And here it must not be forgotten that those striking cases to which our attention is generally called are but a very small minority of the existing forms of life. For that special group of adaptation phenomena classed under the head of Mimicry, Mendelism seems to offer an interpretation simpler than that at present in vogue. This perhaps may be more clearly expressed by taking a specific case. There is in Africa a genus of Danaine butterflies known as _Amauris_, and there are reasons for considering that the group to which it belongs possesses properties which render it unpalatable to vertebrate enemies such as birds or monkeys. In the same region is also found the genus _Euralia_ belonging to the entirely {145} different family of the Nymphalidae, to which there is no evidence for assigning the disagreeable properties of the Danaines. Now the different species of _Euralia_ show remarkably close resemblances to the species of _Amauris_, which are found flying in the same region, and it is supposed that by "mimicking" the unpalatable forms they impose upon their enemies and thereby acquire immunity from attack. The point at issue is the way in which this seemingly purposeful resemblance has been brought about. One of the species of _Euralia_ occurs in two very distinct forms (Pl. VI.), which were previously regarded as separate species under the names _E. wahlbergi_ and _E. mima_. These two forms respectively resemble _Amauris dominicanus_ and _A. echeria_. For purposes of argument we will assume _A. echeria_ to be the more recent form of the two. On the modern Darwinian view certain individuals of _A. dominicanus_ gradually diverged from the _dominicanus_ type and eventually reached the _echeria_ type, though why this should have happened does not appear to be clear. At the same time those specimens which tended to vary in the direction of _A. echeria_ in places where this species was more abundant than _A. dominicanus_ were encouraged by natural selection, and under its guiding hand the form _mima_ eventually arose from _wahlbergi_.