66 THE ORIGIN OF AUSTRALIA 
flora and fauna are of recent origin, that the Marsupials 
are quite new and unique, and that both are the direct 
consequence of the deterioration of climate which took place 
when the separation of the Australian Archipelago was 
superseded by the federation of the Australian Continent. 
V. THE IMPERFECTION OF THIS RECORD. 
40. This paper can only be a sketch of the evidence 
and of the conclusions at which I have arrived. The 
details are so numerous and voluminous that it will require 
a volume to set them forth, and this volume I shall under- 
take at once. 
41. So much it is necessary to indicate, lest the reader 
imagine that because I deal chiefly with the Flora and 
Mammalia, I have not taken account of the evidence, for 
and aganist, which is deducible from the study of other 
forms of hfe. 
42. In my forthcoming work [ shall also deal with the 
views of other authors. There is not much to controvert. 
My explanation is mainly a constructive one, and only 
destructive on points ot minor importance—points which 
do not affect the main conclusion—points which have 
always been felt to be difficulties. 
VI. THE EXISTING AUSTRALIAN FLORA. 
43. We are indebted to Sir J. D. Hooker for the first 
comprehensive view of the flora of Australia, and the long 
years that have passed since the: masterly essay “‘ On the 
Flora of Australia” was published in 1859, have not mater- 
ially altered the views therein set forth. 
44. There are several ways of looking at a flora, each 
in its way instructive, a few of which we will glance at, 
leaving particulars for my larger work. 
45. There are some 10,000 known species of plants 
indigenous to Australia. They may be divided into Tropical 
and Temperate, and whereas elsewhere the tropical is always 
richer in species than the temperate flora, the reverse is the 
case in Australia, for over 6,000 species out of 10,000 
belong to the temperate group. This in itself is sufficiently 
remarkable, but its significance only becomes clear when 
