increase where the circumstances surrounding him were favourable to vigorous life. We have never yet, however, seen the full power of reproduction among mankind; the increase of population in America "falls very far short," says the author of the "Elements of Social Science," "of the possible rate of increase, as is seen by the short average of life in America, and by the large amount of the reproductive power which, even in that country, is lost from celibacy and prostitution. . . . . The capacity of increase in the human race, as in all other organized beings, is, in fact, boundless and immeasurable."
But while animated existence increases thus rapidly, no such swift multiplication can be secured of the means of subsistence. The means of subsistence of vegetable life are strictly limited in quantity; the amount obtainable from the soil may be increased by manure, by careful tillage, by rotation of crops, by improved methods of husbandry, but none the less is this amount limitable, while there is no limit to the power of animal life-production; if the soil and air and light could be indefinitely stretched, vegetable life would still suffice without effort to clothe the increased surface. But since the size of the globe inexorably limits the amount of vegetable produce possible of growth, the limited vegetable produce must, in its turn, limit the amount of animal life which can be sustained. While increased knowledge, skill and care may augment the means of subsistence obtainable from the earth, yet animal life multiplies more rapidly than can its food. As is truly said by the author just quoted: "From a consideration of the law of agricultural industry, and an estimate of the rate at which the means of subsistence could be increased in old countries, even under the most favourable circumstances, it may be inferred with certainty that these means of subsistence could not possibly be increased so fast as to permit population to increase at its natural rate. . . Let us apply the American rate of increase to the population of this country. Is it conceivably possible that the population of England or any old country should double itself every twenty-five years? In Great Britain there are now" (the book was written many years ago) "about twenty-one millions; is it conceivable that the means of subsistence could be so rapidly increased as to allow these twenty-one millions to swell to forty-two millions in the first twenty-five years; to eighty-four millions in the next; 168 millions in the next, &c.? The supposition is
