120 ECONOMIC IMPORTANCE OF GREEN PLANTS 



cation of plants and animals marks epochs in the advance of civili- 

 zation. The man of the stone age hunted wild beasts for food, 

 and lived like one of them in a cave or wherever he happened to 

 be ; he was a nomad, a wanderer, with no fixed home. He may 

 have discovered that wild roots or grains were good to eat ; per- 

 haps he stored some away for future use. Then came the idea of 

 growing things at home instead of digging or gathering the wild 

 fruits from the forest and plain. The tribes which first cultivated 

 the soil made a great step in advance, for they had as a result a 

 fixed place for habitation. The cultivation of grains and cereals 

 gave them a store of food which could be used at times when other 

 food was scarce. The word " cereal " (derived from Ceres, the 

 Roman Goddess of Agriculture) shows the importance of this crop 

 to Roman civilization. From earliest times the growing of grain 

 and the progress of civilization have gone hand in hand. As 

 nations have advanced in power, their dependence upon the cereal 

 crops has been greater and greater. 



^' Indian corn," says John Fiske, in The Discovery of America, 

 '' has played a most important part in the history of the New 

 World. It could be planted without clearing or plowing the soil. 

 There was no need of threshing or winnowing. Sown in tilled land, 

 it yields more than twice as much food per acre as any other kind 

 of grain. This was of incalculable advantage to the English 

 settlers in New England, who would have found it much harder 

 to gain a secure foothold upon the soil if they had had to begin by 

 preparing it for wheat or rye." 



To-day, in spite of the great wealth which comes from our 

 mineral resources, live stock, and manufactured products, the 

 surest index of our country's prosperity is the size of the corn 

 and wheat crop. According to the last census, the amount of 

 capital invested in agriculture was over $20,000,000,000, while 

 that invested in manufacture was less than one half that amount. 



Corn. — About three billion bushels of corn were raised in the 

 United States during the year 1910. This figure is so enormous 

 that it has but little meaning to us. In the past half century 

 our corn crop has increased over 350 per cent. Illinois and Iowa 

 are the greatest corn-producing states, each having a yearly record 



