yellow specks, exactly like their elders. The new-born do not
leave their respective nurseries. Packed close together, they
spend the whole of the wintry season there, while the mother,
squatting on the pile of cells, watches over the general safety,
without knowing her family other than by the gentle trepidations
felt through the partitions of the tiny chambers. The Labyrinth
Spider has shown us how she maintains a permanent sitting for two
months in her guard-room, to defend, in case of need, the brood
which she will never see. The Clotho does the same during eight
months, thus earning the right to set eyes for a little while on
her family trotting around her in the main cabin and to assist at
the final exodus, the great journey undertaken at the end of a
thread.
When the summer heat arrives, in June, the young ones, probably
aided by their mother, pierce the walls of their cells, leave the
maternal tent, of which they know the secret outlet well, take the
air on the threshold for a few hours and then fly away, carried to
some distance by a funicular aeroplane, the first product of their
spinning-mill.
The elder Clotho remains behind, careless of this emigration which
leaves her alone. She is far from being faded indeed, she looks
younger than ever. Her fresh colour, her robust appearance suggest
great length of life, capable of producing a second family. On
this subject I have but one document, a pretty far-reaching one,
however. There were a few mothers whose actions I had the patience
to watch, despite the wearisome minutiae of the rearing and the
slowness of the result. These abandoned their dwellings after the
departure of their young; and each went to weave a new one for
herself on the wire net-work of the cage.
They were rough-and-ready summaries, the work of a night. Two
hangings, one above the other, the upper one flat, the lower
concave and ballasted with stalactites of grains of sand, formed
the new home, which, strengthened daily by fresh layers, promised
to become similar to the old one. Why does the Spider desert her
former mansion, which is in no way dilapidated--far from it--and
still exceedingly serviceable, as far as one can judge? Unless I
am mistaken, I think I have an inkling of the reason.
The old cabin, comfortably wadded though it be, possesses serious
disadvantages: it is littered with the ruins of the children's
nurseries. These ruins are so close-welded to the rest of the home
that my forceps cannot extract them without difficulty; and to
remove them would be an exhausting business for the Clotho and
possibly beyond her strength. It is a case of the resistance of
Gordian knots, which not even the very spinstress who fastened them
is capable of untying. The encumbering litter, therefore, will
remain.
If the Spider were to stay alone, the reduction of space, when all
is said, would hardly matter to her: she wants so little room,
merely enough to move in! Besides, when you have spent seven or
eight months in the cramping presence of those bedchambers, what
can be the reason of a sudden need for greater space? I see but
one: the Spider requires a roomy habitation, not for herself--she
is satisfied with the smallest den--but for a second family. Where
is she to place the pockets of eggs, if the ruins of the previous
laying remain in the way? A new brood requires a new home. That,
no doubt, is why, feeling that her ovaries are not yet dried up,
the Spider shifts her quarters and founds a new establishment.
The facts observed are confined to this change of dwelling. I
regret that other interests and the difficulties attendant upon a
long upbringing did not allow me to pursue the question and
definitely to settle the matter of the repeated layings and the
longevity of the Clotho, as I did in that of the Lycosa.
Before taking leave of this Spider, let us glance at a curious
problem which has already been set by the Lycosa's offspring. When
carried for seven months on the mother's back, they keep in
training as agile gymnasts without taking any nourishment. It is a
familiar exercise for them, after a fall, which frequently occurs,
to scramble up a leg of their mount and nimbly to resume their
place in the saddle. They expend energy without receiving any
material sustenance.
The sons of the Clotho, the Labyrinth Spider and many others
confront us with the same riddle: they move, yet do not eat. At
any period of the nursery stage, even in the heart of winter, on
the bleak days of January, I tear the pockets of the one and the
tabernacle of the other, expecting to find the swarm of youngsters
lying in a state of complete inertia, numbed by the cold and by
lack of food. Well, the result is quite different. The instant
their cells are broken open, the anchorites run out and flee in
every direction as nimbly as at the best moments of their normal
liberty. It is marvellous to see them scampering about. No brood
of Partridges, stumbled upon by a Dog, scatters more promptly.
Chicks, while still no more than tiny balls of yellow fluff, hasten
up at the mother's call and scurry towards the plate of rice.
Habit has made us indifferent to the spectacle of those pretty
little animal machines, which work so nimbly and with such
precision; we pay no attention, so simple does it all appear to us.
Science examines and looks at things differently. She says to
herself:
'Nothing is made with nothing. The chick feeds itself; it consumes
or rather it assimilates and turns the food into heat, which is
converted into energy.'
Were any one to tell us of a chick which, for seven or eight months
on end, kept itself in condition for running, always fit, always
brisk, without taking the least beakful of nourishment from the day
when it left the egg, we could find no words strong enough to
express our incredulity. Now this paradox of activity maintained
without the stay of food is realized by the Clotho Spider and
others.
I believe I have made it sufficiently clear that the young Lycosae
take no food as long as they remain with their mother. Strictly
speaking, doubt is just admissible, for observation is needs dumb
as to what may happen earlier or later within the mysteries of the
burrow. It seems possible that the repleted mother may there
disgorge to her family a mite of the contents of her crop. To this
suggestion the Clotho undertakes to make reply.
Like the Lycosa, she lives with her family; but the Clotho is
separated from them by the walls of the cells in which the little
ones are hermetically enclosed. In this condition, the
transmission of solid nourishment becomes impossible. Should any
one entertain a theory of nutritive humours cast up by the mother
and filtering through the partitions at which the prisoners might
come and drink, the Labyrinth Spider would at once dispel the idea.
She dies a few weeks after her young are hatched; and the children,
still locked in their satin bed-chamber for the best part of the
year, are none the less active.
Can it be that they derive sustenance from the silken wrapper? Do
they eat their house? The supposition is not absurd, for we have
seen the Epeirae, before beginning a new web, swallow the ruins of
the old. But the explanation cannot be accepted, as we learn from
the Lycosa, whose family boasts no silky screen. In short, it is
certain that the young, of whatever species, take absolutely no
nourishment.
Lastly, we wonder whether they may possess within themselves
reserves that come from the egg, fatty or other matters the gradual
combustion of which would be transformed into mechanical force. If
the expenditure of energy were of but short duration, a few hours
or a few days, we could gladly welcome this idea of a motor
viaticum, the attribute of every creature born into the world. The
chick possesses it in a high degree: it is steady on its legs, it
moves for a little while with the sole aid of the food wherewith
the egg furnishes it; but soon, if the stomach is not kept
supplied, the centre of energy becomes extinct and the bird dies.
How would the chick fare if it were expected, for seven or eight
months without stopping, to stand on its feet, to run about, to
flee in the face of danger? Where would it stow the necessary
reserves for such an amount of work?
The little Spider, in her turn, is a minute particle of no size at
all. Where could she store enough fuel to keep up mobility during
so long a period? The imagination shrinks in dismay before the
thought of an atom endowed with inexhaustible motive oils.
We must needs, therefore, appeal to the immaterial, in particular
to heat-rays coming from the outside and converted into movement by
the organism. This is nutrition of energy reduced to its simplest
expression: the motive heat, instead of being extracted from the
food, is utilized direct, as supplied by the sun, which is the seat
of all life. Inert matter has disconcerting secrets, as witness
radium; living matter has secrets of its own, which are more
wonderful still. Nothing tells us that science will not one day
turn the suspicion suggested by the Spider into an established
truth and a fundamental theory of physiology.
APPENDIX: THE GEOMETRY OF THE EPEIRA'S WEB
I find myself confronted with a subject which is not only highly
interesting, but somewhat difficult: not that the subject is
obscure; but it presupposes in the reader a certain knowledge of
geometry: a strong meat too often neglected. I am not addressing
geometricians, who are generally indifferent to questions of
instinct, nor entomological collectors, who, as such, take no
interest in mathematical theorems; I write for any one with
sufficient intelligence to enjoy the lessons which the insect
teaches.
What am I to do? To suppress this chapter were to leave out the
most remarkable instance of Spider industry; to treat it as it
should be treated, that is to say, with the whole armoury of
scientific formulae, would be out of place in these modest pages.
Let us take a middle course, avoiding both abstruse truths and
complete ignorance.
Let us direct our attention to the nets of the Epeirae, preferably
to those of the Silky Epeira and the Banded Epeira, so plentiful in
the autumn, in my part of the country, and so remarkable for their
bulk. We shall first observe that the radii are equally spaced;
the angles formed by each consecutive pair are of perceptibly equal
value; and this in spite of their number, which in the case of the
Silky Epeira exceeds two score. We know by what strange means the
Spider attains her ends and divides the area wherein the web is to
be warped into a large number of equal sectors, a number which is
almost invariable in the work of each species. An operation
without method, governed, one might imagine, by an irresponsible
whim, results in a beautiful rose-window worthy of our compasses.
We shall also notice that, in each sector, the various chords, the
elements of the spiral windings, are parallel to one another and
gradually draw closer together as they near the centre. With the
two radiating lines that frame them they form obtuse angles on one
side and acute angles on the other; and these angles remain
constant in the same sector, because the chords are parallel.
There is more than this: these same angles, the obtuse as well as
the acute, do not alter in value, from one sector to another, at
any rate so far as the conscientious eye can judge. Taken as a
whole, therefore, the rope-latticed edifice consists of a series of
cross-bars intersecting the several radiating lines obliquely at
angles of equal value.
By this characteristic we recognize the 'logarithmic spiral.'
Geometricians give this name to the curve which intersects
obliquely, at angles of unvarying value, all the straight lines or
'radii vectores' radiating from a centre called the 'Pole.' The
Epeira's construction, therefore, is a series of chords joining the
intersections of a logarithmic spiral with a series of radii. It
would become merged in this spiral if the number of radii were
infinite, for this would reduce the length of the rectilinear
elements indefinitely and change this polygonal line into a curve.
To suggest an explanation why this spiral has so greatly exercised
the meditations of science, let us confine ourselves for the
present to a few statements of which the reader will find the proof
in any treatise on higher geometry.
The logarithmic spiral describes an endless number of circuits
around its pole, to which it constantly draws nearer without ever
being able to reach it. This central point is indefinitely
inaccessible at each approaching turn. It is obvious that this
property is beyond our sensory scope. Even with the help of the
best philosophical instruments, our sight could not follow its
interminable windings and would soon abandon the attempt to divide
the invisible. It is a volute to which the brain conceives no
limits. The trained mind, alone, more discerning than our retina,
sees clearly that which defies the perceptive faculties of the eye.
The Epeira complies to the best of her ability with this law of the
endless volute. The spiral revolutions come closer together as
they approach the pole. At a given distance, they stop abruptly;
but, at this point, the auxiliary spiral, which is not destroyed in
the central region, takes up the thread; and we see it, not without
some surprise, draw nearer to the pole in ever-narrowing and
scarcely perceptible circles. There is not, of course, absolute
mathematical accuracy, but a very close approximation to that
accuracy. The Epeira winds nearer and nearer round her pole, so
far as her equipment, which, like our own, is defective, will allow
her. One would believe her to be thoroughly versed in the laws of
the spiral.
I will continue to set forth, without explanations, some of the
properties of this curious curve. Picture a flexible thread wound
round a logarithmic spiral. If we then unwind it, keeping it taut
the while, its free extremity will describe a spiral similar at all
points to the original. The curve will merely have changed places.
Jacques Bernouilli, {42} to whom geometry owes this magnificent
theorem, had engraved on his tomb, as one of his proudest titles to
fame, the generating spiral and its double, begotten of the
unwinding of the thread. An inscription proclaimed, 'Eadem mutata
resurgo: I rise again like unto myself.' Geometry would find it
difficult to better this splendid flight of fancy towards the great
problem of the hereafter.
There is another geometrical epitaph no less famous. Cicero, when
quaestor in Sicily, searching for the tomb of Archimedes amid the
thorns and brambles that cover us with oblivion, recognized it,
among the ruins, by the geometrical figure engraved upon the stone:
the cylinder circumscribing the sphere. Archimedes, in fact, was
the first to know the approximate relation of circumference to
diameter; from it he deduced the perimeter and surface of the
circle, as well as the surface and volume of the sphere. He showed
that the surface and volume of the last-named equal two-thirds of
the surface and volume of the circumscribing cylinder. Disdaining
all pompous inscription, the learned Syracusan honoured himself
with his theorem as his sole epitaph. The geometrical figure
proclaimed the individual's name as plainly as would any
alphabetical characters.
To have done with this part of our subject, here is another
property of the logarithmic spiral. Roll the curve along an
indefinite straight line. Its pole will become displaced while
still keeping on one straight line. The endless scroll leads to
rectilinear progression; the perpetually varied begets uniformity.
Now is this logarithmic spiral, with its curious properties, merely
a conception of the geometers, combining number and extent, at
will, so as to imagine a tenebrous abyss wherein to practise their
analytical methods afterwards? Is it a mere dream in the night of
the intricate, an abstract riddle flung out for our understanding
to browse upon?
No, it is a reality in the service of life, a method of
construction frequently employed in animal architecture. The
Mollusc, in particular, never rolls the winding ramp of the shell
without reference to the scientific curve. The first-born of the
species knew it and put it into practice; it was as perfect in the
dawn of creation as it can be to-day.
Let us study, in this connection, the Ammonites, those venerable
relics of what was once the highest expression of living things, at
the time when the solid land was taking shape from the oceanic
ooze. Cut and polished length-wise, the fossil shows a magnificent
logarithmic spiral, the general pattern of the dwelling which was a
pearl palace, with numerous chambers traversed by a siphuncular
corridor.
To this day, the last representative of the Cephalopoda with
partitioned shells, the Nautilus of the Southern Seas, remains
faithful to the ancient design; it has not improved upon its
distant predecessors. It has altered the position of the
siphuncle, has placed it in the centre instead of leaving it on the
back, but it still whirls its spiral logarithmically as did the
Ammonites in the earliest ages of the world's existence.
And let us not run away with the idea that these princes of the
Mollusc tribe have a monopoly of the scientific curve. In the
stagnant waters of our grassy ditches, the flat shells, the humble
Planorbes, sometimes no bigger than a duckweed, vie with the
Ammonite and the Nautilus in matters of higher geometry. At least
one of them, Planorbis vortex, for example, is a marvel of
logarithmic whorls.
In the long-shaped shells, the structure becomes more complex,
though remaining subject to the same fundamental laws. I have
before my eyes some species of the genus Terebra, from New
Caledonia. They are extremely tapering cones, attaining almost
nine inches in length. Their surface is smooth and quite plain,
without any of the usual ornaments, such as furrows, knots or
strings of pearls. The spiral edifice is superb, graced with its
own simplicity alone. I count a score of whorls which gradually
decrease until they vanish in the delicate point. They are edged
with a fine groove.
I take a pencil and draw a rough generating line to this cone; and,
relying merely on the evidence of my eyes, which are more or less
practised in geometric measurements, I find that the spiral groove
intersects this generating line at an angle of unvarying value.
The consequence of this result is easily deduced. If projected on
a plane perpendicular to the axis of the shell, the generating
lines of the cone would become radii; and the groove which winds
upwards from the base to the apex would be converted into a plane
curve which, meeting those radii at an unvarying angle, would be
neither more nor less than a logarithmic spiral. Conversely, the
groove of the shell may be considered as the projection of this
spiral on a conic surface.
Better still. Let us imagine a plane perpendicular to the aids of
the shell and passing through its summit. Let us imagine,
moreover, a thread wound along the spiral groove. Let us unroll
the thread, holding it taut as we do so. Its extremity will not
leave the plane and will describe a logarithmic spiral within it.
It is, in a more complicated degree, a variant of Bernouilli's
'Eadem mutata resurgo:' the logarithmic conic curve becomes a
logarithmic plane curve.
A similar geometry is found in the other shells with elongated
cones, Turritellae, Spindle-shells, Cerithia, as well as in the
shells with flattened cones, Trochidae, Turbines. The spherical
shells, those whirled into a volute, are no exception to this rule.
All, down to the common Snail-shell, are constructed according to
logarithmic laws. The famous spiral of the geometers is the
general plan followed by the Mollusc rolling its stone sheath.
Where do these glairy creatures pick up this science? We are told
that the Mollusc derives from the Worm. One day, the Worm,
rendered frisky by the sun, emancipated itself, brandished its tail
and twisted it into a corkscrew for sheer glee. There and then the
plan of the future spiral shell was discovered.
This is what is taught quite seriously, in these days, as the very
last word in scientific progress. It remains to be seen up to what
point the explanation is acceptable. The Spider, for her part,
will have none of it. Unrelated to the appendix-lacking,
corkscrew-twirling Worm, she is nevertheless familiar with the
logarithmic spiral. From the celebrated curve she obtains merely a
sort of framework; but, elementary though this framework be, it
clearly marks the ideal edifice. The Epeira works on the same
principles as the Mollusc of the convoluted shell.
The Mollusc has years wherein to construct its spiral and it uses
the utmost finish in the whirling process. The Epeira, to spread
her net, has but an hour's sitting at the most, wherefore the speed
at which she works compels her to rest content with a simpler
production. She shortens the task by confining herself to a
skeleton of the curve which the other describes to perfection.
The Epeira, therefore, is versed in the geometric secrets of the
Ammonite and the Nautilus pompilus; she uses, in a simpler form,
the logarithmic line dear to the Snail. What guides her? There is
no appeal here to a wriggle of some kind, as in the case of the
Worm that ambitiously aspires to become a Mollusc. The animal must
needs carry within itself a virtual diagram of its spiral.
Accident, however fruitful in surprises we may presume it to be,
can never have taught it the higher geometry wherein our own
intelligence at once goes astray, without a strict preliminary
training.
Are we to recognize a mere effect of organic structure in the
Epeira's art? We readily think of the legs, which, endowed with a
very varying power of extension, might serve as compasses. More or
less bent, more or less outstretched, they would mechanically
determine the angle whereat the spiral shall intersect the radius;
they would maintain the parallel of the chords in each sector.
Certain objections arise to affirm that, in this instance, the tool
is not the sole regulator of the work. Were the arrangement of the
thread determined by the length of the legs, we should find the
spiral volutes separated more widely from one another in proportion
to the greater length of implement in the spinstress. We see this
in the Banded Epeira and the Silky Epeira. The first has longer
limbs and spaces her cross-threads more liberally than does the
second, whose legs are shorter.
But we must not rely too much on this rule, say others. The
Angular Epeira, the Paletinted Epeira and the Cross Spider, all
three more or less short-limbed, rival the Banded Epeira in the
spacing of their lime-snares. The last two even dispose them with
greater intervening distances.
We recognize in another respect that the organization of the animal
does not imply an immutable type of work. Before beginning the
sticky spiral, the Epeirae first spin an auxiliary intended to
strengthen the stays. This spiral, formed of plain, non-glutinous
thread, starts from the centre and winds in rapidly-widening
circles to the circumference. It is merely a temporary
construction, whereof naught but the central part survives when the
Spider has set its limy meshes. The second spiral, the essential
part of the snare, proceeds, on the contrary, in serried coils from
the circumference to the centre and is composed entirely of viscous
cross-threads.
Here we have, following one after the other merely by a sudden
alteration of the machine, two volutes of an entirely different
order as regards direction, the number of whorls and intersection.
Both of them are logarithmic spirals. I see no mechanism of the
legs, be they long or short, that can account for this alteration.
Can it then be a premeditated design on the part of the Epeira?
Can there be calculation, measurement of angles, gauging of the
parallel by means of the eye or otherwise? I am inclined to think
that there is none of all this, or at least nothing but an innate
propensity, whose effects the animal is no more able to control
than the flower is able to control the arrangement of its
verticils. The Epeira practises higher geometry without knowing or
caring. The thing works of itself and takes its impetus from an
instinct imposed upon creation from the start.
The stone thrown by the hand returns to earth describing a certain
curve; the dead leaf torn and wafted away by a breath of wind makes
its journey from the tree to the ground with a similar curve. On
neither the one side nor the other is there any action by the
moving body to regulate the fall; nevertheless, the descent takes
place according to a scientific trajectory, the 'parabola,' of
which the section of a cone by a plane furnished the prototype to
the geometer's speculations. A figure, which was at first but a
tentative glimpse, becomes a reality by the fall of a pebble out of
the vertical.
The same speculations take up the parabola once more, imagine it
rolling on an indefinite straight line and ask what course does the
focus of this curve follow. The answer comes: The focus of the
parabola describes a 'catenary,' a line very simple in shape, but
endowed with an algebraic symbol that has to resort to a kind of
cabalistic number at variance with any sort of numeration, so much
so that the unit refuses to express it, however much we subdivide
the unit. It is called the number e. Its value is represented by
the following series carried out ad infinitum:
e = 1 + 1/1 + 1/(1*2) + 1/(1*2*3) + 1/(1*2*3*4) + 1/(1*2*3*4*5) +
etc
If the reader had the patience to work out the few initial terms of
this series, which has no limit, because the series of natural
numerals itself has none, he would find:
e=2.7182818...
With this weird number are we now stationed within the strictly
defined realm of the imagination? Not at all: the catenary
appears actually every time that weight and flexibility act in
concert. The name is given to the curve formed by a chain
suspended by two of its points which are not placed on a vertical
line. It is the shape taken by a flexible cord when held at each
end and relaxed; it is the line that governs the shape of a sail
bellying in the wind; it is the curve of the nanny-goat's milk-bag
when she returns from filling her trailing udder. And all this
answers to the number e.
What a quantity of abstruse science for a bit of string! Let us
not be surprised. A pellet of shot swinging at the end of a
thread, a drop of dew trickling down a straw, a splash of water
rippling under the kisses of the air, a mere trifle, after all,
requires a titanic scaffolding when we wish to examine it with the
eye of calculation. We need the club of Hercules to crush a fly.
Our methods of mathematical investigation are certainly ingenious;
we cannot too much admire the mighty brains that have invented
them; but how slow and laborious they appear when compared with the
smallest actualities! Will it never be given to us to probe
reality in a simpler fashion? Will our intelligence be able one
day to dispense with the heavy arsenal of formulae? Why not?
Here we have the abracadabric number e reappearing, inscribed on a
Spider's thread. Let us examine, on a misty morning, the meshwork
that has been constructed during the night. Owing to their
hygrometrical nature, the sticky threads are laden with tiny drops,
and, bending under the burden, have become so many catenaries, so
many chaplets of limpid gems, graceful chaplets arranged in
exquisite order and following the curve of a swing. If the sun
pierce the mist, the whole lights up with iridescent fires and
becomes a resplendent cluster of diamonds. The number e is in its
glory.
Geometry, that is to say, the science of harmony in space, presides
over everything. We find it in the arrangement of the scales of a
fir-cone, as in the arrangement of an Epeira's limy web; we find it
in the spiral of a Snail-shell, in the chaplet of a Spider's
thread, as in the orbit of a planet; it is everywhere, as perfect
in the world of atoms as in the world of immensities.
And this universal geometry tells us of an Universal Geometrician,
whose divine compass has measured all things. I prefer that, as an
explanation of the logarithmic curve of the Ammonite and the
Epeira, to the Worm screwing up the tip of its tail. It may not
perhaps be in accordance with latter-day teaching, but it takes a
loftier flight.
Footnotes:
{1} A small or moderate-sized spider found among foliage.--
Translator's Note.
{2} Leon Dufour (1780-1865) was an army surgeon who served with
distinction in several campaigns and subsequently practised as a
doctor in the Landes. He attained great eminence as a naturalist.-
-Translator's Note.
{3} The Tarantula is a Lycosa, or Wolf-spider. Fabre's Tarantula,
the Black-bellied Tarantula, is identical with the Narbonne Lycosa,
under which name the description is continued in Chapters iii. to
vi., all of which were written at a considerably later date than
the present chapter.--Translator's Note.
{4} Giorgio Baglivi (1669-1707), professor of anatomy and medicine
at Rome.--Translator's Note.
{5} 'When our husbandmen wish to catch them, they approach their
hiding-places, and play on a thin grass pipe, making a sound not
unlike the humming of bees. Hearing which, the Tarantula rushes
out fiercely that she may catch the flies or other insects of this
kind, whose buzzing she thinks it to be; but she herself is caught
by her rustic trapper.'
{6} Provencal for the bit of waste ground on which the author
studies his insects in the natural state.--Translator's note.
{7} 'Thanks to the Bumble-bee.'
{8} Like the Dung-beetles.--Translator's Note.
{9} Like the Solitary Wasps.--Translator's Note.
{10} Such as the Hairy Ammophila, the Cerceris and the
Languedocian Sphex, Digger-wasps described in other of the author's
essays.--Translator's Note.
{11} The desnucador, the Argentine slaughterman whose methods of
slaying cattle are detailed in the author's essay entitled, The
Theory of Instinct.--Translator's Note.
{12} A family of Grasshoppers.--Translator's Note.
{13} A genus of Beetles.--Translator's Note.
{14} A species of Digger-wasp.--Translator's Note.
{15} The Cicada is the Cigale, an insect akin to the Grasshopper
and found more particularly in the South of France.--Translator's
Note.
{16} The generic title of the work from which these essays are
taken is Entomological Memories, or, Studies relating to the
Instinct and Habits of Insects.--Translator's Note.
{17} A species of Grasshopper.--Translator's Note.
{18} An insect akin to the Locusts and Crickets, which, when at
rest, adopts an attitude resembling that of prayer. When
attacking, it assumes what is known as 'the spectral attitude.'
Its forelegs form a sort of saw-like or barbed harpoons. Cf.
Social Life in the Insect World, by J. H. Fabre, translated by
Bernard Miall: chaps. v. to vii.- Translator's Note.
{19} .39 inch.-- Translator's Note.
{20} These experiments are described in the author's essay on the
Mason Bees entitled Fragments on Insect Psychology.--Translator's
Note.
{21} A species of Wasp.--Translator's Note.
{22} In Chap. VIII. of the present volume.--Translator's Note.
{23} Jules Michelet (1798-1874), author of L'Oiseau and L'Insecte,
in addition to the historical works for which he is chiefly known.
As a lad, he helped his father, a printer by trade, in setting
type.--Translator's Note.
{24} Chapter III. of the present volume.--Translator's Note.
{25} A species of Dung-beetle. Cf. The Life and Love of the
Insect, by J. Henri Fabre, translated by Alexander Teixeira de
Mattos: chap. v.--Translator's Note.
{26} A species of Beetle.--Translator's Note.
{27} Cf. Insect Life, by J. H. Fabre, translated by the author of
Mademoiselle Mori: chaps. i. and ii.; The Life and Love of the
Insect, by J. Henri Fabre, translated by Alexander Teixeira de
Mattos: chaps. i. to iv.--Translator's Note.
{28} Chapter II.--Translator's Note.
{29} .39 inch.--Translator's Note.
{30} The Processionaries are Moth-caterpillars that feed on
various leaves and march in file, laying a silken trail as they
go.--Translator's Note.
{31} The weekly half-holiday in French schools.--Translator's
Note.
{32} Cf. Social Life in the Insect World, by J. H. Fabre,
translated by Bernard Miall: chap. xiv.--Translator's Note.
{33} Cf. Insect Life, by J. H. Fabre, translated by the author of
Mademoiselle Mori: chap. v.--Translator's Note.
{34} The Scolia is a Digger-wasp, like the Cerceris and the Sphex,
and feeds her larvae on the grubs of the Cetonia, or Rose-chafer,
and the Oryctes, or Rhinoceros Beetle. Cf. The Life and Love of
the Insect, by J. Henri Fabre, translated by Alexander Teixeira de
Mattos: chap. xi.--Translator's Note.
{35} Cf. Social Life in the Insect World, by J. H. Fabre,
translated by Bernard Miall. chap. xiii., in which the name is
given, by a printer's error, as Philanthus aviporus.--Translator's
Note.
{36} Or Bird Spiders, known also as the American Tarantula.--
Translator's Note.
{37} .059 inch.--Translator's Note.
{38} The Ichneumon-flies are very small insects which carry long
ovipositors, wherewith they lay their eggs in the eggs of other
insects and also, more especially, in caterpillars. Their
parasitic larvae live and develop at the expense of the egg or grub
attacked, which degenerates in consequence.--Translator's Note.
{39} One of the largest families of Beetles, darkish in colour and
shunning the light.--Translator's Note.
{40} The Iulus is one of the family of Myriapods, which includes
Centipedes, etc.--Translator's Note.
{41} A species of Land-snail.--Translator's Note.
{42} Jacques Bernouilli (1654-1705), professor of mathematics at
the University of Basel from 1687 to the year of his death. He
improved the differential calculus, solved the isoperimetrical
problem and discovered the properties of the logarithmic spiral.--
Translator's Note.
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