144 LUTHER BURBANK 



one in four will be green; but that the same law 

 of chances, applied to this more complex case, 

 gives us only one case in sixteen in which two 

 factors for shortness are combined with two 

 factors for greenness in the same group. 



In other words, one pea in sixteen descended 

 in the second generation from the tall pea with 

 green pods and the short pea with yellow pods 

 will have a short vine and at the same time will 

 bear green pods. 



This will be a new variety. It has no new 

 quality, but it has the old qualities in a new 

 combination. 



Extending the experiment one stage further, 

 Mendel found that the second-generation peas 

 that show the recurrence of the recessive factor 

 will breed true to that factor. And this, again, 

 is quite what might be expected on the theory 

 just outlined. For the pea that contains two 

 factors for shortness will obviously have no pro- 

 pensity to grow tall, and the pea that contains 

 two factors for greenness of pod will obviously 

 have no capacity for the production of pods 

 other than green. 



So our short pea vine with its green pods, 

 although it represents a new variety, which, for 

 the sake of argument we assume never to have 

 existed before; and although it appeared sud- 



