CHAPTER III 

 LIFE HISTORY OF A GYMNOSPERM (PINUS STROBUS) 



The White Pine frequently called the Weymouth Pine (Pinus 

 Strobus), one of the principal timber trees of the Northern States 



PIG. 19. Transverse section of white pine stem ot four years' growth, showing 

 cork (a), cortex (&), phloem (c), cambium (d), xylem (e), secretion reservoir (/), 

 pith (g) and medullary ray (&). (Photomicrograph.) X34O. 



and Canada, is also of value in pharmacy and medicine. The inner 

 bark of its trunk and branches is used because of its valuable ex- 

 pectorant properties and is official in the N. F. IV. 



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