20 ON THE DECADENCE OF AUSTRALIAN FORESTS ; 
of these forests, the same thing would have happened on 
previous occasions, and there would not be wanting many 
evidences that it was so; whereas the only instance I have 
been able to adduce is that of the so-called lightning-blasted 
patch on the Europambela run. The force of this contention 
must be admitted, but its strength rather assists in the con- 
firmation of my views, for it is here that the artificial causes 
come into operation. 
The occupation of the country with stock has brought 
about considerable changes in its character, and these have 
become more marked with the excessive stocking which 
has been commonly practised in late years; for runs that 
in 1857 were thought to have as many sheep on them as 
they could fairly carry, have since that time been required 
to agist 50 or 60 per cent. more without artificial feeding. 
The effect of this is to keep the grass short and to harden 
the surface of the soil; consequently, when rain falls it is 
not impeded by the grass and runs more quickly into the 
channels and creeks. There is not, therefore, the same 
amount of soakage into the soil, for the quick flow of the 
water and the hardness of the trampled ground combine 
to prevent much absorption, which in a dry season is 
essential to the health of the trees. Besides this, the 
ground being hard, and the particles of which it is com- 
posed being closely trodden together, it cannot retain the 
moisture which does penetrate into it with the same 
readiness as if it was more porous, nor can it contain so 
much. 
A great deal of the New England country is of a slaty 
formation, and where this is the case the soil is invariably 
poor. The surface, no doubt, before it was stocked, was 
largely composed of decayed vegetable matter, the debris 
of falling leaves from the trees and smaller plants; but 
immediately beneath this there is a bed of poor pipeclay, 
which after much rain becomes so soft that a horse’s feet 
will immediately sink when he places them over it, and as 
he draws them out they bring to the surface the white, 
spuey subsoil; in course of years the trampling of many 
feet has by this simple process pressed the old surface soil 
downwards and drawn up the pipeclay to the top. This of 
course does not apply to the whole of the country, nor even 
i. 
