98 



periderm layers. In the inner bark the bast hbres and uniform parenchymatous 

 cells are the salient features, whilst in the outer, the irregularly shaped parenchy- 

 matous cells are more conspicuous. 



Figure 50. — Transverse section through bark. The three faint bands 

 running across the picture in the top half are periderm 

 layers. C. robusta, x 70. 



(c) Chemistry. 



The specimen of bark investigated was received by the Museum from the 

 Government of Western Australia. It was from timber of small dimensions, being 

 only 2 to 3 inches in diameter ; so that it can hardly be considered representative of 

 the bark of this species. The thicker bark was not available, but there is no reason to 

 suppose that it will be found to materially differ from the other barks of this class, 

 C. glauca, for instance. The bark determined was dark grey externally, fibrous, 

 and not deeply furrowed, as it was too young, and was only from 4 to 6 mm. in 

 thickness. 



The following results were obtained with the air-dried bark : — 



Moisture 



11-4 per cent 



Total extract 



13-5 



Xon-tannin 



4-8 „ 



Tannin 



8-7 „ 



