So 



BASIS OF INVESTIGATION. 



constitution would be born when he was thirty-five, the child with 

 the best brain when he was sixty, and the best all-around child when 

 he was between forty-five and fifty. 



ccj*4. 3.0 4 f 3 o 3 "5- ^o 4? TO S"? C,o £$- 



FIG. 3. DIAGRAM OF THE DEVELOPMENT OF THE BRAIN AND BODY. 



FORMULA FOR HEREDITY. 



To express the matter mathematically let : 



T=age of ancestor at time of reproduction. 



t= average age of reproduction of the race. 



t 1 =age at which ancestor reaches average development with K 



activity. 



K— grade of mental activity of ancestor. 

 k=average mental activity of the race. 



k 1 =grade of mental activity required to maintain ancestor in 

 uniform condition. 



m=change arising from K-k activity in a unit of time. 

 M=average race inheritance. 

 Q=inheritance of any individual. 



Then : — 





Q=M- 



m(T-tV) mCT-t 1 ) mCT-t 1 ) mCT-t 1 ) 



2 4 8 16 



will express the inheritance of an individual as received from a sin- 





