These insects inhabit pits, ponds, low running rivers, or ditches, in cases of different forms, and composed of various materials; some of them inclosed in a very rough shell, found among weeds in standing waters, are generally tinged green; others are bigger than a gentle, and of a yellowish hue, with a black head; they are an excellent bait, and are found in most plenty in gravelly and stony rivulets, and by the sides of streams, in large rivers among stones. To collect them, turn up the stones, and the best will adhere to them; when the quantity wanted is obtained, put them into a linen bag for five or six days, dip them, together with the bag, into water once a day, and hang them up; they will then turn yellow, become tough, and fitter for angling than when first got from the brook. If meant to be kept long, they must be put into a thick woollen bag, with some of the moist gravel or sand from the same rivulet whence they are taken; they must be wetted twice a day, but oftener in very hot weather; when you carry them abroad, fill the bag with water and holding the mouth of it close, let the water run from them; thus they have been kept three weeks. Another way of preserving them is, by placing them in an earthen pot full of river water, with some of the gravel they were bred in at the bottom; but the preceding method is preferable: some use bait pans of different sizes for insects, the tops punched full of holes, not so large as to admit of their escaping when placed in the river, which not only keeps them cool, but supplies them with aliment in the fresh water; some keep them in moss in a woollen bag on a damp floor, taking care that the bag retains a proper moisture. Another mode of preserving caddis, and also grasshoppers, caterpillars, oak-worms, or natural flies, is to take the green withy bark from a bough six or seven inches round, and about a foot in length, turn both ends into the form of a hoop, and fasten them with a large needle and thread; stop up the bottom with cork, and bore the bark full of holes with a red hot wire, tie over it a colewort leaf, and lay it in the grass every night: in this manner caddis may be preserved until they turn to flies. When grasshoppers are to be preserved in the case, some grass must be put into it.