I have already said that, on her return from hunting, the Cerceris alights at the foot of the slope, at some distance from the hole, whither she laboriously drags her prey. It became a matter, therefore, of robbing her of her victim by drawing it away by one foot with my forceps and at once throwing her the live Weevil in exchange. The trick succeeded to perfection. As soon as the Cerceris felt her prey slip from under her belly and escape her, she tapped the ground impatiently with her feet, turned round and, perceiving the Weevil that had taken the place of her own, flung herself upon him and clasped him in her legs to carry him away. But she soon became aware that her prey was alive; and now the tragedy began, only to end with inconceivable rapidity. The Wasp faced her victim and, gripping its snout with her powerful mandibles, soon had it at her mercy. Then, while the Weevil reared on his six legs, the other pressed her forefeet violently on his back, as if to force open some ventral joint. I next saw the assassin’s abdomen slip under the Cleonus’ belly, bend into a curve, and dart its poisoned lancet briskly, two or three times, into the joint of the prothorax, between the first and second pair of legs. All was over in a moment. Without the least convulsive movement, without any of that stretching of the limbs which accompanies an animal’s death, the victim fell motionless for all time, as though struck by lightning. It was terribly and at the same time wonderfully quick. The murderess next turned the body on its back, placed herself belly to belly with it, with her legs on either side, clasped it and flew away. Thrice over I renewed the experiment, with my three Weevils; and the process never varied.