, that of the boy's
blood rises, and between seventeen and forty-five is definitely higher
than in women of the corresponding age. It thus seems quite clear that,
as we should expect, these differences in the blood, which are
certainly, as Dr. Havelock Ellis says, fundamental, make their
appearance definitely at puberty--a fact which supports the view that
fundamental differences of practical importance between the two sexes
before that age are not to be found. Careful comparative study of the
pulse of children is hitherto somewhat inconclusive, though it is well
known that the pulse is more rapid in women than in men.

On the other hand, it seems clear as regards respiration that as early
as the age of twelve there are definite differences between the sexes.
Several thousands of American school children were examined, and between
the ages of six and nineteen the boys were throughout superior in lung
capacity. The girls had almost reached their maximum capacity at the age
of twelve, and thereafter the difference, till then slight, rapidly
increased.[6] It appears that from eight to fifteen years of age a boy
burns more carbon than a girl, the difference, however, being not great.
But at puberty the boy proceeds to consume very nearly twice as much
carbon per hour as his sister.

Perhaps the matter need not be pursued further. It is sufficient for us
to recognize that puberty is really the critical time, and that in the
consideration of womanhood we may, on the whole, be justified in looking
upon the problem of the girl before that age as almost identical with
her brother's. Yet we must be reasonably cautious, since our knowledge
is small, and there is some by no means negligible evidence of
fundamental physiological differences between the sexes before puberty,
relatively slight though these may be. Therefore, though on the whole
we need make few distinctions between the girl and her brother, and
though we are doubtless wrong in the magnitude of the practical
distinctions which we have often made hitherto, yet we must remember
that these are going to be different beings, and that the main
principles which determine our nurture of womanhood may be recalled when
we are doubtful as to practice in the care of the girl child.

Physiological distinctions, we have seen, probably exist during these
early years, but are of less importance than we sometimes have attached
to them, and of no importance at all compared with what i