rls undergo little change in pitch, but become eventually
more powerful, and richer in tone.

This break of the voice, as it is called, occurs at about the age of
fifteen years in this climate, but often a year or two earlier, and not
infrequently a year or two later. The growth of the larynx goes on, with
greater or less rapidity, varying in different individuals, for from six
months to two or three years, until it attains its final size. In boys,
the larynx doubles in size, and the vocal bands increase in the
proportion of five to ten in length. This great gain in the length of
the vocal cords is due to the lateral development of the larynx, for the
male larynx, in its entirety, increases more in depth than in height.
The result is a drop of an octave in the average boy's voice, the longer
bands producing lower tones. The change in size in the female larynx is
in the proportion of five to seven, and the increase is in height
instead of depth or width as in the male larynx. The vocal cords of
women are, therefore, shorter, thinner and narrower than are those of
men.

The reason assigned for the peculiar antics of the boy's voice, during
the break, is unequal rapidity in the growth and development of the
cartilages and of the muscles of the larynx. The muscles develop more
slowly than do the cartilages, and so abnormal physical conditions
produce abnormal results in phonation.

No further changes occur in the laryngeal structure until middle life,
when ossification of the cartilages commences. The thyroid is first
affected, then the cricoid, and the arytenoids much later.

The consequent rigidity of the larynx occasions diminished compass of
the singing-voice, the notes of the upper register being the first to
disappear. In some few cases of arrested development, the voice of the
man retains the soprano compass of the boy through life.

CHAPTER II.

REGISTERS OF THE VOICE.

It may be observed, in listening to an ascending series of tones sung by
an untrained or by a badly-trained adult voice, that at certain pitches
the tone-quality undergoes a radical change; while a well-trained singer
will sing the same series of tones without showing any appreciable break
or change in tone-quality, although the highest note will present a
marked contrast in timbre to the lowest. The breaks or changes in
register so noticeable in the untrained voice are covered or equalized
in the voice trained by correct methods. The