78 THROUGH GLADE AND MEAD. 
than all other plants together. They are the staple 
cereals of the world, cultivated from time immemorial, 
wheat, rye, oats, barley, rice, millet, maize. There can 
be no doubt that they were originally selected from 
wild forms on account of the size, quantity and nutri- 
tive value of their seeds. And when this fact of their 
value was discovered, the discovery would soon follow 
that, by planting these seeds in suitable ground and 
caring fot the growing plants to the exclusion of all 
other vegetation, a certain and reliable source of food 
would be obtained; and here would be a beginning of 
agriculture, with capacity for infinite development. 
Wheat, rye, oats, barley, millet and rice are forms 
belonging to the old world, but now widely scattered 
over the new. The new world has, in return, given 
some gifts to the old, prominent among which are 
maize, the potato and tobacco, but the greatest of these 
is maize. With an acreage in the United States alone 
of seventy-eight million acres it is the largest arable 
crop grown in any country. Its overshadowing influ- 
ence in our agriculture is shown by the fact that the 
area devoted to its culture in many districts exceeds 
that given to the special crop for which that district is 
famous. The eleven states of our cotton belt devote, 
as a whole, a larger area of their cultivated land to corn 
than to cotton. It is so in the great wheat belt. In 
measured quantity our crop of a single year has 
