LUTHER BURBANK 



mountain-ash and rose; also by the hybrid be- 

 tween strawberry and raspberry. 



These strange hybrids would clearly enough 

 have been entitled to recognition as new species 

 had they been able to reproduce themselves. But 

 their sterility reduced them to the rank of mules 

 to make comparison with the most familiar in- 

 stance of an infertile hybrid in the animal world. 



From these sterile hybrids the Sunberry dif- 

 fers fundamentally in that it is if anything more 

 prolific than either of its parents. 



Meantime the Sunberry differs from the hy- 

 brids of another and more familiar type that arise 

 from the union of parents that are so closely re- 

 lated that cross-pollenizing is easily effected be- 

 tween them. Such hybrids, of which we have seen 

 many examples crosses between the different 

 daisies, between black and white blackberries, 

 thorny and thornless briers, stone-seed and stone- 

 less plums, and sundry others follow, as we 

 know, a characteristic line of development. The 

 hybrids of the first generation resemble one parent 

 more than the other. The hybrids of the second 

 generation show wide variation, some of them re- 

 verting to one ancestral strain and some to the 

 other, the characteristics of each strain being vari- 

 ously segregated and recombined. 



Nothing like the direct and complete reproduc- 



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