changes which are necessary to open the way for
this new dispensation. They may fairly ask, however, that hereafter the
displacement of the ancient life shall be brought about with foresight
and with the exercise of the utmost care in minimizing the sacrifices
which we are called on to make. Naturalists may fairly ask men to
remember that each of these species which we are forced to destroy
represents the toil and pains of unimaginable ages, and that when these
creatures are swept away they can never be recovered. Whatever new
species may come, by processes of evolution from the life which remains
after we have done our will with the wilderness, we shall never see
again the forms which have passed away.

It is the worst feature of the destruction which man is bringing upon
the organic species that the assault is most effective on those
varieties which are most interesting both from an intellectual and an
economic point of view. To take only the case of the great birds which
have recently been swept from the earth, we see clearly that we have
with them lost precious opportunities for enlarging our understanding of
nature and have at the same time been deprived of the chance to
domesticate creatures which would most likely have proved of much
economic value. With each of these species which disappears we lose what
may be a precious chance of adding to the small store of animals or
plants which may contribute to the well being of our kind. These
considerations make it plain that it is our duty by our civilization, to
do all in our power to save these species and at the same time to essay
their domestication, for only when under the protection of man can they
be regarded as insured from destruction.

The task of bringing wild creatures into our domestic fold is one of
very varied difficulty. Many plants are easily reconciled to the
conditions of our fields and gardens: they may be said to welcome the
care of man which insures them some protection from the fierce
contention with other life or with the elements to which they are
exposed in their natural conditions. Only here and there is it necessary
by careful breeding to develop domesticated habits to the point where
the forms will endure culture. Where the task is, however, to make avail
of some natural peculiarity which promises to be useful, but is not yet
of economic value, it may require a hundred generations of careful
selection to develop and fix desirable features.