THE RECIPROCAL INFLUENCES OF STOCK AND CI ON 



559 



while others assume large stature, both worked on similar stock. Certain 

 dwarf varieties of peach remain dwarfed regardless of the stock on which 

 they are worked. 



On the other hand, some plants attain greater size on roots other 

 than their own. The common lilac is said to be greatly increased in 

 stature on the ash, though this is a short lived graft. Similar increases 

 are said to obtain when Pinus Gerardiana is worked on P. sylvestris, 

 incense cedar on common cedar^'*^ and in herbaceous grafts, as in 

 Phy salts on potato, Arabis alhida (rock cress) on Brassica oleracea 

 (cabbage, etc.,) and Solanum dulcamara (bitter-sweet) on S. ly coper sicum. 



Rose acacia is considered to grow larger on Eobinia viscosa; likewise 



iiitii 



\\ ih 



iiiLM' Mil f 1 ('/// '//(, sour 

 oraMgc (," kluUt;i " ul India) ; ii;:ihl, saiuu on (.'. LitiLumnn, lough lenioa (, khaiiia ' uf India). 

 Twenty-seven months planted. (After W . Robertson Brown.^^) 



the dwarf double-flowering almond on peach. ^"^ Magnolia glauca 

 (swamp bay) is reported to attain three times its normal size when 

 grafted on M. acuminata (cucumber tree), though this has been suggested 

 as due to the lack of adaptation to ordinary soil in the root of the former, 

 which is a bog plant. 



It is stated that Grimes and Winesap apples increase in vigor when 

 worked on vigorous stocks."^ A similar influence is exercised by 

 American persimmon on Japanese persimmon cions.*^ Prunus pumila 

 (sand cherry) makes an increased growth on plum stock. ^^ Among 

 growers of Vinifera grapes the Rupestris St. George (du Lot) stock is 

 generally known to induce unusually vigorous growth in varieties worked 

 upon it and skilful vignerons recognize this difference when pruning. 



Hedrick^^ reports an experiment in which a number of grape 

 varieties more or less grown in the grape regions of New York were studied 



