LUTHER BURBANK 



just named, are the common Eastern blackberry 

 (Rubus nigrobaccus) , familiar everywhere 

 throughout northeastern America, and a closely 

 related form, considered by some botanists a mere 

 variety, known as Rubus sapivus. 



The common wild plant is an upright grower, 

 stout, has little recurving canes that are usually 

 deeply furrowed lengthwise, and clothed with 

 stout more or less hooked prickles. 



The other species or variety is slightly more 

 erect, with fuller and firmer canes, differing some- 

 what also as to shape of leaves. It bears berries 

 that are usually rounded, generally soft and juicy, 

 and of superior flavor. At my old home in New 

 England this variety grew abundantly on sandy 

 soil, being one of the best wild blackberries in 

 that vicinity. I early noticed that this plant was 

 inclined to vary widely. For example, the vines, 

 although usually stiff, upright growers, some- 

 times more resembled the common blackberry, or 

 even tended to take on the trailing habits of the 

 dewberry. 



When I came to know more about plant de- 

 velopment I recalled this tendency to variation, 

 and felt that here, as always, a fruit of this ten- 

 dency should furnish material for the develop- 

 ment of improved varieties. 



In due course I worked with the various culti- 



[26] 



