THE WORLD’S CEREAL AND FOOD-CROPS 45 
ominous, to anyone who considers to what they point 
for the world’s future. From the use per capita of the 
metals, etc., this will at once be realised, if we remember 
to what numbers the population itself will attain, 
should the rate of increase of the recent past continue 
even for a very limited number of decades, not centuries. 
This is why a review of the world’s recent growth 
in numbers is a desideratum. We shall recur to this 
matter later. 
Many countries are coming to recognise not only 
that future agricultural needs are calling for systematic 
examination, but also that their future supplies of 
timber are also calling for similar attention. The 
features of modern life have intensified the demand 
for this commodity. This, and carelessness in the past, 
have made reafforestation an urgent necessity.  Well- 
organised schemes for minimising the danger of forest- 
fires, and of avoiding the colossal losses that occur 
through them, are being developed. Constructional 
substitutes for timber have been invented, and in the 
future metal and cement structures will minimise the 
use of wood. These things help human increase. 
Nevertheless, the possible expansion-rates of human 
populations outrange all possible developments in this 
direction. It ought not to be forgotten, on the other 
hand, that the forestal areas may have to be encroached 
upon, in order to increase the arable areas devoted to 
the growth of food-stuffs. ‘The forestal areas are at 
present very considerable, but they cannot be very 
largely encroached upon if supplies of timber are to be 
maintained on the scale, per capita, now characteristic 
of world-usage. 
When we realise that our usage of the world’s surface 
can without doubt be greatly improved upon, we are 
brought face to face with the fact that we have an 
urge to elaborate the scheme of our whole life. And 
not merely to elaborate it. We are reckless with the