esent; for differences, however slight, between any two forms, if
not blended by intermediate gradations, are looked at by most
naturalists as sufficient to raise both forms to the rank of species.

Hereafter we shall be compelled to acknowledge that the only distinction
between species and well-marked varieties is, that the latter are known,
or believed to be connected at the present day by intermediate
gradations, whereas species were formerly thus connected. Hence, without
rejecting the considerations of the present existence of intermediate
gradations between any two forms, we shall be led to weigh more
carefully and to value higher the actual amount of difference between
them. It is quite possible that forms now generally acknowledged to be
merely varieties may hereafter be thought worthy of specific names; and
in this case scientific and common language will come into accordance.
In short, we shall have to treat species in the same manner as those
naturalists treat genera, who admit that genera are merely artificial
combinations made for convenience. This may not be a cheering prospect;
but we shall at least be freed from the vain search for the undiscovered
and undiscoverable essence of the term species.

The other and more general departments of natural history will rise
greatly in interest. The terms used by naturalists, of affinity,
relationship, community of type, paternity, morphology [the science of
organic form], adaptive characters, rudimentary and aborted organs,
etc., will cease to be metaphorical and will have a plain signification.
When we no longer look at an organic being as a savage looks at a ship,
as something wholly beyond his comprehension; when we regard every
production of nature as one which has had a long history; when we
contemplate every complex structure and instinct as the summing up of
many contrivances, each useful to the possessor, in the same way as any
great mechanical invention is the summing up of the labour, the
experience, the reason, and even the blunders of numerous workmen; when
we thus view each organic being, how far more interesting--I speak from
experience--does the study of natural history become!

A grand and almost untrodden field of inquiry will be opened, on the
causes and laws of variation, on correlation, on the effects of use and
disuse, on the direct action of external conditions, and so forth. The
study of domestic productions will rise immensely in value. A n