74 LUTHER BURBANK 



Because of the many characters it is necessary 

 to combine in producing a successful prune, it is 

 probable that the work represented by these four 

 varieties is fully equal to the production of ten 

 times that number of standard plums with, 

 probably, proportionate benefits. 



But from the almost numberless varieties, the 

 result of years of selective breeding, there will 

 probably arise individuals year by year that will 

 present new and superior combinations of quali- 

 ties ; and among these may appear at any time a 

 prune that may even surpass my best prunes of 

 the present as markedly as these surpass their 

 predecessors of a generation ago. 



This, indeed, is fully to be expected. Each of 

 my prune trees, with its colony of selected hy- 

 brids, may be regarded as a factory admirably 

 equipped for the turning out of new varieties of 

 prunes. Even though it were left to be operated 

 solely by the bees, its mechanism has been so per- 

 fected, its equipment is so complete, that it can 

 scarcely fail of its purpose. 



