92 



FOUNDATIONS OF BOTANY 



(5) Cambium (e.g., Fig. 57, c). 



(6) Wood-cells (e.g., Figs. 58, 72-73). 



(7) Vessels or ducts (e.g., Figs. 58 and 62). 



(8) Wood parenchyma (e.g., Figs. 58 and 72 in the medullary 



rays). 



(9) Pith (e.g., Figs. 55, 57). 



105. Structure of Coniferous Wood In the wood of 



the cone-bearing trees of the pine family regular ducts or 



FIG. 61. FIG. 62. 



FIG. 61. A Group of Hard Bast Fibers. (Greatly magnified.) 

 a, cut-off ends ; b, lengthwise section of fibers. 



FIG. 62. A Lengthwise Section (greatly magnified) of a Group of Spiral Vessels 

 from the Stem of Sunflower. At the top of the figure some of the spiral 

 threads which line the vessels are seen partly uncoiled. 



vessels are lacking. The main bulk of the wood is com- 

 posed of long cells (often called tracheids), marked with 



