permitted by the female, (it would seem is only _possible_ for her)
when the ovum is present in the womb and ready to be fertilized. _At
all other times, all female animals, except woman, are practically
sexless_. Their sexual organs are dormant, and _nothing can arouse
them_ to activity. Not only do they fail to show any desire for
coitus, but if an attempt should be made to force it upon them, _they
would resist it_ to the utmost of their strength.

But when the ovum is present in the womb, these same female animals
are beside themselves with desire for coitus. They are then spoken of
as "in heat." And until they are satisfied, by meeting the male and
procuring from him the vitalizing fluid which will fertilize their
infertile ovum; or, failing in this, until the ovum passes away from
them, out of the womb, they know no rest. At such times they will
run all risks, incur all sorts of danger, do every possible thing to
secure pregnancy. The thousand-and-one ways which female animals use
to make known to their male mates their sexual desire and needs, when
in heat, is a most interesting and wonderful story, a record made up
of facts which would be well worth any student's knowing. But as all
such knowledge can readily be procured from books which are within the
reach of all, there is no need of noting the data here.

But now, _in woman, all these things are different!_ As a matter of
fact, the presence of the ovum in the womb of a normally made woman
_makes little, and, in many cases, no difference whatever_ as regards
her status concerning the act of coitus! That is, women are never
"in heat," in the same sense in which other female animals are. To be
sure, in some cases, though they are rare, some women are conscious
of a greater desire for coitus just after the ceasing of the menstrual
flow; that is, when the ovum is in the womb. But such cases are so
infrequent that they may well be counted atavistic, that is, of the
nature of a tendency to return to a previous merely animal condition.
For the most part, it is true of all normal women that the presence of
the ovum in the womb makes little difference, one way or another, in
regard to their desire for, or aversion to, the act of coitus.

Now the fact of this remarkable difference in the sex-status of women
and the same quality in all other female animals leads us to a great
number of interesting, not to say startling, conclusions, some of
which are as follows:

I