by division,--on through the beginning of reproduction
proper, where a single parent produces the offspring; then on to the
level where it takes two parents of different structure to produce a
new organism, and sex-life begins. At first Nature does not even
demand that father and mother shall come near each other. In the
water, the female of this type lays an egg, and the male, guided by
his instinct, swims to it and deposits his fertilizing fluid. In plant
life, bird and bee, attracted by wonderfully planned perfumes and
color and honey, are called in to carry the pollen from male to female
cell.

But it is when we come to the highest level that we find even more
subtle ways planned to accomplish the desired end. Here we enter the
realm of individual initiative, for it is not now enough to leave to
external forces the joining of the two life-elements. In order to make
a new individual, father and mother must be drawn together, and so
there enters into the situation a personal relationship with all that
that implies. Because Nature has had to provide ways of drawing
individuals to one another, she has put into the higher types of life
the power of mutual attraction,--a power which in man, the highest of
all types, is responsible for many outgrowths that seem far removed
from the original purpose.

=The Love-Motif.= On the one hand, there is the persistent desire to
be attractive, which manifests itself in the subtlest ways. How many
of the yearnings and activities of human life have their roots in this
ancient and honorable desire! The love of pretty clothes,--however it
may seem to be motivated and however it may be complicated by other
motives,-draws its energy, fundamentally, from the same need that
provides the gay plumage and limpid song of the bird or the painted
wings of the butterfly.

On the other hand, there is the capability of being attracted, with
all the personal relationships which spring from the power of admiring
and loving another person. The interest in others does not expend its
whole force on its primary objects,--mate and children. It flows out
into all human relationships, developing all the possibilities of
loving which mean so much in human life; the love of man for man and
woman for woman, as well as mutual love of man and woman. A force like
this, once planted, especially in the higher types of life, does not
spend all its energies in its main trunk. It sends out branches in
many direction