The Sacred Beetle, and Others

by Jean-Henri Fabre

But where? Why, in the narrow part of the pear, in the neck, right at the end! Let us cut this neck lengthwise, taking the necessary precautions not to damage the contents. It is hollowed into a niche with polished and shiny walls. This niche is the tabernacle of the germ, the hatching-chamber. The egg, which is very large in proportion to the size of the mother, is an elongated oval, about ten millimetres in length with a diameter of five millimetres at the widest part.[3] It is white and is separated on all sides from the walls of the chamber by a slight empty space, the only contact being at the rear end of the egg, which adheres to the top of the niche. Lying horizontally, in conformity with the normal [[64]]position of the pear, the whole of it, excepting the point of attachment, thus rests upon an air-mattress, warmest and most buoyant of beds.

Now we know all about it. Let us next try to understand the Scarab’s logic. Let us find out why she has to make that pear of hers, so unusual a shape in insect structures; let us seek to explain the suitability of the egg’s curious position. We are venturing on dangerous ground when we enquire into the how and wherefore of things. We easily lose our footing in that mysterious land where the moving soil gives way beneath us, swallowing the foolhardy in the quicksands of error. Must we abandon such excursions, because of the risk? Why should we?

What does our science, so sublime compared with the feebleness of our resources, so contemptible in the face of the boundless stretches of the unknown, what does it know of absolute reality? Nothing. The world interests us only because of the ideas which we form of it. Remove the idea and everything becomes a desert, chaos, nothingness. An omnium-gatherum of facts is not knowledge, but at most a cold catalogue which we must thaw and quicken at the fire of the mind; we must bring to it thought and the light of reason; we must interpret.

Let us adopt this course to explain the work of the Sacred Beetle. Perhaps we shall end by attributing our own logic to the insect. After all, it will be just as remarkable to see a wonderful agreement prevail between that which reason dictates to us and that which instinct dictates to the insect.

A grave danger threatens the Sacred Beetle in his grub state: the drying-up of the food. The crypt in which the larval life is spent has a layer of earth, some four inches thick, for a ceiling. Of what avail is this flimsy [[65]]screen against the torrid heat that beats down upon the soil, baking it like a brick to a far greater depth than that? At times the temperature of the grub’s abode mounts towards boiling-point; when I thrust my hand into it, I feel the hot air of a Turkish bath.

The provisions, therefore, even though they have to last but three or four weeks, are liable to dry up before that time and to become uneatable. When, instead of the soft bread of its first meal, the unhappy grub finds nothing to stay its stomach but a horrible crust, hard as a pebble and tooth-proof, it is bound to perish of hunger. And it does actually so perish. I have found numbers of these victims of the August sun which, after eating plentifully of the fresh food and digging themselves a cell in it, had succumbed, unable to continue biting into provisions that had become too hard. There remained a thick shell, a sort of closed oven, in which the poor thing lay baked and shrivelled up.

While the grub dies of hunger in a shell which has dried into stone, the full-grown insect that has completed its transformations dies there too, for it is incapable of bursting the prison and freeing itself. I shall come back later to the question of the final emergence and will say no more about it for the present. Let us confine our attention to the troubles of the grub.

The drying-up of the victuals is, I have said, fatal to it. This is proved by the larvæ found baked in their oven; it is also proved, in a more definite fashion, by the following experiment. In July, the period of active nidification, I place in wooden or cardboard boxes a dozen pears unearthed that morning from their native burrows. These boxes, carefully closed, are put away in the dark, in my study, where the same temperature prevails as outside. Well, [[66]]in none of them is the infant reared: sometimes the egg shrivels; sometimes the worm is hatched, but very soon dies. On the other hand, in tin boxes or glass receptacles, everything goes well: not one attempt at rearing fails.

Whence do these differences arise? Simply from this: in the high temperature of July, evaporation proceeds apace under the permeable wooden or cardboard screen; the food-pear dries up; and the unfortunate worm dies of hunger. In the impermeable tin boxes, in the carefully-sealed glass receptacles, there is no evaporation; the provisions retain their softness; and the grubs thrive as well as in their native burrow.

The insect employs two methods to ward off the danger of desiccation. In the first place, it compresses the outer layer with all the strength of its stout, flat fore-arms, turning it into a protective rind more homogeneous and more compact than the central mass. If I break one of these dried-up provision-boxes, the rind usually comes clean away, leaving the centre part bare. The whole suggests the shell and kernel of a nut. The pressure exercised by the mother when manipulating her pear has affected the surface layer to a depth of a few millimetres, and this has produced the rind; the influence of the pressure is not felt lower down, and the result is the big central kernel. In the hot summer months, the housewife puts her bread into a closed pan, to keep it fresh. This is what the insect does, in its fashion: by dint of compression, it covers the family bread with a pan.