PLANT COMMUNITIES: SEASONAL CHANGES. 335 



yellow-green of the young leaves, which presents to us a warm- 

 ing glow of color. Then the snow-clad fields change to gray, 

 and soon are enveloped in a living sea of color. The quiet 

 hum of myriads of opening buds and flowers in harmony with 

 the general awakening of nature, and the trickling streamlets 

 which unite into the gurgling brooks, makes sweet music to 

 our attentive minds. 



501. Contrast of color in evergreens. — The evergreens dis- 

 play a striking contrast of color. The leafy, fan-shaped 

 branches of the hemlock-spruce (tsuga) are fringed with the 

 light green of the new growth. The pines lift up numbers of 

 cylindrical shoots, with the leaf fascicles for a time sheathed in 

 the whitened scales, while the shoots are tipped with the brown 

 or flame-colored female flowers, reminding one of a Christmas 

 tree lighted with numerous candles. The numerous clusters of 

 staminate flowers suggest the bundles of toys and gifts, and one 

 inquires if this beautiful aspect of some pines when putting on 

 their new growth did not suggest the idea of the Christmas tree 

 at yule time. 



502. The summer tints are more subdued. — As summer time 

 draws on the new needles of the pine are unsheathed, the light 

 green tints of the forest are succeeded by darker and subdued 

 colors, which better protect the living substance from the 

 intense light and heat of midsummer. The physiological 

 processes for which the leaf is fitted go on, and formative 

 materials are evolved in the countless chlorophyll bodies and 

 transported to growing regions, or stored for future use. In 

 transpiration the leaf is the terminus of the great water current 

 started by the roots. Here the nutrient materials, for which 

 the water serves as a vehicle, are held back, while the surplus 

 water evaporates into the air in volumes which surprise us when 

 we know that it is unseen. 



503. Autumn colors. — As summer is succeeded by autumn, 

 a series of automatic processes goes on in the plant which fits 

 it for its long winter rest again. Long before the frosts appear, 



