roductive organs are
developed, the boy or girl ceasing to be the neutral child and
acquiring the distinctive characteristics of man or woman. The actual
season of puberty varies in different individuals from the eleventh to
the sixteenth year, and although the changes during this time are not
sudden, they are comparatively rapid.

By Adolescence we understand the time during which the individual is
approximating to the adult type, puberty having been already
accomplished. Adolescence corresponds to the latter half of the
developmental period, and may be prolonged even up to twenty-five
years.

CHAPTER I.

CHANGES OBSERVABLE DURING PUBERTY AND ADOLESCENCE IN GIRLS.

1. Changes in the Bodily Framework.--During this period the girl's
skeleton not only grows remarkably in size, but is also the subject of
well-marked alterations and development. Among the most evident
changes are those which occur in the shape and inclination of the
pelvis. During the years of childhood the female pelvis has a general
resemblance to that of the male, but with the advent of puberty the
vertical portion of the hip bones becomes expanded and altered in
shape, it becomes more curved, and its inner surface looks less
directly forward and more towards its fellow bone of the other side.
The brim of the pelvis, which in the child is more or less
heart-shaped, becomes a wide oval, and consequently the pelvic girdle
gains considerably in width. The heads of the thigh bones not only
actually, in consequence of growth, but also relatively, in
consequence of change of shape in the pelvis, become more widely
separated from each other than they are in childhood, and hence the
gait and the manner of running alters greatly in the adult woman. At
the same time the angle made by the junction of the spinal column with
the back of the pelvis, known as the sacro-vertebral angle, becomes
better marked, and this also contributes to the development of the
characteristic female type. No doubt the female type of pelvis can be
recognised in childhood, and even before birth, but the differences of
male and female pelves before puberty are so slight that it requires
the eye of an expert to distinguish them. The very remarkable
differences that are found between the adult male and the adult female
pelvis begin to appear with puberty and develop rapidly, so that no
one could mistake the pelvis of a properly developed girl of sixteen
or eighteen years of age