there work of this kind has been successfully carried out in
selected instances. What a suitable drive upon the whole matter would
yield in happiness to the individual and dollars and cents to society,
time alone will show.

CHAPTER XIII

THE EFFECT UPON HUMAN EVOLUTION

The ubiquitous and deep-seated influence of the internal secretions
upon life and personality comprises but a fraction of what is known,
and only a hint of what is to become known. There is an endocrine
aspect to every human being and every human activity, normal and
abnormal, internal process and its external expression, regulated
by laws of which we are beginning to catch a glimpse. Their control
promises us now a dominion over the most intimate and inaccessible
recesses of our lives in a way comparable only to the control we now
exercise over the forces and energies once revered as the instruments
of the gods--light, heat, magnetism, electricity. We have learned how
to control and change our environment. We are now learning, endocrine
research is now discovering, how to control and change ourselves.

The story of the evolution of the two types of control has many
analogies. When man ceased looking upon his surroundings as inhabited
by spirits of good and evil, as he conceived himself, and discovered
that they were composed of things malleable and analysable in his
hands, he became their master. When now he drops the old superstitions
about himself as a spirit, an emulsion of a spirit of good and spirit
of evil, and sees himself more and more clearly as the most complex
of chemical reactions, regulated and determined as are the simple
and complex chemical reactions around him, he will begin to rule and
modify himself as he rules and modifies them. Whether or not he will
ultimately come to this final lucidity of thought and action, it
behooves us to consider some of the uses to which our present
knowledge might be put.

Since every step of the daily routine or adventure, from waking to
sleeping, eating, drinking, marrying and giving in marriage, working,
idling, fighting, playing, feeling, enjoying, sorrowing, every shade
of emotion and nuance of mood, in short every phase of happiness
and unhappiness, are endocrine episodes in the life history of the
individual, the sphere of applications is as long and broad and deep
as life itself. Not only do the internal secretions open up before us
the great hope--that Life at last will cease to stu