"The name }} is assigned by botanists to a large group or natural class of ic or flowerless plants, which form the principal and characteristic vegetation of the waters. The sea, in no climate from the s to the , is altogether free from them, though they abound on some shores much more than on others, a subject which will come particularly under notice when we speak of the distribution of their several tribes. Species abound likewise in fresh water, whether running or stagnant, and in mineral springs. The strongly impregnated sulphureous streams of Italy,—the eternal snows of the and regions,—and the of Iceland, have each their peculiar species ; and even chemical solutions, if long kept, produce Algae. Very few, comparatively, inhabit stations which are not submerged or exposed to the constant dripping of water; and, in all situations where they are found, great dampness, at least, is necessary to their production."