Two examples of each sex of this moth are figured on Plate 46, and these show the normal form of the species; the central markings of the fore wings vary in width and intensity, and in some specimens the whole of the central area is more or less filled up with black or sooty black. Sometimes the wings are partially suffused with blackish, and the normal markings are consequently somewhat obscured. Examples wholly suffused with black are referable to var. _eremita_, a form not uncommon on the continent, and modifications of it are found in a wild state in this country. By selecting parents showing a tendency to vary in the direction of this dark form, it has been found possible to obtain a good percentage of darkened specimens, some of them closely approximating to var. _eremita_. The early stages are figured on Plate 47. The eggs of this species are laid in August in the chinks of bark on tree trunks, and do not hatch until the spring. Caterpillar, whitish varying to greyish, a deep brown stripe along the middle of the back with an irregular black line on each side of it; the stripe is interrupted by a whitish or greyish patch on rings seven to nine; on ring two there is a black mark, and occasionally red dots appear on eight and nine; black dots on the back and sides are furnished with hairs. Head, brownish marked with a paler tint. It feeds from April to July on the leaves of oak and various other trees, including apple and pine. The chrysalis, which is enclosed in a somewhat transparent silken cocoon spun up in a fissure of the bark, is brownish, hairy, and has a very glossy metallic appearance. The moth emerges at the end of July and in August. It flies {106} at night, and may be seen resting by day on the trunks of trees. Although it occurs in most of the counties of England from Yorkshire southwards, and in some parts of Wales, it is nowhere so often met with as in the New Forest, Hants. Distribution, Central Europe extending to parts of Northern Europe, and southwards to North Italy and Greece, and eastwards to Ussuri and Japan. LACKEYS AND EGGARS (_Lasiocampidæ_).