DEVELOPMENT AND ITS RESULTS. 17 



Development by selection and protection 

 from the struggle for existence is thus 

 limited by sterility or precocity. 



The results of experience, therefore, con- 

 firm our abstract deductions 



That the development of a type cannot 

 exceed a full expression of the energy 

 of its life-forces ; and 

 That without modification of a Specific 

 life-force there can be no specific varia- 

 tion. 



