CONTENTS 



Page 



Preface iii 



Introduction vi 



Chapter 



I Process of PoTtfer Changes 13 



II. Some Eminent Men 29 



III The Age of Parents 45 



IV. From Savagery to Civilization.. 56 



V^-Evolution of Intelligence and 



Longevity 70 



VI. Disease and Immunity 82 



105 



