LUTHER BURBANK 



All of this, of course, is taking liberties with the 

 future. In the case of the balloon-flower, such 

 hybridizations have not as yet been successfully 

 carried out. But in suggesting the possible results 

 of such potential hybridization, we are merely 

 drawing analogies from almost numberless experi- 

 ments with other races of flowers, and we have 

 every warrant for drawing such conclusions as 

 those just suggested. Certainly we are justified 

 in the conclusion that we have not tested to the 

 fullest the possibilities of variation that we are 

 not by any means "getting the utmost variation 

 out of the flower" until we have supplemented 

 the method of selection with that of hybridization. 



I may add that there are yet other possibilities 

 of stimulating variation by chemical treatment of 

 the developing ovaries of the flower itself; or by 

 subjecting the plant to unusual conditions of hot- 

 house temperature; but experiments of this type, 

 reference to which has been made in an earlier 

 chapter, have not fallen within the scope of my 

 own work, and as yet have been carried out only 

 tentatively by others. So I mention them here only 

 as suggesting that there are other possibilities so 

 various and so complicated as to give full assur- 

 ance that no single line of investigation will ever 

 reach a stage where it loses interest because it has 

 brought the investigator to the end of the road. 



[38] 



