xiv CONTENTS 



CHAPTER XII 



FAGB 



HEREDITY AND DEVELOPMENT 416 



§ I. Theories of Development. § 2. Wetsmann's Theory of the 

 Germ-Plasm. § 3. Note on Rival Theories. § 4. Weismann's 

 Theory of Germinal Selection. 



CHAPTER Xni 



HEREDITY AND SEX 476 



§ I. The Problem of the Determinatio/i of Sex. § 2. Variety of 

 Possible Factors in Sex-Determination. § 3. Alleged Determining 

 Influence of External Factors. § 4. Influence of the Parents. 

 § 5. Internal Conditions. § 6. ^ Statistical Investigation. § 7. 

 Inconclusive Conclusion. 



CHAPTER XIV 



SOCIAL ASPECTS OF BIOLOGICAL RESULTS .... 506 



§ I. Relations of Biology and Sociology. § 2. The Chief Value 

 of the Sociological Appeal to Biology. § 3. Originative Factors 

 in Evolution. § 4. Social Aspects of Heredity. § 5. Directive 

 Factors in Evolution. 



BIBLIOGRAPHY . ........ 539 



SUBJECT-INDEX TO BIBLIOGRAPHY 587 



INDEX . = 597 



