The Cicada’s tunnel runs to a depth of between fifteen and sixteen inches. It is cylindrical, winds slightly, according to the exigencies of the soil, and is always nearly perpendicular, for it is shorter to go that way. The passage is quite open throughout its length. It is useless to search for the rubbish which this excavation ought, one would think, to produce; we see none anywhere. The tunnel ends in a blind alley, in a rather wider chamber, with level walls and not the least vestige of communication with any gallery prolonging the well. Reckoned by its length and its diameter, the excavation represents a volume of about twelve cubic inches. What has become of the earth removed? Sunk in very dry and very loose soil, the well and the chamber at the bottom ought to have crumbly walls, which would easily fall in, if nothing else had taken place but the work of boring. My surprise was great to find, on the contrary, coated surfaces, washed with a paste of clayey earth. They are not by a long way what one could call smooth, but at any rate their irregularities are covered with a layer of plaster; and their slippery materials, soaked with some agglutinant, are kept in position. The larva can move about and climb nearly up to the surface and down again to its refuge at the bottom without producing, with its clawed legs, landslips which would block the tube, making ascent difficult and retreat impossible. The miner shores up his galleries with pit-props and cross-beams; the builder of underground railways strengthens his tunnels with a casing of brickwork; the Cicada’s larva, which is quite as clever an engineer, cements its shaft so as to keep it open however long it may have to serve. If I surprise the creature at the moment when it emerges from the soil to make for a neighbouring branch and there undergo its transformation, I see it at once beat a prudent retreat and, without the slightest difficulty, run down again to the bottom of its gallery, proving that, even when the dwelling is on the point of being abandoned for good, it does not become blocked with earth. The ascending-shaft is not a piece of work improvised in a hurry, in the insect’s impatience to reach the sunlight; it is a regular manor-house, an abode in which the grub is meant to make a long stay. So the plastered walls tell us. Any such precaution would be superfluous in the case of a mere exit abandoned as soon as bored. There is not a doubt but that we have here a sort of meteorological station in which observations are taken of the weather outside. Underground, fifteen inches down, or more, the larva ripe for its emergence is hardly able to judge whether the climatic conditions be favourable. Its subterranean weather is too gradual in its changes to be able to supply it with the precise indications necessary for the most important action of its life, its escape into the sunlight for the metamorphosis.