We know, of course, that the colours of butterflies and moths can be caused to vary through external and especially climatic influences, but this would only account for simple modifications of colour, and not for the origin of the complex colour patterns that actually occur. I therefore believe with Darwin that sexual selection has had much to do with this by giving a slight preference to the variations produced by spontaneous germinal selection, and thus preventing the majority of varied ids once acquired from being scattered again, but always collecting more of them, and so securing free play for the increase of the new character through intra-germinal processes. In this way have arisen not only the brilliance of our Lycænidæ and of the large Morphidæ of South America, but also many of the coloured spots, streaks, bands, eyes, and other components which have gradually in the course of time evolved into the complex colour pattern of many of our modern butterflies. I should like to remind any one who doubts this of a fact which corroborates the view that personal selection has co-operated in the production of these colours--I refer to the inconspicuous colouring of the females of many of these brilliant males--while in contradistinction to these cases there are other species in which both sexes are alike brilliant, so that it is impossible that mere spontaneous germinal selection can have determined that the females, because of their femaleness, should vary in a different manner from the males. But while I believe that sexual selection in particular has had much to do with producing the colours of Lepidoptera, the basis of all these colour variations must still be looked for in germinal selection, and we shall see later on how it is possible to think of the diversified and often relatively abrupt transformations of marking as the resultant of the co-operation of climatic influences with germinal selection.