elopment of the individual life, and less for
mere physical parenthood. We shall argue that, in the case of mankind,
and pre-eminently in the case of woman, this enrichment and development
of the individual life is best and most surely attained by parenthood or
foster-parenthood, made self-conscious and provident, and magnificently
transmuted by its extension and amplification upon the psychical plane
in the education of children and, indeed, the care and ennoblement of
human life in all its stages.

This law of Spencer's has been discussed at length by the present writer
in a previous volume,[2] and we may therefore now proceed to its notable
illustration in the case of womanhood and the female sex in general, as
made by Geddes and Thomson now more than twenty years ago. It is
surprising that the distinguished authors do not seem to have recognized
that their law is a special case of Spencer's; but one of them granted
this relation in a discussion upon the present writer's first eugenic
lecture to the Sociological Society.[3]

We must therefore now briefly but adequately consider the argument of
the remarkable book published by the Scottish biologists in 1889, and
presented in a new edition in 1900. The latter date is of interest,
because it coincides with the re-discovery of the work of Mendel,
published in 1865, to which we must afterwards more than once refer; and
the work of the Mendelians during the subsequent decade very
substantially modifies much of the authors' teaching upon the
determination of sex, and the intimate nature of the physiological
differences between the sexes. We have learnt more about the nature of
sex in the decade or so since the publication of the new edition of the
"Evolution of Sex" than in all preceding time. Such, at least, is the
well-grounded opinion of all who have acquainted themselves with the
work of the Mendelians, as we shall see: and therefore that book is by
no means commended to the reader's attention as the last word upon the
subject. The rather would one particularly direct him to the following
prophetic and admirable passage in the preface of 1900:--

"Our hope is that the growing strength of the still young school of
experimental evolutionists may before many years yield results
which will involve not merely a revision, but a recasting of our
book."

--a passage which may well content the authors to-day, when its
fulfilment is so signal.

Yet assu