FOUR BURBANK PRUNES 67 



flesh is less interrupted, probably an advantage 

 to the development of both. 



The clingstone is thus the more normal 

 condition of fruits. Most fruits are cling- 

 stone until brought under cultivation. All fruits, 

 both wild and cultivated, are clingstone 

 until toward the time the ripening process 

 commences. 



That many cultivated fruits are freestone is 

 no doubt the result of artificial selection to meet 

 a very natural demand. 



Nuts furnish analogies that help us to under- 

 stand the relations of seed stone and fruit. The 

 case of the almond, which was perhaps more 

 nearly the parent form of stone fruits, is partic- 

 ularly instructive. In place of the rich surround- 

 ing meat which we see in peaches, apricots, and 

 plums, the almond has a leathery skin, which is 

 inedible. This generally clings to the stone per- 

 sistently in the wilder forms, but with the best 

 cultivated almonds the nut drops readily from 

 the husk or outside covering. 



Similar to the persistency with which the flesh 

 of the plum clings to the stone is the attachment 

 of the husk in the walnuts and the chestnut, in 

 each of which the husk separates with more diffi- 

 culty in the wild than in the best cultivated 

 varieties. 



