“I found in the middle of May one male and ten females, which I put into a glass filled with water, where they lived together very quietly for eight days. I put some duck-weed (_Lemna_) into the glass to afford them shelter, and the females began to stretch diagonal threads in a confused manner from it to the sides of the glass about half way down. Each of the females afterwards fixed a close bag to the edge of the glass, from which the water was expelled by the air from the spinneret, and thus a cell was formed capable of containing the whole animal. Here they remained quietly, with their abdomens in their cells, and their bodies still plunged in the water; and in a short time brimstone-colored bags of eggs appeared in each cell, filling it about a fourth part. On the 7th of July several young ones swam out from one of the bags. All this time the old ones had nothing to eat, _and yet they never attacked one another_, as other spiders would have been apt to do (Clerck, Aranei Suecici, cap. viii.).” “These spiders,” says De Geer, “spin in the water a cell of strong, _closely woven, white silk_ in the form of half the shell of a pigeon’s egg, or like a diving bell. This is sometimes left partly above water, but at others is entirely submersed, and is always attached to the objects near it by a great number of irregular threads. It is closed all round, but has a large opening below, which, however, I found closed on the 15th of December, and the spider living quietly within, with her head downwards. I made a rent in this cell, and expelled the air, upon which the spider came out; yet though she appeared to have been laid up for three months in her winter quarters, she greedily seized upon an insect and sucked it. I also found that the male as well as the female constructs a similar subaqueous cell, and during summer no less than in winter (De Geer, Mém. des Insectes, vii. 312.).” “We have recently kept one of these spiders,” says Mr. Rennie, “for several months in a glass of water, where it built a cell half under water, in which it laid its eggs.” Thus it appears, that by the successive descents of the little water-spider under the impulsion of its instinct, produce effects in its subaqueous pavilion equivalent to those produced in the diving-bell, or diving helmet, by the successive strokes of the condensing air-pump of scientific man! In the language of the book of Psalms, this insect “LAYETH THE BEAMS OF” her “CHAMBERS IN THE WATERS,” and there secures her subaqueous chambers in the manner described.