INHERITED SEED-CHARACTERS 51 



The two characters, to be dealt with now, appear 

 earlier than the earliest of the five which we have 

 so far considered, namely stature. But these two 

 characters appear by the heading of the chapter 

 to be characters of " the seed " ; yet I have just 

 said that the difference between grey-seeded and 

 white-seeded plants was the latest to appear. How 

 can characters of " the seed " be both the earliest 

 and the latest to appear ? What is the meaning 

 of this apparent contradiction ? There is no con- 

 tradiction, and we can understand how a character 

 of " the seed " can be both the earliest and latest 

 to appear when we understand what a seed is. 



Suppose that you decide to repeat Mendel's 

 experiments with peas, and to cross tails with 

 dwarfs ; suppose that you decide to breed tails 

 and dwarfs separately for five generations to make 

 sure that they breed true to their characters before 

 you cross them ; and suppose, further, that you 

 buy some seed of a tall variety and some of a 

 dwarf, and sow it ; the plants raised may be de- 

 scribed as belonging to the first generation of the five 

 that you propose to breed. Now, consider one of 

 the seeds produced by one of these plants. Only the 

 seed-coat — the thin, outer skin of the seed — is a part 

 of this plant of the first generation ; all that is 

 inside this seed-coat is the embryo plant of the 

 next, or second, generation, together with its first 

 two relatively enormous " leaves." If the seed is 

 soaked and dissected the two hemispherical " leaves," 

 or cotyledons as they are called, are seen to fill up 



