312 HANDBOOK OF NATURE STUDY 



and light ; climate and temperature influence his well-being, 

 and he depends for food on the soil he tills. 



Man has, however, on his part, exerted a most powerful 

 influence upon nature. By converting forests and prairies 

 into fields, by draining swamps, by building cities, roads, 

 and railways, he has changed the aspect of whole conti- 

 nents. He has exterminated many animals and domes- 

 ticated others, causing them to increase far beyond the 

 number which they could have reached in a wild state. 

 Man's physical strength is not great, if we compare him 

 with the largest animals; but his hand, directed by a 

 superior intellect, is able either to subdue or exterminate 

 the fiercest and largest animals. His intellect has invented 

 means which enable him to cross the never-resting ocean, 

 as well as the dreary desert ; he can live tinder the heat of 

 an equatorial sun and on the ice fields of Greenland; the 

 sunlight paints his pictures, and the lightning's flash con- 

 veys his thoughts around the globe ; he is fulfilling the 

 prophetic words, " Replenish the earth and subdue it, and 

 have dominion over the fish of the sea and over the fowl of 

 the air, and over everything that moveth upon the earth." 



Man is the only being on earth that is conscious of the laws 

 and workings of nature. 



86. Just as every plant, every animal, and every stone 

 on the earth is only a part of the whole and is intimately 

 connected with the whole, so the earth itself is only one of 

 the large heavenly bodies of our solar system. For its life- 

 giving warmth and light, the earth depends on the sun; and if 

 his blazing light should ever be extinguished, all life on our 

 earth would become extinct. 



