144 FOREST CULTURE AND 
judged with caution. Even from elevations compar- 
atively inconsiderable, as such nearly always proved 
away from the eastern coast, the orb of vision is lim- 
ited. A traveler may, buoyant with hope, commence 
his new daily conquest on the delightful natural lawns 
or the verdant slopes of a trap formation ; and, before 
many hours’ ride, he may, to his dismay, be brought 
without water to a bivouac between the sand - waves 
of decomposed barren rocks. But as suddenly a few 
hours’ perseverance may bring him again into geo- 
logical regions of fertility when he least expected it ; 
smiling landscapes may again burst into his view, 
and he may establish his next camp on limpid water, 
sufficient for the requirements of a future city. The 
nature of a country is not ruled by climate and lati- 
tude alone, but quite as much, if not more, by its 
geological structure. Glancing on the map of an un- 
explored country, we are apt to take in our conject- 
ures the former alone for a guide, until the latter, by 
actual field-operations, becomes our stronghold in to- 
pographical mapping. It would thus be unsafe to as- 
sume that the great western half of the interior consists 
mainly of desolate, uninhabitable desert-country, or 
even to contend that the reappearance on Termination 
Lake, or on the Murchison river, of so very many of 
the plants which give to the saltbush country, or the 
Mallee and Brigalow scrubs, on the extensive depres- 
sion of the Darling system, their physiognomy, neces- 
sitates their uninterrupted extension from the rear of 
Arnhems-land to the Murray Desert, or to Shark Bay. 
From demonstrating-facts like these we dare no more 
infer but that likely many similar tracts of flat coun- 
try are stretching over portions of the wide interven- 
