A STUDY IN PLANT VARIATION 265 



seems therefore that the best horticultural results can be obtained if 

 hardy fruits are more and more developed and selected for the colder 

 sections of our country. 



The hybridizing experiments of Burbank included the crossing of the 

 present species with hybrids of the Japenese Plum (P. tr if lor a). There 

 resulted from these crosses three interesting varieties of which the 

 "Giant Maritima" seems to be the most marked. The fruit begins to 

 ripen in California early in July and when ripe is of a deep crimson 

 covered with a thin pale bloom. The flesh until fully ripe is very firm 

 and solid, but it breaks down quickly when ripe. It is honey yellow, 

 with a pale greenish tinge. The quaUty is good. The fruit is fragrant, 

 and as large as any other plum known in 1905. It was grafted into 

 numerous older trees and appears to be a strong grower. He states that 

 it will never prove of much commercial value as it lacks firmness of 

 texture. The second variety was called "East." It was not as good 

 as he had anticipated, it was too soft for shipping, but proved to be a 

 desirable variety for home consumption. In quality of fruit, it was 

 probably inferior to the best Japanese hybrids. It ripens from August 1 

 to 15. "Pride," the third variety, is of little value as a shipping plum. 

 It ripens too quickly so that it will not stand shipping to any great dis- 

 tance. It is apple shaped, dark red, a good grower, an excellent bearer 

 and ripens about August 20th. He further states that in addition to 

 these, nearly 2000 other promising maritima hybrids are now being 

 grow^n from these crosses. Many of them are excellent in habit, produc- 

 tiveness, and hardiness and from them he hopes to introduce many 

 new forms. 



The writer has grown in the Botanic Gardens of the University of 

 Pennsylvania P. maritima budded on domestic stock, which at the pre- 

 sent time is growing very rapidly, although no blooms have appeared 

 as yet. It is the writer's hope that interesting forms may result from 

 proper cultivation and selection of the budded stock, and in this connec- 

 tion he desires to express his personal gratitude to Messrs. Hoopes Bro. 

 and Thomas, West Chester, Pa. for their skill in efifecting these graft 

 unions for him. 



This work was conducted under the direction of Professor John M. 

 Macfarlane, of the University of Pennsylvania, to whom the writer is 

 indebted for many helpful suggestions and criticisms, and for which he 

 expresses his full appreciation. 



