302 LUTHER BURBANK 



painted with marvelous hues that are so unique 

 as to have given their names to prominent pig- 

 ments of the painter's color box ; and incorporate 

 curious series of minute oil wells laden with es- 

 sential essences of no less individual quality. 



These traits, among others, mark the citrus 

 fruits as constituting a highly specialised and 

 isolated group of plants. 



It is not to be expected that any one of them 

 could be hybridized with a member of any other 

 family. But, on the other hand, within the bounds 

 of the citrus family there is full opportunity, as 

 I have already pointed out, for cross-fertilization. 



Many interesting developments would have re- 

 sulted from the hybridization of oranges, lemons, 

 limes, and citrons in my orchard had not the frost 

 treated the tenderlings so harshly. Not unlikely 

 there would have been developed new citrus 

 fruits differing from any existing one as mark- 

 edly as the piumcot differs from apricot and 

 plum. This, of course, is only matter of conjec- 

 ture, for the experiments were cut short, as al- 

 ready told, before they passed beyond the early 

 stages. 



Still the fact that I was able to effect hybrid- 

 ization between the various citrus fruits is highly 

 suggestive and should prove stimulative to other 

 workers. 



