61 
“3. They increase the relative humidity of the air, and in con- 
sequence reduce the amount of evaporation. This effect is strongly 
marked on hills in the tropics. 
“4, the mechanical action of their roots and stems the 
plants composing forest vegetation assist in preventing land-slips, 
erosion of hill-sides, the silting up of rivers, and arrest the progress 
of shifting sands. 
“5, They tend to increase the precipitation of moisture. 
“6. They act as wind-breaks, and protect adjoining cultivated 
areas against the action of cold or dry wind. 
pl Be act as barriers against the spread of fungoid and 
insect attacks from one cultivated centre to another. 
** Almost all these effects are more pronounced in the tropics, 
especially in localities with well-marked wet and dry seasons, than 
they are in the temperate zone,” 
The regulation of the water supply is one of the most important 
and far reaching effects of forests in such a country as the Gol 
Coast. With the cutting down of forests a gradual change in 
the vegetation at once sets in, if such forest be well within the 
region of ‘Rain Forest’ no very serious consequences may result, 
if, on the other hand, the forest area lies on the borders of the rain 
forest region the reckless cutting down of the tree vegetation will 
so alter the conditions that the character of the country will 
quickly change from that of rain forest to deciduous forest and 
finally to that of the Savannah country. The places once occupied 
by trees will be invaded by grasses and as soon as they have 
established a footing the forest is doomed; the region becomes 
suffer and their cultivation may utimately become impossible. 
It is clear therefore that the Forests of the Gold Coast and of 
our other West African possessions need efficient control and super- 
vision. 
Mr. Thompson deals very fully with this side of the subject and 
points out the lines which legislation might follow. The chief 
anger menacing the Gold Coast Forests is not their over-exploita- 
tion for forest produce but their wholesale destruction for farming 
purposes. It would appear, therefore, that any measures adopted 
for the “ reservation” or “ protection ” of the forests should also be 
accompanied by provision for the instruction of the natives in 
ethods of more intensive agriculture. At page 82 of the Report 
some general remarks will be found on the question of agricultural 
instruction in its relation to forestry. 
