PROPAGATION BY GRAFTING 215 



ample, if one or more buds of the Ben Davis apple are 

 caused to unite by grafting with the stem of a Baldwin 

 apple, the parts that grow thereafter from the Ben Davis 

 buds, though nourished by sap that has passed through 

 the Baldwin roots and stem, with rare exceptions, con- 

 tinue to be Ben Davis, while the parts that grow from the 

 Baldwin stock continue to be Baldwin. To this fact is 

 due the chief value of grafting, viz., it enables us to 

 change the character of a plant. 



384. Objects of grafting. — Grafting enables us 



(a) To change a plant of an undesirable variety into one or 

 more desirable ones ; 



(6) To preserve and multiply plants of varieties that cannot 

 be preserved or multiplied by growing them from their seeds; 



(c) To hasten the flowering or fruiting of seedlings grown with 

 a view to improving varieties; 



id) To change the size of trees, so as to dwarf them; 



(«) To restore lost or defective branches; 



(/) To adapt varieties to special soils; 



ig) To save girdled trees; 



(h) To avoid insect injury to the trunk or root, as in grafting 

 the peach on the plum, or the European grape on the American. 



385. The plants that unite by grafting. — In plants 

 capable of being grafted, the following statements will 

 ordinarily be found true : Different varieties of the same 

 species (21) almost always unite by grafting; examples, 

 the Ben Davis and Baldwin apples, the Bartlett and 

 Seckel pears. 



Plants of different species of the same genus (21) 

 often unite by grafting; examples, the peach unites 

 with the plum, many pears unite with the quince, the 

 tomato unites with the potato. 



Plants of different genera in the same family or order 



