LUTHER BURBANK 



by some biologists, but there is a large amount of 

 evidence to support it. 



To illustrate from the case in point, it appears 

 that, as a rule, when red flowers are crossed with 

 flowers of another color, say white, the red tends 

 to prove dominant. Similarly, when a white 

 poppy is crossed with Mr. Burbank's blue one, 

 the progeny are white. This is consistent, at 

 least, with the theoretical assumption that new 

 characters dominate old ones, and that red is the 

 newest flower color and white a newer color than 

 blue. 



I must not claim space to elucidate either theory 

 in detail here. But I may point out, in passing, 

 that the theory that new strains are dominant to 

 older ones aids us sometimes in the interpretation 

 of the observed results of experiments in plant 

 breeding. We should expect, for example, that 

 the spines would be dominant to spinelessness in 

 ease of the blackberry and cactus, for it may be 

 assumed that the spines were a comparatively 

 recent development in the evolutionary scale. 

 Again, pigment would be dominant to lack of pig- 

 ment in the blackberry; for the fact that the 

 young berries are colorless or green strongly sup- 

 ports the assumption that the primordial an- 

 cestors of the blackberry bore colorless fruit. 



FIXING CHAEACTEKS 



In a slightly different connection it may be 

 noted that study of dominance and recessiveness 



[38] 



