may be expected ultimately to die out; but "the mills of the gods grind so
exceeding slow" that we cannot say that any particular grist has been
actually ground out under human observation.

If it be asked how the asserted principle is proved or made probable, we
can here merely say that the proof is wholly inferential. But the inference
is drawn from such a vast array of facts that it is wellnigh irresistible.
It is the legitimate explanation of those arrangements in Nature to secure
cross-fertilization in the species, either constantly or occasionally,
which are so general, so varied and diverse, and, we may add, so exquisite
and wonderful, that, once propounded, we see that it must be true.* What
else, indeed, is the meaning and


* Here an article would be in place, explaining the arrangements in Nature
for cross-fertilization, or wide-breeding, in plants, through the agency,
sometimes of the winds, but more commonly of insects; the more so, since
the development of the principle, the appreciation of its importance, and
its confirmation by abundant facts, are mainly due to Mr. Darwin. But our
reviews and notices of his early work "On the Contrivances in Nature for
the Fertilization of Orchids by Means of Insects, in 1862, and his various
subsequent papers upon other parts of this subject, are either too technical
or too fragmentary or special to be here reproduced. Indeed, a popular
essay is now hardly needed, since the topic has been fully presented, of
late years, in the current popular and scientific journals, and in common
educational works and text-books, so that it is in the way of becoming a
part--and a most inviting part--of ordinary botanical instruction. use of
sexual reproduction? Not simply increase of numbers; for that is otherwise
effectually provided for by budding propagation in plants and many of the
lower animals. There are plants, indeed, of the lower sort (such as