This curious life and this marvellous foresight are not confined to one kind of grub. Besides the Capricorn of the Oak there is the Capricorn of the Cherry-tree. In appearance the latter is an exact copy of the former, on a much smaller scale; but the little Capricorn has different tastes from its large kinsman’s. If we search the heart of the cherry-tree it does not show us a single grub anywhere: the entire population lives between the bark and the wood. This habit is only varied when transformation is at hand. Then the grub of the cherry-tree leaves the surface, and scoops out a cavity at a depth of about two inches. Here the walls are bare: they are not lined with the velvety fibres dear to the Capricorn of the Oak. The entrance is blocked, however, by sawdust, and a chalky lid similar to the other except in point of size. Need I add that the grub lies down and goes to sleep with his head against the door? Not one forgets to take this precaution. There is also a Saperda of the Poplar and a Saperda of the Cherry-tree. They have the same organisation and the same tools; but the former follows the methods of the Capricorn of the Oak, while the latter imitates the Capricorn of the Cherry-tree. The poplar-tree is also inhabited by the Bronze Buprestis, which takes no defensive measures before going to sleep. It makes no barricade, no heap of shavings. And in the apricot-tree the Nine-spotted Buprestis behaves in the same way. In this case the grub is inspired by its intuitions to alter its plan of work to suit the coming Beetle. The perfect insect is a cylinder; the grub is a strap, a ribbon. The former, which wears unyielding armour, needs a cylindrical passage; the latter needs a very low tunnel, with a roof that it can reach with the pads on its back. The grub therefore changes its manner of boring: yesterday the gallery, suited to a wandering life in the thickness of the wood, was a wide burrow with a very low ceiling, almost a slot; to-day the passage is cylindrical. A gimlet could not bore it more accurately. This sudden change in the system of roadmaking on behalf of the coming insect once more shows us the foresight of this “bit of intestine.” I could tell you of many other wood-eaters. Their tools are the same; yet each species displays special methods, tricks of the trade that have nothing to do with the tools. These grubs, then, like so many insects, show us that instinct is not made by the tools, so to speak, but that the same tools may be used in various ways.