THE ANTHRAX FLY
I
A STRANGE MEAL
I made the acquaintance of the Anthrax in 1855 at Carpentras, when I
was searching the slopes of which I have already told you, the slopes
beloved of the Anthophora-bees. Her curious pupa, so powerfully
equipped to force an outlet for the perfect insect, which is incapable
of the least effort, seemed worthy of investigation. For that pupa is
armed with a ploughshare in front, a trident at its tail, and rows of
harpoons on its back, with which to rip open the Osmia-bee’s cocoon and
break through the hard crust of the hill-side.
Let us, some day in July, knock away the pebbles that fasten the nests
of the Mason-bees to the sloping ground on which they are built.
Loosened by the shock, the dome comes off cleanly, all in one piece.
Moreover—and this is a great advantage—the cells are all exposed at the
base of the nest, for at this point they have no other wall than the
surface of the pebble. Without any scraping, which would be wearisome
work for us and dangerous to the Bees, we have all the cells before our
eyes, together with their contents—a silky, amber-yellow cocoon, as
delicate and transparent as the skin of an onion. Let us split the
dainty wrappers with the scissors, cell by cell, one after another. If
fortune be at all kind, as it always is to the persevering, we shall
end by finding cocoons harbouring two larvæ together, one more or less
faded in appearance, the other fresh and plump. We shall also find
some, no less plentiful, in which the withered larva is accompanied by
a family of little grubs wriggling uneasily round it.
It is easy to see that a tragedy is happening under the cover of the
cocoon. The flabby, faded larva is the Mason-bee’s. A month ago, in
June, having finished its ration of honey, it wove itself a silken
sheath in which to take the long sleep that precedes its
transformation. It was bulging with fat, and was a rich and a
defenceless morsel for any enemy that could reach it. And enemies did
reach it. In spite of obstacles that might well seem insurmountable,
the wall of mortar and dome-shaped cover, the enemy grubs appeared in
the secret retreat, and began to eat the sleeper. Three different
species take part in this murderous work, often in the same nest, in
adjoining cells. We will concern ourselves only with the Anthrax Fly.
The grub, when it has eaten its victim and is left alone in the
Mason-bee’s cocoon, is a naked worm, smooth, legless, and blind. It is
creamy-white, and each of its segments or divisions forms a perfect
ring, very much curved when at rest, but almost straight when
disturbed. Including the head I can count thirteen segments,
well-marked in the middle of the body, but in the fore-part difficult
to distinguish. The white, soft head shows no sign of any mouth, and is
no bigger than a tiny pin’s head. The grub has four pale red stigmata,
or openings through which to breathe, two in front and two behind, as
is the rule among Flies. It has no walking-apparatus whatever; it is
absolutely incapable of shifting its position. If I disturb its rest,
it curves and straightens itself alternately, tossing about violently
where it lies; but it does not manage to progress.
But the most interesting point about the grub of the Anthrax is its
manner of eating. A most unexpected fact attracts our attention: the
curious ease with which this larva leaves and returns to the Bee-grub
on which it is feeding. After watching flesh-eating grubs at hundreds
and hundreds of meals, I suddenly find myself confronted with a manner
of eating that is entirely unlike anything I ever saw before.
This, for instance, is the Amophila-grub’s way of devouring its
caterpillar. A hole is made in the victim’s side, and the head and neck
of the grub dives deep into the wound. It never withdraws its head,
never pauses to take breath. The voracious animal always goes forward,
chewing, swallowing, digesting, until the caterpillar’s skin is empty.
Once the meal is begun, the creature does not budge as long as the food
lasts. If moved by force it hesitates, and hunts about for the exact
spot where it left off eating; for if the caterpillar be attacked at a
fresh point it is liable to go bad.
In the case of the Anthrax-grub there is none of this mangling, none of
this persistent clinging to the original wound. If I tease it with the
tip of a pointed brush it at once retires, and there is no wound to be
seen on the victim, no sign of broken skin. Soon the grub once more
applies its pimple-head to its meal, at any point, no matter where, and
keeps itself fixed there without any effort. If I repeat the touch with
the brush I see the same sudden retreat and the same calm return to the
meal.
The ease with which this larva grips, leaves, and regrips its victim,
now here, now there, and always without a wound, shows that the mouth
of the Anthrax is not armed with fangs that can dig into the skin and
tear it. If the flesh were gashed by pincers of any kind, one or two
attempts would be necessary before they could leave go or take hold
again; and besides, the skin would be broken. There is nothing of the
kind: the grub simply glues its mouth to its prey, and withdraws it. It
does not chew its food like the other flesh-eating grub: it does not
eat, it inhales.
This remarkable fact led me to examine the mouth under the microscope.
It is a small conical crater, with yellowish-red sides and very faint
lines running round it. At the bottom of this funnel is the opening of
the throat. There is not the slightest trace of mandibles or jaws, or
any object capable of seizing and grinding food. There is nothing at
all but the bowl-shaped opening. I know of no other example of a mouth
like this, which I can only compare to a cupping-glass. Its attack is a
mere kiss, but what a cruel kiss!
To observe the working of this curious machine I placed a new-born
Anthrax-grub, together with its prey, in a glass tube. Here I was able
to watch the strange repast from beginning to end.
The Anthrax-grub—the Bee’s uninvited guest—is fixed by its mouth or
sucker to any convenient part of the plump Bee-grub. It is ready to
break off its kiss suddenly, should anything disturb it, and to resume
it as easily when it wishes. After three or four days of this curious
contact the Bee-grub, formerly so fat, glossy, and healthy, begins to
look withered. Her sides fall in, her fresh colour fades, her skin
becomes covered with little folds, and she is evidently shrinking. A
week is hardly passed when these signs of exhaustion increase to a
startling degree. The victim is flabby and wrinkled, as though borne
down by her own weight. If I move her from her place she flops and
sprawls like a half-filled indiarubber bottle. But the kiss of the
Anthrax goes on emptying her: soon she is but a sort of shrivelled
bladder, growing smaller and smaller from hour to hour. At length,
between the twelfth and fifteenth day, all that remains of the
Mason-bee’s larva is a little white grain, hardly as large as a pin’s
head.
If I soften this small remnant in water, and then blow into it through
a very fine glass tube, the skin fills out and resumes the shape of the
larva. There is no outlet anywhere for the compressed air. It is
intact: it is nowhere broken. This proves that, under the cupping-glass
of the Anthrax, the skin has been drained through its pores.
The devouring grub, in making its attack, chooses its moment very
cunningly. It is but an atom. Its mother, a feeble Fly, has done
nothing to help it. She has no weapons; and she is quite incapable of
penetrating the Mason-bee’s fortress. The future meal of the Anthrax
has not been paralysed, nor injured in any way. The parasite arrives—we
shall presently see how; it arrives, scarcely visible, and having made
its preparations it installs itself upon its monstrous victim, whom it
is going to drain to the very husk. And the victim, though not
paralysed nor in any way lacking in vitality, lets it have its way, and
is sucked dry without a tremor or a quiver of resistance. No corpse
could show greater indifference to a bite.
Had the Anthrax-grub appeared upon the scene earlier, when the Bee-grub
was eating her store of honey, things would surely have gone badly with
it. The victim, feeling herself bled to death by that ravenous kiss,
would have protested with much wriggling of body and grinding of
mandibles. The intruder would have perished. But at the hour chosen so
wisely by it all danger is over. Enclosed in her silken sheath, the
larva is in the torpid state that precedes her transformation into a
Bee. Her condition is not death, but neither is it life. So there is no
sign of irritation when I stir her with a needle, nor when the
Anthrax-grub attacks her.
There is another marvellous point about the meal of the Anthrax-grub.
The Bee-grub remains alive until the very end. Were she really dead it
would, in less than twenty-four hours, turn a dirty-brown colour and
decompose. But during the whole fortnight that the meal lasts, the
butter-colour of the victim continues unaltered, and there is no sign
of putrefaction. Life persists until the body is reduced to nothing.
And yet, if I myself give her a wound, the whole body turns brown and
soon begins to rot. The prick of a needle makes her decompose. A mere
nothing kills it; the atrocious draining of its strength does not.
The only explanation I can suggest is this, and it is no more than a
suggestion. Nothing but fluids can be drawn by the sucker of the
Anthrax through the unpierced skin of the Bee-grub: no part of the
breathing-apparatus or the nervous system can pass. As these two
essentials remain uninjured, life goes on until the fluid contents of
the skin are entirely exhausted. On the other hand, if I myself injure
the larva of the Bee, I disturb the nervous or the air-conducting
system, and the bruised part spreads a taint all over the body.
Liberty is a noble possession, even in an insignificant grub; but it
has its dangers everywhere. The Anthrax escapes these dangers only on
the condition of being, so to speak, muzzled. It finds its own way into
the Bee’s dwelling, quite independently of its mother. Unlike most of
the other flesh-eating larvæ it is not fixed by its mother’s care at
the most suitable spot for its meal. It is perfectly free to attack its
prey where it chooses. If it had a set of carving-tools, of jaws and
mandibles, it would meet with a speedy death. It would split open its
victim and bite it at random, and its food would rot. Its freedom of
action would kill it.
II
THE WAY OUT
There are other grub-eaters which drain their victims without wounding
them, but not one, among those I know, reaches such perfection in this
art as the Anthrax-grub. Nor can any be compared with the Anthrax as
regards the means brought into play in order to leave the cell. The
others, when they become perfect insects, have implements for mining
and demolishing. They have stout mandibles, capable of digging the
ground, of pulling down clay partition-walls, and even of grinding the
Mason-bee’s tough cement to powder. The Anthrax, in her final form, has
nothing like this. Her mouth is a short, soft proboscis, good at most
for soberly licking the sugary fluid from the flowers. Her slim legs
are so feeble that to move a grain of sand would be too heavy a task
for them, enough to strain every joint. Her great stiff wings, which
must remain full-spread, do not allow her to slip through a narrow
passage. Her delicate suit of downy velvet, from which you take the
bloom by merely breathing on it, could not withstand the contact of
rough tunnels. She is unable to enter the Mason-bee’s cells to lay her
egg, and equally unable to leave it when the time comes to free herself
and appear in broad daylight.
And the grub, for its part, is powerless to prepare the way for the
coming flight. That buttery little cylinder, owning no tools but a
sucker so flimsy and small that it is barely visible through the
magnifying-glass, is even weaker than the full-grown insect, which at
least flies and walks. The Mason-bee’s cell seems to this creature like
a granite cave. How can it get out? The problems would be insoluble to
these two incapables, if nothing else played its part.
Among insects the pupa—the transition stage, when the creature is no
longer a grub but is not yet a perfect insect—is generally a striking
picture of complete weakness. A sort of mummy, tightly bound in
swaddling-clothes, motionless and unconscious, it awaits its
transformation. Its tender flesh is hardly solid; its limbs are
transparent as crystals, and are held fixed in their place, lest a
movement should disturb the work of development. In the same way, to
secure his recovery, a patient whose bones are broken is held bound in
the surgeon’s bandages.
Well, here, by a strange reversal of the usual state of things, a
stupendous task is laid upon the pupa of the Anthrax. It is the pupa
that has to toil, to strive, to exhaust itself in efforts to burst the
wall and open the way out. To the pupa falls the desperate duty, to the
full-grown insect the joy of resting in the sun. The result of these
unusual conditions is that the pupa possesses a strange and complicated
set of tools that is in no way suggested by the grub nor recalled by
the perfect Fly. This set of tools includes a collection of
ploughshares, gimlets, hooks, spears, and other implements that are not
found in our trades nor named in our dictionaries. I will do my best to
describe the strange gear.
By the time that July is nearly over the Anthrax has finished eating
the Bee-grub. From that time until the following May it lies motionless
in the Mason-bee’s cocoon, beside the remains of its victim. When the
fine days of May arrive it shrivels, and casts its skin; and it is then
that the pupa appears, fully clad in a stout, reddish, horny hide.
The head is round and large, and is crowned on top and in front with a
sort of diadem of six hard, sharp, black spikes, arranged in
semi-circle. This sixfold ploughshare is the chief digging-implement.
Lower down the instrument is finished off with a separate group of two
small black spikes, placed close together.
Four segments in the middle of the body are armed on the back with a
belt of little horny arches, set in the skin upside down. They are
arranged parallel to one another, and are finished at both ends with a
hard, black point. The belt forms a double row of little thorns, with a
hollow in between. There are about two hundred spikes on the four
segments. The use of this rasp, or grater, is obvious: it helps the
pupa to steady itself on the wall of the gallery as the work proceeds.
Thus anchored on a host of points the brave pioneer is able to hit the
obstacle harder with its crown of awls. Moreover, to make it more
difficult for the instrument to recoil, there are long, stiff bristles,
pointing backwards, scattered here and there among the rows of spikes.
There are some also on other segments, and on the sides they are
arranged in clusters. Two more belts of thorns, less powerful than the
others, and a sheaf of eight spikes at the tip of the body—two of which
are longer than the rest—completes the strange boring-machine that
prepares an outlet for the feeble Anthrax.
About the end of May the colouring of the pupa alters, and shows that
the transformation is close at hand. The head and fore-part of the
creature become a handsome, shiny black, prophetic of the black livery
worn by the coming insect. I was anxious to see the boring-tools in
action, and, since this could not be done in natural conditions, I
confined the Anthrax in a glass tube, between two thick stoppers of
sorghum-pith. The space between the stoppers was about the same size as
the Bee’s cell, and the partitions, though not so strong as the Bee’s
masonry, were firm enough to withstand considerable effort. On the
other hand the side-walls, being of glass, could not be gripped by the
toothed belts, which made matters much harder for the worker.
No matter: in the space of a single day the pupa pierced the front
partition, three-quarters of an inch thick. I saw it fixing its double
ploughshare against the back partition, arching itself into a bow, and
then suddenly releasing itself and striking the stopper in front of it
with its barbed forehead. Under the blows of the spikes the pith slowly
crumbled to pieces, atom by atom. At long intervals the method of work
changed. The animal drove its crown of awls into the pith, and fidgeted
and swayed about for a time; then the blows began again. Now and then
there were intervals of rest. At last the hole was made. The pupa
slipped into it, but did not pass through entirely. The head and chest
appeared beyond the hole, but the rest of the body remained held in the
tunnel.
The glass cell certainly puzzled my Anthrax. The hole through the pith
was wide and irregular: it was a clumsy breach and not a gallery. When
made through the Mason-bee’s walls it is fairly neat, and exactly of
the animal’s diameter. For narrowness and evenness in the exit-tunnel
are necessary. The pupa always remains half-caught in it, and even
pretty securely fixed by the graters on its back. Only the head and
chest emerge into the outer air. A fixed support is indispensable, for
without it the Anthrax could not issue from her horny sheath, unfurling
her great wings and drawing out her slender legs.
She therefore remains steadily fixed by the graters on her back, in the
narrow exit-gallery. All is now ready. The transformation begins. Two
slits appear on the head: one along the forehead, and a second,
crossing it, dividing the skull in two and extending down the chest.
Through this cross-shaped opening the Anthrax Fly suddenly appears. She
steadies herself upon her trembling legs, dries her wings and takes to
flight, leaving her cast skin at the doorway of the gallery. The
sad-coloured Fly has five or six weeks before her wherein to explore
the clay nests amid the thyme and to take her small share of the joys
of life.
III
THE WAY IN
If you have paid attention to this story of the Anthrax Fly, you must
have noticed that it is incomplete. The Fox in the fable saw how the
Lion’s visitors entered his den, but did not see how they went out.
With us the case is reversed: we know the way out of the Mason-bee’s
fortress, but we do not know the way in. To leave the cell whose owner
it has eaten, the Anthrax becomes a boring-tool. When the exit-tunnel
is opened this tool splits like a pod bursting in the sun, and from the
strong framework there escapes a dainty Fly. A soft bit of fluff that
contrasts strangely with the roughness of the prison whence it comes.
On this point we know pretty well what there is to know. But the
entrance of the grub into the cell puzzled me for a quarter of a
century.
It is plain that the mother cannot place her egg in the Bee’s cell,
which is closed and barricaded with a cement wall. To pierce it she
would have to become a boring-tool once more, and get into the cast-off
rags which she left at the doorway of the exit-tunnel. She would have
to become a pupa again. For the full-grown Fly has no claws, nor
mandibles, nor any implement capable of working its way through the
wall.
Can it be, then, the grub that makes its own way into the storeroom,
that same grub that we have seen sucking the life out of the Bee’s
larva? Let us call the creature to mind: a little oily sausage, which
stretches and curls up just where it lies, without being able to shift
its position. Its body is a smooth cylinder, its mouth a circular lip.
It has no means whatever of moving; not even a hair or a wrinkle to
enable it to crawl. It can do nothing but digest its food. It is even
less able than the mother to make its way into the Mason-bee’s
dwelling. And yet its provisions are there: they must be reached: it is
a matter of life and death. How does the Fly set about it? In the face
of this puzzle I resolved to attempt an almost impossible task and
watch the Anthrax from the moment it left the egg.
Since these Flies are not really plentiful in my own neighbourhood I
made an expedition to Carpentras, the dear little town where I spent my
twentieth year. The old college where I made my first attempts as a
teacher was unchanged in appearance. It still looked like a
penitentiary. In my early days it was considered unwholesome for boys
to be gay and active, so our system of education applied the remedy of
melancholy and gloom. Our houses of instruction were above all houses
of correction. In a yard between four walls, a sort of bear-pit, the
boys fought to make room for their games under a spreading plane-tree.
All round it were cells like horseboxes, without light or air: those
were the class-rooms.
I saw, too, the shop where I used to buy tobacco as I came out of the
college; and also my former dwelling, now occupied by monks. There, in
the embrasure of a window, sheltered from profane hands, between the
closed outer shutters and the panes, I kept my chemicals—bought for a
few sous saved out of the housekeeping money. My experiments, harmless
or dangerous, were made on a corner of the fire, beside the simmering
broth. How I should love to see that room again, where I pored over
mathematical problems; and my familiar friend the blackboard, which I
hired for five francs a year, and could never buy outright for want of
the necessary cash!
But I must return to my insects. My visit to Carpentras, unfortunately,
was made too late in the year to be very profitable. I saw only a few
Anthrax Flies hovering round the face of the cliff. Yet I did not
despair, because it was plain that these few were not there to take
exercise, but to settle their families.
So I took my stand at the foot of the rock, under a broiling sun, and
for half a day I followed the movements of my Flies. They flitted
quietly in front of the slope, a few inches away from the earthly
covering. They went from one Bee’s nest to another, but without
attempting to enter. For that matter, the attempt would be useless, for
the galleries are too narrow to admit their spreading wings. So they
simply explore the cliff, going to and fro, and up and down, with a
flight that was now sudden, now smooth and slow. From time to time I
saw one of them approach the wall and touch the earth suddenly with the
tip of her body. The proceeding took no longer than the twinkling of an
eye. When it was over the insect rested a moment, and then resumed
flight.
I was certain that, at the moment when the Fly tapped the earth, she
laid her eggs on the spot. Yet, though I rushed forward and examined
the place with my lens, I could see no egg. In spite of the closest
attention I could distinguish nothing. The truth is that my state of
exhaustion, together with the blinding light and scorching heat, made
it difficult for me to see anything. Afterwards, when I made the
acquaintance of the tiny thing that comes out of that egg, my failure
no longer surprised me: for even in the leisure and peace of my study I
have the greatest difficulty in finding the infinitesimal creature. How
then could I see the egg, worn out as I was under the sun-baked cliff?
None the less I was convinced that I had seen the Anthrax Flies
strewing their eggs, one by one, on the spots frequented by the Bees
who suit their grubs. They take no precaution to place the egg under
cover, and indeed the structure of the mother makes any such precaution
impossible. The egg, that delicate object, is laid roughly in the
blazing sun, among grains of sand, in some wrinkle of the chalk. It is
the business of the young grub to manage as best it can.
The next year I continued my investigations, this time on the Anthrax
of the Chalicodoma, a Bee that abounds in my own neighbourhood. Every
morning I took the field at nine o’clock, when the sun begins to be
unendurable. I was prepared to come back with my head aching from the
glare, if only I could bring home the solution of my puzzle. The
greater the heat, the better my chances of success. What gives me
torture fills the insect with delight; what prostrates me braces the
Fly.
The road shimmers like a sheet of molten steel. From the dusty,
melancholy olive-trees rises a mighty, throbbing hum, the concert of
the Cicadæ, who sway and rustle with increasing frenzy as the
temperature increases. The Cicada of the Ash adds its strident
scrapings to the single note of the Common Cicada. This is the moment!
For five or six weeks, oftenest in the morning, sometimes in the
afternoon, I set myself to explore the rocky waste.
There were plenty of the nests I wanted, but I could not see a single
Anthrax on their surface. Not one settled in front of me to lay her
egg. At most, from time to time, I could see one passing far away, with
an impetuous rush. I would lose her in the distance; and that was all.
It was impossible to be present at the laying of the egg. In vain I
enlisted the services of the small boys who keep the sheep in our
meadows, and talked to them of a big black Fly and the nests on which
she ought to settle. By the end of August my last illusions were
dispelled. Not one of us had succeeded in seeing the big black Fly
perching on the dome of the Mason-bee.
The reason is, I believe, that she never perches there. She comes and
goes in every direction across the stony plain. Her practised eye can
detect, as she flies, the earthen dome which she is seeking, and having
found it she swoops down, leaves her egg on it, and makes off without
setting foot on the ground. Should she take a rest it will be
elsewhere, on the soil, on a stone, on a tuft of lavender or thyme. It
is no wonder that neither I nor my young shepherds could find her egg.
Meanwhile I searched the Mason-bees’ nests for grubs just out of the
egg. My shepherds procured me heaps of the nests, enough to fill
baskets and baskets; and these I inspected at leisure on my work-table.
I took the cocoons from the cells, and examined them within and
without: my lens explored their innermost recesses, the sleeping larva,
and the walls. Nothing, nothing, nothing! For a fortnight and more
nests were searched and rejected, and heaped up in a corner. My study
was crammed with them. In vain I ripped up the cocoons; I found
nothing. It needed the sturdiest faith to make me persevere.
At last I saw, or seemed to see, something move on the Bee’s larva. Was
it an illusion? Was it a bit of down stirred by my breath? It was not
an illusion; it was not a bit of down; it was really and truly a grub!
But at first I thought the discovery unimportant, because I was so
greatly puzzled by the little creature’s appearance.
In a couple of days I was the owner of ten such worms and had placed
each of them in a glass tube, together with the Bee-grub on which it
wriggled. It was so tiny that the least fold of skin concealed it from
my sight. After watching it one day through the lens I sometimes failed
to find it again on the morrow. I would think it was lost: then it
would move, and become visible once more.
For some time the belief had been growing in me that the Anthrax had
two larval forms, a first and a second, the second being the form I
knew, the grub we have already seen at its meals. Was this new
discovery, I asked myself, the first form? Time showed me that it was.
For at last I saw my little worms transform themselves into the grub I
have already described, and make their first start at draining their
victims with kisses. A few moments of satisfaction like those I then
enjoyed make up for many a weary hour.
This tiny worm, the first form or “primary larva” of the Anthrax, is
very active. It tramps over the fat sides of its victim, walking all
round it. It covers the ground pretty quickly, buckling and unbuckling
by turns, very much after the manner of the Looper-caterpillar. Its two
ends are its chief points of support. When walking it swells out, and
then looks like a bit of knotted string. It has thirteen rings or
segments, including its tiny head, which bristles in front with short,
stiff hairs. There are four other pairs of bristles on the lower
surface, and with the help of these it walks.
For a fortnight the feeble grub remains in this condition, without
growing, and apparently without eating. Indeed, what could it eat? In
the cocoon there is nothing but the larva of the Mason-bee, and the
worm cannot eat this before it has the sucker or mouth that comes with
the second form. Nevertheless, as I said before, though it does not eat
it is far from idle. It explores its future dish, and runs all over the
neighborhood.
Now, there is a very good reason for this long fast. In the natural
state of the Anthrax-grub it is necessary. The egg is laid by the
mother on the surface of the nest, at a distance from the Bee’s larva,
which is protected by a thick rampart. It is the business of the
new-born grub to make its way to its provisions, not by violence, of
which it is incapable, but by patiently slipping through a maze of
cracks. It is a very difficult task, even for this slender worm, for
the Bee’s masonry is exceedingly compact. There are no chinks due to
bad building, no cracks due to the weather. I see but one weak point,
and that only in a few nests: it is the line where the dome joins the
surface of the stone. This weakness so seldom occurs that I believe the
Anthrax-grub is able to find an entrance at any spot on the dome of the
Bee’s nest.
The grub is extremely weak, and has nothing but invincible patience.
How long it takes to work its way through the masonry I cannot say. The
work is so laborious and the worker so feeble! In some cases I believe
it may be months before the slow journey is accomplished. So it is very
fortunate, you see, that this first form of the Anthrax, which exists
only in order to pierce the walls of the Bees’ nest, should be able to
live without food.
At last I saw my young worms shrink, and rid themselves of their outer
skin. They then appeared as the grub I knew and was so anxiously
expecting, the grub of the Anthrax, the cream-colored cylinder with the
little button of a head. Fastening its round sucker to the Bee-grub, it
began its meal. You know the rest.
Before taking leave of this tiny animal let us dwell for a moment on
its marvellous instinct. Picture it as having just left the egg, just
awakened to life under the fierce rays of the sun. The bare stone is
its cradle; there is no one to welcome it as it enters the world, a
mere thread of half-solid substance. Instantly it starts on its
struggle with the flint. Obstinately it sounds each pore of the stone;
it slips in, crawls on, retreats, begins again. What inspiration urges
it towards its food, what compass guides it? What does it know of those
depths, or of what lies in them? Nothing. What does the root of a plant
know of the earth’s fruitfulness? Again, nothing. Yet both the root and
the worm make for the nourishing spot, Why? I do not understand. I do
not even try to understand. The question is far above us.
We have now followed the complete history of the Anthrax. Its life is
divided into four periods, each of which has its special form and its
special work. The primary larva enters the Bees’ nest, which contains
provisions; the secondary larva eats those provisions; the pupa brings
the insect to light by boring through the enclosing wall; the perfect
insect strews its eggs. Then the story starts afresh.
NOTES
[1] See Insect Adventures, retold for young people from the works of
Henri Fabre.
[2] English translation by Mr Stephen M’Kenna.