12 A NEW THEORY OF EVOLUTION. 



type, but the expression of the type is the 

 outcome partly of heredity and partly of 

 the conditions of development. 



The respective potencies, in modifying ex- 

 pression of type, of the General life-force, of 

 the Specific life-force, and of the other factors 

 of development, vary in different races and 

 also among individuals of the same* race or 

 family. 



Deductions. 



From the preceding hypothesis come the 

 following deductions : 



Expression of type is affected by the 

 quality or energy of the General and Specific 

 life-forces, and by the conditions of develop- 

 ment. 



The development of a type cannot ex- 

 ceed a full expression of the energy of its 

 life- forces. 



Without modification of a Specific life- 

 force there can be no specific variation in 

 type. 1 



1 " Every variation of a living form, however minute, how- 

 ever apparently accidental, is inconceivable except as the 

 expression of the operation of molecular forces or ' powers ' 

 resident within the organism. And as these forces certainly 

 operate according to definite laws, their general result is, 

 doubtless, in accordance with some general law which sub- 

 sumes them all." Huxley, Darwiniana, p. 182. 



