LUTHER BURBANK 



One of the most curious hybridizing experi- 

 ments that I have ever conducted was made in an 

 effort to test the limitations of affinity between 

 the various members of the rose family. I had 

 on my place a bush of the California dewberry, 

 a plant that differs from most other members of 

 the family in that its staminate and pistillate 

 flowers are borne separately. 



The particular bush in question had only 

 pistillate flowers, and as it grew in isolation, it 

 ordinarily bore no fruit, as its flowers were seldom 

 fertilized. At most it occasionally developed 

 single drupelets, a result no doubt of partial 

 fertilization from grains of pollen accidentally 

 brought from a distance by wind or insect. 



The isolation of the plant, and the fact 

 that it bore unisexual flowers, seemed to offer a 

 favorable opportunity for experiment. 

 SOME HYBRID BERRIES 



Upon this plant I applied the pollen of various 

 species of plants of the same family. The list 

 is a striking one, for it included the apple, the 

 mountain-ash, the hawthorn, the quince, the pear, 

 and various kinds of roses. 



I worked at these hybridizations attentively 

 during the blooming season of the dewberry in 

 the summer of 1886. 



The pistils thus fertilized developed an abun- 



[286] 





