Mimicry 289 



to the theory of mimicry, the other to the influence of local con- 

 ditions, — could not be sustained. 



Fritz Muller's contributions to the problem of Mimicry were all 

 made in S.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 1 contain abundant proofs of his interest in Muller's 

 work upon Mimicry. One deeply interesting letter 2 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 3 ." 



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 Muller'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 Muller'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. 



- Loc. cit. pp. 201, 202. 8 Life and Letters, in. p. 157. 



D. 19 



