number of hexagonal cells, defined by the peculiar arrangement of the triradiate spicula, and having their walls formed by a multitude of nucleated granules (Fig. 4). These angular cells are laid at right angles to the long axis of the Sponge, extending from the outer surface to the inner; and they are crossed, near the middle, by a thin partition, perforated in the centre. In this perforation, several long, whiplike cilia were seen lashing with energy, and the same organs were afterwards found to be connected with the granules of which the cell-walls were composed. By means of the wavings of these cilia, then, the water is made to flow through the cells from without, being discharged into the interior of the sack, and poured out in streams from the orifices (oscula) which terminate the angles of the Sponge.* This beautiful and interesting discovery leaves no doubt of the animal nature of the Sponges. In our next paper we propose to examine in detail the economy, uses, and history of our Officinal Sponge, with some further interesting particulars common to the whole class. P. H. G. * Trans. Micr. Soc. iii. 137. NIAGARA. EVERY good Mussulman considers it a duty to perform, once in his life, a pilgrimage to the shrine of his Prophet at Mecca; and every American endeavours to make at least one visit to the Falls of Niagara. But the most devout Osmanlee that prostrates himself before the tomb of Mahomet can feel no access of fervour that will compare with the sensations inspired, even in a mind and heart of ordinary sensibility, by the sight of this sublime cataract,— the wonder of the Atlantic world,-the glorious temple not made with hands, where the incense of nature rises for ever towards Nature's God, as the compressed waters of one vast inland sea pour down into another. On arriving at Niagara, my young companion and myself, notwithstanding our impatience, had sufficient selfcommand to resolve on economising our enjoyment, or, rather, lengthening it out, in seeing Niagara by degrees; reserving for the last the grand view that comprises the whole of the Falls at once. We found that we were right, and that the sum of our delight was greater in consequence. They commence very gradually, where the bottom of the river first becomes slightly rocky. A few bells of white foam are scattered far apart on the surface of the dark green water, the current seeming to increase in velocity. As it proceeds, the foam-specks become larger and closer till they run into long wreaths. Then these wreaths unite, and become ridges; and the ridges follow each other so closely, that they blend together into high wide crests of foam that stretch from shore to shore; crowding one upon another, hurrying wildly on into those before them, and overtaken by those behind. By the time the Rapids have passed the Cataract Hotel, scarcely a streak of green can be discovered among them, so covered is the whole channel with spreading masses of snowy white. Our next and best view of the Rapids was from the bridge thrown across them to Bath Island, from whence there is another and much smaller one to Ship Island, a picturesque little spot covered with trees, most of them pines, the tallest of which slant backwards, something like the masts of a vessel; and there is one with the stem inclining forward, in the manner of a bowsprit, its lower branches almost dipping into the foam. We sat here awhile on a rustic bench beneath the shade, and looked up and down, and all around, scarcely knowing where to fix our eyes. Our islet lay trembling amidst the turmoil of the white and maddening waters that seemed ready every moment as they hurried past to tear it from its foundation and sweep it away over the Falls. Looking up the stream we saw an ocean of froth, whirling and tumbling amid the sunken reefs; whilst innumerable torrents leaped over the ledges, or, like the jet of a vast fountain, rebounded from the rocks, and danced up, high and sparkling, in the bright summer air. But the rocks, though they enraged the waters to fury, could not arrest their force. On they came, terrific in all their velocity; roaring, rushing, surging, flying along as if madly eager to hasten their headlong plunge down the tremendous precipice. It was here I first experienced those indescribable sensations of delight, overpowered by feelings of awe and reverence, without which few have looked on Niagara. My eyes were filled with tears. I could not speak. I felt as if the spirit of the Creator was before me, and almost in His own divine form I seemed to hear His holy voice, and feared to interrupt it. Retracing our steps, we again crossed the bridges, and then descended a high steep bank, which, when half-way down, brought us in view of the whole of the American Falls the flood, on arriving near the pitch of the precipitous ledge, branching off to supply a whole crescent of cataracts. Rolling over the summits of these cliffs, and pouring down in vast white sheets tinted with the liveliest green, we saw the highest and most beautiful of the Falls descending from the main branch of the Rapids; light, feathery flakes of foam springing off from the sides of the torrent and trickling in silver rills over the dark and broken masses of stone, from whose crevices, for ever wet, grew out such shrubs and plants as love to climb about the rocks and delight in perpetual moisture. When my thoughts and feelings began to take a definite form, my only regret was, that every being that I loved, every one indeed that I knew, was not there at that moment to look at Niagara. It seemed like something too grand, too beautiful, to last; like a magnificent scene that would pass away while we were yet gazing on it. I could imagine nothing more charming than to live in its immediate neighbourhood for at least a year; seeing it under all its different aspects; in sunshine and in tempest; glittering beneath the bright sky of summer, and darkening beneath a canopy of heavy storm-clouds; the lightning flashing across its everrolling torrents, and the thunder of upper air uniting with that whose deep tones ascend for ever from the caverned recesses at its feet. I thought how it must look tinted with the crimson and purple clouds that curtain the close of an autumnal day, "when the clear cold evening's declining," and the fantastic trees of these islands and these rocks come out in the varied and glowing colours of that gorgeous season,-colours scarcely less splendid than those of the sunset sky. And in winter, when it has all its beauties to THE ROCK SCENERY. 175 itself, when the trees are denuded, the rock-plants withered, masses of ice lying along the shores, and the country round presenting one vast desert of snow; even in winter Niagara must still be beautiful in the crystal pendants hung on the rocks and trees by its freezing spray; and sublime in the overpowering force with which it struggles against the ice that vainly essays to block up its progress. The Nature is always true to herself, and the land-scenery about Niagara is in unison with that of the water. rocks, chiefly of brown sandstone and blue limestone, are lofty, wild, and rugged. Some are nearly perpendicular, some slope back, and others project forward, impending over the raging waters. In some places they are deeply honeycombed by the incessant action of the spray. The trees and wild vines that grow from the fissures of these rifted walls appear to give as well as to receive support, clasping their tangled and dripping roots and their twining branches against the masses of cracked, disjointed stone, which seem already loosened in their sockets. Even a lonely cluster of wild flowers sometimes glows beneath the shadow of an overhanging block of stone. The solemn colouring of these gigantic rocks, comprising all the darkest shades of brown and grey, forms a fine contrast to the flowing masses of dazzling white and lovely green to which no pencil has ever yet done justice. The green of the Niagara Falls is indeed like nothing that can be seen elsewhere. It is not the green of the sea in fathom water, nor the deep blue green of the lakes; neither is it the reflexion of the trees on the banks. It is "something more exquisite still," a colour so beautiful, so peculiar, that no art can successfully imitate it. Imagine vast and ever-falling torrents of dissolved alabaster, shaded with liquid emerald slightly blended with molten turquoise, and |