LUTHER BURBANK 



dice — as to the exact number of cases in which 

 shortness of stalk would be combined with the 

 bearing of yellow pods. 



Pairing the Factors 



If we assume — as Mendel finally came to do — 

 that each of the different qualities about which we 

 are speaking is represented in the germ plasm by 

 a definite mechanical factor which must be paired 

 with another factor, either like or unlike itself, in 

 order to stimulate the development of the char- 

 acter it represents, then at least a provisional 

 explanation of the observed facts might be found 

 in supposing that a dominant factor when mated 

 with a recessive one hides or obscures the recessive 

 one in that particular combination; but does not 

 eliminate it. 



And when the factors are again mixed to pro- 

 duce a new generation, they are still equal in 

 number, and if we think of the factors as tangible 

 things — ^let us say like black or white checker men 

 — it will appear that if equal numbers of each are 

 mixed together and taken from a bag in pairs at 

 random or blindfold, it will come about, accord- 

 ing to the mere theory of chances, that one time 

 in four two of the white checkers will be paired. 



This accounts in a crude and mechanical but 

 on the whole a rather satisfactory way for the 

 appearance of the recessive character — say short- 



[92] 



