Organic Inheritance ii 



acquired or altered in the organization of in- 

 dividuals during their lives is preserved by 

 generation and transmitted by individuals 

 which sprang from those which have undergone 

 these changes." By developing functional 

 activity of organs, in other words, by constantly 

 employing them, hereditary as well as other 

 values could be obtained. Thus developed the 

 idea known as use inheritance. 



Darwin believed that evolution takes place 

 through natural selection or the struggle for ex- 

 istence and the survival of the fittest. This, as 

 well as other forms of variability, may depend 

 on changing conditions of life. He held that 

 alterations in the environment acting directly 

 or indirectly on the animal might produce vari- 

 ation in inheritance by becoming cumulative 

 through a series of generations. Conversely, 

 individuals, families and races that can not 

 adapt themselves to a changing enviroimaent 

 wdll gradually yield to the law of natural selec- 

 tion and disappear. Families and races that 

 failed to properly reproduce will yield more 

 quickly to this law both as to cause and effect. 



