Man who preys both on the vegetable and animal species, is himself a prey to neither. He too possesses the reproductive principle far beyond the degree requisite for the bare continuance of his species. What becomes of the surplus of human life to which this principle is competent? It is either, 1st. destroyed by infanticide, as among the Chinese and Lacedemonians; or 2d. it is stifled or starved, as among other nations whose population is commensurate to its food; or 3d. it is consumed by wars and endemic diseases; or 4th. it overflows, by emigration, to places where a surplus of food is attainable.