PRESIDENTIAL ADDRESS. 25 



north of latitude 35°, but which in a few cases are now 

 found as far north as latitude 29°, or just to Queensland, 

 examples being supplied by E. coriacea, stellulata and 

 amygdalina. 



The effect of this uplift, upon the western side of the 

 Main Divide, has been to produce a drier, as well as a 

 hotter summer and colder winter climate, and the 

 Eucalypts in response to this change have gradually 

 adapted themselves to the new conditions with the result 

 that they differ considerably from many on the coast, but 

 most of all from those on the higher mountains. 



Glacial Period. — A most important influence which must 

 have done much to test the cold-resisting capabilities of 

 Eucalypts was the refrigerating period in Post Tertiary 

 or Pleistocene time and of which there is abundant evidence 

 on Mount Kosciusko to-day. 1 It is generally believed that 

 this glacial action, owing to its universality, was the result 

 of temperature change, and not due to any local alteration 

 of mountain levels. In a paper read before the Linnean 

 Society of New South Wales (supra), Professor David has 

 stated that during the glacial period referred to, the snow- 

 line which is now considered to be at about 8,000 feet in 

 the Kosciusko district, came down about 3,000 feet (printed 

 300 erroneously). Assuming that the snow-line came some- 

 thing between 2,000 and 3,000 feet lower than its present 

 position, a consequent lowering of the temperature of 7° to 

 10° Fahr. would be involved. 



The effect of this refrigeration upon all vegetation must 

 have been considerable, and it seems reasonable therefore 

 to expect some modification of plant characters as a result. 

 Since the closing of the Pleistocene glacial period, climatic 



1 Geological Notes on Kosciusko, with Special Reference to Evidences 

 of Glacial Action, by Professor David, f.b.s., Richard Helms, and E. F. 

 Pittman, a.r.s.m., Proc. Linn. Soc. N.S. Wales, Vol. xxvi, (1901). 



