Introduction 



IT would be a difficult task to answer the question, why some 

 plants possess the property of forming wood, while others, nearly 

 related, do not. Why some plants run their course in the brief 

 period of a year, and perish as soon as they have given birth to 

 another generation, while others persist and augment their bulk 

 year by year for centuries. There is much food for reflection 

 here. 



Such plants as are endowed with the faculty of secreting a 

 substance which resists decomposition for a long time, and of 

 fortifying their tissues with it, play a very different part in the 

 world's economy to that of their herbaceous relatives, which to-day 

 are, and to-morrow are cast into the oven. They exist long enough 

 to acquire an individual history. This history may not be 

 written in human records, but it has a record of another kind, 

 which may be read in the structure of the tree itself, which, like 

 the Nautilus, adds a chamber to its habitation every year by 

 surrounding itself with a fresh layer of wood. 



These layers are perhaps the most familiar feature with which 

 all those who have used timber, or have noted the cut ends of 

 fallen trees, are acquainted, but it occurs to few that the inner- 

 most tiny ring enclosing the pith is the section of a stick that 

 was once the seedling tree. The Seedling is a small object, a 

 few inches high at most, and the layers which have been 

 added year by year, were it possible to separate them, would 

 appear as long taper tubes of wood. 



In felling Beech, it is not an uncommon occurrence for the young 

 sapling to be drawn out of the tree as it falls, if the centre layers 

 of the butt have not been severed. It will remain standing upon 

 the stump like a peeled wand, and upon it the original knots can 

 be seen. 



The annual addition to a tree's growth is, in fact, a conical 

 sheath tapering to a point, and capable of accommodating the 

 plant within to its topmost bud. A seedling is two years old, 

 but not as a child, who is two years old to his innermost parts, for 

 the tree is only one year old as regards its outer portion. The 

 two layers are not merged in one another ; the second is merely 

 added. In the case of a full-grown Oak, a century old, only 



xi 



