By placing a captured female _M. Stellatarum_ in a capacious breeding-cage, in the open air, I was enabled to procure eggs. The moth hovered about over the flowers, and laid its small, grass-green, spherical eggs (partly when on the wing), singly, on the leaves, buds, and stalks of _Galium Mollugo_. Altogether 130 were obtained in three days.[106] _First Stage._ After about eight days the caterpillars emerge. They are only two millimeters in length, and are at first yellowish, but soon become green, set with small single bristles, and they possess a short greenish caudal horn, which afterwards becomes black. The head is greenish-yellow. The young larvæ are entirely destitute of marking. (Pl. III., Fig. 1). _Second Stage._ The first moult takes place after four days, the caterpillar now acquiring the marking which it essentially retains to pupation. Fine white subdorsal and spiracular lines appear, and at the same time a dark green dorsal line, which, however, does not arise from the deposition of pigment, as is generally the case, but from a division in the folds of the fatty tissue along this position. (Fig. 2, Pl. III.) The colour is now dirty green in all specimens, the skin being finely shagreened. _Third Stage._ The second moult, occurring after another period of four days, does not bring any change of marking, the colour only becoming somewhat darker. Length, twelve millimeters. _Fourth Stage._ The third moult (after another four days) likewise brings only a change of colouring, which is of such a nature that the caterpillar becomes dimorphic. At the same time that peculiar roughening of the skin takes place which, in the case of _Chærocampa_, was designated as “shagreening.” The colour is now light grass-green in some specimens, and dark green in others; in these last the subdorsal line is edged above with dark brown, and the spiracles are also of this colour. Length, seventeen millimeters. _Fifth Stage._ Four days later, after the fourth ecdysis, the dimorphism becomes a polymorphism. Five chief types can be distinguished:-- _Variety I._--Light green (Fig. 7, Pl. III.); dorsal line, blackish-green, strongly marked; subdorsal line broad, pure white, edged above with dark green; spiracular line, chrome-yellow; horn, black, with yellow tip and blue sides. Spiracles, blackish-brown, with narrow yellow border; legs, and extremities of prolegs, vermilion-red. _Variety II._--Blackish-brown (Fig. 6, Pl. III.); head and prothorax, yellowish-brown; markings the same as above. _Variety III._--Blackish-green or greenish-black (Figs. 10 and 11, Pl. III.); subdorsal line with blackish-green border above, gradually passing into a light green ground-colour; spiracular line, chrome-yellow; head and prothorax, greenish-yellow. _Variety IV._--Light green (Figs. 4 and 12, Pl. III.); dorsal line quite feeble; subdorsal broad, only faintly edged with dark green; subspiracular line, faint yellowish; head and prothorax, green.