happiness to the wasp merely, as the shaking of a rat certainly is to a terrier, whatever other advantages accrue from it. That insects, like other animals, including man—who, indeed, is the crowning instance—take a savage pleasure in overpowering and killing their prey, I have myself very little doubt. We have seen that this wasp stung the caterpillar between the segments of its body, and, as we will assume—for the result seems to warrant the inference—in the central part of it, so that the sting, entering the great nervous cord or ganglion, which is situated in this region, with little swellings at each of the segmental rings, produced the described paralysis. It was Fabre’s view that this must always be the case, and he thought likewise, in accordance with his own observation, that the caterpillar received a sting at the junction of all or nearly all the segments of its body. Otherwise it would be imperfectly stung, and in consequence not sufficiently paralysed to prevent its struggling, and so detaching the young larva, or perhaps the egg, which, as it would seem, is laid on, and not inside, the body of its living provisions. On the other hand, were the caterpillar stung too severely, so as to be killed outright, the grub when hatched would only have putrid meat to feed upon, and this again, it was assumed, would be fatal to its existence. On these grounds Fabre concluded that we had here an instinct which must have been perfect from the beginning, since as anything short of such perfection would be followed by the death of the larva, those gradual steps by which, on the theory of natural selection, all excellence either of structure or instinct has been attained, could not in a case like this have had any existence.