One sees quite well that the acquisitions of the individual have passed to the descendant, but how? How have they fixed themselves in the nerves and blood during a few short days of life? Without any apprenticeship the sphex paralyzes with three stabs the cricket which is to feed its larvæ; if the cricket is killed and not paralyzed, the larvæ will die, poisoned by the carrion; and if the paralysis is not durable the cricket will come to, and destroy the sphex in the egg. The manœuvre of this wasp and of many other killing hymenoptera has this tiresome point for our reasoning, the act must be perfect, on pain of death. Nevertheless it must be admitted that the sphex has formed itself slowly, like all complex animals, and that its genius is only the sum of intellectual acquisition slowly crystallized in the specie.[4] As for the mechanism of this transformation of intelligence into instinct, it has for motive the principle of utility; intelligent acts which are useful for the preservation of the specie, are the only ones which pass into instinct. The science of these hymenoptera goes so far that it was ahead of human science until yesterday. The insect attacks the nervous system; it knows that the power of beginning a movement lies in the nervous system and not in the limbs. If the nervous system is centralized as in weevils, their enemy the cerceris gives only one dagger-stab; if the movement depends on three ganglia, it gives three stabs; if on nine ganglia, nine: thus does the shaggy ammophile when it needs the caterpillar of the noctuelle, commonly called the gray worm, for its larvæ; if a single sting in the cervical ganglion appears too dangerous, the hunter limits himself to chewing it gently, in order to induce the necessary degree of immobility. It is odd that the social hymenoptera who know how to do so many difficult things, are ignorant of this savant dagger-play. The bee stings at random, and so brutally that she mutilates herself while often inflicting but an insignificant wound on her adversary. Collective civilization has diminished the individual genius. [1] Vide Milton and Cheaddle, works already cited. [2] Compare this with the valuable remarks of a gamekeeper, "One must know the habits of animals, even their manias, for they have them, just as we do." Figaro, 31, Aug. 1903.