SEED 239 



in place of smooth seed, and purple flowers 

 in place of white. For the purposes of 

 illustrating his law we may take the char- 

 acters of tallness and dwarfness. Mendel 

 found, when he mated a tall pea with a 

 dwarf pea, that the seed so produced grew 

 plants which were all tall, and, so far as 

 external appearances went, it was impossible 

 to tell any difference between the various 

 individuals. When he allowed these tall 

 peas to fertilize themselves, he secured seeds 

 which produced plants, some of which were 

 tall and some of which were dwarf. As a 

 matter of fact, by breeding many hundreds 

 of individuals, he found that the tall peas as 

 compared with the dwarf were nearly in 

 the proportion of 3 to 1. When the dwarf 

 peas of this generation were allowed to 

 fertilize themselves, it was found that they 

 all bred true, showing no disposition what- 

 ever to revert to the tall type, and this 

 purity of breeding was found to continue 

 through successive generations. As regards 

 the tall peas of the second generation, how- 

 ever, Mendel found that whereas a certain 

 number of them could be depended on to 

 give seed that would only produce tall 

 individuals, the larger number of the tall peas 

 of the second generation yielded seed that 



