guished from a man, this
discovery is of the most vital importance. The experimental facts are
not yet numerous, and if they were not consonant with facts of other
orders, it would be rash to proceed; but it will be evident, in the
sequel, that common experience is well in accord with the experimental
evidence.

It appears that, amongst at any rate the higher animals, the sex of
offspring is determined by the nature of the mother's contribution. The
cell derived from the father is always male--as goes without saying, we
might add, if we knew little of the subject. But the ovum, the cell
derived from the mother, may carry either femaleness or maleness. When
an ovum bearing maleness meets the invariably maleness-bearing sperm,
the resultant individual is a male, of course, and he is male all
through. But when an ovum bearing femaleness meets a sperm, the
resulting individual is female, femaleness being a Mendelian "dominant"
to maleness; if both be present, femaleness appears. The female,
however, is not female all through as the male is male all through. So
far as sex is concerned, he is made of maleness _plus_ maleness; but she
is made of femaleness _plus_ maleness. In Mendelian language the male is
homozygous, so-called "pure" as regards this character. But the female
is heterozygous, "impure" in the sense that her femaleness depends upon
the dominance of the factor for femaleness over the factor for maleness,
which also is present in her. In the Mendelian terminology, she is an
instance of impure dominance. The observed practical equality in the
numbers of the two sexes is in exact accord with this interpretation of
the facts, this proportion being the expected and observed one in many
other cases which doubtless depend upon parallel conditions of the
reproductive cells.

Surely there is great enlightenment here: for the discovery of the
factors determining sex is a very small affair compared with the
suggestive inference as to the constitution of womanhood. Let us compare
man and woman on the basis of this assumption.

In the man there is nothing but maleness. This is not to deny that he
may possess the protective instinct and the tender emotion which is its
correlate, even though these were undoubtedly feminine in origin. But it
is to deny that any injury to, or arrested development of, the male can
reveal in him characters distinctively female. He may fail to become a
man and may remain a boy; or, having been a