After these general remarks on the creatures of the deep, I will now give a brief account of their various groups.
Over an enormous extent the abyssal ocean bottom is found covered with a sheet of almost formless beings, absolutely devoid of internal structure, and consisting merely of living and moving expansions of jelly-like matter. Whether this form of life, still more simple than the Amœba,[X] to which Professor Huxley has given the name of Bathybius Haeckelii, be continuous in one vast sheet or broken up into circumscribed individual particles, it is equally an object of wonder; and as no living thing, however slowly it may live, is ever perfectly at rest, it shows us that the bottom of the sea is, like its surface, the theatre of perpetual change.
[X] See Chapter XVIII., [p. 380].
Living among and upon this Bathybius we find a multitude of other protozoa, foraminifera and other rhizopods, radiolarians, and sponges.
Such is the countless number of the Foraminifera inhabiting the deep seas, that their remains form the chief mass of the soft oozy bottom of the ocean. In the surface layer of the deposit the shells of Globigerina bulloides, the prevailing species, are found fresh, whole, and living, and in the lower layers dead and gradually crumbling down by the decomposition of their organic cement and by the pressure of the layers above. Countless generations are thus piled one upon the other; and each successive stratum, weighing upon those of older date, is laying the foundation of future rocks, which subsequent revolutions may perhaps heave out of the deep and raise in towering pinnacles to the skies.
Sponges[Y] of wonderful beauty and lustre appear to extend in endless variety over the whole of the bottom of the sea. Some (Holtenia Carpenteri) anchor in the ooze by means of a perfect maze of delicate glassy filaments, like fine white hair, spreading out in all directions through the sea's fluid mud; while others (Hyalonema) send right down a coiled whisp of strong spicules, each as thick as a knitting-needle, which open out into a brush as the bed gets firmer, and fix the sponge in its place somewhat on the principle of a screw-pile. "A very singular sponge, from deep water off the Loffoden Islands, spreads into a thin circular cake, and adds to its surface by sending out a flat border of silky spicules, like a fringe of white floss silk round a little yellow mat; and the lovely Euplectella, whose beauty is imbedded up to its fretted lid in the grey mud of the seas of the Philippines, is supported by a frill of spicules standing up round it like Queen Elizabeth's ruff."[Z]
[Y] Ibid. pp. 385-389.
[Z] The Depths of the Sea, p. 73.
The stalked sea-stars, which, as the fossil pentacrinites and encrinites testify, abounded in the past periods of the earth's history, were, until now, supposed to be on the verge of extinction; but when we consider that the first few scrapes of the dredge at great depths have brought new species to light, we are entitled to believe that they constitute an important element in the abyssal fauna, and probably pave large tracts of the sea-bottom with a carpet of animated flowers. Freely-moving sea-stars and sea-urchins have likewise been hauled up in great numbers from abyssal depths; crustaceans have not been found wanting, and the captured shell-fish have shown that the deep-sea molluscs are by no means deficient in colour, though as a rule they are paler than those from shallow water.