The male and female sexual
elements seem to be affected before that union takes place which is to
form a new being. In the case of "sporting" plants, the bud, which in
its earliest condition does not apparently differ essentially from an
ovule, is alone affected. But why, because the reproductive system is
disturbed, this or that part should vary more or less, we are
profoundly ignorant. Nevertheless, we can here and there dimly catch a
faint ray of light, and we may feel sure that there must be some cause
for each deviation of structure, however slight.
How much direct effect difference of climate, food, etc., produces on
any being is extremely doubtful. My impression is, that the effect is
extremely small in the case of animals, but perhaps rather more in
that of plants. We may, at least, safely conclude that such influences
cannot have produced the many striking and complex co-adaptations of
structure between one organic being and another, which we see
everywhere throughout nature. Some little influence may be attributed
to climate, food, etc.: thus, E. Forbes speaks confidently that shells
at their southern limit, and when living in shallow water, are more
brightly coloured than those of the same species further north or from
greater depths. Gould believes that birds of the same species are more
brightly coloured under a clear atmosphere, than when living on
islands or near the coast. So with insects, Wollaston is convinced
that residence near the sea affects their colours.
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