LUTHER BURBANK 



ness of vine or greenness of pod in one individual 

 out of four of the second-generation progeny. 



And when we apply the same reasoning to the 

 case where two pairs of factors are under consid- 

 eration tallness versus shortness, and yellowness 

 versus greenness in the present case it appears 

 that each pair of factors will follow precisely the 

 same law, so that one in four of the second gen- 

 eration descendants will be short and 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 short- 

 ness 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 qual- 

 ity, but it has the old qualities in a new com- 

 bination. 



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 out- 

 lined. For the pea that contains two factors for 



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