Although it might be passed over for a Green-veined White, or other common butterfly, when seen on the wing, it is very different from any of our other species when seen at close quarters. In the greenish mottling of the under side of the hind wings, the male has some likeness to the female Orange-tip, but on the Bath White the green is heavier and less broken up. On the upper side of the fore wings the black markings comprise a spot, sometimes divided, at the end of the cell, and a patch on the tips of the wings; the latter enclose spots of the ground colour. The markings of the under side show through blackish on the upper side of the hind wings. The female differs from the male in having a black spot between veins 1 and 2 of the fore wings, and the markings of the hind wings are blacker, especially on the outer area. The egg is stated by Buckler to be of a bright pinkish-red colour, agreeing in this respect, as well as in size, with the anthers of the flowers of mignonette, upon which plant it is laid in an upright position. The shape is compared to that of an acorn without the cup, and it has twelve or fourteen rather prominent ribs. The full-grown caterpillar is bluish-grey, dotted with glossy black warts, from each of which there is a short blackish hair. The lines along the back and sides are yellow, or white spotted with yellow. Head yellowish, dotted with black, and hairy. August and September. It feeds on garden as well as wild mignonette (_Reseda_). The chrysalis is at first similar in colour to the caterpillar, but it afterwards becomes whitish. It has numerous black dots, and is marked with yellow along the sides and on the back of the thorax. The above descriptions are abridged from Buckler's more detailed account of the life-history of this species. Of the caterpillars resulting from thirty-three eggs, only two attained the chrysalis state, in September. One of these turned black and died in November, and from the other a butterfly emerged in the following June. The figures of caterpillar and chrysalis on Plate 12 are from Buckler's "Larvæ." [Illustration: _Pl._ 12. =Bath White Butterfly.= _Caterpillar and chrysalis (after Buckler)._] [Illustration: _Pl._ 13. =Green-veined White Butterfly.= 1, 2 _male (spring)_, 5, 6, _do. (summer)_; 3, 4 _female (spring)_, 7, 8 _do. (summer)_.] It has been suggested that specimens taken in July and August are the offspring of immigrants that arrive here in May, but there is no conclusive evidence of this. It has, however, been proved that our climate is not suitable for the permanent establishment of the species here.