gy of domestic animals
a strong probability) that variations leading to beauty must often have
occurred in the males alone, and been transmitted to that sex alone.
Thus I should account in many cases for the greater beauty of the male
over the female, without the need of the protective principle." ("More
Letters", II. pages 73, 74. On the same subject--"the gay-coloured
females of Pieris" (Perrhybris (Mylothris) pyrrha of Brazil), Darwin
wrote to Wallace, May 5, 1868, as follows: "I believe I quite follow you
in believing that the colours are wholly due to mimicry; and I further
believe that the male is not brilliant from not having received through
inheritance colour from the female, and from not himself having varied;
in short, that he has not been influenced by selection." It should be
noted that the male of this species does exhibit a mimetic pattern on
the under surface. "More Letters" II. page 78.)

The consideration of the facts of mimicry thus led Darwin to the
conclusion that the female happens to vary in the right manner more
commonly than the male, while the secondary sexual characters of males
supported the conviction "that from some unknown cause such characters
(viz. new characters arising in one sex and transmitted to it alone)
apparently appear oftener in the male than in the female." (Letter from
Darwin to Wallace, May 5, 1867, "More Letters", II. Page 61.)

Comparing these conflicting arguments we are led to believe that the
first is the stronger. Mimicry in the male would be no disadvantage but
an advantage, and when it appears would be and is taken advantage of
by selection. The secondary sexual characters of males would be no
advantage but a disadvantage to females, and, as Wallace thinks, are
withheld from this sex by selection. It is indeed possible that mimicry
has been hindered and often prevented from passing to the males by
sexual selection. We know that Darwin was much impressed ("Descent of
Man", page 325.) by Thomas Belt's daring and brilliant suggestion that
the white patches which exist, although ordinarily concealed, on the
wings of mimetic males of certain Pierinae (Dismorphia), have been
preserved by preferential mating. He supposed this result to have been
brought about by the females exhibiting a deep-seated preference for
males that displayed the chief ancestral colour, inherited from periods
before any mimetic pattern had been evolved in the species. But it has
always appeared to