26 R. H. CAMBAGE. 



conditions appear to have remained practically as we find 

 them to-day. In a paper on the flora of the Nandewar 

 Mountains I have briefly discussed the possibilities of cold- 

 loving plants having migrated north during this glaciation 

 and of their having become stranded upon its termination. * 



Modification of the Eucalypts in New South Wales since 

 the Kosciusko Period. 



In order to fully appreciate the possibilities of modifica- 

 tion and development of the Eucalypts subsequent to the 

 great uplift in Pliocene time, it is necessary to keep fore- 

 most in mind at least three important points. The first 

 of these is that before this great tectonic movement took 

 place, South Eastern Australia was a much more level 

 country with a fairly uniform climate. The second point 

 to be kept in the foreground is that the available geological 

 and physiographic evidence implies that the upward move- 

 ment though gradual, was comparatively rapid, especially 

 where the elevations are greatest, 2 but was of sufficient 

 duration to allow much of the vegetation to adapt itself to 

 the new conditions. A measure of the movement is sup- 

 plied from the fact that pre-existent rivers, in some cases, 

 were enabled to cut down their channels and thereby retain 

 their original courses while elevation was in progress. 3 

 The third factor to be remembered is the Pleistocene glacial 

 period. 



As a uniform climate implies a fairly uniform flora, it 

 would seem that a just conclusion to be arrived at from a 

 contemplation of these various factors and conditions would 

 be that immediately prior to the uplift, the differences in 

 New South Wales, amongst those Eucalyptus characters 



1 Proc. Linn. Soc. N.S. Wales, Vol. xxxvn, (1912). 



3 " Geographical Unity of Eastern Australia," by E. C. Andrews, this 

 ournal, Vol. xliv, p. 461, (1910). 



3 "Notes on the Geography of the Blue Mountains/' by E. C. Andrews 

 Proc. Linn. Soc. N.S. Wales, Vol. xxix, p. 812, (1904). 



