cted like a sponge, taking up the water from the adjacent clay which
consequently preserved its tenacity at all seasons. This edge of clay
along the skirts of plains at the base of the red sand ridges I found the
most favourable ground for travelling upon. Still further back gravel,
consisting of fragments, not much water-worn, of various hard rocks,
appeared, forming low undulations towards the base of more remote hills
which consist of a very hard sandstone. I may here mention however that
the extremity of Dunlop's range which, by approaching the river, there
occupied the place of the hard gravel in other situations, seemed to be
composed of the same rock of which much of that gravel consisted.

Of the hills in general it may be observed that those on the left bank
are most elevated at the higher parts of the river, whereas those on the
right bank rise to greatest height towards the lower parts of the river,
as far as explored by us. The plains extend on each side of the channel
to a distance of six or seven miles and are in general clear of timber.
That deep and extensive bed of clay, so uniformly filling the basin of
this river, has every appearance of a mud deposit.

WOODS AND GRASSES.

Behind the plains the country is sparingly wooded except by the stunted
bush (Myoporum montanum) which forms a thick scrub, especially on the
side of the low hills. On the riverbank trees peculiar to it grow to so
large a size that its course may be easily traced at great distances; and
they thus facilitated our survey most materially. These gigantic trees
consist of that species of eucalyptus called bluegum in the colony; and
their searching roots seem to luxuriate in the banks of streams, lakes,
or ponds, so that the thirsty traveller soon learns to recognise the
shining trunk and white, gnarled arms, as the surest guides to water. The
alluvial portion of the margin of the Darling is narrow, and in most
places overgrown with the dwarf box, which is another species of
eucalyptus. In it are hollow places as already observed, covered with the
Polygonum junceum, which is an unsightly leafless bush or bramble. Grass
is only to be found on the banks of the river and, strictly speaking, the
margin only can be considered alluvial, for this being irrigated and
enriched by the floods it is everywhere abundantly productive of grass,
though none may appear in the back country.

GUM ACACIA ABUNDANT.

In the ground beyond the plains some ca