94 THE GARDEN OF EARTH 



For here are numberless tiny green specks, which lend 

 their colour to the leaves. All through the green leaves 

 of plants, and the green blades of grasses, and young 

 green stems and shoots, they float in vast hordes. 

 They are found also, to some extent, in the petals of 

 flowers, in seeds and fruits, and even in roots; but 

 not nearly so abundantly. 



And it is only where these little green specks con- 

 gregate, that the work can be done of which we have 

 been thinking that particular work which is given to 

 leaves; the taking up of lifeless materials from earth 

 and air, and so changing and fashioning them into new 

 substances, that they are fitted to become food for 

 animals and men. 



A curious fact is that the living cells in a leaf first 

 make this leaf-green; and then, having manufactured 

 it, they use it for their tremendously important work. 



" How can they possibly do all this ? " you may ask ; 

 and indeed you may well ask it ! In one sense I can 

 give no clear answer. In another sense I can. For 

 here comes in the second great power; and that power 

 is Sunlight. 



Sunlight and leaf-green work together in a happy 

 comradeship. Without the Sun, the leaf-green could 

 do nothing ; and without the leaf-green * the Sun could 

 not carry out this task. Each apart from the other is 

 powerless to break up the carbonic-acid gas of the air, 

 keeping the carbon for the building up of the tree, and 

 setting loose the oxygen for us to breathe. Each, 

 apart from the other, is also powerless to provide in 



1 The " leaf -green " is known by the name of " chlorophyll," 



