The emergence-jacket splits without further delay; and the creature sheds its skin from front to back. It is now the normal larva, the only one that Réaumur knew. The cast slough forms a suspensory thread, expanding into a little cup at its free end. In this cup is contained the tip of the abdomen of the larva, which, before dropping to the ground, treats itself to a sun-bath, hardens [[102]]itself, kicks about and tries its strength, swinging indolently at the end of its life-line.
This “little Flea,” as Réaumur calls it, first white, then amber, is at all points the larva that will dig into the ground. The antennæ, of fair length, are free and wave about; the legs work their joints; those in front open and shut their claws, which are the strongest part of them. I know hardly any more curious sight than that of this miniature gymnast hanging by its hinder-part, swinging at the least breath of wind and making ready in the air for its somersault into the world. The period of suspension varies. Some larvæ let themselves drop in half an hour or so; others remain for hours in their long-stemmed cup; and some even wait until the next day.
Whether quick or slow, the creature’s fall leaves the cord, the slough of the primary larva, swinging. When the whole brood has disappeared, the orifice of the cell is thus hung with a cluster of short, fine threads, twisted and rumpled, like dried white of egg. Each opens into a little cup at its free end. They are very delicate and ephemeral relics, which you cannot touch without destroying [[103]]them. The slightest wind soon blows them away.
Let us return to the larva. Sooner or later, without losing much time, it drops to the ground, either by accident or of its own accord. The infinitesimal creature, no bigger than a Flea, has saved its tender, budding flesh from the rough earth by swinging on its cord. It has hardened itself in the air, that luxurious eiderdown. It now plunges into the stern realities of life.
I see a thousand dangers ahead of it. The merest breath of wind can blow the atom here, on the impenetrable rock, or there, on the ocean of a rut where a little water stagnates, or elsewhere, on the sand, the starvation region where nothing grows, or again on a clay soil, too tough for digging. These fatal expanses are frequent; and so are the gusts that blow one away in this windy season which has already set in unpleasantly by the end of October.
The feeble creature needs very soft soil, easily entered, so as to obtain shelter immediately. The cold days are drawing nigh; the frosts are coming. To wander about on the surface of the ground for any length of time would expose us to grave dangers. We [[104]]had better descend into the earth without delay; and that to a good depth. This one imperative condition of safety is in many cases impossible to realize. What can little Flea’s-claws do against rock, flint or hardened clay? The tiny creature must perish unless it can find an underground refuge in time.
The first establishment, which is exposed to so many evil chances, is, so everything shows us, a cause of great mortality in the Cicada’s family. Already the little black parasite, the destroyer of the eggs, has told us how expedient it is for the mothers to accomplish a long and fertile laying; the difficulties attendant upon the initial installation in their turn explain why the maintenance of the race at its suitable strength requires three or four hundred eggs to be laid by each of them. Subject to excessive spoliation, the Cicada is fertile to excess. She averts by the richness of her ovaries the multitude of dangers threatening her.
In the experiment which it remains for me to make, I will at least spare the larva the difficulties of the first installation. I select some very soft, very black heath-mould and pass it through a fine sieve. Its dark [[105]]colour will enable me more easily to find the little yellow creature when I want to see what is happening; and its softness will suit the feeble mattock. I heap it not too tightly in a glass pot; I plant a little tuft of thyme in it; I sow a few grains of wheat. There is no hole at the bottom of the pot, though there ought to be, if the thyme and the wheat are to thrive; the captives, however, finding the hole, would be certain to escape through it. The plantation will suffer from this lack of drainage; but at least I am certain of finding my animals with the aid of my magnifying-glass and plenty of patience. Besides, I shall indulge in no excesses in the matter of irrigation, supplying only enough water to prevent the plants from dying.
When everything is ready and the corn is beginning to put forth its first shoots, I place six young Cicada-larvæ on the surface of the soil. The puny grubs run about and explore the earthy bed pretty nimbly; some make unsuccessful attempts to climb the side of the pot. Not one seems inclined to bury itself, so much so that I anxiously wonder what the object can be of these active and prolonged investigations. Two hours pass and the restless roaming never ceases. [[106]]
What is it that they want? Food? I offer them some little bulbs with bundles of sprouting roots, a few bits of leaves and some fresh blades of grass. Nothing tempts them nor induces them to stand still. They appear to be selecting a favourable spot before descending underground. These hesitating explorations are superfluous on the soil which I have industriously prepared for them: the whole surface, so it seems to me, lends itself capitally to the work which I expect to see them accomplish. Apparently it is not enough.