88 LUTHER BURBANK 



rays in the series that developed from yellow 

 through orange to red. 



But an assumption based solely on this 

 plausible analogy would not call for very serious 

 consideration. The real strength of the theory 

 lies in the support given it by the observed rela- 

 tions of the different flower colors when brought 

 together through cross-pollination of the flowers 

 themselves. 



It is believed, on independent grounds, that 

 the relations of dominance and recessiveness in 

 Mendelian heredity are determined exclusively, 

 or at least in large part, by the newness or old- 

 ness, in an evolutionary sense, of the respective 

 elements that make up a pair of Mendelian fac- 

 tors — referring, it should be understood, to the 

 number of repetitions, not to the mere lapse of 

 time. 



If this assumption is correct — and there is a 

 large amount of evidence drawn from many 

 fields to support it — then a guide is at hand with 

 which to test the theory of color evolution. 



Indeed, it is largely through the application 

 of this guide that the theory of color evolution 

 itself has been developed. 



Making a practical application, it would 

 appear that the color green, as manifested in a 

 flower, is so remote an inheritance that it would 



