CONTENTS xi 



CHAPTER V 

 FACTS OF INHERITANCE 



Progress during the Darwinian Era — Demougtration of Heritable 

 Qualities — Heredity, » Term for the Genetic Relation between 

 Successive Generations — Appreciation of Distinction between 

 Nature and Nurture — The Idea of the Continuity of Generations — 

 Critical Attitude in Begard to Various Conclusions — Mendelism — 

 Methods of Studying Heredity — Microscopical Study of the Germ- 

 cells — Statistical Study : Filial Regression — Galton's Law of 

 Ancestral Inheritance — Experimental Study — Pairing of Similar 

 Pure-bred Forms — Blending — Particulate Inheritance — Exclusive 

 Inheritance — ^Reversion — New Departures — Mendelian Inheritance 

 — Unit Characters — The Case of Andalusian Fowls — Waltzing Mice 

 — Occurrence of Mendelian Inheritance — Practical Importance of 

 Mendelism — Miich Progress but Great Uncertainty — Transmission 

 of Acquired Characters — Disease — Facts and Possibilities — A 

 Striking Case — Logical Position of the Question — Cases where 

 the Theory of Modification-inheritance is Inapplicable — Im- 

 portance of Environment and Function Remains — Selection and 

 Stimulus — Indirect Importance of Modifications — Practical Im- 

 port of the Question as to the Transmission of Acquired 

 Characters — Inheritance of Moral Character — Three General 

 Conclusions . . pp. 129-177 



CHAPTER VI 

 SELECTION : ORGANIC AND SOCIAL 



Influence of Malthus — Darwin's Position — The Theory stated — 

 The Theory of Natural Selection to be tested as an Interpretative 

 Formula — Illustrations of Natural Selection — Objections and 

 Criticisms — Adaptations — Changes since Darwin's Day — Evidences 

 of Natural Selection — Lessening the Burden of the Theory — Sexual 

 Selection — Isolation — Gradual Diminution of Natural Selection in 



