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 [114]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 [115]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, [116]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 [117]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.[118]

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 decimetre1 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 [119]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 [120]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.2 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.

Fig. 11.—The Stercoraceous Geotrupe’s sausage.

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, [122]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.

Fig. 12.—Section of the Stercoraceous Geotrupe’s sausage at its lower end, showing the egg and the hatching-chamber.

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,3 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 decimetres4. 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 [123]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.5 The egg of Geotrupes Hypocrita is a little smaller.