hange which we term
_menstruation._

The ancients had a tradition that in the beginning of things the world
was made from an egg; the naturalists of past generations had this
maxim: Everything living comes from an egg; and science to-day says the
same. For this vesicle we have mentioned is in fact an _egg_, similar in
structure to those which birds, fish, and turtles deposit. The only
differences are, that the one is developed out of the body, the other
within; the one has a shell, the other has none.

Therefore physiologists give this definition: Menstruation is
ovulation,--it is the laying of an egg.

WHAT IS THE AGE OF PUBERTY?

This has been a matter of careful study by physicians. They have
collected great numbers of observations, and have reached this
conclusion: In the middle portion of the temperate zone, the average age
when the first period appears in healthy girls is fourteen years and six
months. If it occurs more than six months later or earlier than this,
then it is likely something is wrong, or, at least, the case is
exceptional.

Exceptional cases, where this average is widely departed from in
apparently perfect health, are rare. But they do occur. We have known
instances where the solicitude of parents has been excited by the long
delay of this constitutional change, and others in which it has taken
place at an almost tender age, without causing any perceptible injury to
the general health.

There is an instance recorded, on good authority, where a French child
but three years old underwent all the physical changes incident to
puberty, and grew to be a healthy woman. But what children can surpass
the American in precocity? This French child-woman is quite left in the
shade by one described in a recent number of a western medical journal,
who _from her birth_ had regular monthly changes, and the full physical
development which marks the perfect woman!

Thus, sometimes, a wide deviation from the average age we have stated
occurs, without having any serious meaning. Yet at no time is such a
deviation to be neglected. In nine out of ten instances it is owing to
some fault in the constitution, the health, or formation, which should
be ascertained and corrected. Otherwise years of broken health and
mental misery may be the sad results. Mothers, teachers, it is with you
this responsibility rests. The thousands of wretched wives, who owe
their wretchedness to a neglect of proper attention at this
tu