198 THE EVOLUTION OF OUR NATIVE FRUITS 



for a brood of natural hybrids between Prunus an- 

 gustifolia and Prunus Americana* 



I am aware that it is a dangerous expedient to 

 invoke hybridity to account for inexplicable behaviors 

 of plants. It is likely to serve only as a cloak for 

 superficial knowledge, but it is convenient, never- 

 theless, and in the present instance there is no other 

 resort to cover the writer's ignorance of the subject. 

 But there is really much explicit foundation for the 

 belief in this hybridity, as I have already explained; 

 and it is known that many of these native plums 

 can lie freely hybridized. I am the more convinced 

 of the validity of this position from the similar 

 behavior of certain wild apples, the vagaries of which 

 are explained in the next chapter. Some of the 

 plums which I have referred t<> Prunus hortulana 

 may be direct developments from the true Chickasaw 

 type, and others may be direct offshoots or variations 

 from the Americana type. In my monograph upon 

 "The Cultivated Native Plums and Cherries" (Bull. 

 38, Cornell Exp. Sta.), I made a sub-group of this 

 hortulana class to comprise "a tew anomalous varie- 

 ties which appear to be intermediate between Prunus 

 hortulana ami /'. Americana. They may be an off- 

 shoot of /'. hortulana, or it is possible that they 

 constitute a distinct species. The Miner is par- 

 ticularly well marked, bul there are others which 

 it is somewhat difficult to separate from /'. hor- 

 tulana. The group differs from the species by 

 the dull and comparatively thick leaves, which arc 



•This disposition was Brsl made in Bot. Gas. 1896, p. 462, bat it was rag. 

 Bested i wo _\ eara earlier (see " San Ival of the Dnlike," 134 . See, also, Hull. 131, 

 Cornell Exp. Sta. Ko (U ■ 



