When man was in the hunting stage of development, wide areas were necessary for the maintenance of scant populations.  With the shepherd stages, the means of subsistence being increased, a larger population was supported on the same territory.  The agricultural stage gave support to a still larger population; and, to-day, with the increased food-getting efficiency of a machine civilisation, an even larger population is made possible.  Nor is this theoretical.  The population is here, a billion and three quarters of men, women, and children, and this vast population is increasing on itself by leaps and bounds.

A heavy European drift to the New World has gone on and is going on; yet Europe, whose population a century ago was 170,000,000, has to-day 500,000,000.  At this rate of increase, provided that subsistence is not overtaken, a century from now the population of Europe will be 1,500,000,000.  And be it noted of the present rate of increase in the United States that only one-third is due to immigration, while two-thirds is due to excess of births over deaths.  And at this present rate of increase, the population of the United States will be 500,000,000 in less than a century from now.

Man, the hungry one, the killer, has always suffered for lack of room.  The world has been chronically overcrowded.  Belgium with her 572 persons to the square mile is no more crowded than was Denmark when it supported only 500 palaeolithic people.  According to Mr. Woodruff, cultivated land will produce 1600 times as much food as hunting land.  From the time of the Norman Conquest, for centuries Europe could support no more than 25 to the square mile.  To-day Europe supports 81 to the square mile.  The explanation of this is that for the several centuries after the Norman Conquest her population was saturated.  Then, with the development of trading and capitalism, of exploration and exploitation of new lands, and with the invention of labour-saving machinery and the discovery and application of scientific principles, was brought about a tremendous increase in Europe’s food-getting efficiency.  And immediately her population sprang up.

According to the census of Ireland, of 1659, that country had a population of 500,000.  One hundred and fifty years later, her population was 8,000,000.  For many centuries the population of Japan was stationary.  There seemed no way of increasing her food-getting efficiency.  Then, sixty years ago, came Commodore Perry, knocking down her doors and letting in the knowledge and machinery of the superior food-getting efficiency of the Western world.  Immediately upon this rise in subsistence began the rise of population; and it is only the other day that Japan, finding her population once again pressing against subsistence, embarked, sword in hand, on a westward drift in search of more room.  And, sword in hand, killing and being killed, she has carved out for herself Formosa and Korea, and driven the vanguard of her drift far into the rich interior of Manchuria.