THE GEOTRUPES: THE PUBLIC HEALTH
To complete the cycle of the year in the full-grown form, to see one’s
self surrounded by one’s sons at the spring festivals, to double and
treble one’s family: that surely is a most exceptional privilege in the
insect world. The Apids, the aristocracy of instinct, perish, once the
honey-pot is filled; the Butterflies, the aristocracy not of instinct,
but of dress, die when they have fastened their packet of eggs in a
propitious spot; the Carabids, richly cuirassed, succumb when the germs
of a posterity are scattered beneath the stones.
So with the others, except among the gregarious insects, where the
mother survives, either alone or accompanied by her attendants. It is a
general law: the insect is born orphaned of both its parents. Now, by
an unexpected turn of fate, the humble scavenger escapes the stern
destiny that cuts down the proud. The Dung-beetle, sated with days,
becomes a patriarch and really deserves to do so, in consideration of
the services rendered.
There is a general hygiene that calls for the disappearance, in the
shortest possible time, of every putrid thing. Paris has not yet solved
the formidable problem of her refuse, which sooner or later will become
a question of life or death for the monstrous city. One asks one’s self
whether the centre of light be not doomed to be extinguished one day in
the reeking exhalations of a soil saturated with rottenness. What this
agglomeration of millions of men cannot obtain, with all its treasures
of wealth and talent, the smallest hamlet possesses without going to
any expense or even troubling to think about it.
Nature, so lavish of her cares in respect of rural health, is
indifferent to the welfare of cities, if not actively hostile to it.
She has created for the fields two classes of scavengers, whom nothing
wearies, whom nothing repels. One of these—consisting of Flies,
Silphids, Dermestes, Necrophores—is charged with the dissection of
corpses. They cut and hash, they elaborate the waste matter of death in
their stomachs in order to restore it to life.
A mole ripped open by the plough-share soils the path with its
entrails, which soon turn purple; a snake lies on the grass, crushed by
the foot of a wayfarer who thought, the fool, that he was performing a
good work; an unfledged bird, fallen from its nest, has flattened
itself piteously at the foot of the tree that carried it; thousands of
other similar remains, of every sort and kind, are scattered here and
there, threatening danger through their effluvia, if nothing come to
establish order. Have no fear: no sooner is a corpse signalled in any
direction than the little undertakers come trotting along. They work
away at it, empty it, consume it to the bone, or at least reduce it to
the dryness of a mummy. In less than twenty-four hours, mole, snake,
bird have disappeared and the requirements of health are satisfied.
The same zeal for their task prevails in the second class of
scavengers. The village hardly knows those ammonia-scented refuges
whither we repair, in the towns, to relieve our wretched needs. A
little wall no higher than that, a hedge, a bush is all that the
peasant asks as a retreat at the moment when he would fain be alone. I
need say no more to suggest the encounters to which such free and easy
manners expose you! Enticed by the patches of lichen, the cushions of
moss, the tufts of homewort and other pretty things that adorn old
stones, you go up to a sort of wall that supports the ground of a
vineyard. Ugh! At the foot of the daintily-decked shelter, what a
spreading abomination! You flee: lichens, mosses and homewort tempt you
no more. But come back on the morrow. The thing has disappeared, the
place is clean: the Dung-beetles have been that way.
To preserve the eyes from offensive sights too oft repeated is, to
those gallant fellows, the least of offices: a loftier mission is
incumbent on them. Science tells us that the most dreadful scourges of
mankind have their agents in tiny organisms, the microbes, near
neighbours of must and mould, on the extreme confines of the vegetable
kingdom. The terrible germs multiply by countless myriads in the
intestinal discharges at times of epidemic. They contaminate the air
and water, those primary necessities of life; they spread over our
linen, our clothes, our food and thus diffuse contagion. We have to
destroy by fire, to sterilize with corrosives or to bury underground
such things as are soiled with them.
Prudence even demands that we should never allow ordure to linger on
the surface of the ground. It may be harmless, it may be dangerous:
when in doubt, the best thing is to put it out of sight. That is how
ancient wisdom seems to have understood the thing, long before the
microbe explained to us the great need for vigilance. The nations of
the East, more exposed to epidemics than ourselves, had formal laws in
these matters. Moses, apparently echoing Egyptian knowledge in this
connection, prescribed the line of conduct for his people wandering in
the Arabian desert:
“Thou shalt have a place without the camp,” he says, “to which thou
mayst go for the necessities of nature, carrying a paddle at thy
girdle. And, when thou sittest down, thou shalt dig round about
and, with the earth that is dug up, thou shalt cover that which
thou art eased of.” (Deut., XXIII., xii–xiv.)
This is a precept of grave import in its simplicity. And we may well
believe that, if Islamism, at the time of its great pilgrimages to the
Kaaba, were to take the same precaution and a few more of a similar
character, Mecca would cease to be an annual seat of cholera and Europe
would not need to mount guard on the shores of the Red Sea to protect
herself against the scourge.
Heedless of hygiene as the Arab, who was one of his ancestors, the
Provençal peasant does not suspect the danger. Fortunately, the
Dung-beetle, that faithful observer of the Mosaic edict, works. It is
his to remove from sight, it is his to bury the germ-crammed matter.
Supplied with implements for digging far superior to the paddle which
the Israelite was to carry at his girdle when urgent business called
him from the camp, he hastens and, as soon as man is gone, digs a pit
wherein the infection is swallowed up and rendered harmless.
The services rendered by these diggers are of the highest importance to
the health of the fields; yet we, who are mainly interested in this
constant work of purification, hardly vouchsafe those sturdy fellows a
contemptuous glance. Popular language overwhelms them with obnoxious
epithets. This appears to be the rule: do good and you shall be
misjudged, you shall be traduced, stoned, trodden underfoot, as witness
the toad, the bat, the hedgehog, the owl and other auxiliaries who, to
serve us, ask nothing but a little tolerance.
Now, of our defenders against the dangers of filth spread shamelessly
in the rays of the sun, the most remarkable, in our climes, are the
Geotrupes: not that they are more zealous than the others, but because
their size makes them capable of bigger work. Moreover, when it becomes
simply a question of their nourishment, they resort by preference to
the materials which we have most to fear.
My neighbourhood is worked by four Geotrupes. Two of them, Geotrupes
Mutator (Marsh) and Geotrupes Sylvaticus (Panz.), are rarities on which
we had best not count for connected studies; the two others, on the
contrary, Geotrupes Stercorarius (Lin.) and Geotrupes Hypocrita
(Schneid.), are exceedingly frequent. Black as ink above, both of them
are magnificently garbed below. One is quite surprised to find such a
jewel-case among the professional scavengers. Geotrupes Stercorarius is
of a splendid amethyst violet on his lower surface, while Geotrupes
Hypocrita is lavish with the ruddy gleams of copper pyrites. These are
the two inmates of my voleries.
Let us ask them first of what feats they are capable as buriers. There
are a dozen, of the two species taken together. The cage is previously
swept clean of what remains of the former provisions, hitherto supplied
without stint. This time, I propose to arrive at what a Geotrupe can
put away at a sitting. At sunset, I serve to my twelve captives the
whole of a heap which a mule has just dropped in front of my door.
There is plenty of it, enough to fill a basket.
On the morning of the next day, the mass has disappeared underground.
There is nothing left outside, or very nearly nothing. I am able to
make a fairly close estimate and I find that each of my Geotrupes,
presuming each of the twelve to have done an equal share of the work,
has stowed away very nearly a cubic decimetre [23] of matter. A Titanic
task, if we remember the insignificant size of the animal, which,
moreover, has to dig the warehouse to which the booty must be lowered.
And all this is done in the space of a night.
So well provided, will they remain quietly underground with their
treasure? Not they! The weather is magnificent. The hour of twilight
comes, gentle and calm. This is the time of the great flights, the
mirthful hummings, the distant explorations on the roads by which the
herds have lately passed. My lodgers abandon their cellars and mount to
the surface. I hear them buzzing, climbing up the wirework, knocking
themselves wildly against the walls. I have anticipated this twilight
animation. Provisions have been collected during the day, plentiful as
those of yesterday. I serve them. There is the same disappearance
during the night. On the morrow, the place is once again swept clean.
And this would continue indefinitely, so fine are the evenings, if I
always had at my disposal the wherewithal to satisfy those insatiable
hoarders.
Rich though his booty be, the Geotrupe leaves it at sunset to sport in
the last gleams of daylight and to go in search of a new workplace.
With him, one would say, the wealth acquired does not count; the only
valid thing is that to be acquired. Then what does he do with his
warehouses, renewed, in favourable times, at each new twilight? It is
obvious that Stercorarius is incapable of consuming provisions so
plentiful in a single night. He has such a superabundance of victuals
in his larder that he does not know how to dispose of them; he is
surfeited with good things by which he will not profit; and, not
satisfied with having his store crammed, the acquisitive plutocrat
slaves, night after night, to store away more.
From each warehouse, set up here, set up there, as things happen, he
deducts the daily meal beforehand; the rest, that is to say, almost the
whole, he abandons. My voleries testify to the fact that this instinct
for burying is more exacting than the consumer’s appetite. The ground
is soon raised, in consequence; and I am obliged, from time to time, to
lower the level to the desired limits. If I dig it up, I find it
choked, throughout its depth, with hoards that have remained intact.
The original earth has become an inextricable conglomerate, which I
must prune with a free hand, if I would not go astray in my future
observations.
Allowing for errors, either of excess or deficiency, which are
inevitable in a subject that does not admit of precise gauging, one
point stands out very clearly from my enquiry: the Geotrupes are
passionate buriers; they take underground a deal more than is necessary
for their consumption. As this work is performed, in varying degrees,
by legions of collaborators, large and small, it is evident that the
purification of the soil must benefit by it to an ample extent and that
the public health is to be congratulated on having this army of
auxiliaries in its service.
In other respects, the plant and, indirectly, a host of different
existences are interested in these interments. What the Geotrupe buries
and abandons the next day is not lost: far from it. Nothing is lost in
the world’s balance-sheet; the stock-taking total is constant. The
little lump of dung buried by the insect will make the nearest tuft of
grass grow a luxuriant green. A sheep passes, crops the bunch of grass:
all the better for the leg of mutton which man is waiting for. The
Dung-beetle’s industry has procured us a savoury mouthful.
In September and October, when the first autumn rains soak the ground
and allow the Sacred Beetle to split his natal casket, Geotrupes
Stercorarius and Geotrupes Hypocrita found their family-establishments,
somewhat makeshift establishments, in spite of what we might have
expected from the name of those miners, so well-styled Geotrupes, that
is to say, “Earth-borers.” When he has to dig himself a retreat that
shall shelter him against the rigours of winter, the Geotrupe really
deserves his name: none can compare with him for the depth of the pit
or the perfection and rapidity of the work. In sandy ground, easily
excavated, I have dug up some that had attained the depth of a metre.
[24] Others carried their digging further still, tiring both my
patience and my implements. There you have the skilled well-sinker, the
incomparable Earth-borer. When the cold sets in, he can go down to some
layer where frost has lost its terrors.
The lodging of the family is another matter. The propitious season is a
short one; time would fail, if each individual grub had to be endowed
with one of those manor-houses. That the insect should devote the
leisure which the approach of winter gives it to digging a hole of
unlimited depth is a capital thing: it makes the retreat doubly safe;
and activity, not yet quite suspended, has for the moment no other
occupation. But, at laying-time, these laborious undertakings are
impossible. The hours pass swiftly. In four or five weeks, a pretty
numerous family has to be housed and victualled, which puts a long,
patiently-sunk pit entirely out of the question.
The burrow dug by the Geotrupe for the benefit of her grub is hardly
deeper than that of the Copris or the Sacred Beetle, notwithstanding
the difference of the seasons. Three decimetres, [25] roughly speaking:
that is all that I find in the fields, where nothing occurs to limit
the depth.
The contents of the rustic dwelling take the form of a sort of sausage
or pudding, which fills the lower part of the cylinder and fits it
exactly. Its length is not far short of a couple of decimetres [26].
This sausage is almost always irregular in shape, now curved, now more
or less dented. These imperfections of the surface are due to the
accidents of a stony ground, which the insect does not always excavate
according to the canons of its art, which favours the straight line and
the perpendicular. The moulded material faithfully reproduces all the
irregularities of its mould. The lower extremity is rounded off like
the bottom of the burrow itself; at the lower end of the sausage is the
hatching-chamber, a round cavity which could hold a fair-sized
hazel-nut. The respiratory needs of the germ demand that the side-walls
should be thin enough to allow easy access to the air. Inside, I catch
the gleam of a greenish, semi-fluid plaster, a dainty which the mother
has disgorged to form the first mouthfuls of the budding worm.
In this round hole lies the egg, without adhering in any way to the
surrounding walls. It is a white, elongated ellipsoid and is of
remarkable bulk in proportion to the insect. In the case of Geotrupes
Stercorarius, it measures seven to eight millimetres in length by four
in its greatest width. [27] The egg of Geotrupes Hypocrita is a little
smaller.
MINOTAURUS TYPHŒUS