David Starr Jordan 



mountain ash and blackberry a salmon-colored 

 fruit with no thorns and no albumen in the seed 

 was developed. A hybrid between the English 

 and the black walnut grows fully four times as 

 fast as the English walnut; it bears little fruit. 

 The seedlings from the fruit produce some 

 English, some black, and some hybrid walnuts, 

 and not rarely entirely new forms. Crossing often 

 brings about great vegetative life at the expense 

 of reproductive life, or the reverse. The young 

 (second generation) hybrids of the black walnut 

 and the English walnut show very great variation 

 in their leaves, resembling neither parent. The 

 hybrids of the English and California black wal- 

 nuts are most rapidly growing trees and unusually 

 productive. The first hybrid, of the English with 

 the Japanese walnut, /z/^/^z/j- sieboldi, is largely like 

 the Japanese in the nuts, but rather more like the 

 English in foliage, the second generation being 

 very variable as usual. 



By crossing types already crossed, we may often 

 bring out the original stock which had been lost 



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