The second step in the procedure was commonly for the wasp to alight upon some neighboring object, usually the branch of a bush or tree, and sting the spider a second time, being evidently in no haste; but the difficulty of following her as she flew, and her habit of alighting above our range of vision, made it almost impossible to see just what she did. She certainly remained on the branch for some moments, either resting quietly or rolling the spider around and around, and had every opportunity to sting it as carefully as she wished; but we afterward found that she followed no exact method, since two thirds of the spiders were killed at the moment of capture, and most of the others died within a week, while a few lived for thirty–five or forty days. In this study we opened five hundred and seventy–three cells and handled over two thousand spiders, watching over them from day to day with a magnifying glass, that no sign of life might be neglected. When Pelopæus has filled her cell, she seals it up and makes another close to it, clusters of from six to twenty being found in one spot. Any especially desirable place is used by great numbers; and they make a lively scene, working eagerly at their nests, dashing off for more mud or bringing in their victims. All animated by the same compelling instinct, they are still individuals, and the character of each enters into her work. One picks up the first spider she sees, no matter how tiny it may be, and makes twenty–five or thirty journeys before her cell is filled, while another seems to have a calculating turn of mind, using four or five big spiders instead of a quantity of small ones. Has she made a note of the calibre of her cell, and determined to save herself trouble by looking farther and selecting the largest ones that will go in? [Illustration: HORIZONTAL CELLS OF THE MUD–DAUBER]