104 



with the manganese compound are stained a dark brown. In Figure 52 similar 

 remarks to Xo. 51 apply in this illustration, but a dorsal ridge is shown on each 

 leaf, giving a slightly different contour to the trefoil. The central axis is 

 composed of three bundles as against four in Figure 53. Figure 53 illustrates 

 a cross section near the upper portion of the leaves and just clear of their free 

 ends, and where three oil ca\'ities have been sectioned, one in each leaf. It is 

 in this part of the leaves that oil cavities are invariably found. The cuticular 

 projections as in Figures 51-53 can be made out in the ventral surfaces forming 

 the decurrent channel. The dark-stained parenchymatous cells containing the 

 manganese compounil here arrange themselves in clusters at the base of the 

 decurrent channels. 



(c) Chemistry of the Leaf Oil. 



The material for this in\-estigation was obtained at Shuttleton, New South 

 Wales, 512 miles west of Sydney. Two consignments were received, in September 

 and December, 1903, and also fruits for separate distillation. The whole of the 

 fruits were removed from the branchlets before distilling, so that the oil here 

 investigated is that from the leaves and terminal branchlets only. The distil- 

 lations were continued for six hours. The results from the two samples of leaf 

 oil agree very well in most respects, the only difference being that in December 

 (midsummer) there is rather more dextro-rotatory limonene present and a little less 

 pinene. (See also under C. calcarata.) 



The results thus illustrate the comparative constancy of the chemical 

 products of individual species of Callitris. The constituents found were those of 

 the Callitris oils generally, although varying in the amount of the individual 

 terpenes and esters from those of the oils of other species. For instance, it varied 

 from the leaf oil of C . robusta of Western Australia — another species with warted 

 fruits — in having considerably less ester, a higher dextro-rotation, and a much 

 greater amount of dextro-rotatory limonene. It contained, however, the sesquiter- 

 pene or similar body found in tlic oil of C. robusta, and this was present in sufficient 

 amount to raise the refractive index beyond 1-48, a result very unusual with the 

 Callitris oils. The esters, although small in amount, consisted principally of 

 bornyl- and gcranyl-acetates, the former of which was dextro-rotatory, thus 

 resembling the other Callitris oils. A little free borneol was present also, because 

 when the crude oil was acetylated in the usual wa\-, the saponification number 

 had more than doubled the original determination, and a small amount of a crystal- 

 line substance was obtained, which was shown to be borneol. The free alcohol 

 usually occurring in the Callitris oils of this group has been found to be dextro- 

 rotatory borneol largely, thus differing from the (jils of the C. rhomboidea group. 

 The terpenes present were principally dextro-rotatory pinene, also the limonenes, 

 of which the dextro-rotatory form predominated. The oil from llic fruits was 

 almost inactive, thus differing greatl\ lioiu lliat of \\\r lia\cs, and agreeing in this 



