CONTENTS 



Preface xiii 



I. Subject Matter of Genetics i 



Materials of Heredity and Their Opera- 

 tion 



II. The Genetic System 37 



Its History during the Life of the Indi- 

 vidual and in the Production of the 

 Next Generation 



III. Operation of the Genetic System, as 



Exemplified by Its Relation to Sex 55 



IV. Relation of Genetic System to Char- 

 acteristics 83 



X-Chromosome as Type 



V. Relation of Genetic System to Char- 

 acteristics 104 



Autosomes and Y-Chromosomes 



VI. Constitution of the Chromosomes 131 



Genes and Their Relations to Character- 

 istics 



VII. The Genetic System as a Whole 164 



V 



