THE RECIPROCAL INFLUENCES OF STOCK AND CI ON 553 



of different families. Biffen^^ succeeded in grafting Trifolium pratense 

 on Anthyllis vulneraria, of a different genus. 



Dawson^^ cited some interesting cases: "The Photinia allied to the 

 beam tree (Pyrus Aria) and the Eriobotrya [loquat], allied to the medlar, 

 both evergreens, will graft on the medlar and not on the hawthorn. 

 Cotoneasters, amelanchiers and Pyrus Aria all do well on hawthorn and 

 last longer but make slower growth than on mountain ash. Pyrus 

 arbutifolia grafts well as a standard on mountain ash. ; . . Pyrus 

 Toringo . . . will grow on seedlings but are better on Pyrus haccata." 



Manning^°^ listed several cases of incompatibility in close relatives. 

 The laburnum, he stated, would not take on locust. Flowering dogwood 

 on cornelian cherry (both in the genus Cornus) made only short-lived 

 unions. The Josika lilac was said to succeed on the ash while the Persian 

 lilac failed, though it grew on the common lilac. Coulter'*^ states that 

 Prumis Padus and P. Laurocerasus show a lack of affinity. Native, Japa- 

 nese and European plums take readily on western sand cherry, though 

 sweet and sour cherries unite with it much less readily." 



The gooseberry will grow on Ribes aureum but not on the cultivated 

 edible currants. ^^ Some varieties of pears unite readily with quince 

 stocks, but others are so conspicuously defective in uniting that they 

 necessitate a resort to double working. 



Berckmanns^" reported that Labrusca and Aestivalis grapes inter- 

 worked readily but that, apparently because of the difference in the 

 texture of the wood, Labrusca varieties would not take on Vulpina. 

 Bioletti^^ recognizes certain of the Vinifera group of grapes as having 

 "defective affinity" in that they do not unite at all well with the stocks in 

 common use; he recommends a special stock for these varieties because it 

 makes an excellent union with them. Among these varieties he lists 

 Emperor, Ferrara, Cornichon, Muscat, Mataro, Folle Blanche, Pinot, 

 Gamay, Gutedel; the stock recommended for them is known as 1202. 



Brown^s cites a case in California in which both cion and stock grew 

 larger than their customary size. "Almonds grafted on peaches," he 

 states, "have developed a circumference of a little less than 10 feet, while 

 the maximum size of either, growing alone, would be scarcely 5 feet. 

 Where almonds are grafted on plum stock, the reverse is true." Measure- 

 ments are cited showing, in the almond on peach, a circumference of 9 

 feet 1 inch above the graft and 10 feet 4 inches below, while the almond 

 on plum, of equal age with the first combination, measured 4 feet below 

 the union and 4 feet 10 inches above. 



Other stone fruits exhibit similar capriciousness. In Vermont the 

 Newman plum seemed to have much greater affinity for peach roots than 

 did Green Gage, Stoddard, Chabot or Milton; in fact the last three did 

 very poorly on peach stock. ^^^ In California certain prunes, including 

 Robe de Sargent, Imperial Epineuse and Sugar, lack affinity for the 



