x CONTENTS 



CHAP. 



duction of Colour. Colour in Animals ; some colours 

 4 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 Eye. 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 fly Drosophila. 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 3 of 

 Heredity. Behaviour of Chromosomes in Germ-cell 

 formation 145 



LITERATURE LIST 151 



GLOSSARY . . . 155 



INDEX 159 



