he quality of their offspring. How cleverly the
biometricians have involved one muddle within another will be evident
not only from considering the evident absurdity of supposing--as their
argument, analyzed, necessarily supposes--that a man's body can be
affected by the diverse fates of germ-cells that have left it, but also
when we observe that one of the commonest and most obvious causes of the
reduction in the size of families is the increasing age at marriage of
both sexes. Two persons may thus marry and become parents at the age of
say thirty, their child ranking as first-born, of course, in the
biometricians' tables; but had they married ten years sooner, a child
born when the parents were thirty might rank as the tenth child, and
would be so reckoned by the biometricians. One does not need to be a
biologist to perceive that conclusions based upon assumptions so
uncritical are worth nothing at all, and it is tempting to suggest that
the biometricians are so called, on a principle long famous, because
they measure everything but life.

It is plainly unnecessary, therefore, for us to trouble about collecting
the innumerable instances where children late in the family sequence
have turned out to be illustrious, or have proved to be idiots. It is
unnecessary because the most obvious criticism of the contention before
us disposes of the proof upon which it is sought to be based.
Nevertheless, of course, though the particular contention about the size
of the family must necessarily be meaningless, unless, as is so very
improbable, it should be shown some day that the bearing of children
affects the maternal organism in some way so as to cause subsequent
children to approximate ever nearer to the type of the race; yet it is
quite conceivable, though quite unproved, that the age of the parents
involves changes in the body which affect, for good or for evil, either
the construction or the general vigour of the germ-cells. As to this
nothing is known, but a great weight of evidence suggests that little
importance, if any, can be attached to this question. Women marrying at
forty or more may give birth to splendid specimens of humanity or to
indifferent ones, and the same may be said of the girl of seventeen,
though as to this more must be said. Similarly, also, it is impossible
to make any general contrasts between the offspring of fathers of
eighteen or fathers of eighty. Correlations may exist, but we know
nothing of the