110 



LETTERS ON TREES. 



of the processes of nutrition and growth," which/ in 

 truth, is in respect of iheivliole of their vital actions, trees 

 are made up of annuals, — growing upon the remains 

 of annuals. And the uses of these remains, in relation 

 to the living annuals, he mentions in terms almost 

 identical with my own : — " The growth of one year 

 (or rather what remains of that growth), is only suh- 

 servient to the circulation of the next," — not being 

 itself (beyond the year of its formation) the seat or 

 subject of any further growth, or indeed of any vital 

 action, but simply serving as the channel by which 

 the sap passes upwards to the living and growing 

 parts above it, and it is ever afterwards of use merely 

 in giving strength and stability to the trunk in order 

 to support the increasing size and weight of the 

 branches and leaves," — that is, it serves as a frame- 

 work or scaffolding to the living annuals growing as 

 parasites upon it (Letter IV. 7). And important as 

 this purely mechanical use which it serves is, it has 

 become useless for every other purpose." Though 

 clothed and decked in a living mantle of green, it 

 is itself really dead. And this beautiful arrangement 

 is an express adaptation to the whole nature and 

 economy of trees. They go on growing to an inde- 

 finite extent," because in the annual formation of 

 " fixed embryos" provision is made for such indefinite 

 growth : Yet this requires a " corresponding increase 

 and strength in those parts which are to support 



