General experience teaches that acquired characters are not usually
inherited; and investigation shows that the apparent exceptions to this
great rule are probably fallacious. Even the alleged instances of
use-inheritance culled by such great and judicious selectors as Darwin
and Spencer break down upon examination; for they can be better
explained without use-inheritance than with it. On the other hand, the
adverse facts and considerations are almost strong enough to prove the
actual non-existence of such a law or tendency. There is no need to
undertake the apparently impossible task of demonstrating an absolute
negative. It will be enough to ask that the Lamarckian factor of
use-inheritance shall be removed from the category of accredited factors
of evolution to that of unnecessary and improbable hypotheses. The main
explanation or source of the fallacy may be found in the fact that
natural selection frequently imitates some of the more obvious effects
of use and disuse.