PROCEEDINGS OF SECTION D. 483 



hillside of granite or sandstone formation seeming an absolute im- 

 possibility. No picture of a black soil plain seems complete without 

 a few myall trees or old stumps. A. aneura, F. v. M. (mulga), belongs 

 to the red soil area, and practically never associates with A. pendula, 

 while A. doratoxylon, A. Cunn., (currawong) selects the very tops of 

 hills, Avith a preference for sedimentary formation. 



Hills of sedimentary origin in the interior are much richer in species 

 numerically than the porphyry hills, though only separated by a few 

 miles. Two in particular have been noted about four miles apart, 

 viz. : — Mount Allen and Double Peak, the former being composed of 

 porphyry and having a sparse flora, while the latter is made up 

 of Silurian slate and thickly covered with vegetation. It was moreover 

 noticed that Casuarina stricta, Ait. (sheoak), was plentiful on the former 

 but absent from the latter, while Acacia doratoxyhn Avas abundant on 

 the latter but not represented on the former. 



My conclusions are that an ecological study of the distribution of 

 the New South Wales flora goes to show that the changes in geological 

 formation have a very marked effect upon the production and grouping 

 of the forests, and a transit from one class of soil to another is invariably 

 followed by a considerable change in the vegetation. In ascending 

 to the highest altitudes, however, the growth of plants is further regu- 

 lated by the influence of climate, though still in conformity with the 

 geological formation. In addition to these factors the further distri- 

 bution is to a great extent governed by the consideration of aspect, 

 whether east or west, and this important point is decided by the position 

 of the Great Dividing Range which passes through the eastern part of 

 the State in a northerly and southerly direction. 



LITERATURE CITED. 



(1) Andrews, E. C, B.A. — The New Zealand Sound and Lake Basins and the 

 Canyons of Eastern AustraUa in their bearing on the theory of the Peneplain. 

 Proc. Linnsean Society, New South Wales, 190(5, p. 499. 



(2) Barwick, A. C. — The Botany of the " Clears " and " Basalt Masses," 

 County of Hunter, New South Wales. Proc. Linnaean Societj', New South Wales, 

 1903, p. 932. 



(3) Bensusan, S. L. — Trans. Inst. Mining and Metallurgy, vol. rx. (1900-01), 

 p. 306. 



(4) Cambage, R. H. — Notes on the Native Flora of New South Wales, Part v., 

 Proc. Linnsean Society, New South Wales, 1905, p. 447. . 



(5) Hamilton, A. G. — On the Flora of Mount Wilson. Proc. Linnsean Society, 

 New South Wales, 1899, p. 346. 



(6) Jaquet, J. B., A.R.S.M., F.G.S., and L. F. Harper, F.G.S.— The Geology 

 of the Pernio- Carboniferous Rocks in the South-eastern portion of New South 

 Wales. Records Geological Survey, New South Wales, 1905, vol. vin. 



(7) Maiden, J. H., F.L.S. — A second contribution towards a Flora of Mount 

 Koscuisko. Agricultural Gazette of New South Wales, 1899. 



(8) Taylor, T. Griffith, B.Sc, B.E.— A correlation of Contour, Climate, and 

 Coal. A contribution to the Physiography of New South Wales. Proc. Linnsean 

 Society, New South Wales, 1906, p. 517. 



i9) Woodhead, T. W., F.L.S. —Ecology of Woodland Plants in the neighbor- 

 hood of Huddersfield. The Journal of the Linnsean Society, vol. xxsvn., p. 396. 



