Vegetation

The growth of plants. Vegetation occurs over the whole globe under the most opposite conditions. Plants flourish in the bed of the ocean as well as on laud; under the ex¬ tremes of cold and heat in the polar and equa¬ torial regions; on the hardest rock and the soft alluvium of the plains amid the snow of the mountains, in boiling springs, in dark caverns or mines. Different circumstances produce dif¬ ferent species and genera. Absence of humidity, and extremes of temperature, are the conditions fatal to vegetable life. Trees and plants which occur in the plains dwindle with increased eleva¬ tion. Plants are capable of extended natura liz a¬ tion, but distinct vegetable regions occur in different zones or on different heights.