206 AUSTRALIAN VEGETATION. 
the current of air to the east and south, miseries from which the 
prevalence of sea-breezes renders the more littoral tracts of West and 
North xVustralia almost free. But in the economy of nature the trees, 
beyond affording shade and shelter, and helping to preserve the 
humidity of the soil, serve other great purposes. Trees, ever active 
in sending their roots downwards, draw unceasingly from below the 
surface-strata those mineral elements of vegetable nutrition on which 
the life of plants absolutely depends, and which with every dropping 
leaf is left as a storage of aliment for the subsequent vegetation. 
How much lasting good could not be effected, then, by mere scat- 
tering of the seeds of our drought-resisting Acacias and Eucalypts and 
Casuarinas at the termination of the hot season along any watercourse, 
or even along the crevices of rocks, or over bare sands or hard clays, 
after refreshing showers? Even the rugged escarpments of the rocky, 
desolate ranges of Tunis, Algiers, and Morocco— even the Sahara itself, 
if it could not be conquered and rendered habitable, might have the 
extent of its oases vastly augmented, fertility might be secured again 
to the Holy Land, and rain to the Asiatic plateau or the desert of 
Ataeamas, or timber and fuel be furnished to Natal and La Plata. An 
experiment instituted on a bare ridge near our metropolis shows what 
may be done. 
Not Australia alone, but some other countries, have judiciously 
taken advantage of the facilities afforded by Australian tree-vegetation 
for raising woods, an object which throughout the interior might be 
initiated by rendering this an additional purpose of the expeditions to 
be maintained in the field for territorial and physiographical explora- 
tion; and more, it might deserve the attention of the Legislature, 
which allots to the pastoral tenants their expansive tracts of country, 
whether or not along with squatting pursuits— indeed, for the actua. 
benefit of the pastoral occupant himself— the inexpensive first steps for 
general forest-culture in the woodless regions should not be commencec. 
Within the ranges which produce these colossal trees but few habi- 
tations exist ; indeed, we might traverse a line of a thousand miles 
yet without a dwelling. The climate is salubrious ; within the shelter^ 
glens it could, in excellence, not be surpassed. Hot winds, from w ll 
our exposed plains, as well as any rises of northern and western aspe > 
so much suffer, never reach the still and mild vnles of the ion- > 
frosts are only experienced in the higher regions. Sp< lOTg ° 
