Conservation distinguished from the conservation movement, 497. — The relation between utilization and exhaustion, 499. — Economic conditions which determine the rate of exhaustion when resources are controlled by individuals, 503. — The connection between the conditions which result in economical utilization by individuals and those determining the aggregate depletion of natural resources, 509. — The costs of conservation, 512. — The absolute limits of conservation, 515. — Conclusions as to conservation policy, 518.