266 



PHYSLOLOGV OF TREES. 



fact ; and though not easy to describe, may 

 easily be comprehended by the assistance of the 

 following figures : — 



The preceding figures are representations of 

 half a transverse section of a stem, six, and six 

 and a half years old. In figure A, o is the pith 5 

 1 is part of the first formed cylinder of wood, or 



