186 DEATH OF THE TREE FOUNDED ON 



remain permanently connected witli its structure is accele- 

 rated during the earlier part of their life, and retarded as 

 they arrive at maturity and towards its close. Thus the 

 growths made yearly are accelerated during the early part 

 of the vegetative season, when the conditions are the most 

 favorable, and gradually retarded as the season advances ; 

 till, finally, the growths cease altogether, and the tree con- 

 tinues in a state of passive vitality through the winter 

 months, being in precisely the same condition as a seed 

 before it germinates. With the return of Spring and warm 

 weather, the vitality of the seed and tree again becomes 

 active ; the former germinates, and the latter puts forth 

 new leaves and shoots, and is again covered with its usual 

 exuberance of foliage. This we have called, in Chapter 

 VI, "the annual wave." 



But there is also a " grand life-wave." For these yearly 

 growths themselves, I mean those made by the main stem 

 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 

 disappears, 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 

 annular 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. 

 Lengthening of the annular 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 



