CHAPTER XXX 



IMPORTANCE OF PLANTS TO MAN 



Economic importance. Plants are of great economic 

 importance to man. Some of them are important 

 because they are beneficial; others, because they are 

 injurious. As to benefits: they supply man "with his 

 cereals and flour, his fruits and garden vegetables, his 

 nuts and spices, his beverages and the sugar to sweeten 

 them, his medicines and his dyestuffs; they supply 

 the material out of which many of his clothes are made, 

 the thread with which they are sewed together, the 

 paper which covers the packages in which they are 

 delivered, and the string with which the package is tied. 

 The various uses of the forest have been mentioned 

 before; the need of trees to protect the earth, their 

 usefulness in the holding of the water supply, their 

 direct economic importance for lumber and firewood. 

 Many of us forget, too, that much of the energy 

 released on this earth to man, as heat, light, or motive 

 power, comes from the dead and compressed bodies of 

 plants which thousands of years ago lived on the earth 

 and now form coal. Plants are thus seen to be of 

 immense direct economic importance to mankind."* 



*Hunter, Essentials of Biology. American Book Company. 



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