CHAPTER II: THE GROWTH OF A TREE 



The great chestnut tree on the hillside has cast its burden 

 of ripe nuts, flung down the empty burs, and given its yellow 

 leaves to the autumn winds. Now the owner has cut down its 

 twin, which was too near a neighbour for the well-being of either, 

 and is converting it into lumber. The lopped limbs have gone 

 to the woodpile, and the boards will be dressed and polished and 

 used for the woodwork of the new house. Here is our opportunity 

 to see what the bark of the living tree conceals to study the 

 anatomy of the tree to learn something of grain, and wood rings 

 and knots. 



The most amazing fact is that this "too, too solid flesh" of 

 the tree body was all made of dirty water and carbonic-acid gas. 

 Well may we feel a kind of awe and reverence for the leaves and 

 the cambium the builders of this wooden structure we call a 

 tree. The bark, or outer garment, covers the tree completely, 

 from tip of farthest root to tip of highest twig. Under the bark 

 is the slimy, colourless living layer, the cambium, which we may 

 define as the separation between wood and bark. It seems to 

 have no perceptible diameter, though it impregnates with its 

 substance the wood and bark next to it. This cambium is a 

 continuous under garment, lining the bark everywhere, covering 

 the wood of every root and every twig as well as of the trunk 

 and all its larger divisions. 



Under the cambium is the wood, which forms the real body 

 of the tree. It is a hard and fibrous substance, which in cross 

 section of root or trunk or limb or twig is seen to be in fine, but 

 distinctly marked, concentric rings about a central pith. This 

 pith is most conspicuous in the twigs. 



Now, what does the chestnut tree accomplish in a single 

 growing season? We have seen its buds open in early spring 

 and watched the leafy shoots unfold. Many of these bore clus- 

 ters of blossoms in midsummer, long yellow spikes, shaking out 

 a mist of pollen, and falling away at length, while the incon- 

 spicuous green flowers developed into spiny, velvet-lined burs 



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