NATURAL SELECTION 



123 



lowing example. In jigiire 57 the two boys and the 

 two varieties of corn, which they are holding, differ 

 in height. The pedigrees of the boys {fig, 58) make 

 it probable that their height is partly inherited, and 



Fig. 55. — A curve resulting from 

 arrangement of beans according to 

 size. (After DeVries.) 



^26 -2(5 -<5 +6 +2(5 +3d 



Fig. 56. — Curve of probability. (After Johannsen.) 



