wij) THE FERTILISATION OF FLOWERS. 37 
efficiency of their mechanism. First, it is necessary 
that carrying agents should be employed to convey 
the pollen; and we find that of these there are two 
classes—the wzzd and various zzsects. These are 
Flora’s carriers, whom she intrusts with a most deli- 
cate mission, and that they perform it well we may 
see by the lavish manner in which the fields, the 
lanes, and woods are adorned with living gems. 
Flowers which are fertilised by the wind are never 
conspicuously coloured; and here we find the reason 
why flowers are brightly coloured. If we observe an 
organ in any plant or animal which is of no apparent 
use to it, we may be sure that it has had a use in the 
past, among the ancestors of the species, for Nature 
does not provide organs or adornments unnecessarily. 
However beautiful in appearance may be a flower, 
we shall find on closer acquaintance that its beauty 
is not merely to gratify our sense of the beautiful, 
but to serve a useful purpose in the economy of 
Nature, and with special reference to the species 
possessing it. Thus there is not a single wind- 
fertilised * flower that is highly coloured, because its 
colouring would be unnecessary; on the contrary, 
nearly all insect-fertilised ~ flowers are brightly and 
conspicuously coloured. Taken in conjunction with 
other facts which we shall adduce, the reason for this 
is sufficiently obvious—the bright hues are to attract 
insects to the flower. Again, wind-fertilised flowers 
produce vast quantities of pollen; insect-fertilised 
flowers produce very little. In the first case, the 
pollen being carried, as in the fir, from tree to tree, 
* Anemophilous. + Entomophilous. 
