PRESIDENTIAL ADDRESS. 19 



from a perusal of the writings of Baker and Smith, 1 

 Bentham, 2 David, 3 Deane, 4 Hedley, 5 Hooker, 6 Jensen, 7 

 Maiden, 8 and Mueller. 9 I also wish to thank Mr. Maiden 

 for granting me access to his unpublished drawings of a 

 large series of anthers, which show the great amount of 

 variation that exists in this important part of the inflor- 

 escence. My thanks are also due to Mr. W. S. Dun, 

 Palaeontologist, Department of Mines, for references to 

 literature relating to Tertiary fossil leaves. 



Factors which regulate development and distribution. 



Broadly speaking, the factors which play the important 

 parts in regulating the development and distribution of 

 plants are : — Physiography, Geology, and Climate. 



Physiography. — The topographic conditions of any 

 country are of extreme importance in their influence upon 

 the distribution of its flora. Where the country is level 

 over a large area, the conditions in regard to rainfall and 

 climate are likely to remain much the same over such area. 

 A range of mountains may give not only the elevation 



1 "A Research on the Eucalypts," by R. T. Baker, f.l.s., and H. G. 

 Smith, f.c.s. 



2 " Flora Australiensis," by George Bentham, f.r.s., etc. 



3 " Geological Notes on Kosciusko, with Special Ref erence to Evidences 

 of Glacial Action," by T. W. Edgeworth David, b.a., f.r.s., etc., Proc. 

 Linn. Soc. N.S. Wales, Vol. xxxin, p. 668, (1908). 



* " Observations on the Tertiary Flora of Australia," by Henry Deane, 

 m.a., f.l.s., etc., Proc. Linn. Soc. N. S. Wales, Vol. xxv, (1900). Presi- 

 dential Addresses, Proc. Linn, Soc. N.S. Wales, 1895 and 1896. 



5 "Presidential Address," by C. Hedley, f.l.s., Proc. Linn. Soc. N. S. 

 Wales, Vol. xxxvi, (1911). 



6 " Flora of Australia, its Origin, Affinities and Distribution/' (1859) 

 by J. D. Hooker. 



7 " Soils in Relation to Geology and Climate," by H. I. Jensen, d.sc, 

 Department of Agriculture, N.S. Wales, Science Bulletin No. 1, 1911. 



8 " A Critical Revision of the Genus Eucalyptus," also various papers 

 in Proc. Linn. Soc. N.S. Wales by J. H. Maiden, f.l.s. 



9 " Eucalyptographia," by Baron von Mueller, 1879-1884. 



