406 Darwin, and after Darwin. 
beauty of flowers, sea-anemones, corals, and so forth, 
cannot possibly be ascribed to sexual selection. 
Now, with regard to this difficulty, we must begin 
by excluding the case of the vegetable kingdom as 
irrelevant. For it has been rendered highly probable— 
if not actually proved—by Darwin and others, that the 
beauty of flowers and of fruits is in large part due to 
natural selection. It is to the advantage of flowering 
plants that their organs of fructification should be 
rendered conspicuous—and in many cases also 
odoriferous,—in order to attract the insects on which 
the process of fertilization depends. Similarly, it is 
to the advantage of all plants which have brightly 
coloured fruits that these should be conspicuous for 
the purpose of attracting birds, which eat the fruits and 
so disseminate the seed. Hence all the gay colours 
and varied forms, both of flowers and fruits, have been 
thus adequately explained as due to natural causes, 
working for the welfare, as distinguished from the 
beauty, of the plants. For even the distribution of 
colours on flowers, or the beautiful patterns which so 
many of them present, are found to be useful in guiding 
insects to the organs of fructification. 
Again, the green colouring of leaves, which lends 
so much beauty to the vegetable world, has likewise 
been shown to be of vital importance to the physiology 
of plant-life; and, therefore, may also be ascribed to 
natural selection. Thus, there remains only the forms 
of plants other than the flowers. But the forms of 
leaves have also in many cases been shown to be 
governed by principles of utility; and the same is to 
be said of the branching structure which is so 
characteristic of trees and shrubs, since this is the 
