5S6 



BIOLOGY AND HUMAN LIFE 



QrO 



ffFrO 



^(ic^iiiiiii^iiii^ 



* 



u^ 



Pedigree i 



DrrO 



kS 



O^^^f^^ 



all normal 



a^ i 



6"^^^^ 



Pedigree 2 



both affected 



Pedigree 3 



died of 



heart 



disorder 



■t^I 



n 





^ 



^^ 



Pedigree 4 



Fig. 243. Heredity of human traits 



Squares represent males: circles represent females. 7, pedigree of a family show- 

 ing artistic (dark upper portion), literary (right section), and musical (left section) 

 ability; 2, family with digestive troubles; 3, family with heart disorders; 4, family 

 with feeble-mindedness (/, died in infancy; .?, uncertain mental condition). (/, 2, 



and 3 after Davenport; 4 after Goddard) 



is in him, without prejudice about the history or the standing 

 of his family. In this country, perhaps more than in any other, 

 individuals with fine and useful abilities have come from fami- 

 lies in the humblest stations. 



