BY SYDNEY B. J. SKERTCHLY. 59 
either to accommodate themselves to the more strenuous 
conditions, or die. Many succumbed : but many conquered 
in the strife : and so we obtained at last a true indigeonus 
flora and fauna. It was an absolutely new state of things 
—the plants took on the remarkable semi-desert peculiarities 
which make them so interesting to the student of evolution, 
and most of the mammals acquired (or if you will, re- 
acquired) the marsupial habit. 
8. It will be noticed that the cases of the flora and fauna 
are not quite parallel. It is true that the Tertiary flora of 
Australia only faintly prefigures the present flora: but 
this is the case everywhere, though in Australia we can say 
that the difference is greater than anywhere else. 
9. But with our fauna it is different. So far as regards 
our Marsupials they are truly Australian : truly and entirely 
new developments. In no part of the world, recent or fossil, 
is anything analogous to them known. They are the real 
Australian Native—far more so than the Blackfellow, 
for he, after all is a man with like passions with ourselves. 
It now remains for me to make good my claim. 
II. THE FACTORS IN THE PROBLEM. 
(a) Orographical. 
10. The Australian Continent, compared with others, 
is unmarked by any great elevated areas; only in three 
parts, a]] in the eastern coastal region, rising to above 5,000 
feet. The greater portion is more or less undulating plain 
and table land lying between 500 and 2,000 feet. The 
major part of the west coast, the shores of the Gulf. of 
Carpentaria, and a large portion of central southern Queens- 
land and New South Wales, and extending south to the 
coast of eastern South Australia, are under 500 feet. 
11. The eastern coast, from Cape York to Tasmania 
(which is geologically part of Australia) is mountainous, 
and in the central area the Macdonnel and a few other 
ranges rise to about 4,000 feet. 
12. Australia is, therefore, a huge series of table lands 
and plains, with an elevated eastern rim, and a few scattered 
central high lands. 
13. Speaking broadly, all the land above 2,000 feet is 
