26 
THE) STORY OF THE) OAK TREE) 
Naturally enough, the botanists have made guesses 
about this mystery, and good enough guesses too, but 
they are not satisfied with their own guesses. They 
have guessed that something called root pressure makes 
the sap ascend, something called osmotic pressure, and 
another something they name capillary attraction draws 
the sap up along the trunk. But do not let anybody 
frighten you by big words. If you study the trees and 
come to know them and to love them, I should not be 
surprised if one of you, when you are grown, and have 
learned much, much more about the trees than I can tell 
you, should lean your ear some day to the root of an 
oak and hear the great secret! 
Wood-Grain 
This is the way that the sap river ran 
From the root to the top of the tree 
Silent and dark 
Under the bark 
Working a wonderful plan 
That the leaves never know, 
And the branches that grow 
On the brink of the tide never see. 
John B. Tabb. 
