Some of these seedlings would probably
inherit the nectar-excreting power. Those individual flowers which had
the largest glands or nectaries, and which excreted most nectar, would
be oftenest visited by insects, and would be oftenest crossed; and so
in the long-run would gain the upper hand. Those flowers, also, which
had their stamens and pistils placed, in relation to the size and
habits of the particular insects which visited them, so as to favour
in any degree the transportal of their pollen from flower to flower,
would likewise be favoured or selected. We might have taken the case
of insects visiting flowers for the sake of collecting pollen instead
of nectar; and as pollen is formed for the sole object of
fertilisation, its destruction appears a simple loss to the plant; yet
if a little pollen were carried, at first occasionally and then
habitually, by the pollen-devouring insects from flower to flower, and
a cross thus effected, although nine-tenths of the pollen were
destroyed, it might still be a great gain to the plant; and those
individuals which produced more and more pollen, and had larger and
larger anthers, would be selected.
When our plant, by this process of the continued preservation or
natural selection of more and more attractive flowers, had been
rendered highly attractive to insects, they would, unintentionally on
their part, regularly carry pollen from flower to flower; and that
they can most effectually do this, I could easily show by many
striking instances.
Pages:
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125