Propagation by Grafting. 221 



384. Objects of Grafting. Grafting enables us 



a— To change a plant of an undesirable variety into 

 one or more desirable ones ; 



b— 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 ; 



d — To change the size of trees, so as to dwarf them. 



e— To restore lost or defective branches; 



f— To adapt varieties to special soils; 



g— 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 Plajits that Unite by Grafting. Plants of 

 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 or- 

 der (21) sometimes unite by grafting. Examples, the 

 chestnut unites with the oak; the pear unites with the 

 thorn. ! I '-J 



Plants belonging to different families rarely unite 

 by grafting. The oak and walnut and the fir and lin- 

 den have been grafted. 



