CONTENTS 



CHAPTER I 



PAGE 



The Problem i 



CHAPTER II 

 Historical 8 



CHAPTER III 

 Mendel's Work . 17 



CHAPTER IV 

 The Presence and Absence Theory .... 29 



CHAPTER V 

 Interaction of Factors ....... 42 



CHAPTER VI 

 Reversion 59 



CHAPTER VII 



Dominance 68 



ix 



