(10/27. 'Nature' 1869 page 11.)
That many flowers have been rendered conspicuous for the sake of guiding
insects to them is highly probable or almost certain; but it may be
asked, have other flowers been rendered inconspicuous so that they may
not be frequently visited, or have they merely retained a former and
primitive condition? If a plant were much reduced in size, so probably
would be the flowers through correlated growth, and this may possibly
account for some cases; but the size and colour of the corolla are both
extremely variable characters, and it can hardly be doubted that if
large and brightly-coloured flowers were advantageous to any species,
these could be acquired through natural selection within a moderate
lapse of time, as indeed we see with most alpine plants. Papilionaceous
flowers are manifestly constructed in relation to the visits of insects,
and it seems improbable, from the usual character of the group, that the
progenitors of the genera Vicia and Trifolium produced such minute and
unattractive flowers as those of V. hirsuta and T. procumbens. We are
thus led to infer that some plants either have not had their flowers
increased in size, or have actually had them reduced and purposely
rendered inconspicuous, so that they are now but little visited by
insects. In either case they must also have acquired or retained a high
degree of self-fertility.
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