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 
Fie. 285. An old grafted apple tree 
This illustrates an old and well-nigh discarded 
method of stem grafting. The stock is much 
Jarger 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 
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. 
