Green Leaves at Work 93 



numerous, as to give their hue to the whole leaf. 

 These specks are chlorophyll bodies, and they are 

 the cause of the rich and tender green in summer 

 fields and woodlands. 



The closely-packed tissue of the upper side of 

 the leaf contains many cells, and hence many 

 chlorophyll bodies. 



But Nature has not economized space in the 

 arrangement of the lower leaf-cells, and where 

 cells are comparatively scarce chlorophyll is scarce 

 also. Hence, the under surfaces of leaves are often 

 pale in hue. 



Chlorophyll is formed only under the direct light 

 of the sun. Tender young leaves, which have 

 been shut up under bud-scales in the dark, con- 

 tain as yet but few of the useful little green 

 grains. The sun has not yet given them their 

 working outfit, so expanding foliage is seldom really 

 green. The budding oaks are of a warm reddish- 

 brown or gosling-gray, according to their species. 

 The new leaves of the poplars are silvery, and 

 those of the willows are almost golden. 



Even the vegetable garden, when things are be- 

 ginning to wake there, is a symphony of delicate 

 color. The very smallest carrot-leaves are yellow 

 or golden brown. 



