296 



of the tracheids with pitted cells in section, 

 scattered irregvilarly throughout tlie xylem ; 



■-^^ 



Figure 211 



-Radial -section tbrouyli timbi-r. Rays arc only faintly 

 indicated. A broad band of traumatic ri-^in mass runs 

 through the* centre of the picture from top to tiottom — 

 a vi.Ty r.arc occurrence in Austr.alian Conifcr.-c. The black 

 interrupted lines are the manganese compoimd in the 

 tracheids, the walls of which are quite covered with bordered 

 pits. .-!, pyramidalis, x 80. 



The rays are fairly numerous, and 

 the cells which are parenchymatous 

 being, perhaps, fewer in height 

 than obtains in most species of 

 the cognate genus Callitris, but 

 resembling these in being only a 

 cell in breadth, at the same time 

 they are relatively wider. About 

 50 per cent, of the ray cells were 

 found to be filled with the man- 

 ganese compound. The radial 

 walls of the tracheids appear to 

 be covered almost entirely with 

 bordered pits (Figure 210), a 

 somewhat characteristic difference 

 from Callitris species. A radial 

 section taken also from the dura- 

 men, indicated in this species by 

 a darker colour than the sapwood, 

 also shows the rays to be fairly 

 numerous^ the simple pits of the 

 rays varying in number from two 

 to four in each lumen. 



Figures 208 and 211 show a 

 transverse and longitudinal section respectively of a comparatively broad and 

 what we regard as a traumatic resin reservoir. 



It may be noted that only one pitted cell occupies the diameter of a 

 tracheid, the walls of which are, as above stated, simply covered with them. 



In the secondary xvlem the cells containing the brown manganese coiu])ound 

 are in jjeripheral zones, mostly close to the autumnal wood. 



A transverse section shows the traclieid walls to be ratlicr more iiregular 

 in shape than those of the CuUiiris. (Figures 207-208.) 



V. iJARK. 



(«) Economic (vide Chemistry). 



{b) Anatomy. 

 Anatomically the bark presents a somewhat similar structure with that 

 of the closely allied genus Callitris. The sclerenchymatous cells form con- 

 centric rings regularly alternating with three rows composed of <iiic cciitrai 



