I therefore took nine females from the colony whence I had got them in the morning; three of these had been already experimented upon. Again they were conveyed in a dark box—each imprisoned in a paper twist. The starting-place was to be the neighbouring town of Carpentras, about three kilometres from the burrows. I meant to release them not amid fields as before, but in a street in the midst of a populous quarter, where the Cerceris, with their rustic habits, had assuredly never penetrated. As the hour was late I put off the experiment, and my captives spent the night in their prison cells. The next morning, towards eight o’clock, I marked them with a double white spot on the thorax to distinguish them from those of the evening before, which had only one, and set them free successively in the middle of the street. Each mounted vertically, as if to get as soon as possible from between the houses and gain a wide horizon, then rising above the roofs, instantly and energetically turned its flight south. And it was from the south that I brought them into the town, and their burrows are south. Nine times with my nine prisoners did I obtain this striking result—that an insect quite beyond its bearings should not hesitate a moment what direction to take to regain its nest. Some hours later I too was at the burrows. I saw several of my yesterday’s Cerceris with a white dot, but none of the last set free. Had they been unable to find the way back? Were they out hunting, or in their galleries recovering from the excitement of such a trial? I do not know. The next morning I came again, and had the satisfaction of finding at work, as active as if nothing extraordinary had happened to them, five Cerceris with two white dots. Three kilometres of distance,—the town with its houses, roofs, and smoky chimneys—all so novel to my rustic Cerceris,—had proved no obstacle to their return home. Taken from its brood and carried an enormous distance, the pigeon returns promptly to its dovecote. If one were to consider the length of journey in proportion to the size of the animal, how superior to the pigeon is the Cerceris carried away three kilometres and returning to its burrow! The size of the insect does not equal a cubic centimetre, while that of the pigeon must quite equal the cube of a decimetre, if it does not exceed it. The bird, a thousand times larger than the Hymenopteron, ought, in order to rival it, to find its dovecote at a distance of 3000 kilometres—thrice the greatest length of France from north to south. I do not know if a carrier-pigeon has ever shown such prowess, but wing-power and yet more lucidity of instinct cannot be measured by yards. Nor can we here consider the question of size, and one can only see in the insect a worthy rival to the bird without deciding which has the advantage.