20 



PHYSICAL BASIS OF HEREDITY 



loll g % 



Short 



00 



FiQ. l.-Cross between a tall and a short race of garden peaa. ^he Fi generation is 

 tall. In the second generation, F2, there are three tails to one short. (Pi, Fx and i^s v^ere 

 reared from peas supplied by Dr. O. E. White.) 



