The males of this form are everywhere ALMOST the same in colour and in
form of wings, save for a few variations in the sparse black markings on
the pale yellow ground. But the females occur in several quite different
forms and colourings, and one of these only, the Abyssinian form, is
like the male, while the other three or four are MIMETIC, that is to
say, they copy a butterfly of quite a different family the Danaids,
which are among the IMMUNE forms. In each region the females have thus
copied two or three different immune species. There is much that is
interesting to be said in regard to these species, but it would be out
of keeping with the general tenor of this paper to give details of this
very complicated case of polymorphism in P. dardanus. Anyone who is
interested in the matter will find a full and exact statement of the
case in as far as we know it, in Poulton's "Essays on Evolution" (pages
373-375). (Professor Poulton has corrected some wrong descriptions which
I had unfortunately overlooked in the Plates of my book "Vortrage uber
Descendenztheorie", and which refer to Papilio dardanus (merope).
These mistakes are of no importance as far as and understanding of the
mimicry-theory is concerned, but I hope shortly to be able to correct
them in a later edition.) I need only add that three different mimetic
female forms have been reared from the eggs of a single female in South
Africa. The resemblance of these forms to their immune models goes so
far that even the details of the LOCAL forms of the models are copied by
the mimetic species.
It remains to be said that in Madagascar a butterfly, Papilio meriones,
occurs, of which both sexes are very similar in form and markings to
the non-mimetic male of P. dardanus, so that it probably represents the
ancestor of this latter species.
In face of such facts as these every attempt at another explanation must
fail. Similarly all the other details of the case fulfil the preliminary
postulates of selection, and leave no room for any other interpretation.
That the males do not take on the protective colouring is easily
explained, because they are in general more numerous, and the females
are more important for the preservation of the species, and must also
live longer in order to deposit their eggs. We find the same state of
things in many other species, and in one case (Elymnias undularis)
in which the male is also mimetically coloured, it copies quite a
differently c
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