HOW POPULATION INCREASES 53 
Hwa-Luh for China’s population, the successive value 
in millions in the two cases are as shown hereunder: — 
Correspondence in the Modes of Population-Increase 
Date- 
seyear for} yyrs a73s 1755 1775 1795 1815 183s 
Date-year for 
Ruocane, cit. } 1800 1820 1840 1860 1880 1900 1920 
Populati 
opulationof 1 133 x54 187 235 288 348 do 
Population of 
Bon or) 137 ¥62 196 232 280 347 419 
If we reduce the population figures for Europe, etc., 
so as to make the two aggregates equal for the 120 
years covered, it gives a better comparison of form. 
The bottom figures would then be: 135, 160, 193, 
229, 276, 342, and 413. 
The present population of China is probably 468 
millions, to which it had nearly attained in 1870 (436 
millions): its increase had markedly dimished over 
half a century ago. The above figures show that the 
population of the western world is revealing something 
of the same characteristics, in respect of the changes 
in the rate of increase, that China did about 85 years 
earlier. This is a striking fact and obviously cannot 
be ignored by the student of the mode of population- 
increase. 
Long ago a much more limited survey of such 
changes of increase as have just been illustrated, 
suggested to a Belgian, Verhulst, that any country 
may be regarded as a sort of totality, analogous in its 
nature to a restricted region populated by organisms, 
the mere multiplication of which was continually and 
increasingly limiting the possibility of their further 
increase in number. The simplest mode of expressing 
this idea, is to assume that the group of organisms tend 
to reproduce themselves, continually reacting to a