becomes capable of being a father. In temperate climates
this age is reached at about fifteen years, though some boys attain it
at twelve and some not until seventeen. The one obvious and invariable
sign of puberty is a change of pitch in the voice, which assumes its
bass character after an embarrassing period of squeaky alternations
between the high and low tones.

The age is a critical one, as several important changes take place in
body and in mind. The reproductive organs undergo considerable
development and become sensitive to any stimulus, physical or mental.
The seminal fluid, which in normal cases has hitherto been secreted
little, if at all, is now elaborated by the testicles, and contains
spermatazoa--minute organisms which are essential to reproduction.
Under the stimulus of sexual thoughts this fluid is secreted in such
quantity as to give rise to involuntary discharge during sleep. These
nocturnal emissions are so often found among boys and young men that
some physiologists consider them to be quite normal. My experience
leads me to doubt this conclusion.

Another physical change associated with puberty is the growth of hair
on the pubes and on the face: in this latter situation the growth is
slow.

With the capacity for fatherhood comes a very strong awakening of the
sexual instinct, which manifests itself in passion and in lust--the
unconscious and the conscious sex hunger. The passion shows itself in
a ludicrously indiscriminate and exaggerated susceptibility to female
attractions--a susceptibility the sexual character of which is usually
quite unrecognised. Among boys who have sex knowledge there is also a
tendency to dwell on sexual thoughts when the mind is not otherwise
occupied. Passion and lust do not at once develop their full strength;
but, coming at a time when self-control is very weak, and coming with
all the attraction of novelty, they often dominate the mind even in
normal cases, and may become tyrannous when the reproductive system
has been prematurely stimulated.

A heightened self-consciousness and an antagonism to authority so
often follow the attainment of puberty that they are usually
considered to be its results. My own experience with boys satisfies me
that this conclusion is not correct. Self-consciousness, when it
occurs in boyhood, is usually the result of an unclean inner life.
Puberty merely increases the self-consciousness by intensifying its
cause. When the mind is clean