The increase of labor is the increase of mankind; of population. The power of multiplication inherent in all organic life may be regarded as infinite. There are many species of vegetables of which a single plant will produce in one year the germs of a thousand; if only two come to maturity, in fourteen years the two will have multiplied to sixteen thousand and more. It is but a moderate case of fecundity in animals to be capable of quadrupling their numbers in a single year; if they only do as much in half a century, ten thousand will have swelled within two centuries to upward to two millions and a half. The capacity of increase is necessarily in a geometrical progression: the numerical ratio alone is different. To this property of organized beings, the human species forms no exception. Its power of increase is indefinite, and the actual multiplication would be extraordinarily rapid, if the power were exercised to the utmost. It never is exercised to the utmost, and yet, in the most favorable circumstances known to exist, which are those of a fertile region colonized from an industrious and civilized community, population has continued, for several generations, independently of fresh immigration, to double itself in not much more than twenty years. Years. Population. Food. 25 11 mills x 25 22 mills 2x 25 44 mills 3x 25 88 mills 4x 25 176 mills 5x By this table it will be seen that if population can double itself in twenty-five years, and if food can only be increased by as much as _x_ (the subsistence of eleven millions) by additional application of another equal quantity of labor on the same land in each period, then at the end of one hundred years there would be the disproportion of one hundred and seventy-six millions of people, with subsistence for only fifty-five millions. Of course, this is prevented either by checking population to the amount of the subsistence; by sending off the surplus population; or by bringing in food from new lands.