66 MARRIAGE AND DISEASE. 



the modification in his descendants. Were it not so, 

 every change in the individual, brought about by 

 education, training, and mode of life, must of necessity 

 cease to exist with the life of the modified individual, 

 and without evolution, heredity could only reproduce 

 the one changeless type, and all nature would be at a 

 standstill. Eibot says : " These modifications, as they 

 accumulate and in course of time become organic, 

 make new modifications possible in the succession of 

 generations. Thus heredity becomes in a manner a 

 creative power." 



