THE ONTHOPHAGI

After the notabilities of the Dung-beetle tribe, there remain, in the very limited radius of my research, the small fry of the Onthophagi, of whom I could gather a dozen different species around my house. What will these little ones teach us?

Even more zealous than their larger comrades, they are the first to hasten to the exploiting of the heap left by the passing mule. They come up in crowds and stay long, working under the spread table that gives them shade and coolness. Turn over the heap with your foot. You will be surprised at the swarming population whose presence no outward sign betrayed. The largest are scarce the size of a pea, but many are much smaller still, are dwarfs, no less busy than the others, no less eager to crumble the filth whose prompt disappearance the public health demands.

In works of major interest, there is none like the humble, with their concerted weakness, for realizing immense strength. Swollen by numbers, the next to nothing becomes an enormous total.

Hurrying in detachments at the first news of the event, assisted moreover in their wholesome task by their partners, the Aphodians, who are as weak as they, the tiny Onthophagi soon clear the ground of its dirt. Not that [[80]]their appetite is equal to the consumption of such plentiful provisions. What food do those pigmies need? An atom. But that atom, selected from among the exudations, must be hunted amid the fragments of the masticated fodder. Hence, an endless division and subdivision of the lump, reducing it to crumbs which the sun sterilizes and the wind dispels. As soon as the work is done—and very well done—the troop of scavengers goes in search of another refuse-yard. Outside the period of intense cold, which puts a stop to all activity, they know no dead season.

And do not run away with the idea that this filthy task entails an inelegant shape and a ragged dress. The insect knows none of our squalor. In its world, a navvy dons a sumptuous jerkin; an undertaker decks himself in a triple saffron sash; a wood-cutter works in a velvet coat. In like manner, the Onthophagus has his own luxury. True, the costume is always severe: brown and black are the predominant colours, now dull, now polished as ebony; but, on this background, what details of sober and graceful ornament! The graver’s work completes the beauty of the dress. Tiny chasings in parallel grooves, gnarly beads, dainty rows of knobs, seed-plots of pearly papillæ are distributed in profusion among nearly all of them. Yes, the little Onthophagi, with their stunted bodies and their nimble activity, are really pretty to look at.

PLATE V

And then how original are their frontal decorations! These peace-lovers delight in the panoply of war, as though they, the inoffensive ones, thirsted for battle. Many of them crown their heads with threatening horns. Let us mention that horned one whose story will occupy us more particularly. I mean Onthophagus [[81]]Taurus, clad in raven black. He wears a pair of long horns, gracefully curved and branching to either side. No pedigree bull, in the Swiss meadows, can match them for curve or elegance.

The Onthophagus is a very indifferent artist: his nest is a rudimentary piece of work, hardly fit to be acknowledged. I obtain it in profusion from the six species which I have brought up in my jars and flower-pots. Onthophagus Taurus alone provides me with nearly a hundred; and I find no two precisely alike, as pieces should be that come from the same mould and the same laboratory.

To this lack of exact similarity, we must add inaccuracy of shape, now more, now less accentuated. It is easy, however, to recognize among the bulk the prototype from which the clumsy nest-builder works. It is a sack shaped like a thimble and standing erect, with the spherical thimble-end at the bottom and the circular opening at the top.

Sometimes, the insect establishes itself in the central region of my apparatus, in the heart of the earthy mass; then, the resistance being the same in every direction, the sack-like shape is pretty accurate. But, generally, the Onthophagus prefers a solid basis to a dusty support and builds against the walls of the jar, especially against the bottom wall. When the support is vertical, the sack is a short cylinder divided lengthwise, with a smooth, flat surface against the glass and a rugged convexity every elsewhere. If the support be horizontal, as is most frequently the case, the cabin is a sort of undefined oval pastille, flat at the bottom, bulging and vaulted at the top. To the general inaccuracy of these contorted shapes, ruled by no very definite pattern, we must add the coarseness of the surfaces, all of which, with the [[82]]exception of the parts touching the glass, are covered with a crust of sand.

The manner of procedure explains this uncouth exterior. As laying-time draws nigh, the Onthophagus bores a cylindrical pit and descends underground to a middling depth. Here, working with the shield, the chine and the fore-legs, which are toothed like a rake, he forces back and heaps around him the materials which he has moved, so as to obtain as best he may a nest of suitable size.

The next thing is to cement the crumbling walls of the cavity. The insect climbs back to the surface by way of its pit; it gathers on its threshold an armful of mortar taken from the cake whereunder it has elected to set up house; it goes down again with its burden, which it spreads and presses upon the sandy wall. Thus it produces a concrete casing, the flint of which is supplied by the wall itself and the cement by the produce of the sheep. After a few trips and repeated strokes of the trowel, the pit is plastered on every side; the walls, encrusted with grains of sand, are no longer liable to give way.

The cabin is ready: it now wants only a tenant and stores. First, a large free space is contrived at the bottom: the hatching-chamber, on whose inner wall the egg is laid. Next comes the gathering of the provisions intended for the worm, a gathering made with nice precautions. Lately, when building, the insect worked upon the outside of the doughy mass and took no notice of the earthy blemishes. Now, it penetrates to the very centre of the lump, through a gallery that looks as though it were contrived with a punch. When trying a cheese, the buyer employs a hollow cylindrical taster, which he [[83]]drives well in and pulls out with a sample taken from the middle of the cheese. The Onthophagus, when collecting for her grub, goes to work as though equipped with one of these tasters. She bores an exactly round hole into the piece which she is exploiting; she goes straight to the middle, where the material, not being exposed to the contact of the air, has kept more savoury and pliable. Here and here alone are gathered the armfuls which, gradually stowed away, kneaded and heaped up to the requisite extent, fill the sack to the top. Finally, a plug of the same mortar, the sides of which are made partly of sand and partly of stercoral cement, roughly closes the cell, in such a way that an outward inspection does not allow one to distinguish front from back.

To judge the work and its merit, we must open it. A large empty space, oval in shape, occupies the rear end. This is the birth-chamber, huge in dimensions compared with its content, the egg fixed on the wall, sometimes at the bottom of the cell and sometimes on the side. The egg is a tiny white cylinder, rounded at either end and measuring a millimetre[1] in length immediately after it is laid. With no other support than the spot on which the oviduct has planted it, it stands on its hind-end and projects into space.

A more or less enquiring glance is quite surprised to find so small a germ contained in so large a box. What does that tiny egg want with all that space? When carefully examined within, the walls of the chamber prompt another question. They are coated with a fine greenish pap, semi-fluid and shiny, the appearance of which does not agree with the outward or inward aspect of the lump from which the insect has extracted its [[84]]materials. A similar lime-wash is observed in the nest which the Sacred Beetle, the Copris, the Sisyphus, the Geotrupe and other makers of stercoraceous preserves contrive in the very heart of the provisions, to receive the egg; but nowhere have I seen it so plentiful, in proportion, as in the hatching-chamber of the Onthophagus. Long puzzled by this brothy wash, of which the Sacred Beetle provided me with the first instance, I began by taking the thing for a layer of moisture oozing from the bulk of the victuals and collecting on the surface of the enclosure without other effort than capillary action. That was the interpretation which I accepted originally.

I was wrong. The truth is worthy of attention in a very different way. To-day, better-informed by the Onthophagus, I know that this lime-wash itself, this semi-fluid cream, is the product of maternal foresight.

What, then, is this lime-wash found in every cell? The answer is compulsory: it is a produce of the mother, a special gruel, a milk-food elaborated for the benefit of the new-born grub.

The young Pigeon puts his beak into that of his parents, who, with convulsive efforts, force down his gullet first a caseous mash secreted in the crop and next a broth of grains softened by being partially digested. He is fed upon disgorged foods, which are helpful to the weaknesses of an inexperienced stomach. The grub of the Onthophagus is brought up in much the same way, at the start. To assist its first attempts at swallowing, the mother prepares for it, in her crop, a light and strengthening cream.

To pass the dainty from mouth to mouth is, in her case, impossible: the construction of other cells keeps her busy elsewhere. Moreover—and this is a more serious detail—the laying takes place egg by egg, at very long [[85]]intervals, and the hatching is pretty slow: time would fail, had the family to be brought up in the manner of the Pigeons. Another method is perforce needed. The childish pap is disgorged all over the walls of the cabin in such a way that the nursling finds itself surrounded by an abundance of bread-and-jam, in which the bread, the food of the sturdy age, is represented by the uncooked material, as supplied by the sheep, whereas the jam, the mess of the puny age, is represented by the same material daintily prepared beforehand in the mother’s stomach. We shall see the babe presently lick first the jam, all around it, and then stoutly attack the bread. A child among ourselves would behave no otherwise.

I should have liked to catch the mother in the act of disgorging and spreading her broth. I was not able to succeed. Things happen in a narrow retreat, which the eye cannot enter when the pastry-cook is busy; and also her fluster at being exhibited in broad daylight at once stops the work.

If direct observation be lacking, at least the appearance of the material speaks very clearly and tells us that the Onthophagus, here rivalling the Pigeon, but with a different method, disgorges the first mouthfuls for her sons. And the same may be said of the other Dung-beetles skilled in the art of building a hatching-chamber in the centre of the provisions.

No elsewhere, in the insect order, except among the Apidæ, who prepare disgorged food in the shape of honey, is this affection present. The Dung-workers edify us with their morals. Several of them practise association in couples and found a household; several anticipate the suckling, the supreme expression of maternal solicitude, by turning their crop into a nipple. Life has its freaks. [[86]]It settles amid ordure the creatures most highly-endowed with family qualities. True, from there it mounts, with a sudden flight, to the sublimities of the bird.

The little worm is hatched in about a week: a strange and paradoxical being. On its back, it has an enormous sugar-loaf hump, the weight of which drags it over and capsizes it each time it tries to stand on its legs and walk. At every moment, it staggers and falls under the burden of the hunch.

Unable to keep its hump upright, the grub of the Onthophagus lies down on its side and licks the cream of its cell all around it. There is cream everywhere, on the ceiling, on the walls, on the floor. As soon as one spot is thoroughly bared, the consumer moves on a little with the help of its well-shaped legs; it capsizes again and starts licking again. The room is large and plentifully supplied; and the jam-diet lasts some time.

The fat babies of the Geotrupe, the Copris and the Sacred Beetle finish at one brief sitting the dainty wherewith their cabined lodge is hung, a dainty scantily served and just sufficient to stimulate the appetite and prepare the stomach for a coarser fare; but the Onthophagus grub, that lean pigmy, has enough to last it for a week and more. The spacious natal chamber, which is out of all proportion with the size of the nursling, has permitted this wastefulness.

At last, the real loaf is attacked. In about a month, everything is consumed, except the wall of the sack. And now the splendid part played by the hump stands revealed. Glass tubes, prepared in view of events, allow me to follow the more and more plump and hunch-backed grub at work. I see it withdraw to one end of the cell, which has become a crumbling ruin. Here it builds a [[87]]casket in which the transformation will take place. Its materials are the digestive residuum, converted into mortar and heaped up in the hump. The stercoral architect is about to construct a masterpiece of elegance out of its own ordure, held in reserve in that receptacle.

I follow its movements under the magnifying-glass. It buckles itself, closes the circuit of the digestive apparatus, brings the two poles into contact and, with the end of its mandibles, seizes a pellet of dung ejaculated at that moment. This pellet, moulded and measured to perfection, is very neatly gathered. A slight bend of the neck sets the rubble-stone in place. Others follow, laid one above the other in minutely regular courses. Giving a tap here and there with its feelers, the grub makes sure of the stability of the parts, their accurate binding, their orderly arrangement. It turns round in the centre of the work as the edifice rises, even as a mason does when building a tower.

Sometimes, the laid stone becomes loose, because the cement has given way. The worm takes it up again with its mandibles, but, before replacing it, coats it with an adhesive moisture. It holds it to its anus, whence trickles, on the moment, almost imperceptibly, a gummy consolidating extract. The hump supplies the materials; the intestines give, if necessary, the connecting glue.

In this way, a nice house is produced, ovoid in shape, polished as stucco within and adorned on the outside with slightly projecting scales, similar to those on a cedar-cone. Each of these scales is one of the rubble-stones out of the hump. The casket is not large: a cherry-stone would about represent its dimensions; but it is so accurate, so prettily fashioned that it will bear comparison with the finest products of entomological industry. [[88]]

[1] ·039 inch.—Translator’s Note. [↑]

[[Contents]]

CHAPTER VII

A BARREN PROMISE

In the nymph of Onthophagus Taurus there rises, on the front edge of the corselet, a single horn, as strong as the two others and shaped like a cylinder ending in a conical knob. It points forward and is fixed in the middle of the frontal crescent, projecting a little beyond it. The arrangement is gloriously original. The carvers of hieroglyphics would have beheld in it the crescent of Isis wherein dips the edge of the world.

Other singularities complete the curious nymph. To right and left, the stomach is armed, on either side, with four little horns resembling crystal spikes. Total, eleven pieces on the harness: two on the forehead; one on the thorax; eight on the abdomen. The beast of yore delighted in queer horns: certain reptiles of the geological period stuck a pointed spur on their upper eyelids. The Onthophagus, more daring, sports eight on the sides of his belly, in addition to the spear which he plants upon his back. The frontal horns may be excused: they are pretty generally worn; but what does he propose to do with the others? Nothing. They are passing fancies, jewels of early youth; the adult insect will not retain the least trace of them.

The nymph matures. The appendages of the forehead, at first quite crystalline, now show, transparently, a streak [[89]]of reddish brown, curved arc-wise. These are real horns taking shape, consistency and colour. The appendage of the corselet and those of the belly, on the other hand, preserve their glassy appearance. They are barren sacks, void of any self-developing germ. The organism produced them in an impetuous moment; now, scornful, or perhaps powerless, it allows the work to wither and become useless.

When the nymph sheds its covering and the fine tunic of the adult form is torn, these strange horns crumble into shreds, which fall away with the rest of the cast clothing. In the hope of finding at least a trace of the vanished things, the lens in vain explores the bases but lately occupied. There is nothing appreciable left: smoothness takes the place of protuberance; nullity succeeds to reality. Of the accessory panoply that promised so much, absolutely naught remains: everything has disappeared, evaporated, so to speak.

Onthophagus Taurus is not the only one endowed with those fleeting appendages, which vanish wholly when the nymph sheds its clothes. The other members of the tribe possess similar horny manifestations on their bellies and corselets. These all disappear entirely in the perfect insect.

A simple setting forth of the facts does not suffice us: we should like to guess at the motive of this corniculate display. Is it a vague memory of the customs of olden time, when life spent its excess of young sap upon quaint creations, banished to-day from our better-balanced world? Is the Onthophagus the dwarfed representative of an old race of horned animals now extinct? Does it give us a faint image of the past?

The surmise rests upon no valid foundation. The [[90]]Dung-beetle is recent in the general chronology of created beings; he ranks among the last-comers. With him there is no means of going back to the mists of the past, so favourable to the invention of imaginary precursors. The geological layers and even the lacustrian layers, rich in Diptera and Weevils, have so far furnished not the slightest relic of the Dung-workers. This being so, it is wiser not to refer to distant horned ancestors as accounting for their degenerate descendant, the Onthophagus.

Since the past explains nothing, let us turn to the future. If the thoracic horn be not a reminiscence, it may be a promise. It represents a timid attempt, which the ages will harden into a permanent weapon. It lets us assist at the slow and gradual evolution of a new organ; it shows us life working on a portion of the adult’s corselet, which does not yet exist, but which is to exist some day. We take the genesis of the species in the act; the present teaches us how the future is prepared.

And what does the insect that has conceived the ambition of later planting a spear upon its chine propose to make of its projected work? At least as an adjunct of masculine finery, the thing is in fashion among various foreign Scarabs that feed themselves and their grubs on vegetable matters in a state of decomposition. These giants among the wing-cased tribe delight in associating their placid corpulence with halberds terrible to gaze upon.

Look at this one—Dynastes Hercules his name—an inmate of the rotten tree-stumps under the torrid West-Indian skies. The peaceable colossus well deserves his name: he measures three inches long. Of what service can the threatening rapier of the corselet and the toothed lifting-jack of the forehead be to him, unless it [[91]]be to make him look grand in the presence of his female, herself deprived of these extravagances? Perhaps also they are of use to him in certain works, even as the trident helps Minotaurus in crumbling the pellets and carting the rubbish. Implements of which we do not know the use always strike us as singular. Having never associated with the West-Indian Hercules, I must content myself with suspicions touching the purpose of his fearsome equipment.

Well, one of the subjects in my voleries would achieve a similar savage finery if he persisted in his attempts. I speak of Onthophagus Vacca. His nymph has on its forehead a thick horn, one only, bent backward; on its corselet it possesses a like horn, jutting forward. The two, approaching their tips, look like a sort of pincers. What does the insect lack in order to acquire, on a smaller scale, the eccentric ornament of the West-Indian Scarab? It lacks perseverance. It matures the appendage of the forehead and allows that of the corselet to perish atrophied. It succeeds no better than Onthophagus Taurus in its attempt to grow a pointed stake upon its chine; it loses a glorious opportunity of making itself fine for the wedding and terrible in battle.

The others are no more successful. I bring up six different species. All, in the chrysalis state, possess the thoracic horn and the eight-pointed ventral coronet; not one benefits by these advantages, which disappear altogether when the adult splits its case. My near neighbourhood numbers a dozen species of Onthophagi; the world contains some hundreds. All, natives and foreigners, have the same general structure; all most probably possess the dorsal appendage at an early age; and none of them, in spite of the variety of the climate, torrid in [[92]]one place, moderate in another, has succeeded in hardening it into a permanent horn.

Could the future not complete a work the design of which is so very clearly traced? We ask ourselves this the more readily inasmuch as every appearance encourages the question. Examine under the magnifying-glass the frontal horns of Onthophagus Taurus in the pupa state; then consider as carefully the spear upon the corselet. At first, there is no difference between them, except the general configuration. In both cases, we find the same glassy aspect, the same sheath swollen with a crystalline moisture, the same incipient organ plainly marked. A leg in formation is not more clearly declared than the horn on the corselet or those on the forehead.

Can time be lacking for the thoracic growth to organize itself into a stiff and lasting appendage? The evolution of the nymph is swift; the insect is perfect in a few weeks. Could it not be that, though this brief space suffice to promote the maturity of the horns on the forehead, the thoracic horn requires a longer time to ripen? Let us prolong the nymphal period artificially and give the germ time to develop itself. It seems to me that a decrease of temperature, moderated and maintained for some weeks, for months if necessary, should be capable of bringing about this result, by delaying the progress of the evolution. Then, with a gentle slowness, favourable to delicate formations, the promised organ will crystallize, so to speak, and become the spear heralded by appearances.

The experiment attracted me. I was unable to undertake it for lack of the means whereby to produce a cold, even and lasting temperature. What should I have obtained if my penury had not made me abandon the [[93]]enterprise? A retarding of the progress of the metamorphosis, but nothing more, apparently. The horn on the corselet would have persisted in its sterility and, sooner or later, would have disappeared.

I have reasons for my conviction. The abode of the Onthophagus while engaged on his metamorphosis is not deep down; variations of temperature are easily felt. On the other hand, the seasons are capricious, especially the spring. Under the skies of Provence, the months of May and June, if the mistral lend a hand, have periods when the thermometer drops in such a way as to suggest a return of winter.

To these vicissitudes let us add the influence of a more northerly climate. The Onthophagi occupy a wide zone of latitude. Those of the north, less favoured by the sun than those of the south, can, if changing circumstances assist at the time of the transformation, undergo long weeks of a decreased temperature which spins out the work of evolution and ought therefore to permit the thoracic armour, at long intervals and casually, to consolidate into a horn. Here and there, then, the conditions of a moderate, or even cold temperature, at the time of the nymphosis, are realized without the aid of my artifices.

Well, what becomes of this surplus time placed at the service of the organic labour? Does the promised horn ripen? Not a bit of it: it withers just as it does under the stimulus of a hot sun. The records of entomology have never spoken of an Onthophagus carrying a horn upon his corselet. No one would even have suspected the possibility of such an armour, if I had not rumoured the strange appearance of the nymph. The influence of climate, therefore, goes for nothing here. [[94]]

Pushed further still, the question becomes more complicated. The horny appendages of the Onthophagus, of the Copris, of Minotaurus and of so many others are the male’s prerogative; the female is without them or wears them only on a reduced and very modest scale. We must look upon these corniculate products as personal ornaments much rather than as implements of labour. The male makes himself fine for the pairing; but, with the exception of Minotaurus, who pins down the dry pellet that needs crushing and holds it in position with his trident, I know none that uses his armour as a tool. Horns and prongs on the forehead, crests and crescents on the corselet are jewels of masculine vanity and nothing more. The other sex requires no such baits to attract suitors: its femininity is enough; and finery is neglected.

Now here is something to give us food for thought. The nymph of the Onthophagus of the female sex, a nymph with an unarmed forehead, carries on its thorax a vitreous horn as long, as rich in promise as that of the other sex. If this latter excrescence be an incompletely-realized incipient ornament, then the former would be so too, in which case the two sexes, both anxious for self-embellishment, would work with equal zeal to grow a horn upon their thorax. We should be witnessing the genesis of a species that would not be really an Onthophagus, but a derivative of the group; we should be beholding the commencement of singularities banished hitherto from among the Dung-beetles, none of whom, of either sex, has thought of planting a spear upon his chine. Stranger still: the female, always the more humbly attired throughout the entomological order, would be vying with the male in her propensity for eccentric adornment. An ambition of this sort leaves me incredulous. [[95]]

We must therefore believe that, if the possibilities of the future should ever produce a Dung-beetle carrying a horn upon his corselet, this upsetter of present customs will not be the Onthophagus succeeding in maturing the thoracic appendage of the nymph, but rather an insect resulting from a new model. The creative power throws aside the old moulds and replaces them by others, fashioned with fresh care, after plans of an inexhaustible variety. Its laboratory is not a peddling rag-fair, where the living assume the cast clothes of the dead: it is a medallist’s studio, where each effigy receives the stamp of a special die. Its treasure-house of forms, of unbounded wealth, excludes any niggardly patching of the old to make the new. It breaks up every mould once used; it does away with it, without resorting to shabby after-touches.

Then what is the meaning of those horny preparations, which are always blighted before they come to aught? Without feeling greatly abashed by my ignorance, I confess that I am absolutely unable to say. In the absence of an appearance of learning, my answer has at least one merit, that of perfect sincerity. [[97]]