variety, it may help in crossing out or
weakening variations which are too far from the average, or both.

Schaefer[4] thinks that an exchange of nuclear substance probably gives
a sort of chemical rejuvenation and very likely stimulates division. At
any rate, the groups in which the reproductive process became thus
partitioned between two kinds of individuals, male and female, not only
survived, but they underwent an amazing development compared with those
which remained sexless.

There came a time in the evolution of the groups possessing sexual
reproduction, when increasing specialization necessitated the division
into reproductive and non-reproductive cells. When a simple cell
reproduces by dividing into two similar parts, each developing into a
new individual like the parent, this parent no longer exists as a cell,
but the material which composed it still exists in the new ones. The old
cell did not "die"--no body was left behind. Since this nuclear
substance exists in the new cells, and since these generations go on
indefinitely, the cells are in a sense "immortal" or deathless. In a
one-celled individual, there is no distinction between germinal and
bodily functions. In the more complicated organisms, however, there are
innumerable kinds of cells, a few (the germ cells) specialized for
reproduction, the others forming the body which eats, moves, sees,
feels, and in the case of man, _thinks_. But the germ-cells or germplasm
continue to be immortal or deathless in the same sense as in the
simplest organisms. The body, in a historical sense, grew up around the
germ-cells, taking over functions a little at a time, until in the
higher animals nutrition and other activities and a large part even of
the reproductive process itself is carried on by body-cells.

When we think of a man or woman, we think of an individual only one of
whose innumerable activities--reproduction--is carried on by germ-cells,
and this one only at the very beginning of the life of a new individual.
Human societies, needless to remark, are not organized by germplasms,
but by brains and hands--composed of body cells. If these brains and
hands--if human bodies--did not wear out or become destroyed, we should
not need to trouble ourselves so much about the germplasm, whose sole
function in human society is to replace them.

Since the individual human bodies and minds which seek after the things
to which we mortals attach value--moral worth, esthe