234 PLANT-BREEDING 



A chestnut without spines on its burs was growing on 

 the Sebastopol farm. It was a single young tree, found 

 among the numerous offspring of a cross between the Japan- 

 ese and the American species, both of which have spiny burs. 

 It was, probably, a pure mutant. 



A blue poppy which appeared in his crosses of Papaver 

 Rhceas and allied species has already been referred to. It 

 was, also, probably, a pure mutation, which, however, 

 showed itself, in the beginning, only in an imperfect degree 

 of development. 



The same holds good for his scarlet California poppy 

 (Eschscholtzia calif ornica) . He discovered the first indication 

 of this mutation, some years ago, when inspecting large beds 

 of ordinary yellow California poppies. One flower caught 

 his eye; it* had on one of its petals a fine longitudinal line of 

 scarlet color. It would, surely, have escaped the eye of 

 most other men, but to Burbank it betrayed the capacity of 

 this one plant to produce a variety of a new and unsuspected 

 color. He isolated the plant and saved the seed. Among 

 the offspring the scarlet color was repeated, but still to an 

 insignificant extent. He repeated the selection during some 

 years until he got a race of a pure and uniform scarlet color 

 in all the flowers and on all the plants. We saw large beds 

 in full bloom but without atavistic reminders of the yellow 

 prototype. 



It would be a most interesting task, full of promise, to 

 try to repeat the observation of the appearance of all these 

 mutants and to follow their origination and their develop- 

 ment under the rigid conditions of scientific research. It 

 might be expected that the material from which Burbank 

 started would, probably, repeat the mutation, even as other 

 horticultural and experimental mutations are known to have 

 been produced repeatedly. In doing so an exact history 

 might be given instead of the more or less vague and incom- 



