FIG. 32. Diagram, photographed from draughtsmen, to illustrate 

 Mendel's Law. 



First line (P) a black dominant and a white recessive. Second line (F 1 ) the hybrid 

 offspring D(R), the black patent, the white latent below. Third line (F 3 ) one " pure*' 

 black, two "impure "blacks, and one "pure" white, iDD+2D(R) + iRR. Fourth line pure 

 extracted dominant to the extreme left, pure extracted recessive to the extreme right ; 

 in the middle, as usual, iDD + aD(R) + iRR. 



[Facing p. 240. 



