Why does the spoiler kill the captured prey instead of simply paralysing it? Is it for want of skill in the use of her sting? Is it because of some difficulty due to the structure of the Flies or to the methods employed in the chase? I must begin by confessing that I have failed in my attempts to place Flies, without killing them, in that state of complete immobility to which it is so easy to reduce a Buprestis, a Weevil or a Scarab by injecting a tiny drop of ammonia with a needle into the thoracic ganglia. In making the experiment, it is difficult to render the insect motionless; and, by the time that it has ceased to move, death has actually occurred, as is proved by its speedy corruption or desiccation. But I have too much confidence in the resources of instinct and have witnessed the ingenious solution of too many problems to believe that a difficulty which baffles the experimenter can bring the insect to a standstill. Therefore, without throwing doubt upon the Bembex’ talents as a slaughterer, I should be inclined to look for other reasons. Perhaps the Fly, so thinly covered, so devoid of any plumpness, in a word, so lean, could not, if paralysed by the sting, resist evaporation long enough and would shrivel up during the two or three weeks of waiting. Consider the puny Sphærophoria, the larva’s first mouthful. How much liquid has that body to satisfy the needs of evaporation? An infinitesimal drop, a mere nothing. The abdomen is a thin strip; its two sides touch. Can such game as this form the basis of preserved food, seeing that evaporation would dry up its juices in a few hours when these are not renewed by nutrition? It is doubtful, to say the least. Let us examine the method of hunting, so as to throw some final light on the subject. In the quarry removed from between the legs of the Bembex, it is not rare to observe signs of a hurried capture, made anyhow, according to the chances of a rough-and-tumble fight. The Fly sometimes has her head turned the wrong way round, as though the spoiler had wrung her neck; her wings are crushed; her fur, when she possesses any, is ruffled. I have seen some that had their bellies ripped open by their assailant’s mandibles and had lost their legs in the battle. As a rule, however, the victim is intact.