66 LUTHER BURBANK 



The following year there was still further im- 

 provement, as plants appeared that showed a 

 much larger invasion of the flower petals by the 

 crimson coloring. And by selecting year after 

 year blossoms that showed this increasing ten- 

 dency to adopt the new color, I produced 

 presently a plant that bore blossoms of a beauti- 

 ful uniform clear crimson No trace of the 

 original yellow color remained. 



This furnishes a very good illustration of 

 selection for color where the material consisted 

 of a small stripe of an unusual color appearing 

 on blossoms otherwise of a fixed hue. 



But the same method of selection may some- 

 times be applied to the improvement of the shade 

 of color, or even to the development of a new 

 color, from a flower that shows only a faint de- 

 parture in shade from the normal. And the same 

 principle of selection, followed oui in precisely 

 the same manner, applies to the development of 

 flowers or fruits of varying size, of larger or 

 smaller stem, abundance of blossom, profusion 

 of leaf or flower or fruit, and the like. 



It is equally possible to alter the proportions 

 of the chemical constituents of a plant in certain 

 instances. 



The case of my Sugar prune, the fruit of 

 which was developed to have a sugar content of 



