316 



INTRODUCTION TO BOTANY 



all temperate regions, have been and are still extensively 

 used. But selection and improvement from these wild ances- 

 tors have given us varieties greatly superior to the wild types. 

 Even to-day, however, there are many people who plant fruit 



trees and act as if they 

 believed that the tree 

 should live and pro- 

 duce as an essentially 

 wild plant. The plants 

 which are the basis of 

 horticulture have many 

 things in common with 

 all other plant life. 

 They must have suit- 

 able soil and moisture, 

 proper exposure to the 

 light, freedom from de- 

 structive enemies, and 

 proper cultivation, else 

 they cannot manufac- 

 ture their own food 

 material and the fruit 

 which men want to 

 produce. Most of the 

 soil of the United 

 States is good for hor- 

 ticulture if men will 

 do the things necessary 

 for proper production 

 of fruit. Distant re- 

 gions may for a time 

 seem attractive to fruit growers, on account of their freedom 

 from diseases, but diseases eventually enter even these distant 

 regions and affect the crop. Migration to new territory is not 

 nearly so important in fruit growing as a thorough study 

 and application of the science of horticulture. 



FIG. 235. An old grafted apple tree 



This illustrates an old and well-nigh discarded 

 method of stem grafting. The stock is much 

 larger than the scion, owing possibly to imper- 

 fect union of tissues and possibly to difference 

 in normal rate of stem thickening. The absence 

 of proper care in pruning this tree is a feature 

 too often seen 



