Of course, each time I gave the Cerceris back her first prey and withdrew my Cleonus to examine it at greater leisure. This examination only confirmed my opinion of the terrible skill of the assassin. It is impossible to find the slightest trace of a wound, or the smallest flow of vital liquids from the point which was struck. But the most striking thing is the rapid, complete annihilation of all movement. Vainly did I seek even immediately after the murder for any trace of sensibility in the three Weevils done to death under my eyes—neither pinching nor pricking provoked it; to do so required the artificial means already mentioned. Thus these robust Cleonus, which, pierced alive with a pin and fixed by a collector on his fatal sheet of cork, would have struggled for days, weeks, nay, whole months, instantly lose all power of motion from the effect of a little prick which inoculates them with a minute drop of poison. Chemistry knows none so active in so small a dose; scarcely could prussic acid produce such an effect, if, indeed, it could do so at all. It is not then to toxology, but to physiology and anatomy that we must turn to find the cause of such instantaneous catalepsy; it is not so much the great virulence of the poison injected, as the importance of the organ injured by it which we must consider in order to explain these marvels. What, then, is found at the point where the sting penetrates? V ONE SKILFUL TO SLAY The Hymenopteron has partly revealed her secret by showing us where the sting strikes. But does that explain the question? Not yet, by any means. Let us retrace our steps, forget for a moment what the insect has taught us, and consider the problem set before the Cerceris. The problem is this: to lay up in an underground cell a certain number of heads of game which may suffice to nourish the larva hatched from the egg laid upon the heap of provender.