The Pines of Australia. 



139 



Figure 79. — Transverse section of timber through spring growth, bounded 

 on the top and bottom by an autumnal ring of tracheids. 

 C. glaiica, X 30. 



Figure SO.— Transverse section of timber. The dark lines are the 

 medullary rays with their manganese compound contents 

 and the rectangular dark markings the similar contents of 

 the tracheids. C glattca, x 80. 



^^<BKp^ 



Figure 81. — Transverse section of timber at junction of spring and 

 autumnal tracheids, C. glaiica, x So. 



Figure 82. — Transverse section of timber showing structure of spring 

 tracheids in greater detail than in Figure Si. C. glauca, 

 X 210. 



Cross sections of timber of C, glauca, R,Br, 



