66 



than the oil of C. glaiica. The yield was 0-558 per cent. The cr3-stanine con- 

 stituent was separated from the oily portion in the manner previously stated, 

 and when puritied was found to be Gnaiol. It was sinnlar in crystalline form, 

 melted at 91° C, and altogether was identical with the substance isolated from 

 the wood of C. glaiica. 



The timber of C. MiicU'dyuiKi has little resemblance to the hard compact 

 wood of the CaUitris generally", so that from this result, it may be assumed that 

 Guaiol will be found occurring in the wood of all the species of Australian 

 CaUitris. 



The timber of C. intratropica ^ecei^•ed from Port Darwin, had the charac- 

 teristic odour of the Australian CaUitris wood most marked. When cut, the 

 Guaiol was so pronounced a constituent that it crystallised upon the planed 

 surface of the wood itself, and suflicient material was obtained to chemically 

 identify it as Guaiol ; so that it was not even necessary to steam-distil the wood. 

 It was thought better, however, to isolate it in the ordinary way, and both Guaiol 

 and Callitrol were obtained. Guaiol often crystallises out on the freshly-cut 

 surfaces of the timber of other species of CaUitris. 



It is, perhaps, worthy of note that this substance is contained in the wood 

 of trees so far removed as the CaUitris (Coniferse) of Australia, and the Z3^go- 

 phyllaceae of South America. 



No other crystalline substance than Guaiol has been detected in the steam- 

 distilled products of CaUitris timber. 



XVIII. BARK. 



Microscopical. 



The bark of the CaUitris in a general sense may be described as consisting 

 of alternating concentric rings of (i) uniseriate sclerenchymatous, elongated, 

 thick-walled fibrous cells, — the bast fibres, (2) a row of parenchymatous cells 

 between, (3) two rows of sieve tubes each adjacent to the bast fibres, and (4) 

 bands of several layers of cork cells or periderm in the outer cortex. 



These various structures characterise botli tli<' iimer and outer cortex. 

 Running radially through these are the parenchymatous-celled medullary rays, 

 dividing the whole into bast rays which correspond to the (■<]ui\ak'nt rays and 

 strands of the wood. 



Throughout are scattered in an irregular manix i' numerous oleo-rcsin 

 xnties. Stone cells were not found. 



