By nubility we mean "the quality or state of being nubile or marriageable". As we have observed, the girl reaches the marriageable age sooner than the boy. A girl of twelve years of age about equals a boy of fifteen, as far as the growth of the body determines maturity; and a girl of fifteen nearly equals a boy of nineteen. At eighteen years of age a girl has usually attained her full stature, and socially is fully the equal of a young man of twenty one years. Along with these physical changes there are corresponding changes in the minds and social inclinations of the girls which indicate their earlier maturity. Normally, a woman is capable of entering upon her reproductive functions at twenty-one years of age, being fully matured and having attained perfect physical development. If she enter upon marriage before her full development there is a tendency to abortion and difficult childbirth. The reproductive power further implies, in addition to bringing forth the child, the capacity to supply nourishment (milk). While a girl of sixteen, seventeen, or eighteen years of age could do this, yet a woman of twenty-one forms a far better wet nurse, and is even better adapted for this function at twenty two or twenty four years of age.
If a woman be too young when she enters upon the process of reproduction, the breasts are not fully developed, and she may run short of milk in six months or less; and, further, she is not psychically developed, and is consequently unfit for motherhood.
In the male sex, adolescence lasts on the average until twenty five years of age, before which time there is not the full development of the manly type. "A young man who marries before his beard is fully grown breaks a law of nature and sins against posterity" (Clouston). Besides the responsibility of procreating healthy children, marriage further entails the exercise of the manifold parental duties.
The undeveloped young man who squanders his semen commits a physiological sin which is manifested by an imperfect development of the mind and lack of consolidation in the physique; and certainly the functions of the testicles, upon which the evolution of the manly type wholly depends, should be the very last to be trifled with.
"Women may be advised to marry not earlier than twenty one between twenty one and twenty eight when in our climate they are best fitted to become wives and mothers. Men had better wait until between twenty-eight and thirty five before they undertake the responsibilities of being parents". However, if circumstances permit, it is undeniably physiological to marry soon after full maturity has been reached.
THE CLIMACTERIC.
The sexual life of both men and women continues until the climacteric, which is a momentous change, or crisis, in the lives of individuals, when the balance between tissue-waste and restitution is disordered. After this event the individual is in the afternoon of life and is again sexless from a physiological standpoint."
This physiological change comes on quite abruptly in women sometime between the forty-second and fiftieth years, with the heaviest figures in the forty fourth year. In men it is gradual and longer deferred, occurring, as a rule, somewhere between the fiftieth and sixty fifth year, though the effects of the change are by no means so clearly appreciable in them as in women.
As a rule, the male reproductive elements, or spermatozoa, disappear from the semen at about the sixty-second year, though the individual may be quite able to copulate satisfactorily for some years more. Exceptionally the virile power remains with men even to the most advanced age; but women, almost without exception, are sterile before they have reached the fiftieth year. With the completion of the functions of sperm formation by the male, and of ovulation, or egg formation, by the female, their sexual lives become forever closed.
Such is the history of life! At first a neuter; then a rapid growth and development of the body with sexuality as the distinguishing and fashioning feature; then the maturation and expansion of the physical and psychical endowments; then the reproductive period, followed by that of quiescence and old age, when
"...Years steal Fire from the mind, as vigor from the limb;
And life's enchanted cup but sparkles near the brim."