There is one spider that makes a bag of silk, something like those just mentioned, on water-plants, and lives in it under water, as in a diving-bell; the opening being below, so that the air cannot escape. Mr. Bell, in “The Journal of the Linnæan Society,” vol. i., 1857, describes the filling of these nests with air by the spider. After the nest had been made as large as half an acorn, she went to the surface, and returned, fourteen times successively, and each time brought down a bubble of air, which she let escape into the nest. The bubble was held by the spinnerets and two hind-feet, which were crossed over them; and the method of catching it was the following: The spider climbed up on threads or plants nearly to the surface, and put the end of the abdomen out of water for an instant, and then jerked it under, at the same time crossing the hind-legs quickly over it. She then walked down the plants to her nest, opened her hind-feet, and let the bubble go. The water-spiders run about on water-plants, and catch the insects which live among them. They lay their eggs in the nest; and the young come out, and spin little nests of their own, as soon as they are big enough. Their hairs keep the skin from becoming wet as they go through the water; and in the nest they are as dry as if it were under a stone, or in a hole on land. COBWEBS. The simple nests and tubes that have been described are made by spiders, most of which spin no other webs. The larger and better known cobwebs for catching insects are made by comparatively few species. On damp mornings in summer the grass-fields are seen to be half covered with flat webs, from an inch or two to a foot in diameter, which are considered by the weatherwise as signs of a fair day. These webs remain on the grass all the time, but only become visible from a distance when the dew settles on them. Fig. 24 is a diagram of one of these nests, supposed, for convenience, to be spun between pegs instead of grass. The flat part consists of strong threads from peg to peg, crossed by finer ones, which the spider spins with the long hind-spinnerets, Fig. 20, swinging them from side to side, and laying down a band of threads at each stroke. The web is so close and tight, that one can hear the footsteps of the spider as she runs about on it. At one side of the web is a tube leading down among the grass-stems. At the top the spider usually stands, just out of sight, and waits for something to light on the web, when she runs out, and snatches it, and carries it into the tube to eat. If any thing too large walks through the web, she turns around, and retreats out of the lower end of the tube, and can seldom be found afterward. In favorable places these webs remain through the whole season, and are enlarged, as the spider grows, by additions on the outer edges, and are supported by threads running up into the neighboring plants. Similar webs are made by several house-spiders, and