CONTENTS 



PAGE 



Introduction. — Genetics, A New Science ... 1 

 Chapter 



I. — The Duality of Inheritance . . 6 



II. — Germ-Plasm and Body, Their Mutual 



Independence .... 27" 



III. — Mendel's Law of Heredity . . 33 



IV. — The Determination of Dominance; 



Heterozygous Characters and Their 

 Fixation; Atavism or Revision. ... 52 



V. — Evolution op New Eaces by Loss or 



Gain op Characters . 72 



VI. — Evolution of New Races by Variations 



IN THE Potency op Characters 87 



VII. — Can. Mendelian Unit-Characters be 



Modified by Selection? . 106 



VIII. — Mendelian Inheritance Without Domi- 

 nance, "Blending" Inheritance 128 



IX. — The Effects of Inbreeding 143 



X. — Heredity and Sex 153 



INDEX 183 



