principles that limit and control the education, and, consequently,
the co-education of our youth. These principles we have learned to
be, three for the two sexes in common, and one for the peculiarities
of the female sex. The three common to both, the three to which both
are subjected, and for which wise methods of education will provide in
the case of both, are, 1st, a sufficient supply of appropriate
nutriment. This of course includes good air and good water and
sufficient warmth, as much as bread and butter; oxygen and sunlight,
as much as meat. 2d, Mental and physical work and regimen so
apportioned, that repair shall exceed waste, and a margin be left for
development. This includes out-of-door exercise and appropriate ways
of dressing, as much as the hours of study, and the number and sort of
studies. 3d, Sufficient sleep. This includes the best time for
sleeping, as well as the proper number of hours for sleep. It excludes
the "murdering of sleep," by late hours of study and the crowding of
studies, as much as by wine or tea or dissipation. All these guide and
limit the education of the two sexes very much alike. The principle
or condition peculiar to the female sex is the management of the
catamenial function, which, from the age of fourteen to nineteen,
includes the building of the reproductive apparatus. This imposes upon
women, and especially upon the young woman, a great care, a
corresponding duty, and compensating privileges. There is only a
feeble counterpart to it in the male organization; and, in his moral
constitution, there cannot be found the fine instincts and quick
perceptions that have their root in this mechanism, and correlate its
functions. This lends to her development and to all her work a
rhythmical or periodical order, which must be recognized and obeyed.
"In this recognition of the chronometry of organic process, there is
unquestionably great promise for the future; for it is plain that the
observance of time in the motions of organic molecules is as certain