July 16. The one spider in the first cell has outlived all the others, but that, too, died to–day. The record of another set of nests is as follows: On July eighth we took a straw with a wasp as she went in with her spider. The cell was not sealed up. It contained fourteen specimens of three species of orb–weavers, and the egg was apparently just laid. The spiders were pushed in very tightly, and the legs and abdomens were, in many cases, bent to one side. All were limp, but alive. By July tenth, four were dead; on July eleventh the egg hatched. By July thirteenth all of the spiders were dead. It is unnecessary to give the history of other nests in detail, since these facts make it clear that there is a great variation in the degree of severity with which the spiders are stung, so that while with some the paralysis is complete, with others it is only partial. Some were killed outright, others lived two or three days, while still others survived for two weeks. Compared with the work of the Pelopæi it would seem that a smaller number of the spiders are killed at once, while a larger number die after the lapse of a few days. None of the victims of Trypoxylon live so long as the most perfectly paralyzed spiders of the mud–daubers. Two of them lived ten and fifteen days respectively, while with Pelopæus one survived until the thirty–eighth and one until the fortieth day. The egg requires from forty to sixty hours for its development, and the larva feeds for seven or eight days before spinning its cocoon. Those that we watched usually disposed first of the abdomen and then of the cephalothorax; sometimes they would consume several abdomens before attacking the other parts. After the body was devoured the legs were picked up and eaten. When the supply of food was generous, portions of the spiders were sometimes left untouched. The cocoons resembled in general appearance and structure those of Pelopæus. When a female returns with her load she usually hunts about for a few moments before finding her nest, sometimes entering, first, two or three that are empty or are occupied by other wasps; but we do not wish to cast any reflection upon the sense of locality of a creature that is able to find one particular straw out of the many thousands in an expanse of stack twenty feet high by twelve wide. We ourselves can testify, from experience, to the extreme difficulty of the task.