large masses of greenstone, basalt and other igneous rocks. It is flanked on both sides by thick beds of
palæozoic formations, chiefly sandstone, but also containing limestone and coal. In the northern portion of
the chain Dr. Leichardt found similar formations—and especially trap and granite near the Burdekin river.
In the Port Phillip district there are similar igneous rocks, and on the coast tertiary formations resting on
the edges of upturned palaeozoic beds. In West Australia, the Darling range consists of granite below,
covered by metamorphic rocks ; and between it and the sea is a plain composed of tertiary beds. In the
colony of North Australia there is a great sandstone plateau, rising about 1800 feet above the sea, and
probably of palaeozoic age ; whilst on the immediate shore and round the Gulf of Carpentaria are beds
supposed to belong to the tertiary period. Similar formations constitute the substratum of the central
desert ; in which Captain Sturt was compelled to turn hack, when half-way to the Gulf of Carpentaria, from
the southern coast. Hence these tertiary rocks are probably continuous through the whole centre of the
island, and during the tertiary period all this portion of the country was submerged, whilst the high lands
on the coast rose like four groups of islands from the shallow sea.”—Athenæum, Nov. 24, 1847.
Whichever of these opinions be the correct one, we certainly find the natural productions of all these
portions of the country composed of precisely the same types, the generality of which differ, entirely from
those of the islands of the Indian Archipelago on the one hand, and of New Zealand and Polynesia on the
other.
With respect to the position of Australia, it will only be necessary to state that it is situated between
the 10th and 45th degrees of south latitude, and the 112th and 154th degrees of longitude east from Greenwich
• its extent, in round numbers, may therefore he said to be 3000 miles in length, or from west;to east,
and inclusive of Van Diemen’s Land nearly the same in breadth, or from north to south. In its present
uplifted position its form is nearly square, with a depressed centre bounded by an almost continuous range
of hills and plateaux, which, varying in altitude from one to six thousand feet above the level of thé sea, in
some places approach the coast and present lofty and inacessible cliffs to the ocean, whiles in others they
trend towards the interior of the country at a distance of from twenty to eighty miles from the coast-line ;
but inasmuch as these elevations are all of an undulating and not of a precipitous character, no part of the
country can be considered as strictly alpine. Nothing can be more different than the features of the
country on the exterior and interior of this great barrier, particularly on the eastern coast, where, between
the mountains and the sea, the vegetation partakes to a great extent of a tropical, character ; it is there, on
the rich alluvial soil, formed by the debris washed down from the hills, that we find various species of
Eucalypti, F id , and other trees, many of which attain an immense altitude, and forests of towering palms;
the surface of the ground beneath clothed with a dense and impervious underwood, composed of dwarf
trees, shrubs and tree-ferns festooned with creepers and parasitic plants in the richest profusion, the
continuity of which is here and. there broken by rich open meadow-like districts admirably adapted for
the pasturing of Cattle, and to which, from the frequent occurrence of the Angophorce, a. tribe of trees in
which the settlers see a fancied resemblance to the apple-trees of Europe, the name of Apple-tree Flats has
been given. Within the ranges, on;the other hand, we find immense open downs and grassy plains, studded
here and there with detached belts and forests of Eucalypti, Acadce, &c., presenting a park-like appearance,
to which, as we advance farther towards the interior, succeed.either extensive marshes or land of a most
sterile description. .The face of this vast country consequently presents much variety of aspect ; the
infrequency of rain tends much to give a sombre brown hue to the surface of the ground, which however is
relieved by the constant verdure of its trees, the peculiar lanceolate form and the pendent position of
which render them almost shadowless. It is in the neighbourhood of the few rivers which intersect
the country, and in the lower flats flooded by the waters, when floods occur, that we find the
vegetation more luxuriant and the trees attaining a fa r greater size ; the sides of the rivers are moreover
fringed with Casuarince and other trees, which, although of large size, never arrive at the altitude of
the stately Eucalypti, which attain, under favourable circumstances, a size and height which appear
perfectly incredible.. Mr. Backhouse states that one’ measured by him on the Lopham Road, near Emu
Bay in Van Diemen’s Land, which, “ was rather hollow at the bottom and broken at the top, was 49 feet
round at about 5 feet from the ground ; another that was solid, and supposed to be 200 feet high, was
41 feet round; and a third, supposed to be 250 feet high, was 554- feet round. As this tree spread much
at the base, it would be nearly 70 feet in circumference at the surface of the ground. My companions
spoke to each other when at the opposite side of this tree from myself, and their voices sounded so distant
that I concluded they had inadvertently left me, to see some other object, and immediately called to them.
They in answer remarked the distant sound of my voice, and inquired if I were behind the tree ! When
the road through this forest was forming, a man who had only about two hundred yards to go, from one
company of work-people, to another, lost himself : he called, and was repeatedly answered ; but getting
further astray, his voice became more indistinct, till it ceased to be heard, and he perished. The largest
trees do not always carry up their width in proportion to their height, but many that are mere spars are
200 feet high.”’v.V
A prostrate tree noticed by Mr. Backhouse in the forest near the junction of the Emu River with the
Loudwater “ was 35 feet in circumference at the base, 22 feet at 66 feet up, 19 feet at 110 feet up ; there
were two large branches at 120 feet ; the general head branched off at 150 feet ; the elevation of the tree,
traceable by the branches on the ground, was 213 feet. We ascended this tree on an inclined plane, formed
by one of its limbs, and walked four abreast with ease upon its trunk ! In its fall it had overturned another
168 feet high, which had brought up with its roots a ball of earth 20 feet across.” There are other
remarkable features, which, as they appertain to districts frequently alluded to in the course of the work,
it becomes necessary to notice, namely the immense deltas formed by the descent of the waters of the
interior, such as the valley of the Murray near its embouchure into the sea, spoken of as the great Murray
scrub of South Australia ; this enormous flat of nearly one hundred miles in length by more than twenty in
breadth is clothed with a vegetation peculiarly its own, the prevailing trees which form a belt down the
centre consisting of dwarf Eucalypti, while the margins are fringed with shrub-like trees of various kinds.
Nor must the immense belts of Banksice, which grow on the sand-hills bordering the sea-coast and in some
parts of the interior, or thè districts clothed with grass-trees (Xanthorrhcea), be passed over unnoticed ; in
the intertropical regions of Australia, of which at present so little is known, we find, besides the Eucalypti,
Banksice and other trees of the southern coast, derise forests of canes, mangroves, &c. Each of these
districts has a zoology peculiarly its own : for instance, the Banksice are everywhere tenanted by the true
Meliphagi ; the Eucalypti by the Ptiloti and Trichoglossi ; the towering fig-trees by the Regent and Satin
birds ; the palms by the Carpophagce or fruit-eating Pigeons, and the grassy plains by the ground Pigeons,
Finches and grass ' Parrakeets., The : circumstance of the boles of the trees being destitute of a thick
corrugated rind or bark will doubtless account for the total absence of any member of the genus Picus or