The nest was completed, but the work of storing it remained to be done. The wasp flew away at nine o’clock, and ten minutes later came back with something, we knew not what, for she dropped into her hole so quickly that she was out of sight almost before we knew she was there. Two minutes later she came up, and was off again. This time she was gone twelve minutes, and when she returned we were again baffled in our effort to see what she was carrying. When she came out she alighted upon a leaf and attended to her toilet, cleaning both body and wings by rubbing them off with her hind legs, and from this time on she never started on a hunting expedition without paying this attention to her personal appearance. On her third trip she was gone twenty minutes, coming back with a small fly; and before we left her at ten o’clock, she had stored six more. When we came back at half past two in the afternoon she was working, and she kept up her goings and comings until four o’clock, when she suspended operations for the day. On the next morning we were called away, and know nothing of what she did, but on the following day, Thursday, we resumed our observations. She worked hard all the morning, but in the afternoon her trips were few, and were made at long intervals. On Friday she worked from eight to nine, when she departed, and never returned. We watched for her, at intervals, all through that day and the next, when we were forced to conclude that our faithful little worker had fallen a victim to some bird or beast. We did not disturb the nest until four days later, when we cut the stalk, and examined it. We found that the tunnel was thirty–nine centimeters in length. This was a long distance for her to excavate, and, all things considered, her progress had been rapid. We have opened a number of stems that had been stored by this species, and all the excavations were from thirty to forty centimeters in length, the width of the gallery being about three and one half millimeters, while on each side there was from one to one and one half millimeters of pith that had not been cut away. Of course these points varied with the diameter of the stem and also with the size of the worker. Our little stirpicola had stored one cell, had laid an egg, and had built a partition of pith across the stem as a floor to the second cell, before her untimely taking off. Had she lived, ten or twelve cells would have been stored, one above the other. The completed cell contained a larva and parts of eighteen flies of different sizes, four species being represented. The flies had all been attacked by the larva, the abdomens of some and the thoraces of others having been eaten. The larva continued to eat for two days, and then spun its cocoon. The flies found in this and in other nests of stirpicola were all dead. All the pupæ that we kept wintered in the cocoon and came out in the spring. [Illustration: AMMOPHILA SLEEPING IN THE GRASS (AFTER BANKS)]