TREES AND TREES. 93 
Biology, botany, chemistry and the laws of light, heat 
and color can be studied in their growth and structure ; 
and he who enters this gateway of investigation will 
find a new and charmed land before him—it may be a 
wonder-land—but the first step taken will lead to the 
desire to explore the whole magic domain. As he looks 
upon that well-proportioned trunk towering into cloud- 
land, with its wide spreading branches crowned with. 
millions of shining leaves, he will wish to know how 
these have been silently gathered, atom by atom, from 
chaotic inorganic matter and so perfectly arranged and 
so exquisitely painted—how the cells of root, stem and 
leaf are formed—the material that enters into their 
composition—how they multiply and divide and arrange 
themselves like a big army of little workers to build up 
the huge citadel and to provide for the perpetuation of 
its kind. He will wish to know how the millions of 
root mouths suck the food from the earth and send it so 
far through such myriads of circling channels to. the 
leaves for digestion and assimilation—how the tree 
breathes through its countless stomata, leaf-mouths, ex- 
haling oxygen and inhaling carbon in sunlight, and 
reversing the process in the dark. He will wish to know 
why alternate leaves arrange themselves spirally on the 
stem with mathematical exactness; why the root seeks 
darkness and the stem the light, and why leaves are 
attracted strongly toward the blue and violet rays of 
light, while the yellow rays assist more in their develop- 
ment and growth. 
