The Life of the Grasshopper

by Jean-Henri Fabre

There remains the second, which lasts longer. The whole of the insect is free, except the tip of the abdomen, which is still contained in its scabbard. The cast skin continues to grip the twig. Stiffening as the [[44]]result of quick desiccation, it preserves without change the attitude which it had at the start. It forms the pivot for what is about to follow.

Fixed to his slough by the tip of the abdomen, which is not yet extracted, the Cicada turns over perpendicularly, head downwards. He is pale-green, tinged with yellow. The wings, until now compressed into thick stumps, straighten out, unfurl, spread under the rush of the liquid with which they are gorged. When this slow and delicate operation is ended, the Cicada, with an almost imperceptible movement, draws himself up by sheer strength of loin and resumes a normal position, head upwards. The fore-legs hook on to the empty skin; and at last the tip of the belly is drawn from its sheath. The extraction is over. The work has required half an hour altogether.

Here is the whole insect, freed from its mask, but how different from what it will be presently! The wings are heavy, moist, transparent, with their veins a light green. The prothorax and mesothorax are barely tinged with brown. All the rest of the body is pale-green, whitish in places. It must [[45]]bathe in air and sunshine for a long time before strength and colour can come to its frail body. About two hours pass without producing any noticeable change. Hanging to his cast skin by his fore-claws only, the Cicada sways at the least breath of air, still feeble and still green. At last the brown tinge appears, becomes more marked and is soon general. Half an hour has effected the change of colour. Slung from the suspension-twig at nine o’clock in the morning, the Cicada flies away, before my eyes, at half-past twelve.

The cast skin remains, intact, save for its fissure, and so firmly fastened that the rough weather of autumn does not always succeed in bringing it to the ground. For some months yet, even during the winter, one often meets old skins hanging in the bushes in the exact position adopted by the larva at the moment of its transformation. Their horny nature, something like dry parchment, ensures a long existence for these relics.

Let us hark back for a moment to the gymnastic feat which enables the Cicada to leave his scabbard. At first retained by the tip of the abdomen, which is the last part to remain in its case, the Cicada turns over [[46]]perpendicularly, head downwards. This somersault allows him to free his wings and legs, after the head and chest have already made their appearance by cracking the armour under the pressure of a hernia. Now comes the time to free the end of the abdomen, the pivot of this inverted attitude. For this purpose, the insect, with a laborious movement of its back, draws itself up, brings its head to the top again and hooks itself with its fore-claws to the cast skin. A fresh support is thus obtained, enabling it to pull the tip of its abdomen from its sheath.

There are therefore two means of support: first the end of the belly and then the front claws; and there are two principal movements: in the first place the downward somersault, in the second place the return to the normal position. These gymnastics demand that the larva shall fix itself to a twig, head upwards, and that it shall have a free space beneath it. Suppose that these conditions were lacking, thanks to my wiles: what would happen? That remained to be seen.

I tie a thread to the end of one of the hind-legs and hang the larva up in the peaceful atmosphere of a test-tube. My thread [[47]]is a plumb-line which will remain vertical, for there is nothing to interfere with it. In this unwonted posture, which places its head at the bottom at a time when the near approach of the transformation demands that it should be at the top, the unfortunate creature for a long time kicks about and struggles, striving to turn over and to seize with its fore-claws either the thread by which it hangs or one of its own hind-legs. Some of them succeed in their efforts, draw themselves up as best they can, fasten themselves as they wish, despite the difficulty of keeping their balance, and effect their metamorphosis without impediment.

Others wear themselves out in vain. They do not catch hold of the thread, they do not bring their heads upwards. Then the transformation is not accomplished. Sometimes the dorsal rupture takes place, leaving bare the mesothorax swollen into a hernia, but the shelling proceeds no farther and the insect soon dies. More often still the larva perishes intact, without the least fissure.

Another experiment. I place the larva in a glass jar with a thin bed of sand, which makes progress possible. The animal moves along, but is not able to hoist itself up anywhere: [[48]]the slippery sides of the glass prevent this. Under these conditions, the captive expires without trying to transform itself. I have known exceptions to this miserable ending; I have sometimes seen the larva undergo a regular metamorphosis on a layer of sand thanks to peculiarities of equilibrium which were very difficult to distinguish. In the main, when the normal attitude or something very near it is impossible, metamorphosis does not take place and the insect succumbs. That is the general rule.

This result seems to tell us that the larva is capable of opposing the forces which are at work in it when the transformation is at hand. A cabbage-silique, a pea-pod invariably burst to set free their seeds. The Cicada-larva, a sort of pod containing, by way of seed, the perfect insect, is able to control its dehiscence, to defer it until a more opportune moment and even to suppress it altogether in unfavourable circumstances. Convulsed by the profound revolution that takes place in its body on the point of transfiguration, but at the same time warned by instinct that the conditions are not good, the insect makes a desperate resistance and dies rather than consent to open. [[49]]