We grow accustomed to marvels, and from our familiarity with other wasps we take as a matter of course the unerring accuracy with which Bembex swoops down upon the exact spot at which the entrance to her nest is hidden. And yet how strange a power it is! There is not the least sign to help her—not a stone, not a blade of grass is to be seen on the field. Our method of marking a nest which we wished to find again was to place tiny pebbles at exactly equal distances from it, one on either side, so that the middle point of the straight line between them gave us the desired spot; and the wasp doubtless uses the same method, only her landmarks are sometimes so infinitesimal that we do not recognize them. Bouvier finds that when he cuts away the plants around the nest of B. labiatus, clearing a space of twenty–eight or thirty inches square, the wasp is much confused, flying about for a long time before she is able to find her home. He once placed a flat stone over the entrance. The wasp alighted upon it, and after scratching vainly for a while made her way in. The stone was left in this position for two days, during which time Bembex learned to regard it as a landmark, for upon its being removed to a distance of eight inches she still followed it upon returning with her fly, and insisted upon finding her nest near it. [Illustration: NEST OF BEMBEX] An observation of Marchand points to the same conclusion. He says:— On July seventeenth, 1900, during a short sojourn at Pouliguen, on returning from a hunt after Diptera and Hymenoptera in the cliffs of Caudan, about eleven in the morning, in tropical heat, I paused to take breath near the old mill of Caudan and looked about for a little shade before continuing my walk to Pen–Château. I had seated myself on the stones of a slope shaded from the sun and was wiping the perspiration from my forehead, when I saw a large wasp arrive directly before me. I instinctively followed it with my eyes; it paused some yards from the mill on the side of the cliff, and began to open a nest which was placed scarcely twenty inches from the foot of a swallow–wort, a rather common plant in the neighborhood of the ruin. She was Bembex rostrata at work at provisioning her nest. Moved by curiosity, instead of going on to breakfast, I awaited the exit from the nest, which took place in about five minutes. Bembex scratched the sand and took flight from the side of the cliff. How long would she be away? I looked at my watch and arose.