THE PRIMITIVE OCEAN.

The greatest of all histories, traced in mighty characters by the Almighty himself, is that of the earth-rind. The leaves of this giant volume are the strata which have been successively deposited in the bosom of the sea, or raised by volcanic powers from the depths of the earth; the wars which it relates are the Titanic conflicts of two hostile elements, water and fire, each anxious to destroy the formations of its opponent; and the historic documents which bear witness to that ancient strife lie before us in the petrified or carbonified remains of extinct forms of organic existence—the medals of creation.

It is only since yesterday that science has attempted to unriddle the hieroglyphics in which the past history of our planet reveals itself to man, and it stands to reason that in so difficult a study truth must often be obscured by error; but although the geologist is still a mere scholar, endeavouring to decipher the first chapters of a voluminous work, yet even now the study of the physical revolutions of our globe distinctly points out a period when the molten earth wandered, a ball of liquid fire, through the desert realms of space. In those times, so distant from ours that even the wildest flight of imagination is unable to carry us over the intervening abyss, the waters of the ocean were as yet mixed with the air, and formed a thick and hazy atmosphere through which no radiant sunbeam, no soft lunar light, ever penetrated to the fiery billows of molten rock, which at that time covered the whole surface of the earth. What pictures of desolation rise before our fancy, at the idea of yon boundless ocean of fluid stone, which rolled from pole to pole without meeting on its wide way anything but itself. Ever and ever in the dark-red clouds shone the reflection of that vast conflagration, witnessed only by the eye of the Almighty, for organic life could not exist on a globe which exclusively obeyed the physical and chemical laws of inorganic nature.

But while the fiery mass with its surrounding atmosphere was circling through the icy regions of ethereal space (the temperature of which is computed to be lower than 60° R. below freezing point), it gradually cooled, and its hitherto fluid surface began to harden to a solid crust. Who can tell how many countless ages may have dropped one after the other into the abyss of the past, ere thus much was accomplished; for the dense atmosphere constantly threw back again upon the fiery earth-ball the heat radiating from its surface, and the caloric of the vast body could escape but very slowly into vacant space?

Thus millions of years may have gone by before the aqueous vapours, now no longer obstinately repelled by the cooling earth-rind, condensed into rain, and, falling in showers, gave birth to an incipient ocean. But it must not be supposed that the waters obtained at once a tranquil and undisturbed possession of their new domain, for, as soon as they descended upon the earth, those endless elementary wars began, which, with various fortunes, have continued to the present day.

As soon as the cooling earth-rind began to harden, it naturally contracted, like all solid bodies when no longer subject to the influence of expanding heat, and thus in the thin crust enormous fissures and rents were formed, through which the fluid masses below gushed forth, and, spreading in wide sheets over the surface, once more converted into vapours the waters they met with in their fiery path.

But after all these revolutions and vicissitudes which opposed the birth of ocean, perpetually destroying its perpetually renewed formation, we come at last to a period when, in consequence of the constantly decreasing temperature of the earth-rind, and its increasing thickness, the waters at last conquered a permanent abode on its surface, and the oceanic empire was definitively founded.

The scene has now changed; the sea of fire has disappeared, and water covers the face of the earth. The rind is still too thin, and the eruptions from below are still too fluid to form higher elevations above the general surface: all is flat and even, and land nowhere rises above the mirror of a boundless ocean.

This new state of things still affords the same spectacle of dreary uniformity and solitude in all its horrors. The temperature of the waters is yet too high, and they contain too many extraneous substances, too many noxious vapours arise from the clefts of the earth-rind, the dense atmosphere is still too much impregnated with poisons, to allow the hidden germs of life anywhere to awaken. A strange and awful primitive ocean rises and falls, rolls and rages, but nowhere does it beat against a coast; no animal, no plant, grows and thrives in its bosom; no bird flies over its expanse.

But meanwhile the hidden agency of Providence is unremittingly active in preparing a new order of things. The earth-rind increases in thickness, the crevices become narrower, and the fluid or semi-fluid masses escaping through the clefts ascend to a more considerable height.

Thus the first islands are formed, and the first separation between the dry land and the waters takes place. At the same time no less remarkable changes occur, as well in the constitution of the waters as in that of the atmosphere. The farther the glowing internal heat of the planet retires from the surface, the greater is the quantity of water which precipitates itself upon it. The ocean, obliged to relinquish part of its surface to the dry land, makes up for the loss of extent by an increase of depth, and the clearer atmosphere allows the enlivening sunbeam to gild here the crest of a wave, there a naked rock.

And now also life awakens in the seas, but how often has it changed its forms, and how often has Neptune displaced his boundaries since that primordial dawn. Alternately rising or subsiding, what was once the bottom of the ocean now forms the mountain crest, and whole islands and continents have been gradually worn away and whelmed beneath the waves of the sea, to arise and to be whelmed again. In every part of the world we are able to trace these repeated changes in the fossil remains embedded in the strata that have successively been deposited in the sea, and then again raised above its level by volcanic agencies, and thus, by a wonderful transposition, the history of the primitive ocean is revealed to us by the tablets of the dry land. The indefatigable zeal of the geologists has discovered no less than thirty-nine distinct fossiliferous strata of different ages, and as many of these are again subdivided into successive layers, frequently of a thickness of several thousand feet, and each of them characterised by its peculiar organic remains, we may form some idea of the vast spaces of time required for their formation.

The annals of the human race speak of the rise and downfall of nations and dynasties, and stamp a couple of thousand years with the mark of high antiquity; but each stratum or each leaf in the records of our globe has witnessed the birth and the extinction of numerous families, genera, and species of plants and animals, and shows us organic Nature as changeable in time as she appears to us in space. As, when we sail to the southern hemisphere, the stars of the northern firmament gradually sink below the horizon, until finally entirely new constellations blaze upon us from the nightly heavens; thus in the organic vestiges of the palÆozoic seas we find no form of life resembling those of the actual times, but every class

Then spiral-armed Brachiopods were the chief representatives of the molluscs; then crinoid star-fishes paved the bottom of the ocean; then the fishes, covered with large thick rhomboidal scales, were buckler-headed like the Cephalaspis, or furnished with wing-like appendages like the Pterichthys; and then the Trilobites, a crustacean tribe, thus named from its three lobed skeleton, swarmed in the shallow littoral waters where the lesser sea-fry afforded them an abundant food. From a comparison of their structure with recent analogies, it is supposed that these strange creatures swam in an inverted position close beneath the surface of the water, the belly upwards, and that they made use of their power of rolling themselves into a ball as a defence against attacks from above. The remains of seventeen families of Trilobites, including forty-five genera and 477 species, some of the size of a pea, others two feet long, testify the once flourishing condition of these remarkable crustaceans, yet but few of their petrified remains, so numerous in the Silurian and Devonian strata, are found in the carboniferous or mountain limestone, and none whatever in formations of more recent date. Thus, long before the wind ever moaned through the dense fronds of the tree ferns and calamites which once covered the swampy lowlands of our isle, and long before that rich vegetation began, to which we are indebted for our inexhaustible coal-fields, now frequently buried thousands of feet below the surface on which they originally grew, the Trilobites belonged already to the things of the past!

In the seas of the mesozoic or mediÆval period, new forms of life appear upon the scene. A remarkable change has taken place in the cephalopods; for the chambered and straightened Orthoceratites and many other families of the order have passed away, and the spiral Ammonites, branching out into numerous genera, and more than 600 species, now flourish in the seas, so that in some places the rocks seem, as it were, composed of them alone. Some are of small dimensions, others upwards of three feet in diameter. They are met with in the Alps, and have been found in the Himalaya Mountains, at elevations of 16,000 feet, as eloquent witnesses of the vast revolutions of which our earth has been the scene. Carnivorous, and resembling in habits the Nautili, their small and feeble representatives of the present day, their immense multiplication proves how numerous must have been the molluscs, crustaceans, and annelides, on which they fed, all like them widely different from those of the present day.

Then also flourished the Belemnites (Thunder-stones), supposed by the ancients to be the thunderbolts of Jove, but now known to be the petrified internal bones of a race of voracious ten-armed cuttle-fishes, whose importance in the oolitic or cretaceous seas may be judged of by the frequency of their remains, and the 120 species that have been hitherto discovered. Belemnites two feet long have been found, so that, to judge by analogies, the animals to which they belonged as cuttle-bones must have measured eighteen or twenty feet from end to end, a size which reduces the rapacious Onychoteuthis of the present seas to dwarfish dimensions.

But of all the denizens of the mesozoic seas none were more formidable than the gigantic Saurians, whose approach put even the voracious sharks to flight. The first of these monsters that raises its frightful head above the waters is the dreadful Ichthyosaurus, a creature thirty or even fifty feet long, half fish, half lizard, and combining in strange assemblage the snout of the porpoise, the teeth of the crocodile, and the paddles of the whale. Singular above all is the enormous eye, in size surpassing a man's head. Woe to the fish that meets its appalling glance! No rapidity of flight, no weapon, be it sword or saw, avails, for the long-tailed gigantic saurian darts like lightning through the water, and its dense harness bids defiance to every attack. Not only have fifteen distinct species of Ichthyosauri been distinguished, but the remains of crushed and partially digested fish-bones and scales, which are found within their skeleton, indicate the precise nature of their food. Their fossil remains abound along the whole extent of the lias formation, from the coasts of Dorset, through Somerset and Leicestershire to the coast of Yorkshire, but the largest specimens have been found in Franconia.

Along with this monster, another and still more singular deformity makes its appearance, the Plesiosaurus, in which the fabulous chimÆras and hydras of antiquity seem to start into existence. Fancy a crocodile twenty-seven feet long, with the fins of a whale, the long and flexible neck of a swan, and a comparatively small head. With the appearance of this new tyrant, the last hope of escape is taken from the trembling fishes; for into the shallow waters, inaccessible to the more bulky Ichthyosaurus, the slender Plesiosaurus penetrates with ease.

A race of such colossal powers seemed destined for an immortal reign, for where was the visible enemy that could put an end to its tyranny? But even the giant strength of the saurians was obliged to succumb to the still more formidable power of all-changing time, which slowly but surely modified the circumstances under which they were called into being, and gave birth to higher and more beautiful forms.

In the tertiary period, the dreadful reptiles of the mesozoic seas have long since vanished from the bosom of the ocean, and cetaceans, walruses, and seals, unknown in the primitive deep, now wander through the waters or bask on the sunny cliffs. With them begins a new era in the life of the sea. Hitherto it has only brought forth creatures of base or brutal instinct, but now the Divine spark of parental affection begins to ennoble its more perfect inhabitants, and to point out the dim outlines of the spiritual world.

During all these successive changes the surface of the earth has gradually cooled to its present temperature, and many plants and animals that formerly enjoyed the widest range must now rest satisfied with narrower limits. The sea-animals of the north find themselves for ever severed from their brethren of the south, by the impassable zone of the tropical ocean; and all the fishes, molluscs, and zoophytes, whose organisation requires a greater warmth, confine themselves to the equatorial regions.

As the tertiary period advances towards the present epoch, the species which flourished in its prime become extinct, like the numberless races which preceded them; new modifications of life, more and more similar to those of the present day, start into existence; and, finally, creation appears with increasing beauty in her present rich attire.

Thus old Ocean, after having devoured so many of his children, has transformed himself at last into our contemporaneous seas, with their currents and floods, and the various animals and plants growing and thriving in their bosom.

Who can tell when the last great revolutions of the earth-rind took place, which, by the upheaving of mighty mountains or the disruption of isthmuses, drew the present boundaries of land and sea? or who can pierce the deep mystery which veils the future duration of the existing phase of planetary life?

So much is certain, that the ocean of the present day will be transformed as the seas of the past have been, and that "all that it inhabit" are doomed to perish like the long line of animal and vegetable forms which preceded them.

We know by too many signs that our earth is slowly but unceasingly working out changes in her external form. Here lands are rising, while other areas are gradually sinking; here the breakers perpetually gnaw the cliffs, and hollow out their sides, while in other places alluvial deposits encroach upon the sea's domain.

However slowly these changes may be going on, they point to a time when a new ocean will encircle new lands, and new animal and vegetable forms arise within its bosom. Of what nature and how gifted these races yet slumbering in the lap of time may be, He only knows whose eye penetrates through all eternity; but we cannot doubt that they will be superior to the present denizens of the ocean.

Hitherto the annals of the earth-rind have shown us uninterrupted progress; why, then, should the future be ruled by different laws? At first the sea only produces weeds, shells, crustacea; then the fishes and reptiles appear; and the cetaceans close the vista. But is this the last word, the last manifestation of oceanic life, or is it not to be expected that the future seas will be peopled with beings ranking as high above the whale or dolphin as these rank above the giant saurians of the past?