93 



edges of the assimilatory surfaces, which are backed by comparatively large epidermal 

 cells, and much larger than the hypodermal. The palisade cells form a good 

 marginal proportion of that part of the leaf substance. The clusters of dark 

 patches at the base of the decurrent channels are the parenchymatous cells 

 containing the manganese compound. In Figure 44 the chief feature of the 

 section, taken just below the free ends of the leaf, is the amount of leaf space 

 occupied by the oil cavity in each leaf, the secretory cells forming a distinct 

 jing. Between the base of the decurrent channel and the central axis, it will 

 be noticed that parenchymatous cells are closely packed, and having the man- 

 ganese contents staining black. 



The trefoil formed by the three-leaf sections varies in shape as in other 

 species. 



(c) Chemistry of the Leaf Oil. 



This material was forwarded by the Government of ^^'estern Australia, and 

 was received on the 15th July, 1903. There were numerous fruits upon the 

 branchlets, but these were removed and distilled separately. This oil is, therefore, 

 that of the leaves with terminal branchlets only. The distillation was continued 

 for six hours, and 287 lb. of material gave 12 oz. of oil, equal to 0-261 per cent. 

 The crude oil was somewhat dark in colour, but it had the odour of the Callitris 

 oils generally, particularly those containing a fair amount of the ester of borneol. 

 Up to the present time (1910) it has not deposited a resin on the sides of the bottle, 

 which result distinguishes it at once from all our samples of C. glauca and C. ver- 

 rucosa. It is also distinguished from the oil of C. glauca by a considerably less 

 rotation, a higher specific gravity, the presence of a sesquiterpene in small quantity, 

 and a less yield. It was also, at this later date, soluble in 10 volumes of 80 per 

 cent, alcohol by weight, and although somewhat less soluble in alcohol than when 

 freshly distilled, yet it did not become insoluble like the crude oils of C. glauca. 

 This fact probably accounts for the non-deposition of the insoluble resin. The 

 oil contained a large amount of dextro-rotatory pinene, proved by its chemical 

 combinations ; and judging from the results of the specific gravity and the rotation 

 of the larger fraction, together with the results of the redistillation, there is less 

 limonene and dipentene in the oil of this species than in that of C. glauca and 

 allied species. 



The ester content was fairly high for an oil of this group. It was found to 

 consist principally of the mixed acetic acid esters of borneol and geraniol. It 

 will be observed that the oil distilled from the fruits of this species had an 

 optical rotation in the opposite direction to that from the leaves, and that the 

 ester content was considerably less also. 



The specific gravity of the crude oil at 15° C. = 0-8825; rotation, 

 [(7]d = 4- 10-3°; refractive index at 19° C. = 1-4752. The saponification number 



