640 



PRESIDENT S ADDRESS. 



mammals, and then we find all at once an abundance of highly 

 differentiated marsupials with monotremes whose descendants com- 

 paratively little changed in type we have around us at the jDresent 

 day. That these highly differentiated Australian types had no 

 representation, so far as is known, outside Australia, except in the 

 extreme south of the American continent, is a fact full of signifi- 

 cance. 



It would appear then as if at the end of the Mesozoic period 

 before the evolution of the higher orders of mammals took 

 place there must have existed a territory already inhabited by 

 marsupials, which then became cut off from the rest of the land to 

 the north, and that in this land — a portion of the pre-existing 

 Gondwana Land of Suess, or Antarctica of Forbes — the differen- 

 tiation of the marsupials occurred, and that further this land, 

 which may have been shifting in character, was at the end of the 

 Miocene or beginning of the Pliocene, connected with Tasmania. 

 Mr. C. Hedley's paper on the " Surviving Refugees of Antarctic 

 Lands," read before the Royal Society of ]N"ew South Wales last 

 year, deserves thoughtful consideration. 



I have devoted some space to the above matter because it bears 

 on the question of the origin of Australian Vegetation. It is 

 clear that the peculiar Australian types could not have been immi- 

 grants b}^ the same route as the marsupials, or, indeed, immigrants 

 at all, but the above considerations show the great probability of 

 the existence of extensive land surfaces in the Antarctic regions 

 at the end of the Mesozoic and in the earlier Tertiary times; that 

 the connection with more northern lands was of a somewhat 

 fleeting character, and that while it permitted of the passage of 

 one element of the Australia Flora from South America to Tas- 

 mania, the succession of these fluctuating land surfaces did not 

 allow of any large migration of Australian types in the opposite 

 direction. 



In his " Introduction to the Flora of Tasmania," published in 

 1860, Hooker sets forth the facts connected with the distribution 

 of plant life in Australia and Antarctic lands. This able work 

 is still the best complete treatise on the subject, and only requires 



