Against my position the objection has often been urged that an arrangement cannot arise or be maintained through natural selection unless it is _of direct use_ to the individual in which it occurs. Sexual reproduction cannot therefore have been established simply because it advances, or even because it makes possible the adaptations of species, for these adaptations only came about occasionally, perhaps once in a thousand generations or even less frequently; thus the intervening generations could derive no advantage of any kind from the arrangement in question, and therefore, according to the law of the degeneration of unused characters, it must have long since been lost. I mentioned this objection before, but was obliged to postpone a detailed consideration of it until we had discussed germinal selection. We admit, of course, that characters are only preserved intact as long as they are of advantage sufficient to turn the scale in favour of their possessors, and that they begin to fall from their height of perfection when that is no longer the case; we admit also that new adaptations are not continually necessary, but are so only at intervals of long series of generations, and yet the objection cited seems to me baseless. Leaving out of account, for the moment, the first introduction of amphimixis, let us deal with it as an existing occurrence, for the tenacious persistence of which we wish to find reasons. Is it really the case that amphimixis is only of importance in connexion with the new adaptation of a species, and that it has nothing to do with the persistence of the species in the state of adaptation already attained? According to the conception of the processes within the germ-plasm which we have already stated, it is impossible that this should be the case, for continual slight fluctuations are occurring in the determinants in consequence of the fluctuations of the nutritive stream, and these slight variations, plus or minus, do not in many cases equalize one another or counteract one another by turning again in a contrary direction; they go on increasing in the direction in which they have begun. It is only when personal selection opposes them that they come to a standstill, and this can only happen when they attain to selection-value, that is to say, when they reach a level at which they become disadvantageous in the struggle of persons. But as germinal variations of this kind are continually occurring, personal selection must keep continual watch over them, and eradicate them as soon as they have attained selection-value.