There is often a tendency in the female to assume the colour of the male, and this is usually seen on the hind wings, but occasionally on the fore wings also. In the extreme form of this phase of variation, var. _ceronus_, the whole of the upper surface, with the exception of the orange-spotted borders, is almost as blue as that of the male. This is a parallel aberration to that of the Chalk Hill Blue known as _syngrapha_, but it seems to be somewhat rarer in this country. Figures of the early stages will be found on Plate 111. The egg is greenish-white, becoming rather greener in tint towards the top, which is depressed; the netting is whitish and shining, and somewhat rougher on the sides than towards and on the top. Buckler describes the full-grown caterpillar as deep, full green in colour, covered with tiny black speckles, bearing little black bristles, which are longest on the dorsal humps and on the yellow-edged ridge above the spiracles; on the top of each of the eight pairs of dorsal humps is a deep bright yellow longitudinal dash, somewhat wider behind than in front; these dashes form in effect two yellow stripes interrupted by the deeply sunk segmental divisions; the line along the back is darker than the ground colour, and the spiracles are black. The head is dark brown, and there are two yellow dots on the first ring of the body near the head. The chrysalis, when first formed, is greenish-brown with the wing-cases greenish, the whole afterwards becomes ochreous; the thorax and wing-cases are rather glossy, and the body is slightly hairy. Buckler states that some of his caterpillars buried themselves about half an inch deep in the loose soil, and formed a weak sort of cocoon; others, not having been supplied with soil that could be so easily penetrated, retired under the stems of their food-plants, and in angles formed by the branching stems spun a few weak threads to keep themselves in place.