So, in the case of the mimetic butterflies, we do not need to assume that they all previously required protection in the sense that they would have become extinct had they not assumed a likeness to an immune species. We may indeed conclude, on other grounds, that it was the rarer species which increased their number of individuals by the mimetic protection, and in doing so they certainly enhanced at the same time their chance of survival as a species. In the more abundant species mimetic resemblance to species whose unpalatability rendered them immune could not have been evolved, as it would have been disadvantageous, not only for the model, but for the mimicking species itself, while in species less rich in individuals, such resemblance would necessarily have a protective value, no matter whether the species was in danger of extinction or not. The process of selection must have started simply because the mimetic individuals survived more frequently than the others, and the mimetic resemblance must have gone on increasing as long as the increase brought with it a more effective protection. It is, therefore, a fallacious objection to say that a species, whose existence was threatened, would, considering the slowness of the process of selection, have died out altogether before it could have acquired effective protection by mimicking an immune species. The assumption is false--the widespread, hazy idea that the process of natural selection can only begin when the existence of the species is threatened. On the contrary, every species utilizes every possibility of improvement; and every improvement for which variation supplies the necessary material is possible. The augmentation of the profitable variations follows as a necessity from the more frequent survival of the best-adapted individuals, and this 'more frequent survival' will be not only a relative one, due to the fact that the better adapted individuals will be less decimated, it will also be absolute, because more individuals of the species will survive than before. Of this _Papilio merope_ may serve as an example; in Madagascar it now flies about only slightly varied from the original form, var. _meriones_. Here, therefore, the species is maintained, without the aid of mimetic protection. We do not know if the reason for this lies in the absence of an immune model, or in the non-appearance of suitable mimetic variants, or in other conditions; but we know that without mimicry the species holds its own against its enemies. But if, in Abyssinia, a female of this butterfly exhibited variations which would make her resemble, in any degree, the unpalatable _Danias chrysippus_, these mimetic variants would be less decimated than the original form of female, and would, therefore, gain stability, and gradually increase both in mimetic resemblance and in the number of individuals. But is this any reason why the original form of the female should diminish