136 LUTHER BURBANK 



able pedigree, at least as regards some of their 

 strains. 



When I say that something like seven and a 

 half million seedlings of the plum have passed 

 under my hand and eye in the course of my many 

 series of experiments in the perfection of this 

 fruit, the reader will not wonder that there are 

 gaps in the record, otherwise there would be only 

 records not plums. 



DIFFICULTIES INVOLVED 



On the other hand, it must be understood that 

 there are almost numberless instances in which 

 the hybridizing of different strains of plums has 

 been effected by hand, in accordance with the 

 most rigid scientific methods, and accurately 

 recorded in my plan books. Indeed, this is true 

 in almost all cases of the first cross through which 

 a tendency to variation has been brought about. 



The first generation hybrids are usually very 

 much alike, and inspection of them often gives no 

 clues to the ultimate results to be expected. But 

 in the next generation all the divergent char- 

 acteristics of both racial strains strive for repre- 

 sentation, and the diversity of forms produced 

 may baffle anything like accurate description. 



Beyond this stage it is usually necessary for 

 the practical breeder to turn over the task of 



