The Sacred Beetle, and Others

by Jean-Henri Fabre

What can this shell be, usually made of earth and open at one side so that the grub may reach the column of provisions overhead? I am at an utter loss to know. Shell, especially made of earth, there is none, nor any opening. I see and see again, as often as I wish, a round cell, closed everywhere and built at the lower end of the [[209]]food-cylinder, but nothing else, nothing that even vaguely resembles the structure described.

Which of the two is responsible for the imaginary construction? Can the German entomologist have sinned through superficial observation? Or did the Lyons entomologist misinterpret the older author? I lack the necessary documents to bring the mistake home to the right person. Is it not pathetic to see these masters, who are so punctilious about a joint of the palpi, so cantankerous about the first claim to some barbaric appellation, almost indifferent when they come to treat of habits and industry, which are the supreme expression of an insect’s life? Nomenclators’ entomology is making enormous strides: it overwhelms us, swamps us. The other, biologists’ entomology, the only interesting branch of the science, the only one really worthy of our attention, is neglected to such an extent that the commonest species has no history or calls for serious revision of the little that has been written about it. Vain lamentations: things will go on in the same old way for a long time to come.

To return to the Geotrupes’ sausage. Its shape is diametrically opposite to that which we have studied in the case of the Copris and the Sacred Beetle, who are sparing of material but very generous with their labour, taking great care to give their work the shape best suited to preserve it against dryness. With their ovoids and their spheres surmounted by a neck, they are able to keep the modest family-ration fresh. The Geotrupes knows nothing of these scientific methods. More primitive in her ways, she sees well-being only in overabundance. Provided that the gallery be crammed with food, she little cares how shapeless her pile may be. [[210]]

Instead of avoiding dryness, she appears to go in search of it. Just look at the sausage. It is inordinately long and clumsily put together. There is no compact, impermeable rind; and there is an excessive amount of surface, touching the earth for the whole length of the cylinder. This is exactly what is needed to bring about quick desiccation; it is the converse of the problem of the smallest surface, solved by the Sacred Beetle and the others. Then what becomes of my views on the shape of those provisions, views so well founded, according to our logic? Can I have been taken in by a blind geometry, which achieves a rational result by chance?

To any one who says so let the facts reply. Here is their answer: the manufacturers of spheres build their nests at the height of the summer, when the ground is parched; the manufacturers of cylinders build theirs in the autumn, when the earth becomes saturated with rain. The first have to guard their family against the danger of bread too hard to eat. The second know nothing of starvation through desiccation; their provisions, potted in cool earth, retain indefinitely the proper degree of softness. The moistness, not the shape, of the sheath is the safeguard of the ration inside it. The rainfall at this time of the year is in inverse ratio to that of summer; and this is enough to render useless the precautions taken in the dog-days.

Let us probe deeper and we shall see that the cylinder is preferable to the sphere in autumn. When October and November come, the rains are frequent and persistent; but a day’s sunshine is enough to dry the soil to the shallow depth where the Geotrupes’ nest lies. It is a serious matter not to lose the enjoyment of this fine day. How will the grub benefit by it? [[211]]

Imagine the larva enclosed in the big ball which the copious quantity of food placed at its disposal might well supply. Once saturated with moisture by a shower, this sphere would retain it stubbornly, for its form is that of least evaporation and of least contact with the sun-warmed soil. In vain, within twenty-four hours, will the surface layer of the ground be restored to its normal coolness: the globular mass will retain its excess of water, for lack of adequate contact with the sun- and air-dried earth. In the too-humid and too-thick recess, the provisions will go musty; the heat from outside will be inopportune, as will the air; and the larva will derive little advantage from this late autumn sun, whose tardy rays ought to ripen it to perfection and give it the necessary vigour to brave the trials of winter.

What was a good quality in July, when it was necessary to guard against excessive dryness, becomes a bad one in October, when excessive damp is to be avoided. The cylinder is therefore substituted for the sphere. The new shape, with its exaggerated length, fulfils the converse condition of that beloved by the pill-makers: here, with a similar volume, the surface is developed to its extreme limits. Is there a reason for this complete change? No doubt; and I seem to perceive it. Now that dryness is no longer to be feared, will not this kind of shape, with its large surface, enable the mass of foodstuff to get rid of its superfluous moisture more readily? Should it rain, its wide area certainly will make it liable to more rapid saturation; but also, when the fine weather returns, the surplus water will soon disappear thanks to the extensive contact with a quickly-drained soil.

Let us conclude by enquiring how the roly-poly is manufactured. To watch the performance in the fields appears [[212]]to me a very difficult, not to say impracticable undertaking. With my cages, success is certain, provided that we exercise a little patience and dexterity. I let down the board which keeps the artificial soil in place at the back. This now reveals its vertical surface, which I explore bit by bit with the point of a knife until I strike a burrow. If the operation be cautiously conducted, without the disturbance due to an ill-calculated landslip, the labourers are discovered at their toil, paralysed, it is true, by the sudden flood of light and as it were petrified in the attitude of work. The arrangement of the workshop and the materials, the position and posture of the workers enable us easily to reconstruct the scene, though it be abruptly suspended and not renewed so long as our inspection lasts.

One fact, to begin with, thrusts itself upon our attention, a fact of deep interest and so exceptional that this is the first example with which my entomological studies have presented me. In each burrow laid bare I always find two collaborators, a pair: I find the male lending the mother his assistance. The household duties are divided between the two. My notes give the following scene, to which we can easily restore its animation according to the pose of the immobilized actors.