The shaft found and the stone lifted, she must return to the prey, not without some uncertainty when comings and goings have been too many. Although it was left in a place obvious enough, the Ammophila often seems at a loss when the time comes to drag it home; at least, if there be a very long search for the burrow, one sees her suddenly stop and go back to the caterpillar, feel it and give it a little bite, as if to make sure that it is her very own game and property, hurrying back to seek for the burrow, but returning a second time if needful, or even a third, to visit her prey. I incline to believe that these repeated visits are made to refresh her memory as to where she left it. This is what happens in very complex cases, but generally the insect returns without difficulty to the spot whither its vagrant life may have led it. For guide it has that local memory whose marvellous feats I shall later have occasion to relate. As for me, in order to return next day to the burrow hidden under the little flat stone, I dared not trust to my memory, but had to use notes, sketches, to take my bearings, and stick in pegs—in short, a whole array of geometry. The temporary closing of the burrow with a flat stone as practised by A. sabulosa and A. holosericea appears unknown to the two other species; at least I never saw their homes protected by a covering. This is natural in the case of A. hirsuta, for, I believe, this species hunts the prey first and then burrows near the place of capture. As provender can therefore be at once stored it is useless to take any trouble about a cover. As for A. holosericea, I suspect there is another reason for not using any temporary door. While the two others only put one caterpillar in each cell, she puts as many as five, but much smaller ones. Just as we ourselves neglect to shut a door where some one is constantly passing to and fro, perhaps this Ammophila neglects to place a stone on a well which she will go down at least five times within a short space of time. All four lay up caterpillars of moths for their larvæ. A. holosericea chooses, though not exclusively, those slender, long caterpillars known as Loopers. They move as a compass might by opening and closing alternately, whence their expressive French name of Measurers. The same burrow includes provisions of varied colours—a proof that this Ammophila hunts all kinds of Loopers so long as they are small, for she herself is but feeble and the larva cannot eat much, in spite of the five heads of game set before it. If Loopers fail, the Hymenopteron falls back on other caterpillars equally small. Rolled up from the effect of the sting which paralysed them, all five are heaped in the cell; the top one bears the egg for which the provender is destined.