64 THE SHADOW OF THE WORLD’S FUTURE 
world-average, however, it would make the ultimate 
total of population possible for the whole world as low 
as only 3552 millions, see Chapter III. But further, 
if the supposed possibilities of improvement could reach 
the 800 millions referred to in that chapter, instead 
of remaining at 503 millions, this would indicate a 
limit of 5650 millions of inhabitants. These results, 
4200, 3552, and 5650 millions, are all very moderate, 
as compared with undisciplined speculations on the 
basis of mere guessing as to how many people the 
earth can carry. What has been pointed out by H. 
Brenier, however, indicates that 4200 millions is an 
underestimate. It is also very probable, as already 
shown, that the 31-2 per cent. is too low an estimate 
of the productive surface.