couleurs chercher a attirer l attention des femelles, lesquelles ne
paraissaient indifferentes a ce manege, elles nageaient avec une molle
lenteur vers les males et semblaient se complaire dans leur voisinage.
After the male has won his bride, he makes a little disc of froth by
blowing air and mucus out of his mouth. He then collects the fertilised
ova, dropped by the female, in his mouth; and this caused M. Carbonnier
much alarm, as he thought that they were going to be devoured. But the
male soon deposits them in the disc of froth, afterwards guarding them,
repairing the froth, and taking care of the young when hatched. I
mention these particulars because, as we shall presently see, there are
fishes, the males of which hatch their eggs in their mouths; and those
who do not believe in the principle of gradual evolution might ask how
could such a habit have originated; but the difficulty is much
diminished when we know that there are fishes which thus collect and
carry the eggs; for if delayed by any cause in depositing them, the
habit of hatching them in their mouths might have been acquired.
To return to our more immediate subject. The case stands thus: female
fishes, as far as I can learn, never willingly spawn except in the
presence of the males; and the males never fertilise the ova except in
the presence of the females. The males fight for the possession of the
females. In many species, the males whilst young resemble the females
in colour; but when adult become much more brilliant, and retain their
colours throughout life. In other species the males become brighter
than the females and otherwise more highly ornamented, only during the
season of love. The males sedulously court the females, and in one
case, as we have seen, take pains in displaying their beauty before
them. Can it be believed that they would thus act to no purpose during
their courtship? And this would be the case, unless the females exert
some choice and select those males which please or excite them most. If
the female exerts such choice, all the above facts on the ornamentation
of the males become at once intelligible by the aid of sexual
selection.
We have next to inquire whether this view of the bright colours of
certain male fishes having been acquired through sexual selection can,
through the law of the equal transmission of characters to both sexes,
be extended to those groups in which the males and females are
brilliant in the same, or nearly the same degree and manner. In such a
genus as Labrus, which includes some of the most splendid fishes in the
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