LEAVES. 39 



later, and then the second will be a month later, like- 

 wise. One of the very earliest to expand its foliage, 

 is the balsam-poplar. The buds of this are covered 

 with aromatic resin, so that with the evolution of the 

 yellow tips, the air becomes loaded with fragrance, 

 and very delightful is it to perceive the presence of 

 the tree when going along quietly after dark, by the 

 richness of the odor that presently meets our nostrils. 

 The foliage when it first comes out, is remarkable for 

 its yellowness. This tint is so far from uncommon, 

 that it may be regarded as the normal and character- 

 istic color of very young foliage, and of such as has 

 not been exposed to the full influence of the solar 

 light ; in the balsam-poplar, however, it is specially 

 noticeable. After a few days, when the warmth and 

 brightness of the sun's rays have made themselves 

 felt, the leaves acquire the ordinary green hue. The 

 influence of light in thus giving color to vegetable 

 matter, is one of the most striking and beautiful opera- 

 tions that we can witness in surveying nature. Let 

 any fruit be half concealed by thick foliage, and it re- 

 mains pale. If a stone lie upon the lawn or anywhere 

 conceal the grass, on removing it, the space that was 

 covered is found to be destitute of true green. In a 

 few days, however, all is changed ; the sun, like a 

 great magician, touches what was so pallid with his 

 beams of enchantment, and rich and glorious hues are 

 almost immediately called forth. Everywhere, in the 



