urs 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 Muller even goes so far as to believe that the sight of gaudy
butterflies might influence the taste of distinct species." ("Life and
Letters", III. page 157.)

This remarkable suggestion affords interesting evidence that F. Muller
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 is well known that when the sexes
differ the females are almost invariably more perfectly mimetic than the
males and in a high proportion of cases are mimetic while the males are
non-mimetic.

The difficulty was met several years later by Fritz Muller's well-known
theory, published in 1879 ("Kosmos", May 1879, page 100.), and
immediately translated by Meldola and brought before the Entomological
Society. ("Proc. Ent. Soc. Lond." 1879, page xx.) Darwin's letter to
Meldola dated June 6, 1879, shows "that the first introduction of this
new and most suggestive hypothesis into this country was due to the
direct influence of Darwin himself, who brought it before the notice
of the one man who was likely to appreciate it at its true value and to
find the means for its presentation to English naturalists." ("Charles
Darwin and the Theory of Natural Selection", page 214.) Of the
hypothesis itself Darwin wrote "F. Muller's view of the mutual
protection was quite new to me." (Ibid. page 213.) The hypothesis of
Mullerian mimicry was at first strongly