Louis Berman was an Associate in Biology and Chemistry at Columbia University. Berman concludes his introduction by saying, "The stone wall before the honest mechanist is the abolition of purpose, and design, an old insoluble problem upon his premises. Preach, until you are blue in the face, behaviorist tropisms, in which man is pushed and pulled about in his environment as are iron filings in a magnetic field. Think up objective physiologies in which your life and mine become a series of concatenated influences and compound reflexes. Play with words like the concentration reflex when you mean idea, and the symbolic reflex when you mean language. But your most rigid nomenclature will never abolish the mystic personal purpose in the equation, no matter how low the step in the animal series to which you descend. The declaration that a man is dominated by certain glands within his body should not be taken to give aid and comfort to those who would banish mind from the universe." Topics covered include How the glands of internal secretion were discovered, The glands: thyroid and pituitary, The adrenal glands, gonads, and thymus, The glands as an interlocking directorate, How the glands influence the normal body, The mechanics of the masculine and feminine, The rhythms of sex, How the glands influence the mind, The backgrounds of personality, The types of personality, Some historic personages, Applications and possibilities, and The effect upon human evolution.