42 



TREES IN WINTER 



By aid of the markings just discussed on the stem the past his- 

 tory of the tree can be deciphered often for a considerable num- 



}—■ - Outer Bark 

 Inner BarK 

 --Cambium^ 



r Summer Wood 

 ■Spring Wood 

 |-AnnualPmg 



-Medullary Raij 



Med. "Ray 



' — Inner Bark "">^'' 

 Sap wood --' 

 -Outer BarK 



^^ Spring Wood 



Heart wood 



Fig. 22. Diagram to iUustrate structure of a block of Oak wood. 



