Towards the end of May and in June is the usual time for this butterfly to be on the wing. It has, however, been noticed as early as about the middle of April, and as late as the middle of July, and rarely in August and September. The specimens, seen in the last-mentioned months, may have represented a second brood, and, if so, a very unusual event. Possibly, however, they may have been specimens whose emergence had for some reason not understood, been retarded. There is at least one record of the insect remaining in the chrysalis for two winters. Although generally distributed throughout England, Wales, and Ireland, and occurring in Scotland as far north as the Caledonian Canal, it seems to be more common in some districts than in others. Abroad, its range extends over Europe, and through Asia as far east as Amurland and China. The Wood White (_Leucophasia sinapis_). The graceful little butterfly figured on Plate 19 is creamy white, with a rather square black or blackish spot on the tip of the fore wings of the male. In the female the spot is reduced to some blackish scales on and between the veins. Occasionally there is a second brood in the year, and the specimens of this flight have smaller and rounder black spots in the males, and almost none at all in the females. Specimens of the female sex entirely devoid of black marking are referable to var. _erysimi_ (see fourth figure in second row, Plate 16). Series of each brood are shown on Plate 16, which is reproduced from a photograph by Mr. Hamm. The lower specimen in each series has been reversed to show the seasonal variation of the under side. The row of specimens on the left are of the first brood, and the second and last examples in this series show the characters of var. _lathyri_--black tips to the fore wings, and dusky band-like shades on the hind wings; the under sides of the hind wings dull greenish--to which form a good many of our spring specimens belong. The specimens of the second generation are referable to var. _diniensis_. The species is sometimes referred to _Leptosia_, Hüb. The egg, which is figured on Plate 18, is yellowish-white in colour; it is ribbed, and rather glassy in appearance. The caterpillars have been known to hatch out about a week after the eggs were laid. [Illustration: _Pl._ 16. =Wood White Butterfly.=] [Illustration: _Pl._ 17. =Orange-tip Butterfly.= 1, 5 _male_; 2 _do. (Irish)_; 3, 6 _female_; 4 _do. (Irish)_.]