And never once, throughout the whole cruise, was any single bone of Man brought up from the ocean-bed.
After all is this surprising? Where even whale-skeletons are mastered, small chance can remain for a human skeleton to stand out long against absorption.
The marvel is how tiny foraminifer shells can last as they do. The majority no doubt disappear. Unless they reach the bottom quickly, and are there covered up and protected, they must soon be dissolved.
Yet that vast numbers do thus escape we know by the masses of ooze found over the sea-bottom; by the fifty millions or more of square miles of the ocean-floor carpeted with coral muds and sands, and with oozes of foraminifera and kindred shells.
Only down to a depth of about two miles. Beyond that, carbonate-of-lime shells are seldom found. It is believed that these light shells take as much as three or four days to sink one mile; and in about two miles they all succumb to the power of sea-water. But the hard little diatom cases are present in all depths, more especially in Earth’s colder regions, where they abound most freely.
The ocean-bed has been described as one huge sepulchre, full of the remains of once-living creatures. And this is true; yet by itself it gives a very one-sided view. Not less is the ocean-bed to be described as a world of abounding Life.
Everywhere, throughout the whole sea, in all parts, above and below and between—near the surface, on the floor, in all intermediate reaches—living creatures flourish in numbers past imagination.
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.