56
SEX IN EDUCATION.
obey the law of periodicity; just as the male organization, to do its best, must obey the law of sustained effort.
When old age begins, whether, normally, at seventy or eighty, or, prematurely, at lifty or thirty, repair does not equal waste, and degeneration of tissue results. More cells are destroyed by wear and tear than are made up from nutriment. The friction of the machine rubs the stuff of life away faster than it can be replaced. The muscles stiffen, the hair turns white, the joints crack, the arteries ossify, the nerve-centres harden or soften: all sorts of degeneration creep on till death appears, — Mors janua vitas. There the curves unite, and men and women are alike again.
Sleep, whose inventor received the benediction of Sancho Panza, and whose power Dryden apostrophized, —
“ Of all the powers the hest:
Oh ! peace of mind, repairer of decay,
Whose balm renews the limbs to labor of the day,” —
is a most important physiological factor.