PLANT COVERING OF THE EARTH. 171 



essential to him, and he thus can measure how 

 great is his enjoyment in the sight of forests. 



The woods not only afford a noble life in their 

 own trees, but they supply a place for the protec- 

 tion of a host of beautiful animals. A large number 

 of our birds are not found in countries where trees 

 do not abound. Our squirrels and various other 

 mammals depend upon the forests for their main- 

 tenance. Thus the woods maintain a wider range 

 of animals than can possibly exist in countries 

 w T here there are no forests. 



