248 
THE GEELONG NATURALIST. ^R 
period one vast plateau of sandstone, for the edges of this, where 
highest and apparently least reduced by denudation, are of that 
sediment, and the interior too, though much washed and scooped 
out by the floods of years, shows nothing against this idea. To the 
south of the plain are to be seen fine bold sandstone cliffs; while to 
the west the soil becomes more and more barren, with swamps 
Jaden with salt and gypsum, and the sandstone gradually becoming 
more saliferous and ferruginous, until at last it gives place to 
granite. The northern watershed shows in places sandstone 
plateau and cliffs, with deserts of light shifty sand; and the 
eastern margin of the great plain is generally a sandstone table- 
land, but which has undergone many changes, both by volcanic 
action and the effects of water. Thus we see that the soil is almost 
alike throughout this vast plain, only differing upon the eastern 
and western margins. 
The strips of country on the seaboard, however, are of a totally 
different character, especially the western, northern, and eastern 
portions. Here it is that almost all the upheavals have taken 
place. Long extinct voleanoes have vomited forth floods of basalt 
and trap, which have formed rich nourishing soils; and in the 
cracks and rents of these mountains, splendid alluvial deposits -have 
accumulated. 
The botanical features of this country are quite in keeping 
with its curious formation. Everywhere are found the same gaunt 
Eucalypti and hardy Acacias; but in many places we find mingled 
with these many varieties of flora, like those found in the nearest. 
country: for instance in the northern portions of the continent 
palms, bamboos, and even the nutmeg, flourish as well as they do in 
their own countries. Dr. Hooker says that as many as 500 distinct 
species of Indian flora are to be found in Northern Australia ; whilst 
on the other hand not a single species of a purely indigenous 
Australian plant is found off the continent. This fact leads us to 
believe that this vast continent of Australia must have been formed 
by an upheaval that took place thousands of years later than that 
which brought the southern portions of Asia above the waters. 
Again we find in the south plants such as only grows in South 
America, and the sandy arid tracts of the west, give birth to plants 
of exactly the same nature as some found in Africa, thus showing 
that at some remote period this land was connected with South 
races and Africa, or at least only a narrow neck of sea divided 
them. 
It will be easily seen that so large a country as Australia must 
have an immense variety of climate; and as forests are as much 
effected by climate as by soil, it will be impossible for me to dwell 
for any length of time on the many different classes that exist, so I 
shall just briefly touch on a few of the most interesting character- 
istics of the northern forests, and then pass on to our own familiar 
ones of Victoria. 
