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NATURE FOR ITS OWN SAKE 



which it runs over daily with the shifting of 

 the sun. Light transforms all things, and we 

 have already seen what changes it may produce 

 upon the foliage of a mountain-top. The 

 leaves are heightened, deepened, bleached, or 

 distorted, according to their texture or light- 

 reflecting capacity. Often the green of a tree- 

 top is turned to cold gray under a noonday 

 sun, and at sunset, when the trunks of the 

 trees are in shadow and their tops in full sun- 

 light, everyone knows what a sharp contrast 

 appears. The top is yellow, the body dark 

 green. If the tree has a glossy leaf, the whole 

 top may be a mass of reflected light. The 

 tall tulip, the sycamore, or the chestnut at 

 evening, with its loftiest leaves apparently 

 changed into small shields of flashing light, is 

 not an uncommon spectacle. 



I fear that many of us have small conception 

 of the changes that may take place in a green 

 leaf in the course of a single day. It is green 

 in our hand, and we naturally think it must be 

 green on the tree ; and so the easy conclusion is 

 reached that leaves in summer are green and 

 never anything else. But they are seldom the 

 same green for any length of time. I once tried 

 to keep a record from day to day of the color- 



