I have been able to watch the Ammophila use her instrument on the robust caterpillar, and never did the infused science of instinct show me anything more striking. With a friend—alas! soon after snatched from me by death—I was returning from the tableland of Les Angles after preparing snares to put the cleverness of Scarabæus sacer to the proof, when we caught sight of an Ammophila hirsuta very busy at the foot of a tuft of thyme. We instantly lay down very close by. Our presence noways alarmed the insect, which alighted for a moment on my sleeve, decided that since her visitors did not move they must be harmless, and returned to her tuft of thyme. Well used to the ways of Ammophila, I knew what this audacious tameness meant—she was occupied by some serious affair. We would wait and see. The Ammophila scratched in the ground round the collar of the plant, pulling up thin little grass roots, and poked her head under the tiny clods which she raised up, ran hurriedly, now here, now there, round the thyme, visiting every crack which gave access under it; yet she was not digging a burrow, but hunting something hidden underground, as was shown by manœuvres like those of a dog trying to get a rabbit out of its hole. And presently, disturbed by what was going on overhead and closely tracked by the Ammophila, a big gray worm made up his mind to quit his abode and come up to daylight. It is all over with him; the hunter is instantly on the spot, gripping the nape of his neck and holding on in spite of his contortions. Settled on the monster’s back the Ammophila bends her abdomen, and methodically, deliberately—like a surgeon thoroughly familiar with the anatomy of his subject—plunges a lancet into the ventral surface of every segment, from the first to the last. Not one ring is omitted; with or without feet each is stabbed in due order from the front to the back. This is what I saw with all the leisure and ease required for an irreproachable observation. The Hymenopteron acts with a precision of which science might be jealous; it knows what man but rarely knows; it is acquainted with the complex nervous system of its victim, and keeps repeated stabs for those with numerous ganglia. I said “It knows; is acquainted”: what I ought to say is, “It acts as if it did.” What it does is suggested to it; the creature obeys, impelled by instinct, without reasoning on what it does. But whence comes this sublime instinct? Can theories of atavism, of selection, of the struggle for life, interpret it reasonably? For my friend and myself it was and is one of the most eloquent revelations of the ineffable logic which rules the world and guides the unconscious by the laws which it inspires. Stirred to the heart by this flash of truth, both of us felt a tear of emotion rise to our eyes. XVI THE BEMBEX