1650. The different Scale insects (Cocci) (fig. 290.) frequently produce as much mischief, in the garden, the greenhouse, and the stove, as the plant-lice: they are known by their oval form, and whilst young they have short feet, thus bearing some resemblance to the house-bug; some species are clothed with white down, and others look like brown inanimate scales upon the bark: these last are the Coccus hesperidum L., and are generally found upon the orange, myrtle, and camellia. The vine is exposed to another kind (C. vitis L.), which will not live in the open air, but sometimes so abounds upon vines in stoves and greenhouses, that the stems appear covered with spots of white cotton. Plum trees are likewise injured by another of these pests (C. persicarum Reaumur), which is very small (a); when magnified, the upper side (b) represents a shield, and the legs are only seen when the insect is turned on its back (c); it is principally found on twigs, and the females resemble small red globules. Mr. Kirby (Int. to Ent., 197.) mentions a coccus peculiar to the currant bush: the eggs were of a beautiful pink, and were enveloped in a large mass of cotton-like web, which could be drawn out to a considerable length. The female of another species, found on the apple (C. arborum linearis T.), has the exact shape of a mussel-shell. The leaves of the oak are inhabited by another small species (C. folii quercus R.) (fig. 290. d); when magnified, the rudiments of wings are seen both in the upper (e) and under (e) sides. The coccus of the beech (C. fagi) is still more minute, and causes small tubercles to arise on the twigs (g).