THE CIONUS
An insect, well known to every one, is often but a stupid creature,
while another, of which nothing is known, is of real value. When
endowed with talents worthy of attention, it passes unrecognized; when
richly clad and of handsome appearance, it is familiar to us. We judge
it by its coat and its size, as we judge our neighbour by the fineness
of his clothing and the importance of the position which he fills. The
rest does not count.
Of course, if it is to be honoured by the historian, it is best that
the insect should enjoy popular renown. This saves the reader trouble,
as he at once knows precisely what we are speaking of; furthermore, it
shortens the story, which is not hampered by long and tedious
descriptions. Moreover, if size facilitates observation, if elegance of
shape and brilliance of costume captivate the eye, we should be wrong
not to take this magnificence into our reckoning.
But far more important are the habits, the ingenious devices, which
give a real charm to entomological study. Now it so happens that among
the insects it is the largest, the most magnificent, that are generally
the most inefficient: a freak of nature that recurs elsewhere. What can
we expect of a Carabus, all shimmering with metallic gleams? Nothing
but feasting amid the foam secreted by a murdered snail. What can we
expect of the Cetonia, who looks as though she had escaped from a
jeweller’s show-case? Nothing but drowsy slumbers in the heart of a
rose. These magnificoes cannot do anything; they have no craft, no
trade.
If, on the contrary, we wish to see original inventions, artistic
masterpieces and ingenious contrivances, we must apply to the humble
creatures that are oftener than not unknown to any one. And we must not
allow ourselves to be disgusted by the spots frequented. Ordure has
beautiful and curious things in store for us, the like of which we
should never find on the rose. The Minotaur [65] has edified us by his
domestic habits. Long live the modest! Long live the little!
One of these little ones, smaller than a peppercorn, will set us a
great problem, full of interest but probably insoluble. The official
nomenclators call it Cionus thapsus, Fab. If you ask me what Cionus
means, I shall reply frankly that I have not the least idea. Neither
the writer of these lines nor the reader is any the worse off for that.
In entomology a name is all the better for meaning nothing but the
insect named.
If an amalgam of Greek or Latin has a meaning that alludes to the
insect’s manner of living, the reality is often inconsistent with the
word, because the nomenclator, working in a necropolis, has preceded
the observer, who is concerned with the living species. Moreover, rough
guesses and even glaring mistakes too often disfigure the records of
the insect world.
At the present moment, it is the word thapsus that deserves reproach,
for the plant exploited by the Cionus is not the botanists’ Verbascum
thapsus at all, but quite another plant, of wholly different character,
Verbascum sinuatum. A lover of the way-side, having no fear of the
ungrateful soil and the white dust, the scallop-leaved mullein is a
southern plant which spreads over the ground a rosette of broad, fluffy
leaves, the edges of which are gashed with deep, wavy incisions. Its
flower-stalk is divided into a number of twigs bearing yellow blossoms
whose staminal filaments are bearded with violet hairs.
At the end of May, let us open the umbrella, the collector’s chief
engine of the chase, underneath the plant. A few blows of a
walking-stick on the chandelier ablaze with yellow flowers will bring
down a sort of hail. This is our friend the Cionus, a roundish little
creature, huddled into a globule on its short legs. Its costume is not
lacking in elegance and consists of a scaly jacket flecked with black
specks on an ash-grey background. The insect is distinguished above all
by two large tufts of black velvet, one on its back and the other at
the lower extremity of the wing-case. No other Weevil of our
country-side wears the like. The rostrum is fairly long, powerful and
depressed towards the thorax.
For a long while this Weevil, with her decoration of black spots, has
occupied my mind. I should like to know her larva, which, as everything
seems to prove, must live in the capsules of the scallop-leaved
mullein. The insect belongs to the series that nibble at seeds
contained in a shell; it ought to share their botanical habits. But
vainly, whatever the season, do I open the capsules of the exploited
plant: never do I find the Cionus there, nor its larva, nor its nymph.
This little mystery increases my curiosity. Perhaps the dwarf has
interesting things to tell us. I propose to wrest her secret from her.
It so happens that a few scallop-leaved mulleins are spreading their
rosettes amid the pebbles of my enclosure. They are not populated, but
I can easily colonize them with specimens from the country round about,
obtained by a few battues over the umbrella. No sooner said than done.
From May onwards I have before my door, without fear of disturbance by
passing Sheep, the means of following the Cionus’ doings, in comfort,
at any hour of the day.
My colonies flourish. The strangers, satisfied with their new
camping-ground, settle down on the twigs on which I have placed them.
They browse and gently tease one another with their legs: many of them
pair off and gaily spend their lives revelling in the sunshine. Those
coupled together, one on top of the other, are subject to sudden
lurches from side to side, as though impelled by the release of a
vibrating spring. Pauses follow, of varying length; then the lurches
are repeated, cease and begin again.
Which of the two supplies the motive force of this little piece of
machinery? It seems to me that it is the female, who is rather larger
than the male. The jerking would then be a protest on her part, an
attempt to free herself from the embraces of her companion, who holds
on despite all this shaking. Or again, it may be a common
manifestation, the pair joyfully exulting in a nuptial rolling from
side to side.
Those who are not coupled plunge their rostrum into the budding flowers
and feast deliciously. Others bore little brown holes in the tiny
twigs, whence oozes a drop of syrup which the Ants will come and lick
up presently. And that, for the moment, is all. There is nothing to
tell us where the eggs will be laid.
In July, certain capsules, still quite small, green and tender, have at
their base a brown speck which might well be the work of the Cionus
placing her eggs. I have my doubts: most of these punctured capsules
contain nothing. The grubs then left their cell shortly after the
hatching, the aperture, still open, allowing them to pass.
This emancipation of the new-born grubs, this premature exposure to the
dangers of the outside world, is not consistent with the habits of the
Weevils, who are great stay-at-homes while in the larval state.
Legless, plump, fond of repose, the grub shrinks from change of place;
it grows up on the spot where it was born.
Another circumstance increases my perplexity. Among the capsules which
the Weevil seems to have perforated with her rostrum, some contain eggs
of an orange yellow, grouped into a single heap of five or six or more.
This multiplicity gives us food for reflection. When fully matured, the
capsules of the scallop-leaved mullein are small, greatly inferior in
size to those of other plants of the same genus. When still very young,
green and tender, those containing the eggs are hardly as big as half a
grain of wheat. There is not food for so many feasters in so tiny a
morsel; there would not be enough for one.
All mothers are provident. The exploiter of the mullein cannot have
endowed her six or more nurselings with such scanty possessions. For
these various reasons, I doubt at first whether these are really the
Cionus’ eggs. What follows is not calculated to decrease my hesitation.
The orange eggs hatch out, producing grubs which within twenty-four
hours abandon their exiguous natal chamber. They emerge through the
orifice which has been left open; they spread over the capsule,
cropping its down, a pasture sufficient for their first mouthfuls. They
descend to the thin little twigs, which they strip of their bark, and
gradually move on to the small adjacent leaves, where the banquet is
continued. Let us leave them to grow. Their final transformation will
tell me that I really have the authentic larva of the Cionus before my
eyes.
They are bare, legless grubs, of a uniform pale yellow, excepting the
head, which is black, and the first segment of the thorax, which is
adorned with two large black spots. They are varnished all over their
bodies with a glutinous humour, so much so that they stick to the
paint-brush used to collect them and are difficult to shake off. When
teased, they emit from the end of their intestine a viscous fluid,
apparently the origin of their varnish.
They wander idly over the young twigs, whose bark they gnaw down to the
wood; they also browse on the leaves growing from the twigs, which are
much smaller than those upon the ground. Having found a good
grazing-place, they stay there without moving, curved into a bow and
held in position by their glue. Their walk is an undulating crawl,
based upon the support of their sticky behind. Helpless cripples, but
coated with an adhesive varnish, they are firmly enough fixed to resist
a shake of the bough that bears them without falling off. When you have
no sort of grapnel to hold on by, the idea of clothing yourself in
glue, so that you may shift your position without danger of falling,
even in a gust of wind, is an original invention of which, as yet, I
know no other instance.
Our grubs are easily reared. Placed in a glass jar, with a few tender
twigs of the plant that feeds them, they go on browsing for some time
and then make themselves a pretty ampulla in which the transformation
will take place. To observe this performance and discover the method
employed was the chief purpose of my inquiry. I succeeded, though not
without a great expenditure of assiduity.
All its life long, the larva is smeared, on both its dorsal and its
ventral surface, with a viscous, colourless, strongly adhesive fluid.
Touch the creature lightly, anywhere, with the tip of a camel-hair
pencil. The glutinous matter yields and draws out into a thread of a
certain length. Repeat the touch in the hot sunshine, in very dry
weather. The viscosity is not diminished. Our varnishes dry up; the
grub’s does not; and this is a property of the greatest value, enabling
the feeble larva, without fear of being shrivelled by the wind or the
rays of the sun, to adhere firmly to its food-plant, which loves the
open air and warm, sunny places.
The laboratory producing this sticky varnish is easily discovered; we
have only to make the creature move along a slip of glass. We see from
time to time a sort of treacly dew oozing from the end of the intestine
and lubricating the last segment. The glue is therefore supplied by the
digestive canal. Is there a special glandular laboratory there, or is
it the intestine itself that prepares the product? I will leave the
question unanswered, for nowadays I no longer have the steady hand or
the keen sight required for delicate dissection. The fact remains that
the grub daubs itself with a glue of which the end of the intestine is
at least the storehouse, if it is not the actual source.
How is the sticky emission distributed over the whole body, both above
and below? The larva is a legless cripple; it moves about by obtaining
a hold with its behind. Moreover, it is well segmented. The back, in
particular, has a series of fairly protuberant cushions; the ventral
surface, on the other hand, is puckered by knotty excrescences, which
change their shape considerably in the act of crawling. When moving,
with the flexible fore-part of the body groping to find its way, the
grub consists of a series of waves that follow one another in perfect
order.
Each wave starts from the hinder extremity and by swift degrees reaches
the head. Straightway a second wave follows in the same direction,
succeeded by a third, a fourth and so on, indefinitely. Each of these
waves, proceeding from one end of the grub to the other, is a step. So
long as the wave continues, the fulcrum, that is, the orifice of the
intestine, remains in its place, at first a little before and then a
little behind the movement as a whole. Hence the source of the sticky
dew grazes first the tip of the abdomen and then the end of the back of
the moving grub. In this way the tiny drop of gum is deposited above
and below.
The glue has still to be distributed. This is done by crawling. Between
the puckers, the cushions, which the locomotory wave brings together
and then separates, alternately come into contact and open clefts into
which the sticky fluid gradually makes its way by capillary action. The
grub clothes itself in glue without exercising any special skill,
merely by moving along. Each locomotory wave, each step, supplies its
quota to the viscous doublet. This makes up for the losses which the
larva cannot fail to suffer on the road as it roams from pasture to
pasture; and, since the fresh material balances the wastage of the old,
a suitable coat is obtained, neither too thin nor too thick.
The complete coating is rapidly effected. With the tip of a camel-hair
pencil, I wash a grub in a little water. The viscosity dissolves and
disappears; and the water used for washing the larva, evaporated on a
slip of glass, leaves a mark like that of a weak solution of gum
arabic. I place the grub to dry on blotting-paper. When I now touch it
with a straw, it no longer sticks to it; it has lost its coating of
varnish.
How will it replace it? This is a very simple matter. I allow the grub
to move about at will for a few minutes. No more is needed; the layer
of gum is restored; the creature sticks to the straw that touches it.
To sum up, the varnish with which the Cionus’ larva is covered, is a
viscous fluid, soluble in water, quickly emitted and extremely slow to
dry, even in an intensely hot sun and in the parching breath of the
north-wind.
Having obtained these data, let us see how the ampulla is constructed
in which the transformation will take place. On the 8th of July 1906,
my son Paul, my zealous collaborator now that my once sturdy legs are
failing me, brings me, on returning from his morning walk, a
magnificent branching head of mullein peopled by the Cionus. It
contains an abundance of larva. Two of them in particular delight me:
while the others stand browsing, these two wander about restlessly,
indifferent to their food. Beyond any doubt, they are looking for a
spot favourable to the process of the nymphosis.
I place each of them singly in a small glass tube which will allow me
to observe them easily. In case they might find the food-plant useful,
I supply them with a sprig of mullein. And now, lens in hand, from
morning to evening and then by night, as far as drowsiness and the
doubtful light of a candle will permit, let us be on the alert; for
very interesting things are about to happen. Let me describe them hour
by hour.
8 A.M.—The larva is not making use of the twig with which I provided
it. It is crawling along the glass, darting its pointed head now this
way, now that. With a gentle creeping movement that causes an
undulation of the back and belly, it is trying to settle itself
comfortably. After two hours of this effort, which is certain to be
accompanied by an emission of viscous fluid, it finds a position to its
taste.
10 A.M.—Being now fixed to the glass, the larva has shrunk into the
semblance of a little barrel, or a grain of wheat with rounded ends. At
one end is a shining black speck. This is the head, jammed into a fold
of the first segment. The grub’s colour is unchanged: it is still a
dirty yellow.
1 P.M.—A copious emission of fine black granules, followed by semifluid
dejecta. To avoid soiling its future residence and to prepare the
intestine for the delicate chemistry about to follow, the grub purges
itself beforehand of its impurities. It is now a uniform pale yellow,
without the cloudy markings that disfigured it at first. It is lying at
full length on its ventral surface.
3 P.M.—Under the skin, especially on the back, the lens reveals subtle
pulsations, slight tremors, like those of a liquid surface on the point
of boiling. The dorsal vessel itself is dilating and contracting,
throughout its length, more actively than usual. This means a fit of
fever. Some internal change must be preparing, which will affect the
whole organism. Can it be the preparation for a moult?
5 P.M.—No, for the grub is no longer motionless. It leaves its heap of
dirt and begins to move along impetuously, more restlessly than ever.
What is happening that is in any way unusual? I think I can obtain some
idea of it with the aid of logic.
Remember that the sticky coat in which the grub is clad does not dry
up: this is a condition indispensable to liberty of movement. If
changed into a hard varnish, a dry film, it would hamper, would indeed
stop the crawling; but, so long as it remains liquid, it is the drop of
oil that lubricates the locomotory machine. This moist coating will,
however, constitute the material of the nymphosis-bladder: the fluid
will become gold-beater’s-skin, the liquid will solidify.
This change of condition at first suggests oxidation. We must abandon
this idea. If the hardening were really the result of oxidization, the
grub, being sticky from its birth and always exposed to the air, would
long ago have been clad not in a delicate coat of adhesive, but in a
stiff parchment sheath. Desiccation obviously must take place at the
last moment and rapidly, when the grub is preparing to change its
shape. Before then, this desiccation would be a danger; now, it is an
excellent means of defence.
To ‘fix’ oil-paintings our ingenuity employs siccatives, that is to
say, ingredients that act upon the oil, giving it a resinous
consistency. The Cionus likewise has its siccative, as the following
facts prove. It may be that the grub was labouring to produce this
desiccating substance, by some profound change in the process of its
organic laboratory, at the time when its poor flesh was quivering with
feverish tremors; it may be that it was proceeding to spread the
siccative over the whole surface of its body by taking a long walk, the
last of its larval life.
7 P.M.—The larva is once more motionless, lying flat on its belly. Is
this the end of its preparations? Not yet. The globular structure must
have a foundation, a base on which the grub can support itself in order
to dilate its ampulla.
8 P.M.—Round the head and the fore-part of the thorax, which, like the
rest of the body, are touching the slip of glass, a border of pure
white now appears, as though snow had fallen at these points. This
forms a sort of horse-shoe enclosing an area in which the snowy deposit
is continued in a vague mist. From the base of this border some threads
of the same white substance radiate in short tufts. This structure
denotes work done with the mouth, a miniature wire-drawing. And in fact
no such white substance is seen anywhere except around the head. Thus
the creature’s two ends take part in the building of the hut: the one
in front provides the foundations, the one behind provides the edifice.
10 P.M.—The larva shrinks. With its support, that is to say, its head
anchored to the snowy cushion, it brings its hinder end a little
nearer; it coils up, hunches its back and gradually turns itself into a
ball. Though not yet perceptible, the ampulla is being prepared. The
siccative has taken effect; the original gumminess has been transformed
into a sort of skin, flexible enough at this moment to be distended by
the pressure of the back. When its capacity is large enough, the grub
will become unglued, throw off its envelope and find itself at liberty
in a spacious enclosure.
I should much like to see this peeling, but things happen so slowly as
to drive one to despair. Let us go to bed. What I have seen is enough
to enable me to guess the little that remains to be seen.
Next day, when the pale dawn gives me sufficient light, I hasten to my
two larvæ. The bladder is completed. It is a graceful ovoid of the
finest gold-beater’s-skin, adhering at no point to the insect inside.
It has taken some twenty hours to manufacture. It has still to be
strengthened with a lining. The transparency of the wall enables us to
follow the operation.
We see the grub’s little black head rising and falling, swerving this
way and that and from time to time gathering with its mandibles, at the
door of the intestine, a particle of cement, which is instantly placed
in position and meticulously smoothed. So the interior of the hut is
plastered, point after point, by small touches. Lest I should not see
clearly through the wall, I cut off the top of a bladder, partly
uncovering the larva. The work is continued without much hesitation.
The strange method is revealed as plainly as one could wish. The grub
makes use of its behind as a store of consolidating cement; the end of
the intestine serves as the equivalent of the hod from which the
bricklayer takes his trowelful of mortar.
This original mode of procedure is familiar to me. At one time, a big
Weevil, the Spotted Larinus, inhabiting the blue-headed globe-thistle
(Echinops Ritro), enabled me to witness a similar method. The Larinus
also expels its own cement. With the tips of its mandibles it gathers
it from the evacuating orifice, applying it with strict economy.
Moreover it has other materials at its disposal, the hairs and remnants
of the florets of its thistle. Its cement is used only to plaster and
glaze the work. The Cionus’ larva, on the other hand, employs nothing
but the oozings of its intestine; consequently the little hut resulting
is of incomparable perfection.
Besides the Spotted Larinus, my notes mention other Weevils, for
instance, the Garlic-weevil (Brachycerus algirus), whose larvæ possess
the art of coating their cells with a thin glaze provided by the rump.
This intestinal artifice seems, therefore, to be pretty frequently
employed by the Weevils that build little chambers in which the
metamorphosis is to take place; but none of them excel in it as does
the Cionus. Its task becomes yet more interesting when we consider
that, in the same factory, after a very brief interval, three different
products are compounded: first a liquid glue, a means of adhesion to
the swaying support of the mullein lashed by the winds; then a
siccative fluid which transforms the sticky coating into
gold-beater’s-skin; and lastly a cement which strengthens the bladder
separated from the larva by a sort of moult. What a laboratory, what
exquisite chemistry in a scrap of intestine!
What use are these minute details, noted hour by hour? Why these
puerilities? What matters to us the industry of a wretched grub, hardly
known even to the professional experts?
Well, these puerilities involve the most weighty problems that we are
privileged to discuss. Is the world an harmonious creation, governed by
a primordial force, a causa causarum? Or is it a chaos of blind
conflicting forces, whose reciprocal thrusts produce a chance
equilibrium, for better or for worse? Minute entomological details
examined with some thoroughness, may serve us better than syllogisms,
in the scientific investigation of these trifles and others like them.
The humble Cionus, for its part, tells us of a primordial force, the
motive power of the smallest as of the greatest things.
A day is not too long to give the bladder a good lining. Next day the
larva moults and passes into the nymphal state. Let us complete its
story with the data gleaned in the fields. The cocoons are often found
on the grass near the food-plant, on the stalks and dead blades of the
Gramineæ. Generally, however, they occupy the little twigs of the
mullein, stripped of their bark and withered. The adult insect emerges
sooner or later in September. The gold-beater’s-skin capsule is not
torn irregularly, at random; it is neatly divided into two equal parts,
like the two halves of a soap-box.
Has the enclosed insect gnawed the casing with its patient tooth and
made a fissure along the equator? No, for the edges of either
hemisphere are perfectly clean-cut. There must, therefore, have been a
circular line ready to facilitate the opening. All that the insect had
to do was to hunch its back and give a slight push, in order to
unfasten the roof of its cabin all in one piece and set itself free.
I can just see this line of easy rupture on certain intact capsules. It
is a faint line ringing the equator. What does the insect do beforehand
to contrive that its cell shall open in this way? A humble plant,
flowering early in the spring, the blue or scarlet pimpernel, has also
its soap-box, its pyxidium, which splits easily into two hemispheres
when the time comes for the seed to be scattered. In either case it is
the work of an unconscious ingenuity. The grub does not plan its
methods any more than the pimpernel: it has hit upon its ingenious
scheme of joining the halves of its capsule by the inspiration of
instinct alone.
More numerous than the capsules which burst accurately are others which
are clumsily torn by a shapeless breach. Through this some parasite
must have emerged, some ruthless creature which, unacquainted with the
secret of the delicate joint, has released itself by tearing the
gold-beater’s-skin. I find its larva in cells which are not yet
perforated. It is a small, white grub, fixed to a discoloured tit-bit
which is all that remains of the Cionus’ nymph. The intruder is sucking
dry the rightful occupant, whose budding flesh is still quite tender. I
think I can identify the murderess as a bandit of the Chalcid tribe,
which is addicted to such massacres.
Her appearance and her gluttonous ways have not misled me. My
rearing-jars provide me with abundant supplies of a small
bronze-coloured Chalcid with a large head and a round, tapering body,
but with no visible boring-tool. To inquire her name of the experts
will not help me much. I do not ask the insect, ‘what are you called?’
but ‘what are you able to do?’
The anonymous parasite hatched in my jars has no implement similar to
that of the Leucospis, [66] the chief of the Chalcididæ; it has no
probe which is able to penetrate a wall and place the egg, at some
distance, on the food-ration. Her germ, therefore, was laid in the very
flanks of the Cionus’ larva, before the latter had built its shell.
The methods of these tiny brigands appointed to the task of thinning
out the too numerous are extremely varied. Each guild has its own
method, which is always horribly effective. How should so small a
creature as the Cionus cumber the earth? No matter: it has to be
massacred, to perish in its cradle, a victim of the Chalcid. Like other
creatures, the peaceful dwarf must furnish its share of organizable
matter, which will be further and further refined as it passes from
stomach to stomach.
Let us recapitulate the habits of the Cionus, very strange habits in an
insect of the Weevil series. The mother entrusts her eggs to the
swelling capsules of the scallop-leaved mullein. So far, everything is
according to rule. Other Weevils, as a matter of fact, prefer, when
setting their children up in life, the pods of some other mullein, or
those of the figwort or of the snap-dragon, two plants belonging to one
and the same botanical family. But now we are suddenly confronted with
the strange and exceptional. The mother Cionus chooses the mullein with
the smallest capsules, whereas in the neighbourhood and at the same
season there are others loaded with fruit whose dimensions would
provide spacious lodgings and abundance of food. She prefers dearth to
plenty and narrow to spacious quarters.
Worse still. Indifferent to leaving provision for her brood, she
nibbles the tender seeds, destroys them, extirpates them, in order to
obtain a cavity in the heart of the tiny globule. Into this she slips
more or less half a dozen eggs. With the edible substance left, were
the whole cell to be consumed, there would not be enough to feed a
single grub.
When the bread-pan is empty, the house is deserted. The young abandon
their famine-stricken dwelling on the day when they are hatched. They
are bold innovators and practise a method which is held in detestation
among the Weevils, who are all pre-eminently stay-at-homes: they dare
the dangers of the outer world: they travel, passing from one leaf to
another in search of food. This strange exodus, unprecedented in a
Weevil, is not a mere caprice but a necessity imposed on them by
hunger; they migrate because their mother has not provided them with
anything to eat.
If travelling has its pleasures, enough to make the insect forget the
delights of the cell in which it digests at peace, it also has its
drawbacks. The legless grub can progress only by a sort of creeping
gait. It has no instrument of adherence which will enable it to remain
fixed to the twig, whence the least breath of wind may make it fall.
Necessity is the mother of invention. To guard against the danger of
falling, the wanderer smears itself with a viscous fluid, which
varnishes it and makes it adhere to the trail which it is following.
But this is not all. When the ticklish moment of the nymphosis arrives,
a retreat in which the grub can undergo its transformation in peace
becomes indispensable. The vagabond has nothing of the sort. It is
homeless, it sleeps in the open air; yet it is able, when the time
comes, to make itself a tent, a capsule, the materials for which are
supplied by its intestine. No other insect of its order can build a
home like this. Let us hope that the hateful Chalcid, the murderer of
nymphs, will not visit it in its pretty little tent.
The grub that lives on the scallop-leaved mullein has shown an utter
revolution in the habits of the Weevil clan. The better to judge of
this, let us consult a cognate species, placed not far from the Cionus
by the classifiers; let us compare the two kinds of life, on the one
hand the exception and on the other the rule. The comparison will be
all the more useful inasmuch as the new witness also exploits a
mullein. It is known as Gymnetron thapsicola, Germ.
Dressed in russet homespun, with a plump round body and about the size
of the Cionus: there you have the creature. Note the qualifying
thapsicola, meaning an inhabitant of the thapsus. On this occasion, I
am glad to see, the term could not possibly be happier: it enables the
novice to identify the insect exactly, without other data than the name
of the plant on which it lives.
The botanist gives the name of Verbascum thapsus to the common mullein,
or shepherd’s club, a lover of the tilled fields in both the north and
the south. Its bloom, instead of branching out like that of the
scallop-leaved mullein, consists of one thick cone of yellow flowers.
These flowers are followed by close-packed capsules about as big as a
fair-sized olive. Here we no longer have the niggardly pods in which
the grub of the Cionus would die of starvation if it did not abandon
them as soon as it is hatched; these caskets contain plenty of victuals
for one larva and even for two. A partition divides them into two equal
compartments, both of them crammed with seeds.
The fancy took me to estimate roughly the mullein’s wealth of seeds. I
have counted as many as 321 in a single shell. Now a spike of ordinary
size contains 150 capsules. The total number of seeds is therefore
48,000. What can the plant want with such abundance? Allowing for the
small number of seeds required to maintain the species in a thriving
state, it is evident that the mullein is a hoarder of nutritive atoms;
it creates foodstuffs; it summons guests to its opulent banquet.
Knowing these facts, the Gymnetron, from May onwards, visits the
luxuriant flower-spike and there installs her grubs. The inhabited
capsules may be recognized by the brown speck at their base. This is
the hole bored by the mother’s rostrum, the aperture needed for
inserting the eggs. Usually there are two, corresponding with the two
cells of the fruit. Soon the oozings from the cell set hard and dry and
obstruct the tiny window; and the capsule is closed again, without any
communication with the outer world.
In June and July, let us open the shells marked with brown specks.
Nearly always we find two grubs, looking fat as butter, with their
fore-parts swollen and their hinder parts shrunken and curved like a
comma. Not a vestige of legs, which members would be very useless in
such a lodging. Lying at its ease, the grub has plenty of food ready to
its mouth: first the tender, sugary seeds; then the placenta, their
common support, which is likewise fleshy and highly flavoured. It is
pleasant to live under such conditions, motionless and devoting one’s
self entirely to the joys of the stomach.
It would take a cataclysm to upset the smug hermit. This cataclysm I
bring about by opening the cell. Then and there, the grub begins to
twist and wriggle desperately, hating any exposure to the air and
light. It takes more than an hour to recover from its excitement. Here
assuredly is a grub that will never be tempted to leave its home and go
wandering about like the Cionus’ larva. It is most highly domestic by
inheritance and domestic it will remain.
It refuses even to go next door. In the same capsule, on the other side
of the partition, a neighbour is nibbling away. Never does it pay the
neighbour a visit, though it could easily do so by perforating the
partition, which at this moment is an actual sort of cake, no less
tender than the seeds and the placenta. Each holds the other’s share of
the capsule inviolable. On the one hand is one grub; on the other hand
is another; and never do the two hold the least communication through
the little skylight. A grub’s home is its castle.
The Gymnetron is so happy in her cell that she stays there a long time
after assuming her adult form. For ten months out of the twelve she
does not leave it. In April, when the buds of the new twigs are
swelling, she pierces the natal capsule, now a mighty donjon; she comes
out and revels in the sun on the recent flower-spikes, which grow daily
longer and thicker; she frisks in couples and, in May, establishes her
family, which will obstinately repeat the sedentary habits of the
elders.
With these data before us, let us philosophize awhile. Every Weevil
spends its larval life on the spot where the egg was laid. Various
larvæ, it is true, when the time of metamorphosis approaches, migrate
and make their way underground. The Brachycerus abandons its clove of
garlic, the Balaninus its nut or acorn, the Rhynchites its vine-leaf or
poplar-leaf cigar, the Ceuthorhynchus its cabbage stalk. But these
instances of desertion on the part of grubs which have attained their
full growth do not in any way invalidate the rule: all Weevil-larvæ
grow up in the actual place where they are born.
Now here, by a most unexpected change of tactics, the Cionus-grub,
while still quite young, quits its natal cell, the capsule of the
mullein; it longs for the outer world, that it may browse in the open
air on the bark of a twig; and this entails upon it two inventions
elsewhere unknown: the sticky coat, which gives it a firm hold when it
moves from place to place, and the gold-beater’s-skin ampulla, which
serves to house the nymph.
What is the cause of this aberration? Two theories are suggested, one
based on decadence, the other on progress. Of old, we tell ourselves,
the mother Cionus, far back in the ages, used to obey the conventions
of her tribe. Like the other Weevils that munch unripe seeds, she
favoured large capsules, enough to feed a sedentary family. Later, by
inadvertence or flightiness or for some other reason, she turned her
attention to the stingy scollop-leaved mullein. Faithful to ancient
custom she rightly chose for her domain a plant of the same family as
that which she first exploited; but it unfortunately happens that the
mullein adopted is incapable of feeding a single grub in its fruit,
which is too small for the purpose. The mother’s ineptitude has led to
decadence; the perils of a wandering life have taken the place of a
peaceful, sedentary existence. The species is on the high road to
extinction.
Again, we might argue as follows, at the outset, the Cionus had the
scallop-leaved mullein as her portion; but, since the grubs do not
thrive when thus installed, the mother is searching for a better means
of setting them up in life. Gradual experiment will one day show her
the way. From time to time, indeed, I find her on Vervascum maiale or
Verbascum thapsus, both of which have large capsules; only she is there
by accident, in the course of a trip, thinking of obtaining a good
drink and not of laying her eggs. Sooner or later, the future will
establish her there for the sake of her family. The species is in
process of improvement.
By dressing up the matter in uncouth phrases, calculated to conceal the
vagueness of the thought behind them, we might represent the Cionus as
a magnificent example of the changes which the centuries bring about in
the habits of insects. This would sound extremely learned, but would it
be very intelligible? I doubt it. When my eyes fall upon a page
bristling with barbarous and so-called scientific locution, I say to
myself:
‘Take care! The author has not quite grasped what he is saying, or he
would have found, in the vocabulary hammered out by so many brilliant
minds, words that would express his thought more plainly.’
Boileau, [67] who has been denied poetic inspiration, but who certainly
possessed common-sense and plenty of it, tells us:
‘Ce que l’on conçoit bien s’énonce clairement.’ [68]
Just so, Nicolas! Yes, clearness, clearness always! He calls a spade a
spade. Let us do as he does, let us qualify as gibberish any
over-learned prose that reminds us of Voltaire’s witty sally:
‘When the listener does not understand and the speaker does not himself
know what he is saying, then they are talking metaphysics.’
‘And advanced science,’ let us add.
We will confine ourselves to stating the problem of the Cionus, without
much hope that some day it will be clearly solved. For that matter, if
the truth be told, it may be that there is no problem at all. The grub
of the Cionus was a vagabond in the beginning and a vagabond it will
remain, among the other Weevil-grubs, which are all essentially
stay-at-home larvæ. Let us leave it at that: it is the simplest and
most lucid explanation.
NOTES
[1] The Vocontii were a nation of Gauls inhabiting the Viennaise,
between the Allobroges on the north, the Caturiges and the estates of
King Cottius on the east, the Cavares on the west and the Memini and
Vulgientes on the south. Vasio (Vocontia), now Vaison, was their
capital.—Translator’s Note.
[2] Caius Plinius Secundus (23–79), known as Pliny the Elder, or the
Naturalist, to distinguish him from his nephew Caius Plinius Cæcilius
Secundus (61–c. 115), commonly called Pliny the Younger, the historian.
He was the author of the famous Naturalis Historia.—Translator’s Note.
[3] The Garden Warbler, or Bush-pipet, a bird which is considered a
great delicacy, especially in the autumn, when it feeds on figs, grapes
and so on. Cf. The Hunting Wasps, by J. Henri Fabre, translated by
Alexander Teixeira de Mattos: chap. xii.—Translator’s Note.
[4] From Massalia, the ancient name of Marseilles, of which Phocæa, in
Asia Minor, was the mother city.—Translators Note.
[5] ‘The god made these hours of leisure for us.’—Translator’s Note.
[6] Colony of Nîmes. Nemansus was the Latin name of Nîmes.—Translator’s
Note.
[7] A form of Mussel.—Translator’s Note.
[8] Another genus of bivalve molluscs.—Translator’s Note.
[9] Piddocks.—Translator’s Note.
[10] Or Cone-shells.—Translator’s Note.
[11] Bivalved Ostracods.—Translator’s Note.
[12] A genus of molluscs including the Surf Clams and related
species.—Translator’s Note.
[13] Gastropods with a rough, spinose shell.—Translator’s Note.
[14] Gastropods with an elongated, turreted shell.—Translator’s Note.
[15] Or Mitre-shells. Gastropods with a fusiform shell suggesting a
bishop’s mitre.—Translator’s Note.
[16] Or Ground-beetle. Cf. The Glow-worm and Other Beetles, by J. Henri
Fabre, translated by Alexander Teixeira de Mattos: chap.
xiii.—Translator’s Note.
[17] Cf. The Sacred Beetle and Others, by J. Henri Fabre, translated by
Alexander Teixeira de Mattos: passim.—Translator’s Note.
[18] Cf. The Glow-worm and Other Beetles: chap. viii.—Translator’s
Note.
[19] The Great Water-beetle. Cf. The Glow-worm and Other Beetles: chap.
x.—Translator’s Note.
[20] The Whirligig Beetle. Cf. The Life of the Fly, by J. Henri Fabre,
translated by Alexander Teixeira de Mattos: chap. vii.—Translator’s
Note.
[21] A carnivorous Water-beetle. Cf. idem: chaps. vii. and
viii.—Translator’s Note.
[22] Cf. The Life of the Grasshopper, by J. Henri Fabre, translated by
Alexander Teixeira de Mattos: chapters i. to v.—Translator’s Note.
[23] Cf. idem: chapter xiv. and passim.—Translator’s Note.
[24] Cf. The Life of the Fly: chapter iii.—Translator’s Note.
[25] Cf. The Life of the Caterpillar, by J. Henri Fabre, translated by
Alexander Teixeira de Mattos: chapter xiv., in which the activities of
one of the Ichneumon-flies, Microgaster glomeratus are
described.—Translator’s Note.
[26] Marcus Vitruvius Pollio (fl. 1st century B.C.), the Roman
architect and engineer, author of De Architectura.—Translator’s Note.
[27] For the Onitis and Onthophagus Dung-beetles, cf. The Sacred Beetle
and Others: chapters xi. and xiv. to xviii.—Translator’s Note.
[28] Rose-chafers. Cf. More Hunting Wasps: chap. iv.—Translator’s Note.
[29] ·585 by ·39 inch.—Translator’s Note.
[30] ·585 inch.—Translator’s Note.
[31] Cf. The Sacred Beetle and Others: chaps. ix., x. and
xvi.—Translator’s Note.
[32] Or Burying-beetle. Cf. The Glow-worm and Other Beetles: chaps. xi.
and xii.—Translator’s Note.
[33] Cf. The Hunting Wasps: chaps. iv. to x.—Translator’s Note.
[34] The Large White, or Cabbage, Butterfly. Cf. The Life of the
Caterpillar: chap. xiv.—Translator’s Note.
[35] A genus of very decorative Butterflies, including such well-known
species as the Red Admiral, the Painted Lady, the Camberwell Beauty,
the Tortoiseshell Butterfly and the Peacock Butterfly.—Translator’s
Note.
[36] Cf. The Hunting Wasps: chaps. i. to iii.—Translator’s Note.
[37] The nearest mountain to the author’s village. Cf. The Hunting
Wasps: chap. xi.—Translator’s Note.
[38] From the Latin balanus, an acorn.—Translator’s Note.
[39] The Life of the Grasshopper: chap. xiv.—Translator’s Note.
[40] The Mason-bee. Cf. The Mason-bees: passim.—Translator’s Note.
[41] Jean de La Fontaine (1621–1695).—Translator’s Note.
[42] Cf. The Hunting Wasps: passim; also More Hunting Wasps, by J.
Henri Fabre, translated by Alexander Teixeira de Mattos:
passim.—Translator’s Note.
[43] The Silk-worm Moth.—Translator’s Note.
[44] Francis Vincent Raspail (1794–1878), a French physician and
politician, one of the early advocates of universal
suffrage.—Translator’s Note.
[45] H. pomatia is the Large Edible Snail.—Translator’s Note.
[46] Or Wheel Animalcule.—Translator’s Note.
[47] For these Cotton-bees and Resin-bees, cf. Bramble-bees and Others,
by J. Henri Fabre, translated by Alexander Teixeira de Mattos: chaps.
ix. and x.—Translator’s Note.
[48] Cf. The Glow-worm and Other Beetles: chaps. ix. and
x.—Translator’s Note.
[49] ·156 inch.—Translator’s Note.
[50] About 1⁄25 inch.—Translator’s Note.
[51] Cf. The Sacred Beetle and Others: chaps. ix. and x.—Translator’s
Note.
[52] For both these Beetles and also for the next insect mentioned in
the text, Phanæus Milon, cf. The Glow-worm and Other Beetles: chap.
ix.—Translator’s Note.
[53] Marcus Terentius Varro (B.C. 116–circa B.C. 27), a famous Roman
scholar, author of De Re Rustica and for some time director of the
public library.—Translator’s Note.
[54] Lucius Junius Moderatus Columella (fl. 1st century A.D.), author
of a work, De Re Rustica, bearing the same title as
Varro’s.—Translator’s Note.
[55] A very large, prehistoric Bear (Ursus spelæus) whose remains are
common in European caves, including those of England.—Translator’s
Note.
[56] The modern classification places the Pea- and Haricot-weevils in a
separate family, the Bruchidæ, whereas the family of the Curculionidæ
includes most of the other, or true, Weevils.—Translator’s Note.
[57] 1⁄25 inch.—Translator’s Note.
[58] Or, if the reader prefers, the Swell-belly. Gus, in the Provençal
dialect, means both ‘guts’ and ‘bigger.’—Translator’s Note.
[59] ‘And Thestylis wild thyme and garlic beats
For harvest hinds, o’erspent with toil and heats.’—
Pastorals, ii., Dryden’s translation.
[60] Book i., line 227 et seq.—Author’s Note.
[61] ‘Vile vetches would you sow, or lentils lean?
The growth of Egypt, or the kidney-bean?
Begin when the slow Waggoner descends,
Nor cease your sowing till mid-winter ends.’
—Dryden’s translation.
[62] The Academician (1842–1905).—Translator’s Note.
[63] Annales politiques et littéraires: Les Enfants jugés par leurs
Pères. Christmas number, 1901.—Author’s Note.
[64] The enclosed piece of waste land on which the author used to study
his insects in the wild state. Cf. The Life of the Fly: chap.
i.—Translator’s Note.
[65] The essays on Minotaurus typhæus will appear in the next volume of
the series, to be entitled Mere Beetles.—Translator’s Note.
[66] The Life of the Fly: chaps. ii. and iii.—Translators Note.
[67] Nicolas Boileau-Despréaux (1636–1711), author of L’Art poétique
and other poetical, critical and satirical works.—Translator’s Note.
[68] ‘That which is well conceived is also clearly stated.’