Let us first study the dark tip. In _L. sinapis_ we have seen that it extends right to the margin of the wing in the male, but in the female is reduced to a dusky spot away from the margin. In _A. cardamines_ the margin is not coloured quite up to the edge, but a row of tiny white spots, like a fringe of seed pearls, occupies the inter-spaces of the veins. On the underside these white spots are prolonged into short bars, see Plate IV. In the continental species _A. belemia_ we see the dark tip to be in a very elementary condition, being little more than an irregular band formed of united spots, there being as much white as black in the tip, Fig. 5, Plate IV. In _A. belia_, Fig. 6, Plate IV., the black tip is more developed, and in the variety _simplonia_ still more so, Fig. 7, Plate IV. We here see pretty clearly that this dark tip has been developed by the confluence of irregular spots. Turning now to the discoidal spot we shall observe a similar development. Thus in:-- _A. cardamines_, male, it is small and perfect. Do. female, " larger " _A. belemia_ " large " _A. belia_ " large with white centre. Do. _v. simplonia_ " small and perfect. [15]_A. eupheno_, female, " nearly perfect. Do. male, " a band. We here find two distinct types of variation. In _A. belia_ we have a tendency to form an ocellus, and in _A. eupheno_ the spot of the female is expanded into a band in the male. The orange flush again offers us a similar case; and with regard to this colour we may remark that it seems to be itself a development from the white ground-colour of the family in the direction of the red end of the spectrum. Thus in the Black-veined white (_Aporia cratægi_) we have both the upper and under surfaces of the typical cream-white, for there is no pure white in the family. In the true whites the under surface of the hind-wings is lemon-yellow, in the female of _A. eupheno_ the ground of the upper surface is faint lemon-yellow, and in the male this colour is well-developed. The rich orange, confined to a spot in _G. rhamni_ becomes a flush in _G. Cleopatra_, and a vivid tip in _A. cardamines_. These changes are all developments from the cream white, and may be imitated accurately by adding more and more red to the primitive yellow, as the artist actually did in drawing the plate. [Illustration: Plate IV. SPOTS AND STRIPES.]