542 HEREDITY 
Fic. 475.—A diagram illustrating Mendel’s discovery concerning the in- 
heritance of tallness and dwarfness in the Garden Pea. At the top are the - 
parents of the cross, the tall variety at the left. and the dwarf variety at the 
right. In the line immediately below is the first (F;) generation, all plants of 
which are tall and thus like the tall parent, and each of which upon being self- 
fertilized produced a progeny (fF: generation) consisting of tall and dwarf 
plants in the ratio of 3:1, as shown in the third line. As shown in the lower 
line (F; generation), the dwarfs and one-third of talls of the #2: generation bred 
true, that is, they produced progeny like themselves, while two-thirds of the 
fall once produced a progeny consisting of tall and dwarf plants in the ratio 
of 3:1. 
