About the same time I notice frequently, on the asphodels in the paddock and on those of the neighbouring hills, certain indications that the eggs have recently hatched out. There are certain cast-off articles of clothing, certain rags and tatters, left on the threshold of the egg-chamber by the new-born grubs as they leave it and hurry in search of a new lodging. We shall see in a moment what these vestiges mean.
But in spite of my visits, which were so assiduous as to deserve success, I had never contrived to see the young Cigales emerge from their egg-chambers. My domestic researches had been pursued in vain. Two years running I had collected, in boxes, tubes, and bottles, a hundred twigs of every kind which were peopled by the eggs of the Cigale; but not one had shown me what I so desired to witness: the issue of the new-born Cigales.
Réaumur experienced the same disappointment. He tells us how all the eggs supplied by his friends were abortive, even when he placed them in a glass tube thrust under his armpit, in order to keep them at a high temperature. No, venerable master! neither the temperate shelter of our studies and laboratories, nor the incubating warmth of our bodies is sufficient here; we need the supreme stimulant, the kiss of the sun; after the cool of the mornings, which are already sharp, the sudden blaze of the superb autumn weather, the last endearments of summer.
It was under such circumstances, when a blazing sun followed a cold night, that I found the signs of completed incubation; but I always came too late; the young Cigales had departed. At most I sometimes found one hanging by a thread to its natal stem and struggling in the air. I supposed it to be caught in a thread of gossamer, or some shred of cobweb.
At last, on the 27th of October, despairing of success, I gathered some asphodels from the orchard, and the armful of dry twigs in which the Cigales had laid their eggs was taken up to my study. Before giving up all hope I proposed once more to examine the egg-chambers and their contents. The morning was cold, and the first fire of the season had been lit in my room. I placed my little bundle on a chair before the fire, but without any intention of testing the effect of the heat of the flames upon the concealed eggs. The twigs, which I was about to cut open, one by one, were placed there to be within easy reach of my hand, and for no other reason.
Then, while I was examining a split twig with my magnifying-glass, the phenomenon which I had given up all hope of observing took place under my eyes. My bundle of twigs was suddenly alive; scores and scores of the young larvæ were emerging from their egg-chambers. Their numbers were such that my ambition as observer was amply satisfied. The eggs were ripe, on the point of hatching, and the warmth of the fire, bright and penetrating, had the effect of sunlight in the open. I was quick to profit by the unexpected piece of good fortune.
At the orifice of the egg-chamber, among the torn fibres of the bark, a little cone-shaped body is visible, with two black eye-spots; in appearance it is precisely like the fore portion of the butter-coloured egg; or, as I have said, like the fore portion of a tiny fish. You would think that an egg had been somehow displaced, had been removed from the bottom of the chamber to its aperture. An egg to move in this narrow passage! a walking egg! No, that is impossible; eggs "do not do such things!" This is some mistake. We will break open the twig, and the mystery is unveiled. The actual eggs are where they always were, though they are slightly disarranged. They are empty, reduced to the condition of transparent skins, split wide open at the upper end. From them has issued the singular organism whose most notable characteristics are as follows:—
In its general form, the configuration of the head and the great black eyes, the creature, still more than the egg, has the appearance of an extremely minute fish. A simulacrum of a ventral fin increases the resemblance. This apparent fin in reality consists of the two fore-limbs, which, packed in a special sheath, are bent backwards, stretched out against one another in a straight line. Its small degree of mobility must enable the grub to escape from the egg-shell and, with greater difficulty, from the woody tunnel leading to the open air. Moving outwards a little from the body, and then moving back again, this lever serves as a means of progression, its terminal hooks being already fairly strong. The four other feet are still covered by the common envelope, and are absolutely inert. It is the same with the antennæ, which can scarcely be seen through the magnifying-glass. The organism which has issued from the egg is a boat-shaped body with a fin-shaped limb pointing backwards on the ventral face, formed by the junction of the two fore-limbs. The segmentation of the body is very clear, especially on the abdomen. The whole body is perfectly smooth, without the least suspicion of hair.
What name are we to give to this initial phase of the Cigale—a phase so strange, so unforeseen, and hitherto unsuspected? Must I amalgamate some more or less appropriate words of Greek and fabricate a portentous nomenclature? No, for I feel sure that barbarous alien phrases are only a hindrance to science. I will call it simply the primary larva, as I have done in the case of the Meloides, the Leucospis, and the Anthrax.
The form of the primary larva of the Cigale is eminently adapted to its conditions and facilitates its escape. The tunnel in which the egg is hatched is very narrow, leaving only just room for passage. Moreover, the eggs are arranged in a row, not end to end, but partially overlapping. The larva escaping from the hinder ranks has to squeeze past the empty shells, still in position, of the eggs which have already hatched, so that the narrowness of the passage is increased by the empty egg-shells. Under these conditions the larva as it will be presently, when it has torn its temporary wrappings, would be unable to effect the difficult passage. With the encumbrance of antennæ, with long limbs spreading far out from the axis of the body, with curved, pointed talons which hook themselves into their medium of support, everything would militate against a prompt liberation. The eggs in one chamber hatch almost simultaneously. It is therefore essential that the first-born larvæ should hurry out of their shelter as quickly as possible, leaving the passage free for those behind them. Hence the boat-like shape, the smooth hairless body without projections, which easily squeezes its way past obstructions. The primary larva, with its various appendages closely wrapped against its body by a common sheath, with its fish-like form and its single and only partially movable limb, is perfectly adapted to make the difficult passage to the outer air.