Heredity — Genetics 111 



II 



III 



IV 





^. 



Fig. 354. — Pedigree of deafness (otosclerosis). Black symbols indicate persons 

 having the trait. Squares represent males; circles, females. I, II, III, IV repre- 

 sent four generations. 



a 



II 



a 



\\\ 



IV 



« 



i 



i 



♦■■Qfl 



UtKJ, 



fi 



,i,6.6t a 



Fig. 355. — Pedigree of insanity (an inheritable type). Black symbols indicate 

 persons having the trait. Squares represent males; circles, females. /, //, ///, 

 IV represent four generations. 



IV 

 V 



[^'S6 



Fig. 356. — Pedigree of twinning. One or both twins died at birth in each case. 

 Squares represent males; circles, females. /, //, ///, IV, V, represent five genera- 

 tions. D represents death in infancy. 



