ly developed and her children will not be strong as if
she had not married until after she were twenty."

"But tell me, mother, all about it. I don't see now how the baby
grows?"

"Well, I was showing you the ovary in which are many ova. As the girl
nears the age of fourteen, these ova start to grow and once a month one
ripens and is thrown out of the ovary. It is taken up by the Fallopian
tube, marked _od_ in the picture, and it passes down the tube into the
uterus and through the vagina out into the world."

"Can one tell when it passes?"

"No, but there is a sign that this change has taken place. The uterus is
lined with a membrane in which are many blood vessels, and when the girl
has reached this stage of development and becomes a woman, the vessels
become very full of blood, so full that it oozes out through the walls
of the blood vessels into the cavity of the uterus, and when it passes
out of the vagina the girl becomes aware of it and knows that she has
become a woman.

"This process takes place once a month and is called menstruation, from
the Latin _mensum_, a month."

"Isn't it painful, mother?"

"It ought not to be and is not, if the girl is perfectly well. But
sometimes girls have dressed improperly and have displaced their internal
organs, or they have exhausted themselves with pleasure-seeking, or in
some other way have injured themselves, in which case they may suffer much
pain. When girls get about this age mothers are very anxious about them,
very desirous that they shall naturally and easily step over into the
land of womanhood."

"I should think that girls ought to be taught about themselves, so that
they would not do the things which injure them."

"I think they should, and that is why I am telling you all this to-day
so that when the change comes to you, you will not be frightened and
maybe do something from which you will suffer all your life long, as
many girls have done.

"The question of tight clothing becomes now much more important than
ever before. You can see at once that the restriction of the clothing
comes just over the part of the body where there is the least
resistance."

"Oh, yes, I remember about the seven upper ribs, that are fastened to
both spine and breast-bone; and the five lower ribs, that are fastened
directly only to the spine and are attached in front to the breast-bone
by cartilage; and the two floating ribs, lowest of all, and fastened
only to the spine. I