"Several distinguished naturalists," says Mr. Darwin, "maintain with
much confidence that organic beings tend to vary and to rise in the
scale, independently of the conditions to which they and their
progenitors have been exposed; whilst others maintain that all
variation is due to such exposure, though the manner in which the
environment acts is as yet quite unknown. At the present time there
is hardly any question in biology of more importance than this of
the nature and causes of variability; and the reader will find in
the present work an able discussion on the whole subject, which will
probably lead him to pause before he admits the existence of an
innate tendency to perfectibility"--or towards BEING ABLE TO BE
PERFECTED.

I could find no able discussion upon the whole subject in Professor
Weismann's book. There was a little something here and there, but
not much.

It may be expected that I should say something here about Mr.
Romanes' latest contribution to biology--I mean his theory of
physiological selection, of which the two first instalments have
appeared in Nature just as these pages are leaving my hands, and
many months since the foregoing, and most of the following chapters
were written. I admit to feeling a certain sense of thankfulness
that they did not appear earlier; as it is, my book is too far
advanced to be capable of further embryonic change, and this must be
my excuse for saying less about Mr. Romanes' theory than I might
perhaps otherwise do. I cordially, however, agree with the Times,
which says that "Mr. George Romanes appears to be the biological
investigator on whom the mantle of Mr. Darwin has most conspicuously
descended" (August 16, 1886). Mr. Romanes is just the person whom