ECONOMIC IMPORTANCE OF GREEN PLANTS 121 



of over four hundred million bushels. The figure on this page 

 shows the principal corn-producing areas in the United States. 



Indian com is put to many uses. It is a valuable food, it con- 

 tains a large proportion of starch, from which glucose (grape sugar) 

 and alcohol are made. Machine oil and soap are made from it. 

 The leaves and stalk are an excellent fodder ; they can be made 

 into paper and packing material. Mattresses can be stuffed with 



"^^ 



/ ^"L 



CORN 



640 to 3200 bushels per saaare mile 

 oyer 3200 „ „ » » 



Indian Corn Production — Percentage 



Illinois 



Iowa 



Mo. 



Neb. Ind. Kan. Tex. Ohio 



Rest of United States 



the husks. The pith is used as a protective belt placed below the 

 water line of our huge battleships. Corn cobs are used for fuel, 

 one hundred bushels having the fuel value of a ton of coal. 



Wheat. — Wheat is the crop of next greatest importance in size. 

 Nearly seven hundred millions of bushels were raised in this 

 country in 1910, representing a total money value of over $700,- 

 000,000. Seventy-two per cent of all the wheat raised comes from 

 the North Central states and California. About three fourths of 

 the wheat crop is exported, nearly one half of it to Great Britain, 

 thus indirectly giving employment to thousands of people on rail- 

 ways and steamships. Wheat has its chief use in its manufacture 



