Having now established the fact that determinants can continue their direction of variation without limit because of internal, that is intra-germinal, reasons, we have come nearer an understanding of many secondary sexual characters, whose resemblance to the excessive developments artificially produced in our domestic poultry is so very striking. Here, too, we shall have to regard germinal selection as the root of the variations of plumage and other distinguishing characters, which have evolved by intra-germinal augmentation into the magnificently coloured crests, tufts, and collars, into the long or graduated, multiplied or erectile tail-feathers of the birds of Paradise, pheasants, and humming-birds. The conception of sexual selection formulated by Darwin will be so far modified, that we are no longer compelled to regard every minute step in this cumulative process as due to the selection of the males by the females. A preference of the finest males may still take place, and is probably general, since only thus could the distinguishing male characters become common property, that is, be transmitted to all or the majority of the ids of the germ-plasm, but the increase of the individual determinants which are in the act of varying goes on in each individual id, quite independently of this personal selection. As it is not a single id with its determinant _a_ in ascending variation that controls the organ _A_, but as it always requires a majority of the ids _a_, this must be secured here by personal selection just as it is in ordinary natural selection. If the handsomest males are the successful competitors, then a majority of the transformed ids _a´_ will be transmitted to a number of their descendants, and the oftener this happens the larger will the majority be, and the less becomes the danger that it will be dispersed again by reducing division and amphimixis. Personal selection is thus in no way rendered superfluous by germinal selection, only it does not produce the augmentation of the distinguishing characters, but is chiefly instrumental in fixing them in the germ-plasm; it collects, so to speak, only the favourably varying ids, and, where complex variations depending on the proper variation of many ids are concerned, it combines these. How very great the influence of personal selection may be in this case of secondary sexual characters we see clearly from the soberly coloured mates of the brilliant males, for here natural selection has been operative in conserving the coloration inherited from remote ancestry.