278 R. H. CAMBAGE. 
Going northerly from herethe great New Hngland plateau, 
with elevations from 3,000 — 4,500 feet and 5,000 feet, forms 
a distinct barrier between eastern and western floras, but 
as Queensland is approached and warmer latitudes are 
entered, and the elevations become slightly reduced, the 
effect of the north and south barrier becomes less, and 
western plants which in southern New South Wales are 
only found below elevations of 1,500 feet, are now able to 
flourish at altitudes of about 3,000 feet. 
Some interesting floral responses to climatic effect 
resulting from topographical features are to be seen near 
Toowoomba in Queensland, where the Main Divide for a 
considerable distance at about eighty miles from the ocean 
is only about 2,000 feet high. Some of the results are that 
such a typical western species as Hucalyptus microtheca 
(the Coolabah of the Bourke district), ascends the Darling 
Downs almost to the summit, and such western species as 
Casuarina Luehmanni (Bull-Oak) and Acacia harpophylla 
(Brigalow) though not on the actual summit, manage to 
cross to the eastern watershed and are found on the lower 
levels around Gatton and Laidley, while areas of brush 
may be seen nestling under the eastern face of the moun- 
tain, practically to the very summit near Toowoomba, but 
sheltered from westerly conditions. Going north-westerly 
from Toowoomba, the Divide recedes from the coast, and 
although some peaks exceed 3,000 feet, for several hundred 
miles it loses much of its identity as a rain regulator owing 
to its moderate elevation, and in some instances to the 
presence of higher mountains to the eastward. Where it 
is crossed near Jericho by the railway line from Rock- 
hampton to Longreach at a point nearly 300 miles from 
the ocean, it is only a very slight rise on an extended 
sandy plateau of scarcely 1,200 feet above sea level, 
while fifty miles to the eastward, the Drummond Range 
rises to about 1,500 feet. On both sides of the water- 
