CHAPTER V 



THE INHERITANCE OF THE CHARACTERS OF THE SEED 

 IN THE CULINARY PEA 



We have so far dealt with only five of the seven 

 characters of the pea experimented with by Mendel ; 

 and the reader may remember that they were dealt 

 with in the order in which they appeared on the 

 plant : the first was the stature of the plant, 

 whether tall or dwarf; the last was the colour of 

 the ripe "seed," whether "grey" or "white." 



Suppose that it is spring, and that you have 

 just sown the seed to produce the second hybrid 

 generation from a cross involving any of the five 

 pairs of characters already dealt with. If the pair 

 of characters is tallness and dwarfness, you will 

 be able to count the numbers of tails and dwarfs 

 as soon as the young plants are a few inches high, 

 that is to say, early in May ; but it will be necessary 

 to wait till the plant is ripe and dry, that is to say, 

 till the middle of August at the earliest,* before the 

 number of white-seeded and grey-seeded plants can 

 be counted. And the numbers of plants with the 

 three characters intervening in the date of their 

 appearance between these two extremes can be 

 counted at intervening dates. 



* Except when there is a drought like that of the summer of 1911. 



50 



