ON THE YOUNG BARK. 27 



terminal branches of the tree and study them carefully, we 

 shall obtain clear and truthful views, not only of the con- 

 dition of the tree during the first years of its life, but of 

 those general and peculiar laws of growth which govern the 

 entire tree itself. All the apparent confusion and irregu- 

 larity among the branches and branchlets of a tree is the 

 result of the operation of fixed and immutable laws of 

 growth, to which the whole tree is subjected in common with 

 each of its parts. The entire tree is not different from one 

 of its branches in the principles of its construction. In 

 fact, if one of the branches were severed from the stem and 

 planted, it would not only represent one of the phases of 

 growth of the tree, at an earlier stage of its life, but under 

 favorable circumstances would actually grow into a separate 

 and independent tree. 



In this, as in the figures of leaves, we have avoided an ex-' 

 travagance of illustration, in order that our book may not be 

 rendered too expensive. Besides, it is unnecessary. Trees 

 are all constructed on the same general plan. Hence, we 

 have taken our material, not from deep resources, but from 

 common objects. It is proper here to remark, that the reader 

 will understand more clearly the positions assumed, if he pro- 

 cure a number of branches of different trees, such as the beech, 

 the hickory, the horse-chestnut, when defoliated or in winter, 

 and attentively study the marks on the exterior of the bark 

 and the mode of ramification. If the branches are gathered 

 when the trees are in leaf, the foliage must be removed. 



The reader is already prepared to admit, without further 

 proof, that the growth of the tree is very fluctuating, and is 

 greatly influenced by changes in the weather. In this re- 

 spect, the organism of a tree is quite as sensitive as the 

 mercurial column in the tube of a Barometer. It is well- 

 known that the age of a tree may be ascertained by counting 

 the rings visible on the cross section of its stem, and that 

 the impress of centuries of seasons has been faithfully re- 

 corded in its woody layers. The seasons also leave their 

 mark on the outside as well as the inside of the tree. When 

 the young shoot, in early spring, unfolds itself from the bud, 



