merated as having been published before January 1, 1904.
These describe not only the different mechanisms of flowers, but deal
also with a series of remarkable adaptations in the pollinating insects.
As a fertilising rain quickly calls into existence the most varied
assortment of plants on a barren steppe, so activity now reigns in a
field which men formerly left deserted. This development of the biology
of flowers is of importance not only on theoretical grounds but also
from a practical point of view. The rational breeding of plants is
possible only if the flower-biology of the plants in question (i.e. the
question of the possibility of self-pollination, self-sterility, etc.)
is accurately known. And it is also essential for plant-breeders that
they should have "the power of fixing each fleeting variety of colour,
if they will fertilise the flowers of the desired kind with their own
pollen for half-a-dozen generations, and grow the seedlings under the
same conditions." ("Cross and Self fertilisation" (1st edition), page
460.)

But the influence of Darwin on floral biology was not confined to the
development of this branch of Botany. Darwin's activity in this domain
has brought about (as Asa Gray correctly pointed out) the revival of
teleology in Botany and Zoology. Attempts were now made to determine,
not only in the case of flowers but also in vegetative organs, in what
relation the form and function of organs stand to one another and
to what extent their morphological characters exhibit adaptation to
environment. A branch of Botany, which has since been called Ecology
(not a very happy term) has been stimulated to vigorous growth by floral
biology.

While the influence of the work on the biology of flowers was
extraordinarily great, it could not fail to elicit opinions at variance
with Darwin's conclusions. The opposition was based partly on reasons
valueless as counterarguments, partly on problems which have still to
be solved; to some extent also on that tendency against teleological
conceptions which has recently become current. This opposing trend
of thought is due to the fact that many biologists are content with
teleological explanations, unsupported by proof; it is also closely
connected with the fact that many authors estimate the importance of
natural selection less highly than Darwin did. We may describe
the objections which are based on the widespread occurrence of
self-fertilisation and geitonogamy as