HEREDITY 



CHAPTER I 



HEREDITY AND INHERITANCE : DEFINED AND ILLUSTRATED 



§ i. Importance of the Study of Heredity. 



§ 2. What the Terms Mean. 



§ 3. Heredity and Inheritance in Relation to other Bio 



logical Concepts. 

 § 4. A Question of Words. 

 § 5. The Problems Illustrated. 

 § 6. Denials of Inheritance. 



§ 1. Importance of the Study of Heredity 



Heredity determines the Individual Life.— There are no 



scientific problems of greater human interest than those of 

 Heredity — that is to say, the genetic relation between successive 

 generations. Since the issues of the individual life are in great 

 part determined by what the living creature is or has to start 

 with, in virtue of its hereditary relation to parents and ancestors, 

 we cannot disregard the facts of heredity in our interpretation 

 of the past, our conduct in the present, or our forecasting of the 

 future. Great importance undoubtedly attaches to Environ- 



