As the months of the year passed, one by one, the young eels grew, lengthening and broadening. As they grew and the tissues of their bodies changed in density, they drifted into light. Upward passage through space in the sea was like passage through time in the Arctic world in spring, with the hours of sunlight increasing day by day. Little by little the blue haze of midday lengthened and the long nights grew shorter. Soon the eels came to the level where the first green rays, filtering down from above, warmed the blue light. So they passed into the zone of vegetation and found their first food.
The plants that received enough energy for their life processes from the sea-strained residue of sunlight were microscopic, floating spheres. On the cells of ancient brown algae the young eels first nourished their glass-clear bodies—plants of a race that had lived for untold millions of years before the first eel, or the first backboned animal of any kind, moved in the earth’s seas. Through all the intervening eons of time, while group after group of living things had risen up and died away, these lime-bearing algae had continued to live in the sea, forming their small protective shields of lime that were unchanged in shape and form from those of their earliest ancestors.
Not only the eels browsed on the algae. In this blue-green zone, the sea was clouded with copepods and other plankton foraging on the drifting plants, and dotted with the swarms of shrimplike animals that fed on the copepods, and lit by the twinkling silver flashes of small fishes that pursued the shrimps. The young eels themselves were preyed upon by hungry crustaceans, squids, jellyfish, and biting worms, and by many fishes who roved openmouthed through the water, straining food through mouth and gill raker.
By midsummer the young eels were an inch long. They were the shape of willow leaves—a perfect shape for drifters in the currents. Now they had risen to the surface layers of the sea, where the black dots of their eyes could be seen by enemies in the bright-green water. They felt the lift and roll of waves; they knew the dazzling brightness of the midday sun in the pure waters of the open ocean. Sometimes they moved in the midst of floating forests of sargassum weed, perhaps taking shelter beneath the nests of flying fishes or, in the open spaces, hiding in the shadow of the blue sail or float of a Portuguese man-of-war.
In these surface waters were moving currents, and where the currents flowed the young eels were carried. All alike were swept into the moving vortex of the north Atlantic drift—the young of the eels from Europe and the young of the eels from America. Their caravans flowed through the sea like a great river, fed from the waters south of Bermuda and composed of young eels in numbers beyond enumeration. In at least a part of this living river, the two kinds or species of eels traveled side by side, but now they could be distinguished with ease, for the young of the American eels were nearly twice as large as their companions.
The ocean currents swept in their great circle, moving from south through west and north. Summer drew to its end. All the sea’s crops had been sown and harvested, one by one—the spring crop of diatoms, the swarms of plankton animals that grew and multiplied on the abundant plants, the young of myriad fishes that fed on the plankton herds. Now the lull of autumn was upon the sea.
The young eels were far from their first home. Gradually the caravan began to diverge into two columns, one swinging to the west, one to the east. Before this time there must have been some subtle change in the responses of the faster-growing group of eels— something that led them more and more to the west of the broad river of moving surface water. As the time approached for them to lose the leaflike form of the larva and become rounded and sinuous like their parents, the impulse to seek fresher, shallowing waters grew. Now they found the latent power of unused muscles, and against the urging of wind and current they moved shoreward. Under the blind but powerful drive of instinct, every activity of their small and glassy bodies was directed unconsciously toward the attainment of a goal unknown in their own experience— something stamped so deeply upon the memory of their race that each of them turned without hesitation toward the coast from which their parents had come.
A few eastern-Atlantic eels still drifted in the midst of the western-Atlantic larvae, but none among them felt the impulse to leave the deep sea. All their body processes of growth and development were geared to a slower rate. Not for two more years would they be ready for the change to the eel-like form and the transition to fresh water. So they drifted passively in the currents.
To the east, midway across the Atlantic, was another little band of leaflike travelers—eels spawned a year before. Farther to the east, in the latitude of the coastal banks of Europe, was still another host of drifting eel larvae, these yet a year older and grown to their full length. And that very season a fourth group of young eels had reached the end of their stupendous journey and was entering the bays and inlets and ascending the rivers of Europe.
For the American eels the journey was shorter. By midwinter their hordes were moving in across the continental shelf, approaching the coast. Although the sea was chilled by the icy winds that moved over it, and by the remoteness of the sun, the migrating eels remained in the surface waters, no longer needing the tropical warmth of the sea in which they had been born.
As the young moved shoreward, there passed beneath them another host of eels, another generation come to maturity and clothed in the black and silver splendor of eels returning to their first home. They must have passed without recognition—these two generations of eels—one on the threshold of a new life; the other about to lose itself in the darkness of the deep sea.
The water grew shallower beneath them as they neared the shore. The young eels took on their new form, in which they would ascend the rivers. Their leafy bodies became more compact by a shrinkage in length as well as in depth, so that the flattened leaf became a thickened cylinder. The large teeth of larval life were shed, and the heads became more rounded. A scattering of small pigment-carrying cells appeared along the backbone, but for the most part the young eels were still as transparent as glass. In this stage they were called “glass eels,” or elvers.
Now they waited in the gray March sea, creatures of the deep sea, ready to invade the land. They waited off the sloughs and bayous and the wild-rice fields of the Gulf Coast, off the South Atlantic inlets, ready to run into the sounds and the green marshes that edged the river estuaries. They waited off the ice-choked northern rivers that came down with a surge and a rush of spring floods and thrust long arms of fresh water into the sea, so that the eels tasted the strange water taste and moved in excitement toward it. By the hundreds of thousands they waited off the mouth of the bay from which, little more than a year before, Anguilla and her companions had set out for the deep sea, blindly obeying a racial purpose which was now fulfilled in the return of the young.
The eels were nearing a point of land marked by the slim white shaft of a lighthouse. The sea ducks could see it—the piebald old-squaw ducks—when they circled high above the sea on their return every afternoon from inshore feeding grounds, coming down at dusk to the dark water with a great rush and a roar of wings. The whistling swans saw it, too, painted by the sunrise on the green sea beneath them as their flocks swept northward in the spring migration. The leader swans blew a triple note at the sight, for the point of land marked the nearness of the first stop on the swans’ long flight from the Carolina Sounds to the great barrens of the Arctic.
The tides were running high with the fullness of the moon. On the ebb tides the taste of fresh water came strongly to the fish that lay at sea, off the mouth of the bay, for all the rivers were in flood.
In the moon’s light the young eels saw the water fill with many fish, large and full-bellied and silvery of scale. The fish were shad returned from their feeding grounds in the sea, waiting for the ice to come out of the bay that they might ascend its rivers to spawn. Schools of croakers lay on the bottom, and the roll of their drums vibrated in the water. The croakers, with sea trout and spots, had moved in from their offshore wintering place, s
eeking the feeding grounds of the bay. Other fish came up into the tide flow and lay with heads to the currents, waiting to snap up the small sea animals that the swiftly moving water had dislodged, but these were bass who were of the sea and would not ascend the rivers.
As the moon waned and the surge of the tides grew less, the elvers pressed forward toward the mouth of the bay. Soon a night would come, after most of the snow had melted and run as water to the sea, when the moon’s light and the tide’s press would be feeble and a warm rain would fall, mist-laden and bittersweet with the scent of opening buds. Then the elvers would pour into the bay and, traveling up its shores, would find its rivers.
Some would linger in the river estuaries, brackish with the taste of the sea. These were the young male eels, who were repelled by the strangeness of fresh water. But the females would press on, swimming up against the currents of the rivers. They would move swiftly and by night as their mothers had come down the rivers. Their columns, miles in length, would wind up along the shallows of river and stream, each elver pressing close to the tail of the next before it, the whole like a serpent of monstrous length. No hardship and no obstacle would deter them. They would be preyed upon by hungry fishes—trout, bass, pickerel, and even by older eels; by rats hunting the edge of the water; and by gulls, herons, kingfishers, crows, grebes, and loons. They would swarm up waterfalls and clamber over moss-grown rocks, wet with spray; they would squirm up the spillways of dams. Some would go on for hundreds of miles—creatures of the deep sea spreading over all the land where the sea itself had lain many times before.
And as the eels lay offshore in the March sea, waiting for the time when they should enter the waters of the land, the sea, too, lay restless, awaiting the time when once more it should encroach upon the coastal plain, and creep up the sides of the foothills, and lap at the bases of the mountain ranges. As the waiting of the eels off the mouth of the bay was only an interlude in a long life filled with constant change, so the relation of sea and coast and mountain ranges was that of a moment in geologic time. For once more the mountains would be worn away by the endless erosion of water and carried in silt to the sea, and once more all the coast would be water again, and the places of its cities and towns would belong to the sea.
Glossary
ABYSS. The central deeps of the ocean, enclosed by the steep walls of the continental slope. The floor of the abyss is a vast and desolate plain, lying, on the average, about three miles deep, with occasional valleys or canyons dropping off to depths of five or six miles. The bottom is covered with a deep, soft deposit composed of inorganic clays and of the insoluble remains of minute sea creatures. The abyss is wholly without light and is uniformly cold.
ALGA (ăl’-ga ; pl. algae [-jē]). The algae belong to the first of the four major divisions of the plant kingdom and are the simplest and probably the oldest plants. They do not have true roots, stems, or leaves, but usually consist of a simple, leaflike frond. They range in size from microscopic spheres to giant seaweeds several hundred feet long. (See oarweed.)
AMPHIPOD.(ăm’-fĭ-pǒd). Belonging to the same large group as crabs, lobsters, and shrimps, the amphipods comprise a large group of crustaceans whose bodies are flattened from side to side and covered with a polished and flexible cuticle that is divided into sections, allowing them to jump or swim with surprising agility. There are about three thousand species of amphipods, most of which live in the sea or about its edge. Perhaps the most familiar of these are the sand fleas. Caprella, the species shown, often attaches itself by the hinder legs to a bit of seaweed and extends its body stiffly, so that it may easily be mistaken for a branch of the weed. It is about half an inch long.
ANCHOVY (ăn-chō’-vǒ ). Anchovies are small, silvery fish of herringlike appearance. They usually travel in schools which are the prey of many larger fishes. The common anchovy or whitebait is from two to four inches long.
ANGLER FISH. The angler is notorious as perhaps the ugliest, most repulsive, and most voracious of fishes. Half of the angler is head, and a good portion of the head is mouth, hence one of its local names: “all-mouth.” The angler is found on both sides of the Atlantic and may be as much as four feet long.
ANGUILLA (ăng-gwĭl’-a ). The scientific name of the common eel.
AVENS, MOUNTAIN. A dwarf, hardy shrub of the rose family, called also “wild betony,” found in Arctic and north temperate regions. The flowers are large and white, and the leaves are said to be one of the chief foods of the ptarmigan in winter.
AURELIA (ô-rē’-lĭ-a ). A flat, saucer-shaped jellyfish of a white or bluish-white color that may be up to a foot in diameter. Its appearance while swimming has suggested the common name “moon jelly.” Unlike many other jellyfishes, it has small and inconspicuous tentacles. The moon jelly is found on both Atlantic and Pacific coasts.
BARNACLE. In spite of the hard shells that enclose it, the barnacle is not related to oysters and clams, as many people suppose, but is a crustacean and so related to crabs, lobsters, and water fleas. The shells remain open while they are covered by water, and the legs, as delicately feathered as an ostrich plume, are thrust out rhythmically to aerate the blood contained in the filaments and to kick small food animals into the mouth. When the tide ebbs, barnacles that grow between the tide lines close their shells with an audible click.
BASKET STARFISH. A species of starfish with intricately branched arms, on the tips of which it walks. It preys on fishes which are so unfortunate as to venture within the brushlike mass of arms; and is found from eastern Long Island northward, in offshore waters.
BEACH FLEA. (See sand flea.)
BEROË (bĕr’-o -ē). One of the larger ctenophores (about four inches long) which feeds largely on its own relatives, often swallowing prey as large as itself. These ctenophores are abundant in New England waters in July and August, appearing at the surface during the warmest part of the day, and dropping to greater depths when the water is cold or rough.
BETONY. (See Avens.)
BIG-EYED SHRIMP. So called because of the large eyes which are very conspicuous in the nearly transparent bodies of these shrimplike crustaceans. Especially interesting are the phosphorescent spots which vary in number and arrangement with the species. These shrimps occur at the surface in swarms, usually accompanied by schools of fish and sometimes by immense flocks of gulls. They are often to be seen in tide rips.
BLENNY. This small fish lives among seaweeds and stones from the tide lines down to depths of thirty to fifty fathoms or sometimes a little deeper. Its body is elongated and somewhat eel-like, with a fin running almost the entire length of the back.
BRANT. Shallow coastal bays are ideal feeding grounds for these black and gray geese, who obtain their favorite food—the roots and lower stems of eel grass—by “tipping up” where the water is shallow enough and pulling up the grass. Their migration routes take them from Virginia and North Carolina to Greenland and the extreme northern Arctic Islands, via Cape Cod, the Gulf of St. Lawrence, and Hudson Bay.
BROWN ALGAE. Among the brown algae is a group (called “round lime bearers”) whose members wear shields of lime united into a remarkable defensive armor. Remains of these shields are found in very ancient geological deposits, at least as remote as Cambrian time. Present-day forms are practically identical in structure with their prehistoric ancestors.
BRYOZOA (brī-o-zō’-a ). Marine and fresh-water animals usually of a delicately branched and mosslike form. Early naturalists considered them plants. Some types form limy crusts of lacelike appearance on stones and seaweeds. The group is a very ancient one.
BYSSUS THREAD (bĭs’;-ŭs). Certain shellfish, such as clams, mussels, and the like, possess (especially during infancy) a gland capable of secreting a fluid that hardens into a tough thread or cord on contact with seawater. This thread, called the byssus, serves to anchor its owner against the pull of surf or tidal flow.
CALANUS (căl’-ă-nŭs). A small copepod crustacean (about an eighth of an inch long)
that is extremely abundant at certain seasons of the year off the New England coast. Its economic importance is considerable, because it is one of the principal foods of the herring and mackerel, also of the Greenland whale. (See copepod and crustacean.)
CERATIUM (sē -rā’-shĭ-ŭm). A single-celled creature about 1/100 of an inch in diameter, claimed by botanists as well as zoologists, but usually considered an animal. It is extremely phosphores- cent, and during the periods of its greatest abundance the sea blazes with light when disturbed.
CERO (sē’-rō). A large, silvery fish of the mackerel tribe, found chiefly in southern waters. Another common name is “kingfish.” It is a strong and active predator, and often is found among schools of menhaden.
CHARA (kā’-ra ). This fresh-water alga forms underwater meadows in ponds or lakes receiving water from lime-containing soils. The plant is characteristically rough and brittle to the touch because of the carbonate of lime deposited in its tissues and on its surface. In some waters it forms large deposits of marl, a crumbling, limy substance used as a fertilizer for soils deficient in lime. The leaflets grow from the central stem in candelabra-like clusters, and the fruiting bodies remind one of translucent Japanese lanterns of pinhead size, some orange and some green.
CHELA (kē’-lå). The large, pincerlike claw of a lobster, the muscles of which are considered the choicest part of the animal for eating. It is an effective weapon for defense or attack.