95 



IV. TIMBER. 



(a) Economics. 



This is a light-coloured, fairly hard timber, having a good straight grain, 

 and very suitable for house-building, railway sleepers, posts, &c., in the white-ant 

 infested districts of Western Australia, as, like its congeners, the termites do not 

 relish it. 



The late Mr. Ednie Brown, Conservator of Forests, Western Australia, spoke 

 well of this timber in this connection, and recommended it on this account for 

 forestry cultivation. 



It could be used for panelling and similar purposes to which the Callitris of 

 Eastern Australia are put. 



Test : — Timber not available. 



(b) Anatomy. 



The specific features characterising the microscopical sections of this wood 

 are, (i) the presence of the dark manganese compound in some of the cells of the 

 secondary xylem or prosenchyma- 

 tous cells, and its frequent absence 

 in the medullary rays. 



The tangential sections 

 shown are characterised by, (i) 

 the absence of the dark brown 

 substance in the lumina, — the 

 knife having cut clear of this com- 

 pound — (2) the rows of bordered 

 pits in section on the radial 

 walls, (3) the few cells in height 

 of the medullary rays, and (4) the 

 almost entire absence of the man- 

 ganese compound content com- 

 pared with those of other species. 

 It must not, however, be con- 

 cluded that it never occurs in the 

 cells of this timber. 



Figure 45. — Transverse section through timber. The one ray in the 

 picture has no cell content. The row of narrow tracheids 

 across' the picture marks the limit of autumnal growth. 

 The black cell contents are the manganese compound. C. 

 robusta, x 80. 



The transverse sections show^ however^ cells of the xylem containing the 

 manganese compound to be promiscuously distributed throughout the prosehchy- 

 matous cells, and scattered irregularly throughout each season's growth of xylem 

 as demonstrated in Figures 45 and 46. 



