To what circumstances are we to attribute this departure from the usual practice? Perhaps to this: the Cricket’s egg stays in the ground for only a few days before hatching; the egg of the Decticus remains there for eight months. The former, save for rare exceptions in a season of drought, lies under a thin layer of dry, loose, unresisting earth; the latter, on the contrary, finds itself in soil which has been caked together by the persistent rains of autumn and winter and which therefore presents serious difficulties. Moreover, the Cricket is shorter and stouter, less long-shanked than the Decticus. These would appear to be the reasons for the difference between the two insects in respect of their methods of emerging. The Decticus, born lower down, under a close-packed layer, needs a climbing-costume with which the Cricket is able to dispense, being less hampered and nearer to the surface and having only a powdery layer of earth to pass through. Then what is the object of the tights which the Cricket flings aside as soon as he is out of the egg? I will answer this question with another: what is the object of the two white stumps, the two pale-coloured embryo wings carried by the Cricket under his wing-cases, which are turned into a great mechanism of sound? They are so insignificant, so feeble that the insect certainly makes no use of them, any more than the Dog utilizes the thumb that hangs limp and lifeless at the back of his paw. Sometimes, for reasons of symmetry, the walls of a house are painted with imitation windows to balance the other windows, which are real. This is done out of respect for order, the supreme condition of the beautiful. In the same way, life has its symmetries, its repetitions of a general prototype. When abolishing an organ that has ceased to be employed, it leaves vestiges of it to maintain the primitive arrangement. The Dog’s rudimentary thumb predicates the five-fingered hand that characterizes the higher animals; the Cricket’s wing-stumps are evidence that the insect would normally be capable of flight; the moult undergone on the threshold of the egg is reminiscent of the tight-fitting wrapper needed for the laborious exit of the Locustidæ born underground. They are so many symmetrical superfluities, so many remains of a law that has fallen into disuse but never been abrogated.