PHENOMENA OF 'INHERITANCE 215 



with regard to several selected traits, viz., 

 genius or marked intellectual capacity, artis- 

 tic faculty, stature, eye color and disease. As 

 a result of his very extensive studies two main 

 principles appeared to be established: 



1. The Law of Ancestral Inheritance which 

 he stated as follows: 



The two parents contribute between them on the 

 average one-half of each inherited faculty, each of 

 them contributing one-quarter of it. The four 

 grandparents contribute between them one-quarter, 

 or each of them one-sixteenth; and so on, the sum 

 of the series 1/2 + 1/4 -f- 1/8 + 1/16 . . . being 

 equal to 1, as it should be. It is a property of this 

 infinite series that each term is equal to the sum of 

 all those that follow : thus 1/2 = 1/4 + 1/8 + 1/16 

 + ...,1/4 = 1/8 + 1/16 + . . . , and so on. 

 The prepotencies of particular ancestors in any 

 given pedigree are eliminated by a law which deals 

 only with average contributions, and the various 

 prepotencies of sex with respect to different quali- 

 ties are also presumably eliminated. 



The average contribution of each ancestor 

 was thus stated definitely, the contribution di- 

 minishing with the remoteness of the ancestor. 

 This Law of Ancestral Inheritance is repre- 

 sented graphically in the accompanying dia- 



