tion of forests in these respects exer- 
cises a, terribly banefu! influence upon 
the country that has once, prodigal-like, 
sold its birthright of trees without mak- 
ing any provision to repair their loss in 
the future. To put it briefly, the worst 
effect of deforestation is 
EROSION. 
To estimate the full significance of this 
term, we must consider briefly ‘the 
part played by trees in all natural sys- 
tems of drainage and water supply. Here 
I may quote Professor Schwappach again: 
“The water from heavy rains, checked 
in its descent by meeting first with the 
foliage of trees, is better retained on 
forest soil than on bare land. Under a 
close cover of trees, there collects a 
‘humus’ soil formed from the decay of 
fallen leaves. Through this sponge-like 
soil-covering the rain water slowly filters, 
and its passage is further retarded by 
the stems and roots of the trees. In 
this way the erosive effects of violent 
rains upon bare hillsides is obviated. 
This is often a very serious danger, not 
only because the good soil is washed 
away, but also on account of lower- 
lying fertile lands being covered by 
boulders, gravel, and sand brought down 
in the flooded waters.” With this state- 
ment of the case, we may compare the 
following extract from Captain Campbell 
Walker’s paper, which, as mentioned 
above, bears more especially upon the 
effects of deforestation in this country. 
“The forests by their presence act as 
storehouses of moisture, both from their 
leafy canopy which covers the earth, 
and the bed of dead leaves on its sur- 
face, the loss of moisture by evaporation 
being by these means reduced to one- 
fifth; and, further, the bed of dead leaves 
acts as a sponge soaking up and retain- 
ing the rain and regulating its distribu- 
tion, while the roots not only act as 
vertical drains promoting the descent of 
the water into the lower strata of the 
earth, there to nourish the springs, but 
bind the soil on the mountain sides 
together, and prevent its being carried 
away into the valley below.” It showld 
now be clear what difference forests — 
make to a country’s river system and 
its soil, They store up water for 
gradual distribution; and they prevent 
the vegetable mould they form from 
being washed away. Consequently, it 
follows that when the bush is cut down, 
not only do streams tend to disappear 
with it, but the rain, when it comes, 
carries the fertile soil from the hillsides 
down into the valleys, and at the same 
time, rushing unimpeded along the 
channels and courses that the storm- 
water has already excavated in the earth, 
causes sudden and disastrous floods, 
