Having proved the inflexible pertinacity of all the Sphegidæ in one colony on whom I cared to experiment, I could not but perplex myself over it. “Does then the insect obey a fixed tendency which circumstances cannot modify?” I asked myself. “Are its actions all done by rule, and is it unable to acquire the least experience from its own proceedings?” Later observations modified this too absolute judgment. The following year, at the proper time, I visited the same spot. The new generation had inherited for their burrows the place chosen by the preceding ones; it had also faithfully inherited their tactics, for the cricket experiment gave the same results. Such as were the Sphegidæ of the past year such are those of the present one, equally persistent in a fruitless attempt. My error grew confirmed until good luck brought me to another colony in a different place. I renewed my experiments. After two or three trials with the old, well-known result, the Sphex got astride of the cricket, seized its antennæ with her mandibles, and dragged it at once into the burrow. Who looked a fool then? The experimenter baffled by the clever Hymenopteron. At the other holes her neighbours, some sooner, some later, found me out, and went down with their prey instead of persisting in leaving it on the threshold to seize it later. What is the meaning of this? This colony, descended from another stock, for sons return to the spot selected by their forefathers, is cleverer than the one observed last year. Craft is inherited; there are sharper-witted tribes and duller ones, apparently according to the faculties of their forefathers. With Sphegidæ, as with us, the kind of intellect changes with the province. Next day I tried the cricket experiment in another locality, and it invariably succeeded. I had come upon a dense-minded tribe, a true colony of Bœotians, as in my earlier observations. VII THREE STROKES OF A DAGGER There can be no doubt that the Sphex uses her greatest skill when immolating a cricket; it is therefore very important to explain the method by which the victim is sacrificed. Taught by my numerous attempts to observe the war tactics of the Cerceris, I immediately used on the Sphex the plan already successful with the former, i.e. taking away the prey and replacing it by a living specimen. This exchange is all the easier because, as we have seen, the Sphex leaves her victim while she goes down her burrow, and the audacious tameness, which actually allows her to take from your fingertips, or even off your hand, the cricket stolen from her and now offered, conduces most happily to a successful result of the experiment by allowing the details of the drama to be closely observed.