In man, then, maturity is indicated by a change of the tone of
voice, by an increase in size and an alteration in appearance of the
sexual organs, as also in an increase of size and alteration in
appearance of the breasts; and above all, in the hair-growth at the
pubes. Man begins to possess seminal fluid about the age of
fourteen, and becomes generatively capable at about the age of
twenty-one years.