The egg of _callunæ_ is figured on Plate 55. It appears rather polished, and in colour is pale brown mottled with darker brown. The eggs are stated to be deposited whilst the female is on the wing, and consequently they fall to the ground or are arrested in their descent by the herbage over which they are scattered. The full-grown caterpillar of _quercus_, beneath the brownish fur with which the body is clothed, is dark brown on the back and rather violet brown on the sides; the ring divisions are velvety black; there is a white stripe along each side and below the stripe some reddish marks; the ring nearest the head is edged with reddish, and the next two rings each have two reddish centred white spots. The dull purplish brown chrysalis is enclosed in a hard oval-shaped cocoon which is spun up on or near the ground in a flimsy web among herbage, dead leaves, etc. Sometimes it is placed among the twigs of the food plant. In Southern England the caterpillars hatch from the egg in August and usually hibernate when quite small. They feed up during the following spring and early summer, perhaps in June or July, and the moth appears in July or August. Occasionally, however, a few individuals depart from the general habit and complete their growth the same year, hibernate in the pupal stage, and produce moths the next year, possibly earlier than hibernating caterpillars. On the other hand, perhaps owing to adverse weather conditions, feeding after hibernation may be continued well on into the autumn, when the caterpillars pupate, {118} but emergence of the moth is postponed until the following year, the second after hatching from the egg. In the case of _callunæ_, at least as regards its normal habit in Scotland and southwards to the moorland districts of Yorkshire and Lancashire, the young caterpillar hibernates the first winter, feeds through the following summer, and passes the second winter as a chrysalis, the moth emerging in the following May or June. Generally speaking, then, it may be stated that _quercus_ has a twelve-month life cycle, whilst that of _callunæ_ extends almost or quite to twenty-four months, of which at least twelve months are passed as a caterpillar. However, as has been noted, _quercus_ sometimes passes one winter as a caterpillar, and another as a chrysalis, thus assuming the _callunæ_ habit; whilst _callunæ_ occasionally attains the perfect state during the summer following that in which the caterpillar left the egg. The food plants comprise bramble, dogwood, hawthorn, heather (_Calluna_), and various low plants; it is even content with ivy.