POPULATION 
69 
America, it may be taken as over 26 per cent. Obviously 
something like 15 per cent. is probably too high an 
estimate of the possible total. Accepting it, the 52-5 
million square miles of entire surface become reduced 
to 7-875 of available surface, that is, 5040 million acres. 
It can hardly be assumed as probable that this area 
can be made to produce more than the equivalent to 
the average of, say, 14 bushels of wheat per acre. This 
at the outside, accepting an annual average require- 
ment of, say, 473 lbs. per person as probably fairly 
correct, would make provision for, say, 1-776 persons, 
hence the possible population would be 5og40—see 
above—multiplied by 1-776, that is, say, 8950 millions, 
an estimate which is almost identical with one 
obtained a little earlier. 
The several figures thus far obtained in this 
review of the possible population of the earth, 
expressed in millions, are then as follows: 13,440," 
4200, 3552, 5650, 17,642,% 5645, 8978, 8400 and 
8950, of which the two largest—marked with asterisks 
were recognised as not really possible estimates. 
The mean of the seven others is 6482 millions. We 
do not submit this as in any way representing the 
probable limit. 
Tt has already been indicated that, neglecting the 
vicissitudes of Nature, “the greatest possible popula- 
tion ” is a function of such things as (2) the efficiency 
of human organisation, (5) the appropriate localisation 
of human beings upon the earth, (¢) the standard-of- 
living adopted, and (4) the degree of freedom of 
migration attained, for the purpose of permitting any 
degree of concentration reached in any region to be 
adjusted to the local population-capacity of other 
regions. It may again be remarked in this connec- 
tion, that even differences in language impose real 
difficulties in making the earth’s inhabitants the 
largest number possible, and because of this it is not