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CONTENTS 



CHAPTER PAGE 



^ Introduction: Attitudes Toward Human Nature 1 



^--IT How the Glands of Internal Secretion Were 



Discovered 28 



II. The Glands: Thyroid and Pituitary .... 46 



III. The Adrenal Glands, Gonads, and Thymus . 69 



IV. The Glands as an Interlocking Directorate . 96 

 V. How the Glands Influence the Normal Body 113 



VI. The Mechanics of the Masculine and Feminine 132 



VII. The Rhythms of Sex 149 



VIII. How the Glands Influence the Mind . . . 166 



IX. The Backgrounds of Personality 186 



X. The Types of Personality 202 



XI. Some Historic Personages 231 



XII. Applications and Possibilities 255 



XIII. The Effect upon Human Evolution .... 275 



