AN INNER LAW OF ITS ORGANISM. 187 



and branches of the tree, are subject to the same law of 

 fluctuation. At first we have powerful year's growths, a 

 rapid increase of shoots and broad wood rings, until the 

 tree gains its maximum height and spread ; then follows 

 a remission of growth, the year's shoots become always 

 shorter and more circumscribed, the increase of shoots dis- 

 appears, and the year's ring, or growth in thickness, becomes 

 smaller and smaller. 



In the gradual expiration of growth at the extremities of 

 the branches, when the tree has attained its greatest alti- 

 tude and passed the period of its prime, the following 

 stages of remission may be distinctly observed : 1. A little 

 annual development, with some branching, yet so that the 

 lateral shoots appear as clusters of leaves, no internodes 

 being formed between them. 2. Only single shoots, a little 

 developed, with here and there a bud formed. 3. Lengthen- 

 ing of the annual growths or shoots only through a bud 

 trace, with the formation of one or two leaves each year ; 

 no side productions whatever, and a vermicular curving of 

 the branches, yet with powerful terminal buds. 4. The 

 terminal bud pines, gradually loses the power of unfolding 

 itself, and finally dies. "With the death of the terminal 

 bud, and the cessation of the formation of any more leaves, 

 the further growth of the branch is necessarily completely 

 arrested. 



The same remission of growth shows itself in the de- 

 velopment of the branches, whose growth is gradually 

 retarded from one generation to another. The power of 

 any branch to give forth branchlets is not indefinite, but 

 has its appointed limits. New shoots are annually put 

 forth by the terminal and lateral buds of the branches, until 

 the vegetative powers of the branch are completely ex- 

 hausted. That, in each succeeding generation of shoots, 

 these powers are more and more enfeebled, is evident if we 

 cast only a momentary glance at the branch and its branch- 

 lets. We see that the branchlets become gradually smaller 

 and finer in proportion as their connection with the parent 

 branch is more remote, until finally the leaves which they 



