professors who are ugly and asthmathic; there are even doctors who can
boast no beauty and but moderate health; there are some of the petted
children of the wealthy, upon whom every care is lavished from birth,
and who still are ill to look at and worse to marry.

All these special causes are admitted, given their due share in lowering
our standards, but there is another far more universal in its
application and its effects. Let us look back on our little ancestors
the beasts, and see what keeps them so true to type.

The type itself set by that balance of conditions and forces we call
"natural selection." As the environment changes they must be adapted to
it, if they cannot so adapt themselves they die. Those who live are, by
living, proven capable of maintaining themselves. Every creature which
has remained on earth, while so many less effective kinds died out,
remains as a conqueror. The speed of the deer--the constant use of
speed--is what keeps it alive and makes it healthy and beautiful. The
varied activities of the life of a leopard are what have developed the
sinuous gracile strength we so admire. It is what the creature does for
its living, its daily life-long exercise which makes it what it is.

But there is another great natural force which works steadily to keep
all animals up to the race standard; that is sexual selection.
Throughout nature the male is the variant, as we have already noted.
His energy finds vent not only in that profuse output of decorative
appendages Ward defines as "masculine efflorescence" but in variations
not decorative, not useful or desirable at all.

The female, on the other hand, varies much less, remaining nearer the
race type; and her function is to select among these varying males the