The reproductive glands, it should not be forgotten, belong to this group, and besides their ordinary products, the germ and sperm cells (ova and spermatozoa) form hormones which circulate in the blood and effect changes in the cells of distant parts of the body.  Through these hormones the secondary sexual characters are produced, including the many differences in the form and structure of the body which are the characteristics of the sexes.  Only in recent years has science discovered that these secondary sexual characters are brought about by the agency of these internal secretions or hormones, passed from the reproductive glands into the circulating blood.  These so-called secondary characters which are the sign of full and healthy development, are dependent, science tells us, upon the state of development of the reproductive organs.

For a clear and illuminating account of the creative and dynamic power of the endocrine glands, the layman is referred to a recently published book by Dr. Louis Berman.(2) This authority reveals anew how body and soul are bound up together in a complex unity.  Our spiritual and psychic difficulties cannot be solved until we have mastered the knowledge of the wellsprings of our being.  “The chemistry of the soul!  Magnificent phrase!” exclaims Dr. Berman.  “It’s a long, long way to that goal.  The exact formula is as yet far beyond our reach.  But we have started upon the long journey, and we shall get there.

“The internal secretions constitute and determine much of the inherited powers of the individual and their development.  They control physical and mental growth, and all the metabolic processes of fundamental importance.  They dominate all the vital functions of man during the three cycles of life.  They cooperate in an intimate relationship which may be compared to an interlocking directorate.  A derangement of their functions, causing an insufficiency of them, an excess, or an abnormality, upsets the entire equilibrium of the body, with transforming effects upon the mind and the organs.  In short, they control human nature, and whoever controls them, controls human nature....

“Blood chemistry of our time is a marvel, undreamed of a generation ago.  Also, these achievements are a perfect example of the accomplished fact contradicting a prior prediction and criticism.  For it was one of the accepted dogmas of the nineteenth century that the phenomena of living could never be subjected to accurate quantitative analysis.”  But the ethical dogmas of the past, no less than the scientific, may block the way to true civilization.