The almost indefinite variety of colouring in the provisions which I unearth from the burrows or see between the legs of the Ammophilæ also proves that the three brigands have no preference and pounce upon the first caterpillar which comes along, provided that it be of a suitable size, neither too large nor too small, and that it belongs to the Moth division. The commonest game consists of those grey-clad caterpillars which penetrate a little way into the ground and devour the plant at the junction of root and stem. What governs the whole history of the Ammophilæ and more particularly attracted my attention is the manner in which the insect overpowers its prey and reduces it to the condition of helplessness which the safety of the larva requires. The game hunted, the caterpillar, possesses a very different structure from that of the victims which we have seen immolated hitherto: Buprestes, Weevils, Locusts and Ephippigers. The creature is composed of a series of similar rings or segments set end to end. Three of these segments, the first three, carry the real legs, which will become the legs of the future Moth; others have membranous legs, or pro-legs, which are peculiar to the caterpillar and not represented in the Moth; others, lastly, have no limbs at all. Each segment has its nerve-nucleus, or ganglion, the seat of sensibility and movement, so that the nervous system includes twelve distinct centres, separated one from the other, without counting the ganglionic neck-piece placed under the skull and comparable, in a manner of speaking, with the brain. We are here very far removed from the nerve-centralization of the Weevils and the Buprestes, which lends itself so well to general paralysis by a single prick of the sting; we are also a long way from the thoracic ganglia which the Sphex smites, one after the other, to suppress all movement in her Crickets. Instead of a solitary centralized point or of three nerve-nuclei, the caterpillar has twelve, separated from one another by the distance between one segment and the next and arranged like a string of beads on the ventral surface, along the median line of the body. Moreover, as is the general rule in the lower animals, where the same organ is repeated a great number of times and loses power by its diffusion, these different nerve-centres are largely independent of one another: each of them exercises its influence over its particular segment; and its functions are only very gradually affected by the derangement of the adjoining segments. One of the caterpillar’s rings can lose its power of moving and feeling and the remainder will nevertheless remain capable of both for a considerable time. These facts are enough to show the great interest attaching to the methods of slaughter which the Wasp adopts with her prey.