Not everywhere equally. Here may be found a wonderful richness of animal-life. There the explorer may alight on a barren region. Yet even those parts more scantily supplied need not be always thus. Living creatures in vast hordes, in enormous companies, drift to and fro, rise upwards and sink downwards; and the district which to-day seems almost devoid of life may to-morrow be thronged with active beings. The Ocean’s inhabitants have been roughly divided into three Classes-- Deep-Sea Life, Intermediate Ocean Life, and Surface Ocean Life. The first of these includes all animals which crawl upon the sea-bed, or which live within about three hundred fathoms of it. The second includes all animals which live between about three hundred fathoms of the sea-bottom and three hundred fathoms of the ocean-surface. The third includes all animals which live within three hundred fathoms of the surface, and those on shallow shores. By far the greater number of living creatures appear to inhabit the surface regions; and it may be that the next in number are those on and near the ocean-bed. This, however, is uncertain. It is difficult to judge about the intermediate depths. All creatures living there must be extremely good swimmers, and they are very shy of nets. We cannot readily picture to ourselves the manner of life which goes on in those intermediate parts. Creatures there have, as it seems, no connection with either the ocean-bed or with shallow shores--no resting-place to which they may turn--in short, no home. Though one may not realise the fact, few animals within our ken have not something in the shape of a home, a _pied à terre_, to use a familiar term, though that “terre” may be under water. The very idea of a life spent always in swimming or floating through boundless depths, never touching firm ground, having no kind of home or retreat, suggests vagabondage, and sounds disconsolate. It may be that the difficulty is at least partly met by those great floating banks of living creatures which are often found. Diatom-Banks have been already spoken of. But other animals of larger growth also band together, forming vast companies. To each individual in such a congeries the Floating Bank would be a home. It would matter little to that individual whether the bank as a whole floated here or drifted there, whether it rose at night to the surface of the sea, or whether in daytime it sank lower to escape from the sun’s glare. Many such banks of life belong strictly to the Surface Class rather than to the Intermediate. But the want of a home applies equally to all creatures who live a free and roving life in the Ocean, unattached to shore or to sea-bed, whether they live above or below the three-hundred fathom limit. Another puzzling question has been as to how deep-sea creatures are fed.