ARTIFICIAL SELECTION 



93 



The stoneless and seedless piiim is being produced by 

 selection from the crossing of the descendants of a single fruit 

 in a small wild plum with only part of a stone with the French 

 prune; the percentage of stoneless fruits is gradually increasing 

 with succeeding generations. The sugar prune, which promises 

 to supplant the French prune in California, is a selected product 

 of a second or third generation variety of the Petit d'Agen, a 

 very variable French prune. The Bartlett plum, cross of the 

 bitter Chinese simoni and the Delaware, a Burbank liyl)rid, has 

 a fragrance and flavor extraordinarily like that of the Bartlett 

 pear. The Climax is a cross of the simoni and the Japanese 

 triflora. The Chinese simoni 

 produces almost no pollen, 

 only a few grains of it ever 

 having been obtained, but 

 these few grains have en- 

 abled Burbank to revolu- 

 tionize the whole plum 

 ship})ing industry. Most 

 of Burbank's plums and 

 prunes are the result of 

 multiple crossings, in which 

 the Japanese Satsuma has 

 played an important part. 

 Hundreds of thousands of 

 seedlings have been grown 

 and carefully worked over 



in the twenty years' experimenting with plums, and single 

 trees have been made to carry as many as 600 var3'ing seed- 

 ling grafts. 



Burbank has originated and introduced the Yan Deman, 

 Santa Rosa, Alpha, Pineapple "No. 80," the flowering Dazzle, 

 and other quinces; the Opulent peach, cross bred from the Muir 

 and Wager; the Winterstein apple, a seedling variety of the 

 Gravenstein; and has made interesting, although not profitable, 

 crosses of the peach and nectarine, peach and almond, and plum 

 and almond. 



Next in extent, probably, to his work with plums is his long 

 and successful experimentation with berries. Tliis work has 

 extended through twenty-five years of constant attention, has 

 involved the use of forty different species of Rubus, and has 



Fig. 59. — The larger plum is the direct seed- 

 ling of the smaller, produced by crossing 

 the trifolia/n (Japan) plum and the little 

 maritima (Atlantic Coast) plum. (After 

 photograph by Burbank.) 



