ellbeing, energy, and mental alertness of the woman.

You see the importance of the internal ovarian secretion, and you will
readily understand why, when the ovaries are removed by operation, the
woman, particularly if she is young, undergoes such marked changes. It
is because we recognize now the great importance of the ovaries that
we always, when operating on diseased ovaries leave at least a small
piece of ovary, if at all possible.

=Number of Ova.= When the female infant is born, her ovaries contain
as many ova or eggs as they ever will contain. In fact, they contain
more than they will at puberty. For it is estimated that at birth each
ovary contains about 100,000 ova; the majority of these, however,
disappear so that at the age of puberty each ovary contains only about
30,000 ova. As only one ovum ripens each month from the time of
puberty to the time of the menopause (i.e., about 300 to 400 ova at
the utmost during a lifetime), and as only a dozen or two ova would
be necessary for the propagation of the race, it seems a
superabundance of ova, an unnecessary lavishness. But nature _is_
lavish where the propagation of the species is concerned. A portion of
an ovary or of both ovaries might become diseased, and thousands of
ova might become unfit for fertilization; nature therefore puts in an
extra reserve supply. We see a still more striking example of this
extreme extravagant lavishness in man; only one spermatozooen is
necessary to impregnate the ovum, and only one spermatozooen can
penetrate the ovum; nevertheless each normal ejaculation of semen
contains between a quarter and half a million spermatozoa.

=The Graafian Follicles.= Each primitive or primordial ovum[3] is
imbedded in a little vesicle or follicle, which is generally known as
_Graafian follicle_, and there are as many Graafian follicles as there
are ova. (The Graafian follicles were first described about 250 years
ago--in 1672--by a Delft physician named De Graaf, hence the name.)
Until puberty, that is the commencement of menstruation, the Graafian
follicles with the ooecytes or primitive ova are in a more or less
dormant condition. But with the onset of puberty there commences a
period of intense activity in the ovaries. This period of activity is
repeated regularly once a month, and it constitutes the process of
_ovulation_ and _menstruation_. The two processes are closely though
not causally connected. Ovulation consists in the monthly matur