98 GROWING GOLD. 



size of a tree is by a fluid or sap rising 

 between the bark and the wood, and which 

 first forms the inner silky bark or liber; 

 these layers form into rings, tubes, or vessels, 

 of which the whole vegetable body is an 

 assemblage, and that the most vigorous trees 

 sooner make the most perfect wood. — Smith's 

 Intro. Bot, p. 33, 34, 36. 



Therefore, if Messrs. Jesse and Withers 

 are right in their statements of the rapid 

 growth of oak trees in the period they give, 

 it follows that a healthy tree would continue, 

 if sufficiently protected, to increase at a 

 compound rate in every part, at the same 

 time ; consequently, it is possible that it does 

 not require much more than double the time 

 the trees of the just named gentlemen had 

 to grow in, to be as large as the Hatfield 

 Bog and Selbourne oaks. It clearly ap- 

 pears that the silky bark is formed quite 

 round each tree, and it is equally so that, 

 however high they are, the sap ascends to 

 the whole length of them every spring; 



