20 R. H. CAMBAGE. 



necessary to produce a cooler climate, but when fringing 

 the ocean with extensive low areas on the side opposite 

 the ocean, it provides two separate aspects totally distinct 

 in character, one being moist while the other is dry. Deep 

 gorges are also developed in the mountain sides and the 

 flora of these differs from that of the adjoining hills. 



A study of the physiography and the geology of South 

 Eastern Australia, serves to show that in early Tertiary 

 time, this area was chiefly a low tableland or peneplain, 1 

 only a few hundred feet above sea level. Such physio- 

 grapic conditions would have had the effect of producing a 

 fairly uniform climate over the greater portion of this area, 1 

 the rainfall would have been more evenly distributed, with 

 the result that there would have been a much greater 

 similarity in the flora for two or three hundred miles inland 

 than is the case at the present day. During Tertiary time 

 some minor upheavals took place, but towards the close of 

 the Tertiary Period, or what Mr. Andrews calls the Kos- 

 ciusko Period, a range of mountains paralleling the coast 

 at an average distance of 70-80 miles therefrom, was 

 uplifted to elevations varying from upwards of 2,000 - 7,300 

 feet above sea level, and with some slight modifications 

 these features remain to the present day. 2 



The effect of this last uplift upon the flora of South 

 Eastern Australia is most marked, for, as is well known, 

 instead of one uniform flora extending back from the ocean 

 a distance of, say, 200 miles, there are now three, and what 

 was the original or typical one, as evidenced by the fossil 

 leaves in the Tertiary drifts on the western portions of the 

 present mountains, is now most nearly represented by 

 portions of that confined to the coastal strip. 



1 "Geographical Unity of Eastern Australia/* E. C. Andrews, this 

 Journal, pp. 421 and 453, (1910). 



8 See Eelief Map of Australia, Presidential Address by Professor David, 

 this Journal, Vol. xlv, Plate I, (1911). 



