Wanderings of an Iceberg—The Tropical Ocean—The Cachalot—The Frigate Bird—The Tropic Bird—The Esculent Swallow—The Flying-fish—The Bonito—The White Shark—Tropical Fishes—Crustaceans—Land Crabs—Molluscs—Jelly Fish—Coral Islands.

Day after day the glacier of the north protrudes its mass farther and farther into the sea, until finally, rent by the tides, and with a crash louder than that of the avalanche, the iceberg rolls into the abyss. The frost-bound waters, that have languished so many years in their Greenland prison, are now drifting to the south, on their way to the tropical ocean; but the sun must rise and set for many a day before they bid adieu to the fogs of the north.

See there yon dismal ice-blocked shore, with the jagged mountains in the background, their snowy peaks rising high into the sky. Screeching sea-birds—fulmars, gulls, guillemots, auks—mix their hoarse voices with the melancholy tones of the breakers and the winds, and between them all resounds, from time to time, the bellowing of the walrus or the roar of the polar bear.

The weak rays of the sun, just dipping over the horizon, have called forth these symptoms of life; but as soon as the great luminary disappears, animal creation becomes mute, and the voices of the air and ocean are again the only sounds which break the silence of the arctic night.

The crystal mass floats along, buried in deep darkness; but soon a new and wondrous sight is seen, for the flaming swords of the northern light flit through the heavens, casting a magic gleam, here on the desert shore, there on the dark bosom of the sea.

Advancing farther and farther to the south, the iceberg loses one after another the witnesses of its first migrations, and wasting more and more, at length entirely merges in the tepid Gulf Stream. The enthralled waters are now all liberated, but many on their western passage are again diverted to the north, and the others reach, only after a long circuit, the mighty equatorial stream, which carries them along, through the torrid ocean, from one hemisphere to the other.

The animal life they meet with in these sunny regions is very different from that which witnessed their passage through the higher latitudes.

The large whalebone whale, the rorqual and narwhal of the north, have disappeared, but pods of the mighty sperm whale rapidly traverse the equatorial seas.

The birds also exhibit new types of being. The royal albatross avoids the torrid zone, but the high-soaring frigate-bird hovers over the waters, where it is seen darting upon the flying-fish, and, like the skua gull of the north, attacking the weaker sea-birds in order to make them disgorge their prey.

‘He is almost always a constant attendant upon our fishermen,’ says Dr. Chamberlain,24 ‘when pursuing their vocation on the sand-banks in Kingston Harbour, or near the Palisados. Over their heads it takes its aËrial stand, and watches their motions with a patience and a perseverance the most exemplary. It is upon these occasions that the pelicans, the gulls, and other sea-birds become its associates and companions. These are also found watching with equal eagerness and anxiety the issue of the fishermen’s progress, attracted to the spot by the sea of living objects immediately beneath them. And then it is, when these men are making their last haul, and the finny tribe are fluttering and panting for life, that this voracious bird exhibits his fierce propensities. His hungry companions have scarcely secured their prey by the side of the fishermen’s canoes, when, with the lightning’s dart, they are pounced upon with such violence that, to escape his rapacious assaults they readily, in turn, yield their hard-earned booty to this formidable opponent. The lightness of its trunk, the short torso and vast spread of wing, together with its long slender and forked tail, all conspire to give it a superiority over its tribe, not only in length and rapidity of flight, but also in the power of maintaining itself, on outspread pinions, in the regions of its aËrial habitations amidst the clouds; where, at times, so lofty are its soarings, that its figure becomes almost invisible to the spectator in this nether world.’

The beautiful tropic birds, whose name implies the limit of their abode—for they are seldom seen but a few degrees south or north of either tropic—hover at such a distance from the nearest land that it is still an enigma where they pass the night—whether they sleep upon the waters, or whether their extraordinary length of wing bears them to some isolated rock. Nothing can be more graceful than their flight. They glide along, most frequently without any motion of their outstretched pinions, but at times this smooth progression is interrupted by sudden jerks. When they see a ship, they never fail to sail round it, and the mariner bound to the equatorial regions hails them as the harbingers of the tropics. The two long straight narrow feathers of which their tail consists, are employed by the natives of the greater part of the South Sea Islands as ornaments of dress, and serve to distinguish the chieftains from the multitude.

The esculent swallow (Colocalia esculenta)—whose edible nest, formed by a secretion which hardens in the air, is one of the greatest dainties of the Chinese epicure—may almost be considered as a sea-bird, as it chiefly inhabits marine caves in various islands of the Indian Archipelago, and exclusively seeks its food in the teeming waters.

The steep sea-walls along the south coast of Java are clothed to the very brink with luxuriant woods, and screw-pines strike everywhere their roots into their sides or look down from the margin of the rock upon the sea below. The surf of ages has worn deep caves into the chalk cliffs, and here the swallow builds her nest. When the sea is most agitated, whole swarms are seen flying about, and purposely seeking the thickest wave-foam, where no doubt they find their food. From a projecting cape, or looking down upon the play of waters, may be seen the mouth of the cave of Gua Rongkop, sometimes completely hidden under the waves, and then again opening its black recesses, into which the swallows vanish, or from which they dart forth with the rapidity of lightning. While at some distance from the coast the blue ocean sleeps in peace, it never ceases to fret and foam against the foot of these mural rocks, where the most beautiful rainbows glisten in the rising vapour.

Who can explain the instinct which prompts the birds to glue their nests to the high dark vaults of those apparently inaccessible caverns? Did they expect to find them a safe retreat from the persecutions of man? Then surely their hopes were vain, for where is the refuge to which his insatiable cupidity cannot find the way? At the cavern of Gua Gede the brink of the coast lies eighty feet above the level of the sea at ebb-tide. The wall first bends inwards, and then at a height of twenty-five feet from the sea throws out a projecting ledge, which is of great use to the nest-gatherers, serving as a support for a rattan ladder let down from the cliff. The roof of the cavern’s mouth lies only ten feet above the sea, which even at ebb-tide completely covers the floor of the cave, while at flood-tide the opening of the vast grotto is entirely closed by every wave that rolls against it. To penetrate into the interior is thus only possible at low water, and during very tranquil weather, and even then it could not be done if the roof were not perforated and jagged in every direction.

The boldest and strongest of the nest-gatherers wedges himself firmly in the hollows, or clings to the projecting stones while he fastens rattan ropes to them, which then hang four or five feet from the roof. To the lower end of these ropes long rattan cables are attached, so that the whole forms a kind of suspension bridge, throughout the entire length of the cavern, alternately rising and falling with its inequalities. The cave is 100 feet broad and 150 feet long, as far as its deepest recesses. If we justly admire the intrepidity of the St. Kildans, who, let down by a rope from the high level of their rocky birthplace, remain suspended over a boisterous sea, we needs must also pay a tribute of praise to the boldness of the Javanese nest-gatherers, who, before preparing their ladders for the plucking of the birds’ nests, first offer solemn prayers to the goddess of the south coast, and deposit gifts on the tomb where the first discoverer of the caves and their treasures is said to repose.

While traversing the tropical ocean, the mariner often sees whole shoals of flying-fishes (Exocoetus volitans, Pterois volitans) dart out of the water to escape the jaws of the bonito and the coryphÆna. But while avoiding the perils of the deep, new dangers await them in the air; for, before they can drop into the sea, the frigate-bird frequently pounces upon them, and draws them head-foremost into his maw.

The bonito and coryphÆna in their turn are often transpierced by the lance of the sword-fish, who, like the saw-snouted pristis, is said to engage even the sperm whale, and to put this huge leviathan to flight.

But of all the monsters of the tropical seas, there is none more dreaded by man than the white shark.

Woe to the sailor that falls overboard while one of these tyrants of the ocean is prowling about the ship; but woe also to the shark who, caught by a baited hook, is drawn on board, for a slow and cruel death is sure to be his lot. Mutilated and hacked to pieces, his torments are protracted by his uncommon tenacity of life.

Such, besides herds of playful dolphins, are the members of the finny creation most commonly met with on the high seas, but in general the waters at a greater distance from the land are poor in fishes. The tropical fishes chiefly abound near the coasts, in the sheltered lagoons, and in the channels which wind through numberless reefs or islands. As the colibris dart from flower to flower in the Brazilian woods, thus the gorgeous balistinÆ and glyphodons sport about the submerged coral-gardens, and enhance the brilliancy of their fairy bowers.

While these lustrous fishes belted with azure, red, and gold, defy the imagination of the poet to describe their beauty, others remind one by their deformity of the chimeras engendered by the diseased brain of a delirious patient. Here we see the hideous frog-fish creeping along like a toad upon his hand-like fin, there the sun-fish swimming about like a vast head severed from its trunk. Cased like the armadillo in an inflexible coat of mail, into which every movable part can be withdrawn, the trunk-fish derides the attack of many an enemy; and inflating its spiny body, the diodon, like the hedgehog of the land, bids defiance to his foes.

On examining the crustacean world, we find that it has established its head-quarters in the tropical zone. There a multitude of wondrous types unknown to the colder regions of the globe attract the attention of the naturalist: the transparent phyllosomas, not thicker than the thinnest wafer, and the strange sword-tails, whose body is covered by a double shield, and terminates in a long horny process, used by the Malays to point their arrows. The crabs and lobsters of the tropical waters are not only more numerous than in our colder seas, but they attain a far greater size than those of the temperate regions of the globe.

The decapod crustaceans (cray-fish) which inhabit our rivers and brooks, are long-tailed like the lobster, but in the torrid zone the river species all belong to the order of the short-tailed crabs, the most perfect and highly developed of the class. Some species even entirely forsake the water and spend their days on shore, not only on the beach, but far inland on the hills. When the season for spawning arrives, large numbers of these land-crabs set out from their mountainous abodes, marching in a direct line to the sea-shore, for the purpose of depositing their eggs, which are attached to the lower surface of the abdomen and are washed off by the surf. This done, they recommence their toilsome march towards their upland retreats, setting out after nightfall and steadily advancing until the dawn warns them to seek concealment in the inequalities of the ground or among any kind of rubbish, where they lie, until the stars again invite them to pursue their course. On their seaward journey, which they prosecute so eagerly that they suffer no opposition to deter them from their purpose, they are in full vigour and fine condition, and this is the time when they are caught in great numbers for the table, their flesh being held in high estimation; but on returning from the coast they are exhausted and unfit for use.

Wherever the West Indian Land Crabs make their home, their burrows are as thickly sown as those of a rabbit warren. Concealed during the greater part of the day in these subterranean abodes, they come out at night to feed, but are always ready to scuttle back at the least alarm. Should, however, their retreat be intercepted they show a bold front to the enemy, seizing him with one of their long claws, and then shaking off the limb at its junction with the body. As the claw retains its tension for some little time after this voluntary separation, the effect is the same as if the creature were still actively biting, and while the enemy’s attention is engaged with these troublesome pincers, the crab takes the opportunity to conceal itself in some crevice. As is the case with all crustaceans, a new limb soon sprouts out and repairs the loss of the discarded member.

A singular species of land decapod, called the Fighting Crab from its bellicose propensities, possesses one large and one very little claw, which gives it a very strange and ridiculous appearance, particularly when, running along at full speed, it holds the large claw in the air, and nods it continually, as beckoning to its pursuer.

The molluscs are no less profusely scattered over the tropical seas and coasts than the higher organised crustaceans. There we find those mighty cephalopods, whose long fleshy processes, as thick as a man’s thigh, are able, it is said, to seize the fisherman in his boat and drag him into the sea; and there is the abode of the tridacna, whose colossal valves, measuring five feet across, attain a weight of five hundred pounds, and serve both as receptacles for holy water in Catholic churches and to collect the rain in the South Sea Islands.

The rarest and most beautiful of shells, the royal Spondylus, the Carinaria vitrea, the Scalaria pretiosa, the CyprÆa aurora, and a host of Volutes, Harps, Marginelles, Cones, &c., of the most exquisite colouring, are all inhabitants of the warmer waters; and the most costly gift of the sea, the oriental pearl, is the produce of a mollusc which is found scattered over many parts of the Indian and Pacific Oceans.

On descending still lower in the scale of marine life, we find the jelly-fish disporting in the tropical waves in hosts as brilliant as the skies. Some are formed like a mushroom, others assume the shape of a belt or girdle; others are globular, while some are circular, flat, or bell-shaped; and others again resemble a bunch of berries. In colour, perhaps the most delicate is the lovely Velella, with its pellucid crest, its green transparent body and fringe of purple tentacles; but it is surpassed in size and gorgeousness by the Physalia, or ‘Portuguese man-of-war,’ whose large air-sack, with its splendid vertical comb, shines in every shade of purple and azure. The greatest marvels of the tropical ocean are, however, beyond comparison, the wondrous buildings of the Lithophytes, or stone polyps, the reefs and coral islands. Here we see them forming vast barriers which fringe the shores for hundreds and hundreds of miles; there they rise in circular atolls over the blue waves, like bridal rings dropped from the heavens upon the surface of the seas. All is wonderful in these amazing constructions—their puny architects, the lagoons they encircle, the power with which they resist the most furious breakers, the little world of plants drifted over the waters, which ultimately covers them with a verdant crown, and invites man to settle on these gardens of the ocean. There the tall cocoa-palm rocks its feathered crest in the breeze, affording both shade and fruit to the islander, and there the sea-bird finds a resting-place after its wide flight over the deserts of the equatorial sea.