478 THE INDIVIDUAL AND THE RACE: 



alitj ceases to exist as such, yet part of it or something that 

 was wrapped up with it continues^ or may continue into an- 

 other individuality. This is the genetic relation — heredity, 

 which has to be considered as a condition of evolution, and 

 likewise as a factor in determining the individual life. 



§ 1. Definition of Heredity, Inheritance, Nurture, 



Development, 



A few definitions, representing condensed discussions, may 

 be useful to start with. Heredity is the relation of organic 

 continuity between successive generations, which secures the 

 general persistence of resemblance between offspring and 

 their parents, between progeny and their ancestors; it im- 

 plies the continuance of a specific dynamic organisation of 

 which the germ-cells are usually the vehicle. In brief, hered- 

 ity is the genetic relation between ancestors and descendants. 



Some use the word heredity to include all the causes or 

 factors which determine the resemblance between individuals 

 who are related to one another. But this resemblance is 

 not wholly due to heredity. Others would say that heredity 

 is the fact that like begets like; but it is more than that, 

 including indeed the possibility of variations. Others would 

 say that heredity is the past living on in the present, but 

 perhaps inheritance is the fitter word to denote that fact. 

 All these definitions suggest part of the truth, but it seems 

 clearest to regard heredity as the organic relation between 

 successive generations, — a relation which secures persistence 

 of characteristics and yet allows new ones to emerge. 



Whatever definition of heredity is adopted, it must be 

 clearly understood that heredity is no mysterious force or 

 principle ; it is a flesh-and-blood linkage, a continuity of 

 germ-plasm, binding one generation to another. In pre-Dar- 



