X CONTENTS 



CHAP. 



duction of Colour.— Colour in Animals ; some coloure 

 'epistatic' over others.— Flower-colours ; Reversion on 

 crossing. — The nature of albinism. — More complex cases 

 of interrelation ; Stocks, Primulas . . . 71 



VII. Some Disputed Questions. Mendelian segregation.— 



Inheritance of acquired characters. — Indirect and ex- 

 perimental evidence. — Telegony. — Maternal Impres- 

 sion 85 



VIII. Heredity in Man. Physical and Mental Characters.— 



Diseases.— Mendelian Characters; Eye-colour, Brachy- 

 dactyly, abnormalities of the Bye. — Non-Mendelian 

 characters; Skin and Hair-colour. — Importance of 

 Heredity in relation to Sociology . . . 101 



IX. Heredity and Sex. Secondary sexual characters.— 

 Dominance altered by Sex. — Sex-limited inheritance; 

 the Currant Moth, Fowls, the &j DrosophUa.— Sex-limited 

 affections in Man ; Colour-blindness, Night-blindness and 

 Haemophilia. — Sex inherited as a Mendelian character. — 

 Sexual Dimorphism 119 



Appendix I. Historical Summary of Theories of Heredity. 

 Lamarck.— Darwin and the Theory of Pangenesis.— 

 Weismann's Theory of Germ-Plasm . . .135 



Appendix II. The Material Basis of Inheritance. The 

 Nucleus and Chromosomes as possible 'bearers' of 

 Heredity. Behaviour of Chromosomes in Germ-cell 

 formation 145 



Literature List l-j' 



Glossary 1^^ 



Index ^^^ 



