20 NATURE STUDY. 



adapted by position, arrangement, and veining to direct 

 water toward the roots. 



Clustered between their broadened bases, often 

 wrapped about by them, are tiny leaf and flower buds. 

 The leaves help to protect these. 



The leaves are not merely arranged so as to give each 

 leaf as much sunlight as possible, but those in high 

 grass grow up toward the sun, and those in shady 

 places grow out from the shade toward the sun. Evi- 

 dently they have some reason for seeking the sun- 

 light. 



If we cover a small growing dandelion plant with an 

 inverted glass tumbler or fruit can, we soon discover, if 

 the plant is in the sun, little drops of moisture on the 

 inner surface of the glass ; if in the shade, the moisture 

 appears more slowly. By preventing the passage of 

 moisture from any part of the plant except the leaves 

 (spreading paper over the ground under the leaves), we 

 can show that the moisture comes from the leaves. We 

 learn that the leaves throw out much of the moisture 

 absorbed by the rootlets, and that the sun or sunlight 

 aids them. They are adapted to throw out moisture by 

 their form, broad and thin, with a very large surface. 

 By their position and arrangement, with nearly all of 

 every leaf exposed to the sun, they get the greatest 

 possible help from the sun. The skin (epidermis) with 

 which they are covered prevents too rapid escape of 

 moisture. Microscopic examination shows great num- 

 bers of little openings in the skin (breathing-pores, or 

 stomatcf), which have the power of closing and opening, 



