I will add that, in other circumstances, I have repeatedly found the same Wasp, whom I presume to be a parasite, in short the Black Tachytes, dragging a Cricket by one of his antennæ. Was he a lawfully-acquired prey? I should like to think so; but the vacillating behaviour of the insect, who went straying about the ruts in the roads as though seeking for a burrow to suit it, always left me uncertain. I have never witnessed its digging-work, if it really undertakes the labour of excavation. And, a more serious matter, I have seen it leave its game on the rubbish-heap, perhaps not knowing what to do with it, for lack of a burrow wherein to place it. Such wastefulness as this seems to me to point to ill-gotten goods; and I ask myself if the Cricket were not stolen from the Sphex at the moment when she abandoned her prey on the threshold. My suspicions also fall upon Tachytes obsoleta, banded with white round the abdomen like Sphex albisecta and feeding her larvæ on Crickets similar to those hunted by the latter. I have never seen her digging any galleries, but I have caught her with a Cricket whom the Sphex would not have rejected. This identity of provisions in species of different genera raises doubts in my mind as to the lawfulness of the booty. Let me add, lastly, to atone in a measure for the injury which my suspicions may do to the reputation of the genus, that I have been the eye-witness of a perfectly straightforward capture of a small and still wingless Cricket by Tachytes tarsina and that I have seen her digging cells and victualling them with game acquired by her own valiant exertions. I have therefore only suspicions to offer in explanation of the obstinacy of the Sphex-wasps in going down their tunnels before carrying in their prey. Can they have some other object besides that of dislodging a parasite who may have arrived during their absence? This is what I despair of ever knowing; for who can interpret the thousand ruses of instinct? Poor human reason, which cannot even fathom the wisdom of a Sphex!