The Glow-Worm and Other Beetles

They also share her talent. The work of both is once again a sort of pear, but constructed in a more ingenious fashion, with an almost conical neck and without any elegant curves. From the point of view of beauty, it falls short of the Sacred Beetle's work. Considering the tools, which have ample free play and are well adapted for clasping, I expected something better from the two modellers. No matter: the work of the Megathopæ conforms with the fundamental art of the other pill-rollers.

A fourth, Bolbites onitoides, compensates us for repetitions which, it is true, widen the scope of the problem but teach us nothing new. She is a handsome Beetle with a metallic costume, green or copper-red according as the light happens to fall. Her four-cornered shape and her long, toothed fore-legs make her resemble our Onites.[63 - Cf. The Sacred Beetle and Others: chap. xvi. —Translator's Note.]

In her, the Dung-beetles' guild reveals itself under a very unexpected aspect. We know insects that knead soft loaves; and here are some which, to keep their bread fresh, discover ceramics and become potters, working clay in which they pack the food of the larvæ. Before my housekeeper, before any of us, they knew how, with the aid of a round jar, to keep the provisions from drying during the summer heats. The work of the Bolbites is an ovoid, hardly differing in shape from that of the Copres; but this is where the ingenuity of the American insect shines forth. The inner mass, the usual dung-cake furnished by the Cow or the Sheep, is covered with a perfectly homogeneous and continuous coating of clay, which makes a piece of solid pottery impervious to evaporation.

The earthen pot is exactly filled by its contents, without the slightest interval along the line of junction. This detail tells us the worker's method. The jar is moulded on the provisions. After the food-pellet has been formed in the ordinary baker's fashion and the egg laid in its hatching-chamber, the Bolbites takes some armfuls of the clay near at hand, applies it to the foodstuff and presses it down. When the work is finished and smoothed to perfection with indefatigable patience, the tiny pot, built up piecemeal, looks as though made with the wheel and rivals our own earthenware in regularity.

The hatching-chamber, in which the egg lies, is, as usual, contrived in the nipple at the end of the pear. How will the germ and the young larva manage to breathe under that clay casing, which intercepts the access of the air?

Have no fears: the pot-maker knows quite well how matters stand. She takes good care not to close the top with the plastic earth which supplied her with the walls. At some distance from the tip of the nipple, the clay ceases to play its part and makes way for fibrous particles, for tiny scraps of undigested fodder, which, arranged one above the other with a certain order, form a sort of thatched roof over the egg. The inward and outward passage of the air is assured through this coarse screen.

One is set thinking in the presence of this layer of clay, which protects the fresh provisions, and this vent-hole stopped with a truss of straw, which admits the air freely, while defending the entrance. There is the eternal question, if we do not rise above the commonplace: how did the insect acquire so wise an art?

Not one fails in obeying those two laws, the safety of the egg and ready ventilation; not one, not even the next on my list, whose talent opens up a new horizon: I am now speaking of Lacordaire's Gromphas. Let not this repellant name of Gromphas (the old sow) give us a wrong notion of the insect. On the contrary, it is, like the last, an elegant Dung-beetle, dark-bronze, thickset, square-shaped like our Bison Onitis[64 - Cf. The Sacred Beetle and Others: chap. xvi. —Translator's Note.] and almost as large. It also practises the same industry, at least as regards the general effect of the work.

Its burrow branches into a small number of cylindrical cells, forming the homes of as many larvæ. For each of these the provisions consist of a parcel of Cow-dung, about an inch deep. The material is carefully packed and fills the bottom of the cavity, just as a soft paste would do when pressed down in a mould. Until now the work is similar to that of the Bison Onitis; but the resemblance goes no farther and is replaced by profound and curious differences, having no connection with what the Dung-beetles of our own parts show us.

As we know, our sausage-makers, Onites and Geotrupes alike, place the egg at the lower end of their cylinder, in a cell contrived in the very midst of the mass of foodstuffs. Their rival in the pampas adopts a diametrically opposite method: she places the egg above the victuals, at the upper end of the sausage. In order to feed, the grub does not have to work upwards; on the contrary, it works downwards.

More remarkable still: the egg does not lie immediately on top of the provisions; it is installed in a clay chamber with a wall about one-twelfth of an inch in thickness. This wall forms an hermetically-sealed lid, curves into a cup and then rises and bends over to make a vaulted ceiling.

The germ is thus enclosed in a mineral box, having no connection with the provision-store, which is kept strictly shut. The newborn grub must employ the first efforts of its teeth to break the seals, to cut through the clay floor and to make a trap-door which will take it to the underlying cake.

A rough beginning for the feeble mandible, even though the material to be bored through is a fine clay. Other grubs bite at once into a soft bread which surrounds them on every side; this one, on leaving the egg, has to make a breach in a wall before taking nourishment.

Of what use are these obstacles? I do not doubt that they have their purpose. If the grub is born at the bottom of a closed pot, if it has to chew through brick to reach the larder, I feel sure that certain conditions of its well-being demand this. But what conditions? To become acquainted with them would call for an examination on the spot; and all the data that I possess are a few nests, lifeless things very difficult to interrogate. However, it is possible to catch a glimpse of one or two points.

The Gromphas' burrow is shallow; those little cylinders, her loaves, are greatly exposed to drought. Over there, as here, the drying up of the victuals constitutes a mortal danger. To avert this peril, by far the most sensible course is to enclose the food in absolutely shut vessels.

Well, the receptacle is dug in very fine, homogeneous, water-tight earth, with not a bit of gravel, not an atom of sand in it. Together with the lid that forms the bottom of its round chamber, in which the egg is lodged, this cavity becomes an urn whose contents are safe from drought for a long time, even under a scorching sun. However late the hatching, the new-born grub, on finding the lid, will have under its teeth provisions as fresh as though they dated from that very day.

The clay food-pit, with its closely-fitting lid, is an excellent method, than which our agricultural experts have discovered no better way of preserving fodder; but it possesses one drawback: to reach the stack of food, the grub has first to open a passage through the floor of its chamber. Instead of the pap called for by its weakly stomach, it begins by finding a brick to chew.

The rude task would be avoided if the egg lay directly on top of the victuals, inside the case itself. Here our logic is at fault: it forgets an essential point, which the insect is careful not to disregard. The germ breathes. Its development requires air; and the perfectly-closed clay urn does not allow any air to enter. The grub has to be born outside the pot.

Agreed. But, in the matter of breathing, the egg is no better off for being shut up, on top of the provisions, in a clay casket quite as air-tight as the jar itself. Examine the thing more closely, however, and you will receive a satisfactory reply. The walls of the hatching-chamber are carefully glazed inside. The mother has taken meticulous pains to give them a stucco-like finish. The vaulted ceiling alone is rugged, because the building-tool now works from the outside and is unable to reach the inner surface of the lid and smooth it. Moreover, in the centre of this curved and embossed ceiling, a small opening has been made. This is the air-hole, which allows of gaseous exchanges between the atmosphere inside the box and that outside.

If it were entirely free, this opening would be dangerous: some plunderer might take advantage of it to enter the casket. The mother foresees the risk. She blocks the breathing-hole with a plug made of the ravelled vegetable fibres of the Cow-dung, a stopper which is eminently permeable. It is an exact repetition of that which the various modellers have shown us at the top of their calabashes and pears. All of them are acquainted with the nice secret of the felt stopper as a means of ventilating the egg in a water-tight enclosure.

Your name is not an attractive one, my pretty Dung-beetle of the pampas, but your industrial methods are most remarkable. I know some among your fellow-countrymen, however, who surpass you in ingenuity. One of these is Phanæus Milon, a magnificent insect, blue-black all over.

The male's corselet juts forward. On the head is a short, broad, flattened horn, ending in a trident. The female replaces this ornament by simple folds. Both carry on the forehead two spikes which form a trusty digging-implement and also a scalpel for dissecting. The insect's squat, sturdy, four-cornered build resembles that of Onitis Olivieri, one of the rarities of the neighbourhood of Montpellier.

If similarity of shape implied purity of work, we ought unhesitatingly to attribute to Phanæus Milon short, thick puddings like those made by Olivier's Onitis.[65 - I owe this detail on the work of Olivier's Onitis to a note and a sketch communicated by Professor Valéry-Mayer, of the Montpellier School of Agriculture. —Author's Note.] Alas, structure is a bad guide where instinct is concerned! The square-chined, short-legged Dung-beetle excels in the art of manufacturing gourds. The Sacred Beetle herself supplies none that are more correctly shaped nor, above all, more capacious.

The thickset insect astonishes me with the elegance of its work, which is irreproachable in its geometry: the neck is shorter, but nevertheless combines grace with strength. The model seems derived from some Indian calabash, the more so as it has an open mouth and the belly is engraved with an elegant engine-turned pattern, produced by the insect's tarsi. One seems to see a pitcher protected by a wickerwork covering. The whole attains and even exceeds the size of a Hen's egg.

It is a very curious piece of work and of a rare perfection, especially when we consider the artist's clumsy and massive build. No, once again, the tool does not make the workman, among Dung-beetles any more than among ourselves. To guide the modeller there is something better than a set of tools: there is what I have called the bump, the genius of the animal.

Phanæus Milon scoffs at difficulties. He does much more than that: he laughs at our classifications. The word Dung-beetle implies a lover of dung. He sets no value on it, either for his own use or for that of his offspring. What he wants is the sanies of corpses. He is to be found under the carcasses of birds, Dogs or Cats, in the company of the undertakers-in-ordinary. The gourd which I will presently describe was lying in the earth under the remains of an Owl.

Let him who will explain this conjunction of the appetites of the Necrophorus[66 - Or Burying-beetle. Cf. Chapters XI (#pgepubid00018). and XII (#pgepubid00019). of the present volume. —Translator's Note.] with the talents of the Sacred Beetle. As for me, baffled by tastes which no one would suspect from the mere appearance of the insect, I give it up.

I know in my neighbourhood one Dung-beetle and one alone who also works among carrion. This is Onthophagus ovatus, LIN., a constant frequenter of dead Moles and Rabbits. But the dwarf undertaker does not on that account scorn stercoraceous fare: he feasts upon it like the other Onthophagi. Perhaps there is a twofold diet here: the bun for the adult; the highly-spiced, far-gone meat for the grub.

Similar facts are encountered elsewhere, with differing tastes. The Hunting Wasp takes her fill of honey drawn from the nectaries of the flowers, but feeds her little ones on game. Game first and then sugar, for the same stomach! How that digestive pouch must change during development! And yet no more than our own, which scorns in later life the food that delighted it when young.

Let us now examine the work of Phanæus Milon more thoroughly. The calabashes reached me in a state of complete desiccation. They are very nearly as hard as stone; their colour inclines to a pale chocolate. Neither inside nor out does the lens discover the slightest ligneous particle pointing to a vegetable residue. The strange Dung-beetle does not, therefore, use cakes of Cow-dung or anything like them; he handles products of another class, which at first are rather difficult to specify.

Held to the ear and shaken, the object rattles slightly, as would the shell of a dry fruit with a stone lying free inside it. Does it contain the grub, shrivelled by desiccation? Does it contain the dead insect? I thought so, but I was wrong. It contains something much more instructive than that.

I carefully rip up the gourd with the point of a knife. Within a homogenous wall, whose thickness is over three-quarters of an inch in the largest of my three specimens, is encased a spherical kernel, which fills the cavity exactly, but without sticking to the wall at any part. The small amount of free play allowed to this kernel accounts for the rattling which I heard when I shook the thing.

In the colour and general appearance of the whole, the kernel does not differ from the wrapper. But break it open and minutely examine the pieces. We now recognize tiny fragments of bone, flocks of down, threads of wool, scraps of flesh, the whole mixed in an earthy paste resembling chocolate.

This paste, when placed on hot charcoal, sifted under the lens and deprived of its particles of dead bodies, becomes much darker, is covered with shiny bubbles and sends forth puffs of that acrid smoke by which we so readily recognize burnt animal matter. The whole mass of the kernel, therefore, is strongly impregnated with sanies.

Treated in the same manner, the wrapper also turns black, but not to the same extent; it hardly smokes; it does not become covered with jet-black bubbles; lastly, it would not anywhere contain bits of carcase similar to those in the central kernel. In both cases, the residue after calcination is a fine, reddish clay.

This brief analysis tells us all about the table of Phanæus Milon. The fare served to the grub is a sort of meat-pie. The sausage-meat consists of a mince of all that the two scalpels of the forehead and the toothed knives of the fore-legs have been able to remove from the corpse: hair and down, small crushed bones, strips of flesh and skin. Now hard as brick, the thickening of this mincemeat was originally a paste of fine clay steeped in the liquor of corruption. Lastly, the light crust of our meat-pies is here represented by a covering of the same clay, less rich in extract of meat than the other.

The pastry-cook gives his work an elegant shape; he decorates it with rosettes, with twists, with scrolls. Phanæus Milon is no stranger to these culinary æsthetics. She turns the crust of her meat-pie into a splendid gourd, with a finger-print ornamentation.

The outer covering, an unprofitable crust, insufficiently steeped in savoury juices, is not, we can easily guess, intended for consumption. It is possible that, somewhat later, when the stomach becomes robust and is not repelled by coarse fare, the grub scrapes a little from the sides of its pasty walls; but, until the adult insect emerges, the calabash as a whole remains intact, having acted at first as a safeguard of the freshness of the force-meat and all the while as a protecting casket for the recluse.

Above the cold pastry, right at the base of the neck of the gourd, is contrived a round cell with a clay wall continuing the general wall. A fairly thick floor, made of the same material, separates it from the store-room. This is the hatching-chamber. Here is laid the egg, which I find in its place but dried up; here is hatched the grub, which, to reach the ball of food, must first open a trap-door through the partition that separates the two stories.

We have here, in short, the edifice of the Gromphas, in a different style of architecture. The grub is born in a casket surmounting the stack of food but not communicating with it. The budding larva must therefore, at the opportune moment, itself pierce the covering of the pot of preserves. As a matter of fact, later, when the grub is on the sausage-meat, we find the floor perforated with a hole just large enough for it to pass through.

Wrapped all round in a thick casing of pottery, the meat keeps fresh as long as is required by the duration of the hatching-process, a detail which I have not ascertained; in its cell, which is also of clay, the egg lies safe. Capital; so far, all is well. Phanæus Milon is thoroughly acquainted with the secrets of fortification and the danger of victuals evaporating too soon. There remain the germ's respiratory requirements.

To satisfy these, the insect has been equally well-inspired. The neck of the calabash is pierced, in the direction of its axis, with a tiny channel which would admit at most the slenderest of straws. Inside, this conduit opens at the top of the dome of the hatching-chamber; outside, at the tip of the nipple, it spreads into a wide mouth. This is the ventilating-shaft, protected against intruders by its extreme narrowness and by grains of dust which obstruct it a little without stopping it up. I said it was simply marvellous. Was I wrong? If a construction of this sort is a fortuitous result, we must admit that blind chance is gifted with extraordinary powers of foresight.

How does the clumsy insect manage to accomplish so delicate and complex a piece of building? Exploring the pampas as I do through the eyes of an intermediary, my only guide in this question is the structure of the work, a structure whence we can deduct the workman's method without going far astray. I therefore imagine the building to proceed in this manner: a small carcase is found, the oozing of which has softened the underlying loam. The insect collects more or less of this loam, according to the richness of the vein. There are no precise limits here. If the plastic material be plentiful, the collector is lavish with it and the provision-box becomes all the more solid. Then enormous calabashes are obtained, exceeding a Hen's egg in volume and formed of an outer wall three-quarters of an inch thick. But a mass of this description is beyond the strength of the modeller, is badly handled and betrays, in its shape, the awkwardness attendant on an over-difficult task. If the material be rare, the insect confines its harvesting to what is strictly necessary; and then, freer in its movements, it obtains a magnificently regular gourd.

The loam is probably first kneaded into a ball and then scooped out into a large and very thick cup by the pressure of the fore-legs and the work of the forehead. Even thus do the Copris and the Sacred Beetle act when preparing, on the top of their round pill, the bowl in which the egg will be laid before the final manipulation of the ovoid or pear.

In this first business, the Phanæus is simply a potter. So long as it be plastic, any clay serves her turn, however meagrely saturated with the juices running from the carcase.

She now becomes a pork-butcher. With her toothed knife, she carves, she saws some tiny shreds from the rotten animal; she tears off, cuts away what she deems best suited to the grub's entertainment. She collects all these fragments and mixes them with choice loam in the spots where the sanies abounds. The whole, cunningly kneaded and softened, becomes a ball made on the spot, without any rolling-process, in the same way as the sphere of the other pill-manufacturers. Let us add that this ball, a ration calculated by the needs of the grub, is very nearly constant in size, whatever the dimensions of the final calabash.

The sausage-meat is now ready. It is set in place in the wide-open clay bowl. Loosely packed, without compression, the food will remain free, will not stick to its wrapper.

Next, the potter's work is renewed. The insect presses the thick lips of the clay cup, rolls them out and applies them to the prepared force-meat, which is eventually contained by a thin partition at the top end and by a thick layer every elsewhere. A wide circular pad is left on the top partition, which is thin in view of the weakness of the grub that is to perforate it later, when making for the provisions. Manipulated in its turn, this pad is converted into a hemispherical hollow, in which the egg is forthwith laid.

The work is completed by rolling out and joining the edges of the little crater, which closes and becomes the hatching-chamber. Here, especially, a delicate dexterity becomes essential. At the same time that the nipple of the calabash is being shaped, the insect, when packing the material, must leave the little channel which is to form the ventilating-shaft, following the line of the axis. This narrow conduit, which an ill-calculated pressure might stop up beyond hope of remedy, seems to me extremely difficult to obtain. The most skilful of our potters could not manage it without the aid of a needle, which he would afterwards withdraw. The insect, a sort of jointed automaton, makes its channel through the massive nipple of the gourd without so much as a thought. If it did give it a thought, it would not succeed.

The calabash is made: there remains the decoration. This is the work of patient after-touches which perfect the curves and leave on the soft loam a series of stippled impressions similar to those which the potter of prehistoric days distributed over his big-bellied jars with the ball of his thumb.