THE CRIOCERES (_continued_)
The Crioceris has found safety inside its opal globe. Safety? Ah, but
what an unfortunate expression I have used! Is there any one in the
world who can flatter himself that he has escaped the spoiler?
In the middle of July, at the time when the Twelve-spotted Crioceris
comes up from under the ground in the adult form, my rearing-jars
yield me swarms of a very small Gall-fly, a slender, graceful,
blue-black Chalcid, without any visible boring-tool. Has the puny
creature a name? Have the nomenclators catalogued it? I do not know,
nor do I much care; the main thing is to learn that the covering of
the asparagus-berry, which becomes an opal globe when the grub has
emptied it, has failed to save the recluse. The Tachina-midge drains
her victim by herself; this other, tinier creature feasts in company.
Twenty or more of them batten on the grub together.
When everything seems to foretell a quiet life, a pigmy among pigmies
appears, charged with the express duty of exterminating an insect
which is protected first by the casket of the berry and next by the
shell, the underground work of the grub. To eat the Twelve-spotted
Crioceris is its mission in life, its special function. When and how
does it deliver its attack? I do not know.
At any rate, proud of her vocation and finding life sweet, the Chalcid
curls her antennae into a crook and waves them to and fro: she rubs
her tarsi together, a sign of satisfaction; she dusts her belly. I can
hardly see her with the naked eye; and yet she is an agent of the
universal extermination, a wheel in the implacable machine which
crushes life as in a wine-press.
The tyranny of the belly turns the world into a robber's cave. Eating
means killing. Distilled in the alembic of the stomach, the life
destroyed by slaughter becomes so much fresh life. Everything is
melted down again, everything has a fresh beginning in death's
insatiable furnace.
Man, from the alimentary point of view, is the chief brigand,
consuming everything that lives or might live. Here is a mouthful of
bread, the sacred food. It represents a certain number of grains of
wheat which asked only to sprout, to turn green in the sun, to shoot
up into tall stalks crowned with ears. They died that we might live.
Here are some eggs. Left undisturbed with the Hen, they would have
emitted the Chickens' gentle cheep. They died that we might live. Here
is beef, mutton, poultry. Horror, it smells of blood, it is eloquent
of murder! If we gave it a thought, we should not dare to sit down to
table, that altar of cruel sacrifices.
How many lives does the Swallow, to mention only the most peaceable,
harvest in the course of a single day! From morning to evening he
gulps down Crane-flies, Gnats and Midges joyously dancing in the
sunbeams. Quick as lightning he passes; and the dancers are decimated.
They perish; then their melancholy remnants fall from the nest
containing the young brood, in the form of guano which becomes the
turf's inheritance. And so it is with all and everything, with large
and small, from end to end of the animal progression. A perpetual
massacre perpetuates the flux of life.
Appalled by these butcheries, the thinker begins to dream of a state
of affairs which would free us from the horrors of the maw. This ideal
of innocence, as our poor nature vaguely sees it, is not an
impossibility; it is partly realized for all of us, men and animals.
Breathing is the most imperious of needs. We live by the air before we
live by bread; and this happens of itself, without painful struggles,
without costly labour, almost without our knowledge. We do not set
out, armed for war, to conquer the air by rapine, violence, cunning,
barter and desperate labour; the supreme element of life enters our
bodies of its own accord; it penetrates us and quickens us. Each of us
has his generous share of it without giving the matter a thought.
To crown perfection, it is free. And this will last indefinitely until
an ever ingenious Treasury invents distributing-taps and pneumatic
receivers from which the air will be doled out to us at so much a
piston-stroke. Let us hope that we shall be spared this particular
item of scientific progress, for that, woe betide us, would be the end
of all things: the tax would kill the tax-payer!
Chemistry, in its lighter moods, promises us, in the future, pills
containing the concentrated essence of food. These cunning compounds,
the product of our laboratories, would not end our longing to possess
a stomach no more burdensome than our lungs and to feed even as we
breathe.
The plant partly knows this secret: it draws its carbon quietly from
the air, in which each leaf is impregnated with the wherewithal to
grow tall and green. But the vegetable is inactive; hence its innocent
life. Action calls for strongly flavoured spices, won by fighting. The
animal acts; therefore it kills. The highest phase, perhaps, of a
self-conscious intelligence, man, deserving nothing better, shares
with the brute the tyranny of the belly as the irresistible motive of
action.
But I have wandered too far afield. A living speck, swarming in the
paunch of a grub, tells us of the brigandage of life. How well it
understands its trade as an exterminator! In vain does the
Crioceris-larva take refuge in an unassailable casket: its executioner
makes herself so small that she is able to reach it.
Adopt such precautions as you please, you pitiable grubs, pose on your
sprigs in the attitude of a threatening Sphinx, take refuge in the
mysteries of a box, arm yourself with a cuirass of dung: you will none
the less pay your tribute in the pitiless conflict; there will always
be operators who, varying in cunning, in size, in implements, will
inoculate you with their deadly germs.
Not even the lily-dweller, with her dirty ways, is safe. Her grub is
as often the prey of another Tachina, larger than that of the Field
Crioceris. The parasite, I am convinced, does not sow her eggs upon
the victim so long as the latter is wrapped in its repulsive
great-coat; but a moment's imprudence gives her a favourable
opportunity.
When the time comes for the grub to bury itself in the ground, there
to undergo the transformation, it lays aside its mantle, with the
object perhaps of easing itself when it descends from the top of the
plant, or else with the object of taking a bath in that kindly
sunlight whereof it has hitherto tasted so little under its moist
coverlet. This naked journey over the leaves, the last joy of its
larval life, is fatal to the traveller. Up comes the Tachina, who,
finding a clean skin, all sleek with fat, loses no time in dabbing her
eggs upon it.
A census of the intact and of the injured larvae provides us with
particulars which agree with what we foresaw from the nature of their
respective lives. The most exposed to parasites is the Field
Crioceris, whose larva lives in the open air, without any sort of
protection. Next comes the Twelve-spotted Crioceris, who is
established in the asparagus-berry from her early infancy. The most
favoured is the Lily-beetle, who, while a grub, makes an ulster of her
excretions.
For the second time, we are here confronted by three insects which
look as if they had all come out of one mould, so much are they alike
in shape. If the costumes were not different and the sizes dissimilar,
we should not know how to tell one from another. And this pronounced
resemblance in figure is accompanied by a no less pronounced lack of
resemblance in instinct.
The evacuator that soils its back cannot have inspired the hermit
living in cleanly retirement inside its globe; the occupant of the
asparagus-berry did not advise the third to live in the open and
wander like an acrobat through the leafage. None of the three has
initiated the customs of the other two. All this seems to me as clear
as daylight. If they have issued from the same stock, how have they
acquired such dissimilar talents?
Furthermore, have these talents developed by degrees? The Lily-beetle
is prepared to tell us. Her grub, let us suppose, once conceived the
notion, when tormented by the Tachina, of making the stercoral slit
open above. By accident, with no definite purpose in view, it emptied
the contents of its intestine over its back. The natty Fly hesitated
in the presence of this filth. The grub, in its cunning, recognized,
as time went on, the benefit to be derived from its poultice; and what
at first was an unpremeditated pollution became a prudent custom.
As success followed upon success, with the aid of the centuries, of
course, for these inventions always take centuries, the dung overcoat
was extended from the hinder end to the fore-part, right down to the
forehead. Finding itself the gainer by this invention, setting the
parasite at defiance under its coverlet, the grub made a strict law of
what was an accident; and the Crioceris faithfully handed down the
repulsive great-coat to her offspring.
So far this is not so bad. But things now begin to become complicated.
If the insect was really the inventor of its defensive methods, if it
discovered for itself the advantage of hiding under its ordure, I look
to its ingenuity to keep up the tricks until the precise moment has
come for burying itself. But, on the contrary, it undresses itself
some time beforehand; it wanders about naked, taking the air on the
leaves, at a time when its fair round belly is more than ever likely
to tempt the Fly. It completely forgets, on its last day, the prudence
which it acquired by the long apprenticeship of the centuries.
This sudden change of purpose, this heedlessness in the face of danger
tells me that the insect forgets nothing, because it has learnt
nothing, because it has invented nothing. When the instincts were
being distributed, it received as its share the overcoat, of whose
methods it is ignorant, though it benefits by its advantages. It has
not acquired it by successive stages, followed by a sudden halt at the
most dangerous moment, the moment most calculated to inspire it with
distrust; it is no more and no less gifted than it was in the
beginning and is unable in any way to alter its tactics against the
Tachina and its other enemies.
Nevertheless, we must not be in a hurry to attribute to the garment of
filth the exclusive function of protecting the grub against the
parasite. It is difficult to see in what respect the Lily-grub is more
deserving than the Asparagus-grub, which possesses no defensive arts.
Perhaps it is less fruitful and, to make up for the poverty of the
ovaries, boasts an ingenuity which safeguards the race. Nor is there
anything to tell us that the soft coverlet is not at the same time a
shelter which screens a too sensitive skin from the sun. And, if it
were a mere fal-lal, a furbelow of larval coquetry, even that would
not surprise me. The insect has tastes which we cannot judge by our
own. Let us end with a doubt and proceed.
May is not over when the grub, now fully-grown, leaves the lily and
buries itself at the foot of the plant, at no great depth. Working
with its head and rump, it forces back the earth and makes itself a
round recess, the size of a pea. To turn the cell into a hollow pill
which will not be liable to collapse, all that remains for it to do is
to drench the wall with a glue which soon sets and grips the sand.
To observe this work of consolidation, I unearth some unfinished cells
and make an opening which enables me to watch the grub at work. The
hermit is at the window in a moment. A stream of froth pours from his
mouth like beaten-up white of egg. He slavers, spits profusely; he
makes his product effervescence and lays it on the edge of the breach.
With a few spurts of froth the opening is plugged.
I collect other grubs at the moment of their interment and install
them in glass tubes with a few tiny bits of paper which will serve
them as a prop. There is no sand, no building-material other than the
creature's spittle and my very few shreds of paper. Under these
conditions can the pill-shaped cell be constructed?
Yes, it can; and without much difficulty. Supporting itself partly on
the glass, partly on the paper, the larva begins to slaver all around
it, to froth copiously. After a spell of some hours, it has
disappeared within a solid shell. This is white as snow and highly
porous; it might almost be a globule of whipped albumen. Thus, to
stick together the sand in its pill-shaped nest, the larva employs a
frothy albuminous substance.
Let us now dissect the builder. Around the oesophagus, which is fairly
long and soft, are no salivary glands, no silk-tubes. The frothy
cement is therefore neither silk nor saliva. One organ forces itself
upon our attention: it is the crop, which is very capacious, and
dilated with irregular protuberances that put it out of shape. It is
filled with a colourless, viscous fluid. This is certainly the raw
material of the frothy spittle, the glue that binds the grains of sand
together and consolidates them into a spherical whole.
When the preparations for the metamorphosis are at hand, the stomachic
pouch, having no longer to do duty as a digestive laboratory, serves
the insect as a factory, or a warehouse for different purposes. Here
the Sitares store up their uric waste products; here the Capricorns
collect the chalky paste which becomes the stone lid for the entrance
to the cell; here caterpillars keep in reserve the gums and powders
with which they strengthen the cocoon; hence the Hymenoptera draw the
lacquer which they employ to upholster their silken edifice. And now
we find the Lily-beetle using it as a store for frothy cement.[1] What
an obliging organ is this digestive pouch!
[Footnote 1: This subject is continued in the essay on the Foamy
Cicadella. Cf. _The Life of the Grasshopper_: chap. xx.--_Translator's
Note_.]
The two Asparagus-beetles are likewise proficient dribblers, worthy
rivals of their kinswoman of the lily in the matter of building. In
all three cases the underground shell has the same shape and the same
structure.
When, after a subterranean visit of two months' duration, the
Lily-beetle returns to the surface in her adult form, a botanical
problem remains to be solved before the history of the insect is
completed. We are now at the height of summer. The lilies have had
their day. A dry, leafless stick, surmounted by a few tattered
capsules, is all that is left of the magnificent plant of the spring.
Only the onion-like bulb remains a little way down. There, postponing
the process of vegetation, it waits for the steady rains of the
autumn, which will renew its strength and make it burgeon into a sheaf
of leaves.
How does the Lily-beetle live during the summer, before the return of
the green foliage dear to its race? Does it fast during the extreme
heat? If abstinence is its rule of life in this season of vegetable
dearth, why does it emerge from underground, why does it abandon its
shell, where it could sleep so peacefully, without the necessity of
eating? Can it be need of food that drives it from the substratum and
sends it to the sunlight so soon as the wing-cases have assumed their
vermilion hue? It is very likely. For the rest, let us look into the
matter.
On the ruined stems of my white lilies I find a portion covered with a
scrap of green skin. I set it before the prisoners in my jars, who
emerged from their sandy bed a day or two ago. They attack it with an
appetite which is extremely conclusive; the green morsel is stripped
bare to the wood. Soon I have nothing left, in the way of their
regulation diet, to offer my famished captives. I know that all the
lilies, native or exotic, the Turk's cap lily, or Martagon, the lily
of Chalcedon, the tiger lily and many others, are to their taste; I do
not forget that the crown imperial fritillary and the Persian
fritillary are equally welcome; but most of these delicate plants have
refused the hospitality of my two acres of pebbles and those which it
is more or less possible for me to grow are now as tattered as the
common lily. There is not a patch of green left on them.
In botany the lily gives its name to the family of the Liliaceae, of
which it is the leading representative. Those who feed upon the lily
ought also, in the absence of anything better, to accept the other
plants of the same group. This is my opinion at first; it is not that
of the Crioceris, who knows more than I do about the virtues of
plants.
The family of the Liliaceae is subdivided into three tribes: the
lilies, the daffodils and the asparaguses. Not any of the daffodil
tribe suit my famishing prisoners, who allow themselves to die of
inanition on the leaves of the following genera, the only varieties
with which the modest resources of my garden have allowed me to
experiment: asphodel, funkia, or niobe, agapanthus, or African lily,
tritelia, hemerocallis, or day lily, tritoma, garlic, ornithogalum, or
star of Bethlehem, squill, hyacinth, muscari, or grape-hyacinth. I
record, for whom it may concern, this profound contempt of the
Crioceris for the daffodils. An insect's opinion is not to be
despised: it tells us that we should obtain a more natural arrangement
by separating the daffodils farther from the lilies.
In the first of the three tribes, the classic white lily, the plant
preferred by the insect, takes the chief place; next come the other
lilies and the fritillaries, a diet almost as much sought after; and
lastly the tulips, which the season is too far advanced to allow me to
submit for the approval of the Crioceris.
The third tribe had a great surprise in store for me. The red
Crioceris fed, though with a very scornful tooth, on the foliage of
the asparagus, the favourite dish of the Field Crioceris and the
Twelve-spotted Crioceris. On the other hand, she feasted rapturously
on the lily of the valley (_Convallaria maialis_) and on Solomon's
seal (_Polygonatum vulgare_), both of which are so different from the
lily to any eye untrained in the niceties of botanical analysis.
She did more: she browsed, with every appearance of a contented
stomach, on a prickly creeper, _Smilax aspera_, which tangles itself
in the hedges with its corkscrew tendrils and produces, in the autumn,
graceful clusters of small red berries, which are used for Christmas
decorations. The fully-developed leaves are too hard for her, too
tough; she wants the tender tips of the nascent foliage. When I take
this precaution, I can feed her on the intractable vine as readily as
on the lily.
The fact that the smilax is accepted gives me confidence in the
prickly butcher's-broom (_Ruscus aculeatus_), another shrub of sturdy
constitution, admitted to the family rejoicings at Christmas because
of its handsome green leaves and its red berries, which are like big
coral beads. In order not to discourage the consumer with leaves that
are too hard, I select some young seedlings, newly sprouted and still
bearing the round berry, the nutritive gourd, hanging at their base.
My precautions lead to nothing: the insect obstinately refuses the
butcher's-broom, on which I thought that I might rely after the smilax
had been accepted.
We have our botany; the Crioceris has hers, which is subtler in its
appreciation of affinities. Her domain comprises two very natural
groups, that of the lily and that of the smilax, which, with the
advance of science, has become the family of the Smilaceae. In these
two groups she recognizes certain genera--the more numerous--as her
own; she refuses the others, which ought perhaps to be revised before
being finally classified.
An exclusive taste for the asparagus, one of the foremost
representatives of the Smilaceae, characterizes the two other
Crioceres, those eager exploiters of the cultivated asparagus. I find
them also pretty often on the needle-leaved asparagus (_A.
acutifolius_), a forbidding-looking shrub with long, flexible stems
bearing many branches, which the Provencal vine-grower uses, under the
name of _roumieu_, as a filter before the tap of the wine-vat, to
prevent the refuse of the grapes from choking up the vent-hole. Apart
from these two plants, the two Crioceres refuse absolutely everything,
even when in July they come up from the earth with the famishing
stomachs which the long fast of the metamorphosis has given them. On
the same wild asparagus, disdainful of the rest, lives a fourth
Crioceris (_C. paracenthesia_), the smallest of the group. I do not
know enough of her habits to say anything more about her.
These botanical details tell us that the Crioceres, which hatch early,
in the middle of summer, have no reason to fear famine. If the
Lily-beetle can no longer find her favourite plant, she can browse
upon Solomon's seal and smilax, not to mention the lily of the valley
and, I dare say, a few others of the same family. The other three are
more favoured. Their food-plant remains erect, green and well provided
with leaves until the end of autumn. The wild asparagus even,
undaunted by the extreme cold, maintains a sturdy existence all the
year round. Belated resources, moreover, are superfluous. After a
brief period of summer freedom, the various Crioceres seek their
winter quarters and go to earth under the dead leaves.