h. |
+--------------------------------------------------------------+

We see, then, that no inferences as to the permanence of varieties in a
state of nature can be deduced from the observations of those occurring
among domestic animals. The two are so much opposed to each other in
every circumstance of their existence, that what applies to the one is
almost sure not to apply to the other. Domestic animals are abnormal,
irregular, artificial; they are subject to variations which never occur
and never can occur in a state of nature: their very existence depends
altogether on human care; so far are many of them removed from that just
proportion of faculties, that true balance of organisation, by means of
which alone an animal left to its own resources can preserve its
existence and continue its race.

_Lamarck's Hypothesis very different from that now advanced._

The hypothesis of Lamarck--that progressive changes in species have been
produced by the attempts of animals to increase the development of their
own organs, and thus modify their structure and habits--has been
repeatedly and easily refuted by all writers on the subject of varieties
and species, and it seems to have been considered that when this was
done the whole question has been finally settled; but the view here
developed renders such hypothesis quite unnecessary, by showing that
similar results must be produced by the action of principles constantly
at work in nature. The powerful retractile talons of the falcon-and the
cat-tribes have not been produced or increased by the volition of those
animals; but among the different varieties which occurred in the earlier
and less highly organized forms of these groups, _those always survived
longest which had the greatest facilities for seizing their prey_.
Neither did the giraffe acquire its long neck by desiring to reach the
foliage of the more lofty shrubs, and constantly stretching its neck for
the purpose, but because any varieties which occurred among its
antitypes with a longer neck than usual _at once secured a fresh range
of pasture over the same ground as their shorter-necked companions, and
on the first scarcity of food were thereby enabled to outlive them_.
Even the peculiar colours of many animals, more especially of insects,
so closely resembling the soil or leaves or bark on which they
habitually reside, are explained on the same principle; for though in
the course of ages vari