XVI TABLE OF CONTENTS 



PAGE 



Later Investigations of Mutations 489 



The Neo-Mutationist Position. R. R. Gates 490 



Mutation. H. J. MuUcr 495 



The Causes of Mutations 502 



Mutation and Evokition. T. H. Morgan 5^4 



Chapter XXXVIII. Ceoss-Breeding and Inbreeding .... 507 



Cross-B reeding 5°7 



Inbreeding 5^° 



PART V. EUGENICS 



Chapter XXXIX. The Inheritance of Human Characters, Phys- 

 ical and Mental. E. R. Downing . . . 5^7 



Chapter XL. Twins and the Relative Potency of Heredity and 



Environment in Development . .■ 53 1 



Chapter XLI. Does Heredity or Environment Make Men? A.E. 



Wiggam 540 



Chapter XLII. Eugenics ajjd Euthenics. P. Popenoe and R. H. 



. ^ Johnson 557 



/ Chapter XLIII. Human Conservation. H. E. Walter , . , . 570 



Chapter XLIV. The Promise of Race Culture. C. W. Saleeby . 581 



Bibliography .' 594 



Glossary 597 



Index 607 



