Mimicry 289 
to the theory of mimicry, the other to the influence of local con- 
ditions,—could not be sustained. 
Fritz Miiller’s contributions to the problem of Mimicry were all 
made in 8.E. Brazil, and numbers of them were communicated, with 
other observations on natural history, to Darwin, and by him sent 
to Professor R. Meldola who published many of the facts. Darwin's 
letters to Meldola? contain abundant proofs of his interest in Miiller’s 
work upon Mimicry. One deeply interesting letter? dated Jan. 23, 
1872, proves that Fritz Miiller before he originated the theory of 
Common Warning Colours (Synaposematic Resemblance or Miillerian 
Mimicry), which will ever be associated with his name, had conceived 
the idea of the production of mimetic likeness by sexual selection. 
Darwin’s letter to Meldola shows that he was by no means inclined 
to dismiss the suggestion as worthless, although he considered it 
daring. “You will also see in this letter a strange speculation, which I 
should not dare to publish, about the appreciation of certain colours 
being developed in those species which frequently behold other forms 
similarly ornamented. I do not feel at all sure that this view is 
as incredible as it may at first appear. Similar ideas have passed 
through my mind when considering the dull colours of all the 
organisms which inhabit dull-coloured regions, such as Patagonia and 
the Galapagos Is.” A little later, on April 5, he wrote to Professor 
August Weismann on the same subject: “It may be suspected that 
even the habit of viewing differently coloured surrounding objects 
would influence their taste, and Fritz Miiller even goes so far as to 
believe that the sight of gaudy butterflies might influence the taste 
of distinct species®.” 
This remarkable suggestion affords interesting evidence that 
F. Miiller was not satisfied with the sufficiency of Bates’s theory. 
Nor is this surprising when we think of the numbers of abundant 
conspicuous butterflies which he saw exhibiting mimetic likenesses. 
The common instances in his locality, and indeed everywhere in 
tropical America, were anything but the hard-pressed struggling 
forms assumed by the theory of Bates. They belonged to the groups 
which were themselves mimicked by other butterflies. Fritz Miiller’s 
suggestion also shows that he did not accept Bates’s alternative 
explanation of a superficial likeness between models themselves, based 
on some unknown influence of local physico-chemical forces. At the 
same time Miiller’s own suggestion was subject to this apparently 
fatal objection, that the sexual selection he invoked would tend 
to produce resemblances in the males rather than the females, while it 
1 Poulton, Charles Darwin and the theory of Natural Selection, London, 1896, pp. 
199—218, 
? Loe. cit. pp. 201, 202. 3 Life and Letters, 11. p. 157. 
D. 19 
