ON THE ORIGIN OF NEW SPECIES 



ter of the leaves the blackberry influence was 

 unmistakably apparent. Strangely enough, 

 the blackberry seeds which came from the 

 cross produced the apple-tree growth. Four 

 to five thousand trees were thus grown, all 

 practically identical in character. All but two 

 of the cross refused to fruit, though almost all 

 of them blossomed abundantly. Some of the 

 blossoms were rose-colored like the apple, 

 some of them almost crimson. Nearly all 

 were thornless. 



A black raspberry was crossed with a black- 

 berry, with the result that most of the product 

 of the union died just as fruit-bearing time 

 came on. Many hybrids, Mr. Burbank notes, 

 die when it comes to the age of reproduction 

 because, for one or another reason, the stamina 

 of the parents is exhausted and the act of 

 fruit production proves too great a strain.* 

 The mountain ash and the blackberry were 

 also crossed, resulting in a salmon-colored 

 fruit, the bush bearing no thorns. Many com- 

 binations of peaches and almonds have been 

 made, further tests in this combination now 

 being under way. In the proving grounds at 

 Sebastopol there stands a row of these peach- 



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