There is ample evidence that the Bembex is aware of the danger. The Wasp knows how disastrous the presence of the hateful Gnat may be to the future of the nest; on this point her prolonged attempts to put off the Tachinæ, her hesitations, her flights leave not the shadow of a doubt. Then how is it, I ask myself once more, that the Fly-huntress allows herself to be worried by another of the tribe, by an infinitesimal bandit, incapable of the least resistance, whom she could reach with a sudden rush if she tried? Why not relieve herself of the prey that clogs her movements and swoop down upon those evil-doers? What would be needed to exterminate the ill-omened brood that hangs around the burrow? A battue that would take her a few seconds. But the harmony of the universe, the laws that regulate the preservation of species, will not have it so; and the Bembex will always allow themselves to be harassed without ever learning from the famous ‘struggle for life’ the radical method of extermination. I have seen them sometimes, when too close-pressed by the Midges, drop their prey and fly away in mad haste, but without any hostile demonstration, though the putting down of the burden left them quite free in their movements. The abandoned prey, but now so ardently coveted by the Tachinæ, lay on the ground, for all to do as they pleased with; and not one of them took any notice of it. This game lying in the open air had no value for the Midges, whose larvæ require the shelter of a burrow. It was valueless also to the suspicious Bembex, who, on returning, felt it for a moment and left it with scorn. A momentary break in her vigilance had made her doubtful of it. We will end this chapter with the story of the larva. Its monotonous life offers nothing remarkable in the fortnight during which it eats and grows. Next comes the construction of the cocoon. The meagre development of the silk-producing organs does not allow the grub a dwelling of pure silk, composed, like those of the Ammophilæ and the Sphex, of several wrappers, one outside the other, which protect the larva and afterwards the nymph against the inroads of damp in a shallow and exposed burrow when the rains of autumn come and the snows of winter. Nevertheless, the Bembex’ burrow is in a worse plight than that of the Sphex, being situated at a depth of a few inches in easily saturated soil. Therefore, in order to construct itself an adequate shelter, the larva makes up by its industry for its small quantity of silk. With grains of sand artistically put together and cemented with the silky material it builds itself an exceedingly solid cocoon, impenetrable to damp.