A SIMPLE ILLUSTRATION 



351 



as: (1) the Law of Segregation, and (2) the Law of Reas- 

 sortment. His momentous discovery was almost wholly- 

 neglected by his own generation and only brought to the 

 attention of the world in general in 1900 when his paper 

 was unearthed by three European botanists (de Vries, 

 Correns, and Tschermak) who were also attempting to 

 discover the laws of heredity. 



THE LAW OF SEGREGATION 



A Simple Illustration. — Although Mendel worked 

 with peas this law can be more readily understood by 

 studying a different experiment (Fig. 97). When a red- 



//y ^v 



Fig. 97. — Diagram to show the results of crossing a red four 

 o'clock by a white one. The upper row shows the red and white 

 parents. The second row shows that the first generation hybrids 

 are all alike and pink in color. The third row shows that when these 

 pink hybrids are self pollinated or bred with one another a second 

 hybrid generation is produced which consists of one-fourth white 

 flowered plants like one grandparent, one-half pink hybrids like the 

 first hybrid generation, and one-fourth red plants like the second 

 grandparent. 



Morgan, Sturtevant, MuUer, Bridges, TJie Mechanism of Mendelian 

 Heredity. 



flowered four o'clock is crossed with a white-flowered one 

 the hybrid offspring, called the Fi generation, are all pink- 

 flowered. If these hybrid pinks are self -pollinated their 

 offspring, called the F2 generation, consists of three 



