TABLE OF CONTENTS xix 



PAGE 



Chapter XXXVIII. Does Heredity or Environment Make Men? 



Albert- Edward Wiggam 491 



Chapter XXXIX. Eugenics and Euthenics. Paul Popenoe and 



Roswell II. Johnson 508 



Chapter XL. Human Conservation. Herbert, E. Walter . . . 521 



1. How Mankind May Be Improved 521 



2. More Facts Needed 521 



3. Further Application of What We Know Necessary .... 522 



4. The Restriction of Undesirable Germ Plasm 523 



5. The Conservation of Desirable Germ Plasm 528 



6. Who Shall Sit in Judgment? 530 



Chapter XLI. The Promise of Race Culture. Caleb Williams 



Saleeby 532 



PART V. ACCESSORY READING 



Chapter XLII. The Relation of Evolution to Materialism. 



Joseph Le Conte 547 



Chapter XLIII. The Statistical Study of Variation .... 555 



Statistical Methods 555 



Bimodal and Multimodal Curves 558 



The Coefficient of Correlation 559 



Chapter XLIY. The Physical Basis of Mendelism. Ernest B. 



Babcock and Roy E. Clausen 561 



Chapter XLV. Natural Selection. Charles Darwin 573 



Foundation Stones of Natural Selection 573 



Darwin's Own Estimate as to the Role of Natural Selection in 



Evolution 573 



Effects of Habit and of the Use or Disuse of Parts; Correlated 



Variation; Inheritance 574 



Darwin's Idea of the Causes Responsible for the Origin of Domes- 

 tic Races 575 



Darwin's Idea of the Origin of Varieties, Species, and Genera in 



Nature 575 



The Term "Struggle for Existence" Used in a Large Sense . . 576 



Geometrical Ratio of Increase 577 



Natural Selection; Or the Survival of the Fittest 577 



Sexual Selection 584 



Illustrations of the Action of Natural Selection, or the Survival 



of the Fittest 586 



Summary of Chapter on Natural Selection 5S7 



Difficulties and Objections to Natural Selection as Seen by Darwin 590 



