CHAPTEE XXYIII. 
NATURAL SELECTION 
The principle of selection has long been applied 
by agriculturists for the purpose of improving their 
stock and their crops. 
One of our neighbors, who thought that the small 
potatoes would do as well for seed as the large ones, 
sold the best and used for seed those too small to sell. 
It required only four years, however, to prove his 
mistake to his entire satisfaction. His potatoes had 
“run out,” as he expressed it. Most of his crop 
were small, while his neighbors had fine tubers. 
All the numerous varieties of potatoes have been 
produced from a single variety by selecting for seed 
those tubers which had the desirable qualities to the 
greatest extent. Food and environment aided in in¬ 
tensifying the variation. 
It is quite probable that the varieties of corn—not 
only the field-corn, but pop-corn and sweet corn— 
came from a single kind. The same is true of most 
of the crops that man raises. 
The tomato is perhaps the most remarkable of our 
garden vegetables. This berry, now so common, has 
had only one century of cultivation. In its original 
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