such strength and rapidity as to defy the efforts of inexperienced primitive man; nature becomes domineering, unmanageable, and man sinks into insignificance. Indeed the most skillful industry of armed and disciplined civilization is unable to keep under control this redundancy of tropical vegetation. The path cleared by the pioneer on penetrating the dense undergrowth, closes after him like the waters of the sea behind a ship; before the grain has time to spring up, the plowed field is covered with rank weeds, wild flowers, and poisonous plants no less beautiful than pernicious. I have seen the very fence-posts sprouting up and growing into trees. So destructive is the vegetation of the Central American lowlands, that in their triumphal march the persistent roots penetrate the crevices of masonry, demolish strong walls, and obliterate stupendous tumuli. The people whose climate makes carbonized food a necessity, are obliged to call into action their bolder and stronger faculties in order to obtain their supplies, while the vegetable-eater may tranquilly rest on bounteous nature. The Eskimo struggles manfully with whale, and bear, and ice, and darkness, until his capacious stomach is well filled with heat-producing food, then he dozes torpidly in his den while the supply lasts; the equatorial man plucks and eats, basks in the open air, and sleeps.
Here we have a medley of heterogeneous and antagonistic elements. Leisure is essential to culture; before leisure there must be an accumulation of wealth; the accumulation of wealth is dependent upon the food-supply; a surplus of food can only be easily obtained in warm climates. But labor is also essential to development, and excessive heat is opposed to labor. Labor, moreover, in order to produce leisure must be remunerative, and excessive cold is opposed to accumulation. It appears, therefore, that an excess of labor and an excess of leisure are alike detrimental to improvement. Again, heat and moisture are essential to an abundant supply of oxidized food. But heat and moisture,
