And still another, of again a different species, forms a test of divers compartments, with a tiny doorway leading from each into the next.
Behind all these extraordinary constructions lies a Mind. But—not the mind of the jelly-speck!
Soft oozes, formed chiefly of Foraminifera and other shells, varying in size from a pin’s head to almost invisible specks—though some few kinds are larger—cover immense reaches of the ocean-bed, extending, it is said, over fifty millions of square miles.
Yet they are not found everywhere below the sea. Near to Continents, if they exist they are lost sight of amid the masses of sand and mud carried down from the land. And in the profounder abysses of the ocean they are lacking.
This last fact was long a puzzle. If the waters above were swarming with live Foraminifera, the dead shells of which must be ever pouring in a quiet rain to the ocean-bed, why should not the same ooze be found there, as elsewhere?
That the waters above, at least in all warmer climates, do swarm thus, is certain. Towards north and south, in colder seas, they rapidly lessen; but in tropical regions, and in warm ocean-streams their numbers are legion. Yet, from depths beyond about two miles, the ooze was not brought up.
One explanation can be given; and it is that of the strong dissolving power of sea-water. After a depth of about two miles, the delicate little shells fail to resist that power. Once at the bottom, they might be covered up and preserved; but they cease to exist en route thither.
So in this as in many other instances, we see opposite forces at work. The one force is perpetually undoing what the other force is perpetually doing. Innumerable multitudes of living creatures are at work, taking lime from the water, and constructing carbonate-of-lime. But the ocean is ever seeking to re-dissolve that carbonate-of-lime.
Another difficult question as to the ooze was—whether the shells of which it is mainly made were those of Foraminifera living in the deep sea, far down below the surface, or of Foraminifera living near the surface. Able men took both sides of the discussion, some ascribing the ooze entirely to deep-sea jelly-specks, others ascribing it entirely to surface jelly-specks.
The question cannot be said yet to have met with complete settlement. But here once more it seems that both sides have been partly in the right.