THE GREY LOCUST
I have just witnessed a moving spectacle: the last moult of a locust;
the emergence of the adult from its larval envelope. It was magnificent.
I am speaking of the Grey Locust, the colossus among our acridians,
which is often seen among the vines in September when the grapes are
gathered. By its size--and it grows as long as a man's finger--it lends
itself to observation better than any other of its tribe.
The larva, disgustingly fat, like a rude sketch of the perfect insect,
is commonly of a tender green; but it is sometimes of a bluish green, a
dirty yellow, or a ruddy brown, or even an ashen grey, like the grey of
the adult cricket. The corselet is strongly keeled and indented, and is
sprinkled with fine white spots. As powerful as in the adult insect, the
hind-leg has a corpulent haunch, streaked with red, and a long shin like
a two-edged saw.
The elytra, which in a few days will extend far beyond the tip of the
abdomen, are at present too small triangular wing-like appendages,
touching along their upper edges, and continuing and emphasising the
keel or ridge of the corselet. Their free ends stick up like the gable
of a house. They remind one of the skirts of a coat, the maker of which
has been ludicrously stingy with the cloth, as they merely cover the
creature's nakedness at the small of the back. Underneath there are two
narrow appendages, the germs of the wings, which are even smaller than
the elytra. The sumptuous, elegant sails of to-morrow are now mere rags,
so miserly in their dimensions as to be absolutely grotesque. What will
emerge from these miserable coverings? A miracle of grace and amplitude.
Let us observe the whole process in detail. Feeling itself ripe for
transformation, the insect climbs up the wire-gauze cover by means of
its hinder and intermediate limbs. The fore-limbs are folded and crossed
on the breast, and are not employed in supporting the insect, which
hangs in a reversed position, the back downwards. The triangular
winglets, the sheaths of the elytra, open along their line of juncture
and separate laterally; the two narrow blades, which contain the wings,
rise in the centre of the interval and slightly diverge. The proper
position for the process of moulting has now been assumed and the proper
The first thing to do is to burst the old skin. Behind the corselet,
under the pointed roof of the prothorax, a series of pulsations is
produced by alternate inflation and deflation. A similar state of
affairs is visible in front of the neck, and probably under the entire
surface of the yielding carapace. The fineness of the membrane at the
articulations enables us to perceive it at these unarmoured points, but
the cuirass of the corselet conceals it in the central portion.
At these points the circulatory reserves of the insect are pulsing in
tidal onsets. Their gradual increase is betrayed by pulsations like
those of a hydraulic ram. Distended by this rush of humours, by this
injection in which the organism concentrates all its forces, the outer
skin finally splits along the line of least resistance which the subtle
previsions of life have prepared. The fissure extends the whole length
of the corselet, opening precisely along the ridge of the keel, as
though the two symmetrical halves had been soldered together.
Unbreakable elsewhere, the envelope has yielded at this median point,
which had remained weaker than the rest of the sheath. The fissure runs
back a little way until it reaches a point between the attachments of
the wings; on the head it runs forward as far as the base of the
antennae, when it sends a short ramification right and left.
Through this breach the back is seen; quite soft, and very pale, with
scarcely a tinge of grey. Slowly it curves upwards and becomes more and
more strongly hunched; at last it is free.
The head follows, withdrawing itself from its mask, which remains in
place, intact in the smallest detail, but looking very strange with its
great unseeing glassy eyes. The sheaths of the antennae, without a
wrinkle, without the least derangement, and in their natural place, hang
over this dead, translucid face.
In emerging from their narrow sheaths, which clasped them so tightly and
precisely, the thread-like antennae have evidently met with no
resistance, or the sheaths would have been turned inside out, or
crumpled out of shape, or wrinkled at least. Without harming the jointed
or knotted covers, the contents, of equal volume and equally knotty,
have slipped out as easily as though they were smooth, slippery objects
sliding out of a loose sheath. The method of extraction is still more
astonishing in the case of the hind-legs.
It is now, however, the turn of the front and intermediate pairs of
legs. They pull out of their gauntlets and leggings without the least
hitch; nothing is torn, nothing buckled; the outer skin is not even
crumpled, and all the tissues remain in their natural position. The
insect is now hanging from the dome of the cover solely by the claws of
the long hind-legs. It hangs in an almost vertical position, the head
downwards, swinging like a pendulum if I touch the cover. Four tiny,
steely claws are its only support. If they gave or unclasped themselves
the insect would be lost, as it is as yet unable to unfurl its enormous
wings; but even had the wings emerged they could not grip the air in
time to save the creature from the consequences of a fall. But the four
claws hold fast; life, before withdrawing from them, left them rigidly
contracted, so that they should support without yielding the struggles
and withdrawals to follow.
Now the wing-covers and wings emerge. These are four narrow strips,
vaguely seamed and furrowed, like strings of rolled tissue-paper. They
are barely a quarter of their final length.
They are so soft that they bend under their own weight, and hang down
the creature's sides in the reverse of their normal position. The free
extremities, which normally point backwards, are now pointing towards
the cricket's head as it hangs reversed. The organs of future flight are
like four leaves of withered foliage shattered by a terrific rainstorm.
A profound transformation is necessary to bring the wings to their final
perfection. The inner changes are already at work; liquids are
solidifying; albuminous secretions are bringing order out of chaos; but
so far no outward sign betrays what is happening in the mysterious
laboratory of the organism. All seems inert and lifeless.
In the meantime the posterior limbs disengage themselves. The great
haunches become visible, streaked on the inner faces with a pale rose,
which rapidly turns to a vivid crimson. Emergence is easy, the thick and
muscular upper portion of the haunch preparing the way for the narrower
part of the limb.
It is otherwise with the shank. This, in the adult insect, is armed
along its whole length by a double series of stiff, steely spines.
Moreover, the lower extremity is terminated by four strong spurs. The
shank forms a veritable saw, but with two parallel sets of teeth; and it
is so strongly made that it may well be compared, the question of size
apart, to the great saw of a quarry-man.
The shank of the larva has the same structure, so that the object to be
extracted is enclosed in a scabbard as awkwardly shaped as itself. Each
spur is enclosed in a similar spur; each tooth engages in the hollow of
a similar tooth, and the sheath is so closely moulded upon the shank
that a no more intimate contact could be obtained by replacing the
envelope by a layer of varnish applied with a brush.
Nevertheless the tibia, long and narrow as it is, issues from its sheath
without catching or sticking anywhere. If I had not repeatedly seen the
operation I could not believe it possible; for the discarded sheath is
absolutely intact from end to end. Neither the terminal spurs nor the
double rows of spines do the slightest damage to the delicate mould. The
long-toothed saw leaves the delicate sheath unbroken, although a puff of
the breath is enough to tear it; the ferocious spurs slip out of it
without leaving so much as a scratch.
I was far from expecting such a result. Having the spiny weapons of the
legs in mind, I imagined that those limbs would moult in scales and
patches, or that the sheathing would rub off like a dead scarf-skin. How
completely the reality surpassed my anticipations!
From the spurs and spines of the sheath, which is as thin as the finest
gold-beaters' skin, the spurs and spines of the leg, which make it a
most formidable weapon, capable of cutting a piece of soft wood, emerge
without the slightest display of violence, without a hitch of any kind;
and the empty skin remains in place. Still clinging by its claws to the
top of the wire cover, it is untorn, unwrinkled, uncreased. Even the
magnifying-glass fails to show a trace of rough usage. Such as the skin
was before the cricket left it, so it is now. The legging of dead skin
remains in its smallest details the exact replica of the living limb.
If any one asked you to extract a saw from a scabbard exactly moulded
upon the steel, and to conduct the operation without the slightest
degree of tearing or scratching, you would laugh at the flagrant
impossibility of the task. But life makes light of such absurdities; it
has its methods of performing the impossible when such methods are
required. The leg of the locust affords us such an instance.
Hard as it is when once free of its sheath, the serrated tibia would
absolutely refuse to leave the latter, so closely does it fit, unless it
were torn to pieces. Yet the difficulty must be evaded, for it is
indispensable that the sheaths of the legs should remain intact, in
order to afford a firm support until the insect is completely
The leg in process of liberation is not the leg with which the locust
makes its leaps; it has not as yet the rigidity which it will soon
acquire. It is soft, and eminently flexible. In those portions which the
progress of the moult exposes to view I see the legs bend under the mere
weight of the suspended insect when I tilt the supporting cover. They
are as flexible as two strips of elastic indiarubber. Yet even now
consolidation is progressing, for in a few minutes the proper rigidity
will be acquired.
Further along the limbs, in the portions which the sheathing still
conceals, the legs are certainly softer still, and in the state of
exquisite plasticity--I had almost said fluidity--which allows them to
pass through narrow passages almost as a liquid flows.
The teeth of the saws are already there, but have nothing of their
imminent rigidity. With the point of a pen-knife I can partially uncover
a leg and extract the spines from their serrated mould. They are germs
of spines; flexible buds which bend under the slightest pressure and
resume their position the moment the pressure is removed.
These needles point backwards as the leg is drawn out of the sheath; but
they re-erect themselves and solidify as they emerge. I am witnessing
not the mere removal of leggings from limbs already clad in finished
armour, but a kind of creation which amazes one by its promptitude.
Very much in the same way, but with far less delicate precision, the
claws of the crayfish, at the period of the moult, withdraw the soft
flesh of their double fingers from their stony sheath.
Finally the long stilt-like legs are free. They are folded gently
against the furrowed thighs, thus to mature undisturbed. The abdomen
begins to emerge. Its fine tunic-like covering splits, and wrinkles, but
still encloses the extremity of the abdomen, which adheres to the
moulted skin for some little time longer. With the exception of this one
point the entire insect is now uncovered.
It hangs head downwards, like a pendulum, supported by the talons of the
now empty leg-cases. During the whole of the lengthy and meticulous
process the four talons have never yielded. The whole operation has been
conducted with the utmost delicacy and prudence.
The insect hangs motionless, held by the tip of the abdomen. The abdomen
is disproportionately distended; swollen, apparently, by the reserve of
organisable humours which the expansion of the wings and wing-covers
will presently employ. Meanwhile the creature rests and recovers from
its exertions. Twenty minutes of waiting elapse.
Then, exerting the muscles of the back, the suspended insect raises
itself and fixes the talons of the anterior limbs in the empty skin
above it. Never did acrobat, hanging by the toes to the bar of a
trapeze, raise himself with so stupendous a display of strength in the
loins. This gymnastic feat accomplished, the rest is easy.
With the purchase thus obtained the insect rises a little and reaches
the wire gauze, the equivalent of the twig which would be chosen for the
site of the transformation in the open fields. It holds to this with the
four anterior limbs. Then the tip of the abdomen is finally liberated,
and suddenly, shaken by the final struggle, the empty skin falls to the
This fall is interesting, and reminds me of the persistence with which
the empty husk of the Cigale braves the winds of winter, without falling
from its supporting twig. The transfiguration of the locust takes place
very much as does that of the Cigale. How is it then that the acridian
trusts to a hold so easily broken?
The talons of the skin hold firmly so long as the labour of escape
continues, although one would expect it to shake the firmest grip; yet
they yield at the slightest shock when the labour is terminated. There
is evidently a condition of highly unstable equilibrium; showing once
more with what delicate precision the insect escapes from its sheath.
For want of a better term I said "escape." But the word is ill chosen;
for it implies a certain amount of violence, and no violence must be
employed, on account of the instability of equilibrium already
mentioned. If the insect, shaken by a sudden effort, were to lose its
hold, it would be all up with it. It would slowly shrivel on the spot;
or at best its wings, unable to expand, would remain as miserable scraps
of tissue. The locust does not tear itself away from its sheath; it
delicately insinuates itself out of it--I had almost said flows. It is
as though it were expelled by a gentle pressure.
Let us return to the wings and elytra, which have made no apparent
progress since their emergence from their sheaths. They are still mere
stumps, with fine longitudinal seams; almost like little ropes'-ends.
Their expansion, which will occupy more than three hours, is reserved
for the end, when the insect is completely moulted and in its normal
We have just seen the insect turn head uppermost. This reversal causes
the wings and elytra to fall into their natural position. Extremely
flexible, and yielding to their own weight, they had previously drooped
backwards with their free extremities pointing towards the head of the
insect as it hung reversed.
Now, still by reason of their own weight, their position is rectified
and they point in the normal direction. They are no longer curved like
the petals of a flower; they no longer point the wrong way; but they
retain the same miserable aspect.
In its perfect state the wing is like a fan. A radiating bundle of
strong nervures runs through it in the direction of its length and forms
the framework of the fan, which is readily furled and unfurled. The
intervals are crossed by innumerable cross-nervures of slighter
substance, which make of the whole a network of rectangular meshes. The
elytrum, which is heavier and much less extensive, repeats this
At present nothing of this mesh-work is visible. Nothing can be seen but
a few wrinkles, a few flexuous furrows, which announce that the stumps
are bundles of tissue cunningly folded and reduced to the smallest
The expansion of the wing begins near the shoulder. Where nothing
precise could be distinguished at the outset we soon perceive a
diaphanous surface subdivided into meshes of beautiful precision.
Little by little, with a deliberation that escapes the magnifier, this
area increases its bounds, at the expense of the shapeless bundle at the
end of the wing. In vain I let my eyes rest on the spot where the
expanding network meets the still shapeless bundle; I can distinguish
nothing. But wait a little, and the fine-meshed tissues will appear with
To judge from this first examination, one would guess that an
organisable fluid is rapidly congealing into a network of nervures; one
seems to be watching a process of crystallisation comparable, in its
rapidity, to that of a saturated saline solution as seen through a
microscope. But no; this is not what is actually happening. Life does
not do its work so abruptly.
I detach a half-developed wing and bring it under the powerful eye of
the microscope. This time I am satisfied. On the confines of the
transparent network, where an extension of that network seems to be
gradually weaving itself out of nothing, I can see that the meshes are
really already in existence. I can plainly recognise the longitudinal
nervures, which are already stiff; and I can also see--pale, and without
relief--the transverse nervures. I find them all in the terminal stump,
and am able to spread out a few of its folds under the microscope.
It is obvious that the wing is not a tissue in the process of making,
through which the procreative energy of the vital juices is shooting its
shuttle; it is a tissue already complete. To be perfect it lacks only
expansion and rigidity, just as a piece of lace or linen needs only to
In three hours or more the explanation is complete. The wings and elytra
stand erect over the locust's back like an immense set of sails; at
first colourless, then of a tender green, like the freshly expanded
wings of the Cigale. I am amazed at their expanse when I think of the
miserable stumps from which they have expanded. How did so much material
contrive to occupy so little space?
There is a story of a grain of hemp-seed that contained all the
body-linen of a princess. Here we have something even more astonishing.
The hemp-seed of the story needed long years to germinate, to multiply,
and at last to give the quantity of hemp required for the trousseau of a
princess; but the germ of the locust's wing has expanded to a
magnificent sail in a few short hours.
Slowly the superb erection composed of the four flat fan-like pinions
assumes rigidity and colour. By to-morrow the colour will have attained
the requisite shade. For the first time the wings close fan-wise and lie
down in their places; the elytra bend over at their outer edges, forming
a flange which lies snugly over the flanks. The transformation is
complete. Now the great locust has only to harden its tissues a little
longer and to tan the grey of its costume in the ecstasy of the
sunshine. Let us leave it to its happiness, and return to an earlier
The four stumps which emerge from their coverings shortly after the
rupture of the corselet along its median line contain, as we have seen,
the wings and elytra with their innumerable nervures. If not perfect,
at least the general plan is complete, with all its innumerable details.
To expand these miserable bundles and convert them into an ample set of
sails it is enough that the organism, acting like a force-pump, should
force into the channels already prepared a stream of humours kept in
reserve for this moment and this purpose, the most laborious of the
whole process. As the capillary channels are prepared in advance a
slight injection of fluid is sufficient to cause expansion.
But what were these four bundles of tissue while still enclosed in their
sheaths? Are the wing-sheaths and the triangular winglets of the larva
the moulds whose folds, wrinkles, and sinuosities form their contents in
their own image, and so weave the network of the future wings and
Were they really moulds we might for a moment be satisfied. We might
tell ourselves: It is quite a simple matter that the thing moulded
should conform to the cavity of the mould. But the simplicity is only
apparent, for the mould in its turn must somewhere derive the requisite
and inextricable complexity. We need not go so far back; we should only
be in darkness. Let us keep to the observable facts.
I examine with a magnifying-glass one of the triangular coat-tails of a
larva on the point of transformation. I see a bundle of moderately
strong nervures radiating fan-wise. I see other nervures in the
intervals, pale and very fine. Finally, still more delicate, and running
transversely, a number of very short nervures complete the pattern.
Certainly this resembles a rough sketch of the future wing-case; but
how different from the mature structure! The disposition of the
radiating nervures, the skeleton of the structure, is not at all the
same; the network formed by the cross-nervures gives no idea whatever of
the complex final arrangement. The rudimentary is succeeded by the
infinitely complex; the clumsy by the infinitely perfect, and the same
is true of the sheath of the wing and the final condition of its
contents, the perfect wing.
It is perfectly evident, when we have the preparatory as well as the
final condition of the wing before our eyes, that the wing-sheath of the
larva is not a simple mould which elaborates the tissue enclosed in its
own image and fashions the wing after the complexities of its own
The future wing is not contained in the sheath as a bundle, which will
astonish us, when expanded, by the extent and extreme complication of
its surface. Or, to speak more exactly, it is there, but in a potential
state. Before becoming an actual thing it is a virtual thing which is
not yet, but is capable of becoming. It is there as the oak is inside
A fine transparent cushion limits the free edge of the embryo wing and
the embryo wing-case. Under a powerful microscope we can perceive
therein a few doubtful lineaments of the future lace-work. This might
well be the factory in which life will shortly set its materials in
movement. Nothing more is visible; nothing that will make us foresee the
prodigious network in which each mesh must have its form and place
predetermined with geometrical exactitude.
In order that the organisable material can shape itself as a sheet of
gauze and describe the inextricable labyrinth of the nervuration, there
must be something better and more wonderful than a mould. There is a
prototypical plan, an ideal pattern, which imposes a precise position
upon each atom of the tissue. Before the material commences to circulate
the configuration is already virtually traced, the courses of the
plastic currents are already mapped out. The stones of our buildings
co-ordinate according to the considered plan of the architect; they form
an ideal assemblage before they exist as a concrete assemblage.
Similarly, the wing of a cricket, that wonderful piece of lace-work
emerging from a tiny sheath, speaks to us of another Architect, the
author of the plans according to which life labours.
The genesis of living creatures offers to our contemplation an infinity
of wonders far greater than this matter of a locust's wing; but in
general they pass unperceived, obscured as they are by the veil of time.
Time, in the deliberation of mysteries, deprives us of the most
astonishing of spectacles except our spirits be endowed with a tenacious
patience. Here by exception the fact is accomplished with a swiftness
that forces the attention.
Whosoever would gain, without wearisome delays, a glimpse of the
inconceivable dexterity with which the forces of life can labour, has
only to consider the great locust of the vineyard. The insect will show
him that which is hidden from our curiosity by extreme deliberation in
the germinating seed, the opening leaf, and the budding flower. We
cannot see the grass grow; but we can watch the growth of the locust's
Amazement seizes upon us before this sublime phantasmagoria of the grain
of hemp which in a few hours has been transmuted into the finest cloth.
What a mighty artist is Life, shooting her shuttle to weave the wings of
the locust--one of those insignificant insects of whom long ago Pliny
said: _In his tam parcis, fere nullis, quae vis, quae sapientia, quam
How truly was the old naturalist inspired! Let us repeat with him: "What
power, what wisdom, what inconceivable perfection in this least of
secrets that the vineyard locust has shown us!"
I have heard that a learned inquirer, for whom life is only a conflict
of physical and chemical forces, does not despair of one day obtaining
artificially organisable matter--_protoplasm_, as the official jargon
has it. If it were in my power I should hasten to satisfy this ambitious
But so be it: you have really prepared protoplasm. By force of
meditation, profound study, minute care, impregnable patience, your
desire is realised: you have extracted from your apparatus an albuminous
slime, easily corruptible and stinking like the devil at the end of a
few days: in short, a nastiness. What are you going to do with it?
Organise something? Will you give it the structure of a living edifice?
Will you inject it with a hypodermic syringe between two impalpable
plates to obtain were it only the wing of a fly?
That is very much what the locust does. It injects its protoplasm
between the two surfaces of an embryo organ, and the material forms a
wing-cover, because it finds as guide the ideal archetype of which I
spoke but now. It is controlled in the labyrinth of its course by a
device anterior to the injection: anterior to the material itself.
This archetype, the co-ordinator of forms; this primordial regulator;
have you got it on the end of your syringe? No! Then throw away your
product. Life will never spring from that chemical filth.
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