PEAS AND BEANS 147 



the new varieties are often practically fixed from 

 the outset. 



With beans it is less easy to trace and classify 

 the opposing "unit" characters, and in practice 

 it is often necessary to select rigidly and con- 

 tinuously for five or six successive generations 

 in order to fix a new variety. 



An illustration of the complexities that may 

 result when beans of different kinds are crossed 

 was given me at the outset of my work as a plant 

 developer. 



Crossing the Pole Beans 



One of my first experiments in hybridizing 

 was made by crossing the horticultural pole bean 

 or wren's egg with another variety of pole bean 

 known as the red cranberry bean. 



The hybridization was effected with some diffi- 

 culty, inasmuch as only one blossom in perhaps 

 fifty responded to cross-pollenization and a part 

 of the offspring seemed to lack vitality, as I suc- 

 ceeded in bringing but one plant to maturity. 

 But this was in some respects the most astonish- 

 ing bean plant that I have ever seen. It bore 

 long black pods and the beans within them were 

 as black as ink. 



Yet one of the parent beans had produced a 

 crimson pod with a red seed, and the other a 



