flowers painted on the walls of a room, and vainly endeavour to insert
their proboscis into them. Fritz Muller informs me that several kinds
of butterflies in S. Brazil shew an unmistakable preference for certain
colours over others: he observed that they very often visited the
brilliant red flowers of five or six genera of plants, but never the
white or yellow flowering species of the same and other genera, growing
in the same garden; and I have received other accounts to the same
effect. As I hear from Mr. Doubleday, the common white butterfly often
flies down to a bit of paper on the ground, no doubt mistaking it for
one of its own species. Mr. Collingwood (22. Rambles of a Naturalist
in the Chinese Seas, 1868, p. 182.) in speaking of the difficulty in
collecting certain butterflies in the Malay Archipelago, states that a
dead specimen pinned upon a conspicuous twig will often arrest an
insect of the same species in its headlong flight, and bring it down
within easy reach of the net, especially if it be of the opposite sex.
The courtship of butterflies is, as before remarked, a prolonged
affair. The males sometimes fight together in rivalry; and many may be
seen pursuing or crowding round the same female. Unless, then, the
females prefer one male to another, the pairing must be left to mere
chance, and this does not appear probable. If, on the other band, the
females habitually, or even occasionally, prefer the more beautiful
males, the colours of the latter will have been rendered brighter by
degrees, and will have been transmitted to both sexes or to one sex,
according to the law of inheritance which has prevailed. The process of
sexual selection will have been much facilitated, if the conclusion can
be trusted, arrived at from various kinds of evidence in the supplement
to the ninth chapter; namely, that the males of many Lepidoptera, at
least in the imago state, greatly exceed the females in number.
Some facts, however, are opposed to the belief that female butterflies
prefer the more beautiful males; thus, as I have been assured by
several collectors, fresh females may frequently be seen paired with
battered, faded, or dingy males; but this is a circumstance which could
hardly fail often to follow from the males emerging from their cocoons
earlier than the females. With moths of the family of the Bombycidae,
the sexes pair immediately after assuming the imago state; for they
cannot feed, owing to the rudimentary condition of their mouths. The
females, as several entomologists have remarked to me, lie in an almost
torpid state, and appear not to evince the least choice in regard to
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