EFFECT OF SETTLEMENT UPON INDIGENOUS VEGETATION, 191 
that the Acacias do this by flattening their leafstalks into phyllodia 
and the Eucalypts by twisting the leafstalk, he goes on to say : 
‘In support of this conclusion, I was told when at Melbourne, 
that when native vegetation was cleared away from under gum 
trees, they ceased to thrive, and after a time perished. I was 
shown a number of gum trees not far from the city, scattered 
over some public land covered only with short turf, which seemed 
to be mostly in a dying condition.”* I scarcely agree with this 
conclusion. Griesbach expressly says ‘‘ The growth of grass 
beneath is aided” and Moseley says that under the dying trees the 
turf was still present, but short. He would therefore seem to say 
that it is the undergrowth other than grass which is of advantage 
to the trees. But everyone knows that as a rule Eucalyptus 
forests are singularly free from undergrowth. And I have known 
large areas of land which were cleared of all but the trees and the 
grass, and had been so for years, and yet the trees were perfectly 
healthy and flourished as well as the primeval forests on the hill- 
sides within a mile. R. Brough Smyth remarks: ‘In the camp- 
ing places of the cattle you see many stately trees destroyed. The 
grass is beaten down and the long roots of the trees exposed to 
the intense heat of the sun, and the frosts of winter. When the 
roots are protected by litter or earth, the trees quickly recover 
and spread their branches with a luxuriance not observable even 
in the natural forest.”{ This I quite agree with. The benefit 
derived from the grass is merely mechanical, and could the trees 
have an even firm coating of soil without grass they would be just 
as healthy. The destruction of the grass affects the trees because 
it permits the water to tear away the protecting soil from the roots. 
The making of roads causes a great alteration of surface drain- 
age. Everyone who has travelled much on bush roads must have 
seen deep gullies cut along the road sides by the rush of water in 
the drainage channels on each side, and this of course acts in the 
same way as above. 
* Loc. cit. 
+ Goldfields &c., p. 28. 
