268 R. H. CAMBAGE. 
understood if it be regarded as an uplifted plateau which 
for a great portion of its length presents its higher and 
steeper face to the east, and in most cases, with a more 
gradual slope to the westward. In its southern part, 
where it crosses from New South Wales into Victoria, both 
faces are steep, particularly the western, while on the 
Blue Mountains west of Sydney, there is a distinct down- 
ward warp to the eastward, up which the railway has to 
climb from HKmu Plains. 
As the streams on the eastern side of the mountains are 
generally short, and in view of the elevation of their sources 
consequently rapid, they have already succeeded in 
entrenching themselves to depths of several thousand feet, 
according to the height of the plateau, with the result that 
the line of the water-parting is being gradually but surely 
forced to the westward. ‘he effect of these parallel 
gorges, which are being thus formed, is to isolate sections 
of the plateau into lateral spurs, and in frequent instances 
the elevations on these spurs, especially where residuals of 
older levels occur, are greater than those of the Main 
Divide itself. Another feature of the water-parting is that 
it occupies various positions on these mountains, being 
sometimes in the centre, but very often towards the edges, 
and in some instances coincides with the actual margin of 
the plateau, as at the head of the Kybean River, south- 
east of Cooma. It will be seen, therefore, that the ridge 
which divides the waters on the plateau, often exercises less 
influence on the climate and vegetation than many of the 
lateral ranges, or in other words, it is the steep eastern 
margin of the plateau, rather than a slight dividing ridge 
on the tableland, which dominates the climate of the coastal 
belt and influences the character of the resultant flora. 
In Australia there is a type of vegetation known as brush 
or jungle, (in Queensland the term ‘‘scrub”’ is now largely 
