D?xR<? or R9xD<?. . Parent-forms (Pi). 



D(R) . 



. Hybrid-offspring (F^). 



3D 



I R . Generation of inbred hybrids 

 (F^). 



I D 



+ 



2D(R) 



3D 



I R R . (F') 



I D -t- 2 D(R) 



D 



3D 



I D +Td(R) 



I 

 D 



iR 



R R . (F*) 



R R R . (F6) 



Fig. 47. — Mendelism. 



{From J. A. Thompson," Heredity.'') 



Or more shortly : 



D 



I 

 D 



t 

 D 



R , , P3 — great-grandparentai generation, 



I 



R , . P2 — grandparental generation. 



I 



R . . P^ — parental generation. 



I 



D(R) 



, F^ — first filial (hybrid) generation. 



I RR . F2— s e c o n d filial 



I DD 2 D(R) 



"Extracted ■' pure Impure dominants. Pure recessives. (inbred) generation, 

 dominants. 



I 



DD iDD 



2D(R) 



I RR RR . F3— third generation. 



DD DDiDD 2D(R) iRR RR RR .. F*— fourth generation. 



Fig. 48. — Mendelism. 

 [From J. A. Thompson, " Heredity.") 



