We return to the Sphex, with whose burrow we must make acquaintance before going further. It is made of fine sand, or rather in the fine dust at the bottom of a natural shelter. Its passage is very short—an inch or two without a turn, leading into a single spacious oval chamber, and all is a rude, hastily made den, rather than a dwelling hollowed with art and leisure. I have already said that the captured prey, left for a brief moment or two where it was hunted, is the cause of the simplicity of this abode and of there being but one chamber or cell to each hollow. For who can say whither the chances of the day’s hunt may lead? The dwelling must be near the heavy prey, and to-day’s abode, too far off to admit of carrying the second ephippiger there, cannot be used to-morrow. Thus each time prey is caught there must be new digging out—a new burrow with its one cell, now here, now there. Now let us try some experiments to see how the insect behaves amid circumstances new to it. First experiment.—A Sphex, dragging her prey, is at a few inches from her burrow. Without disturbing her I cut the antennæ of the ephippiger, which we already know serve as harness. Having recovered from her astonishment at the sudden lightening of her load, the Sphex returns and unhesitatingly seizes the base of the antennæ, the short stumps not cut off. Very short they are—hardly a millimetre long; no matter, they suffice for the Sphex, who grips what remains of her ropes and drags anew. With many precautions not to hurt her, I cut off the two stumps, now level with the skull. Finding nothing to seize at the parts familiar to her, she takes hold on one side of one of the long palpi of her victim, and drags it, not at all put out by this modification in her style of harnessing herself. I leave her alone. The prey is got home and placed with its head to the mouth of the burrow. The Sphex enters to make a short inspection of the interior before proceeding to store provisions. Her tactics recall those of S. flavipennis in like circumstances. I profit by this brief moment to take the abandoned prey, deprive it of all its palpi, and place it a little farther off—a pace from the burrow. The Sphex reappears and goes straight to her game, which she saw from her threshold. She seeks above the head, she seeks below, on one side, and finds nothing to seize. A desperate attempt is made; opening wide her mandibles she tries to grasp the ephippiger by the head, but her pincers cannot surround anything so large, and slip off the round, polished skull. She tries several times in vain; at length, convinced of the futility of her efforts, draws back, and seems to renounce further attempts. She appears discouraged—at least she smooths her wings with her hind feet, while with her front tarsi, first passing them through her mouth, she washes her eyes, a sign among Hymenoptera, as I believe, that they give a thing up.