LUTHER BURBANK 



a hybrid blackberry, for example, may bear faci- 

 tors for thornlessness, while others bear factors 

 for thorns. But this can be shown only when the 

 seeds have been planted and have germinated. 



In the case of the corn, on the other hand, the 

 qualities of the individual kernels are revealed in 

 the outward appearance of the kernels themselves. 

 The kernel that bears the factors for yellowness 

 will be yellow; the kernel that bears the factor 

 for starchiness will be plump and rounded; and 

 the kernel that bears the factor for sweetness will 

 be wrinkled because of its sugary content. 



So a glance at the crossbred ear of com reveals 

 at once the story of its ancestry. 



So striking is the illustration of Mendelian 

 heredity when yellow field corn and white sweet 

 corn are crossed, as in my early experiments, that 

 recent tests, in which actual count of the different 

 types of kernels has been made, have shown 

 results of mathematical exactness. 



Thus in an experiment recorded by Mr. R. H. 

 Lock, of Cambridge University, in which a smooth 

 yellow type of corn was crossed with a wrinkled 

 white variety, the grains of different colors ob- 

 tained from a certain number of ears borne by the 

 plants of the second generation were distributed 

 almost as evenly as if the work had been done by 

 hand by a careful human calculator. 



[36] 



