222 FAMILIAR FEATURES OF THE ROADSIDE. 



sunlight does not readily get at the narrow leaves, and 

 they reilect very little light. Quite the opposite is 

 true of a young leaf of the gray birch (yBetula popu- 

 lifoUa). This is bright, shiny yellow-green, very 

 responsive to sunlight, and in strong contrast with 

 the dull dark hue of the long-beaked willow leaf. 

 But of all the yellow-green leaves which we can find 

 in the woodland not one is comparable to that of 

 either the young red mulberry {Morns rxibra) or 

 the young Indian poke ( Yeratrum viride) ; these are 

 inexpressibly tender and pure in color. 



It is only by comparison that we can gauge the 

 strength of color. Ked reveals its full power only 

 by its environment ; this can be proved in an instant 

 by a very simple experiment. Suppose we take a bit 

 of purple paper, and, cutting a round hole in the 

 center, place a bit of scarlet paper behind it ; next, 

 we will treat a bit of yellow paper in the same way, 

 placing another piece of the same scarlet paper be- 

 hind that. What is the result ? The two scarlets 

 no longer appear equally strong ; that behind the 

 yellow paper seems to be much darker ! 



The distant mountain appears quite blue ; but if 

 there is a lingering uncertainty about that, it all van- 

 ishes if we will suifer for an instant the discomfort 

 of turning our heads upside down and viewing the 

 landscape that way. The mountain is now intensely 



