Marine vegetation

“ Care must be taken to observe whether, when the sun shines and the light is bright, the silvery bubbles of oxygen form upon the fronds of the marine vegetation; and if not, it is certain that the marine plants are not in a healthy state, and must be renewed. ”

“ Usually this tropical animal frequents the shallow smooth waters of the bays, inlets, and river estuaries where marine vegetation (fucus and seaweeds) is in abundance, and there it leisurely feeds, being lethargic in disposition, but an immense eater. ”

“ As this era begins, the sea bottoms, the extensive continental shelves, and the numerous shallow near-shore basins are covered with prolific vegetation. The more simple and primitive forms of animal life have already developed from preceding vegetable organisms, and the early animal organisms have gradually made their way along the extensive coast lines of the various land masses until the many inland seas are teeming with primitive marine life. ”

“ Rushes, flags, and aquatic grasses may now be seen standing in diminutive tufts out of the water; and a terrestrial vegetation at least continues to exist, though it can scarce be said to thrive, on banks covered by the tide at full. The lacustrine flora increases, both in extent and luxuriance, as that of the sea diminishes; and in the upper reaches we fail to detect all trace of marine plants: the algæ, so luxuriant of growth along the straits of this “miniature Mediterranean,” altogether cease ”

“ The winds contribute to the material which falls into the sea; plant life also furnishes its quota; accumulations of vegetation are ultimately consolidated among the formations as beds of coal; and animal life adds to the marine formations, for corals, shells, and bones are all brought to be buried in the sand, and often extensive formations of calcareous matter are thus produced. ”

“ Corals and other quick-growing calcareous marine organisms are the most powerful in this respect by creating new land in the ocean. Vegetation of all sorts acts in a similar way, either in forming soil and assisting in breaking up rocks, in filling up shallow lakes, and even, like the mangrove, in reclaiming wide stretches of land from the sea. Plant life, utilizing solar light to combine the inorganic elements of water, soil and air into living substance, is the basis of all animal life. ”

“ If the marine had been converted into terrestrial vegetation, we ought to have, in the Lake of Stennis, for example, plants of an intermediate character between the algæ of the sea, and the monocotyledons of the lake. But no such transition-plants are found. The algæ, as our author observes, become dwarfish and ill-developed. They cease to exist as the water becomes fresher, “until at length we find, instead of the brown, rootless, flowerless fucoids and confervæ of the ocean, the green, rooted, flowering flags, rushes, and aquatic grasses of the fresh water. ”

“ These strata consist of the accumulated exuviae of shell-fish, the animals perished age after age but their shells remained, and in progression of time produced the amazing quantities of lime-stone which almost cover the earth. Other marine animals called coralloids raised walls and even mountains by the congeries of their calcareous habitations, these perpendicular corralline rocks make some parts of the Southern Ocean highly dangerous, as appears in the journals of Capt. ”

“ Under such extreme conditions none of the higher land plants venture down towards the unfriendly sea. To see the overlap of the terrestrial and maritime vegetation well developed we seek conditions entirely different, where amid shallow inlets and salt-marshes land and sea merge imperceptibly.{203} Here the absence of higher plants from the areas below high water, as compared with their abundance above water-level, is a conspicuous feature. ”

“ Unlike the plains and savannahs we crossed yesterday, where the ground is parched up in the dry season, the Atlantic forest, bathed in the rains distilled from the north-east trades, is ever verdant. Perennial moisture reigns in the soil, perennial summer in the air, and vegetation luxuriates in ceaseless activity and verdure, all the year round. Unknown are the autumn tints, the bright browns and yellows of English woods, much less the crimsons, purples, and yellows of Canada, where the dying foliage rivals, nay, excels the expiring dolphin in splendour. ”

“ We have results before us, in this extent of space, identical with those of many hundred thousand years of time; and if terrestrial plants were as certainly developments of the low plants of the sea as the huge oak is a development of the immature seedling, just sprung from the acorn, so vast a stretch of sea-coast could not fail to present us with the intermediate vegetation in all its stages. ”

“ Whatever is beautiful, wondrous, or uncommon in the great classes of fish and Echinoderms, jelly-fishes and Polypes, and the Mollusks of all kinds, is crowded into the warm and crystal waters of the tropical ocean—rests in the white sands, clothes the rough cliffs, clings, where the room is already occupied, like a parasite, upon the first comers, or swims through the shallows and depths of the elements—while the mass of the vegetation is of a far inferior magnitude. ”

“ In the sea, the tropical plains with their tangled vegetation and plentiful animal life are represented by the still more uniform plain forming the submerged continental 13 shelf with its strange forests of flowerless plants, the seaweeds. These submarine jungles shelter hosts of animal species, many of which swarm in countless myriads. This life embraces all grades of invertebrates, such as the microscopic protozoa, sponges, radiate animals like the coral-polyps, starfishes, sea-urchins, etc., and crustaceans in vast variety, and, among vertebrates, includes fishes, reptiles, and mammals. ”

“ The breakers then washed up portions of the coral on to the summit of the reef, which by degrees crumbled away from the action of the atmosphere. Sea-birds made it their home, and deposited the seeds of various plants, while the ocean washed up other seeds still containing germinating powers. Thus vegetation commenced; and the trees and shrubs decaying, more vegetable mould was formed to support the existence of a further succession of trees and shrubs. ”

“ Species, it is well known, both of plants and animals, are limited to particular localities of [325] variable, and often of no great, extent. If marine, an alteration in the sea bottom will prove fatal to many. If terrestrial, an increase of altitude, the conversion of dry land into marshes and lakes, or of lakes and marshes into meadow and arid loamy soil, will completely alter the flora and fauna of the district in question. Look into any estuary or rocky pool along the shore of the ocean, swarming with testacea, and crustacea; every bowlder incrusted with corallines ”

“ Although there is such a contrast in the degree of uniformity of their life-conditions between land and water plants, a strictly aquatic plant being but slightly affected by changes in the physical conditions that are accompanied by a complete transformation in the character of the terrestrial vegetation, yet—and this is the important point—we find the same principle of differentiation at work with both land and water plants. ”

“ Viewing generally the migration of the Seed Plants from land to water, we see that the fresh waters of the world, untenanted by other large plants, have been{207} fully colonized, generally a long time ago, and by plants of rather early types. But as regards the sea, the luxuriant Algal vegetation which is in possession of our shores has no reason to tremble for its supremacy. ”

“ As the localization of marine plants and animals is in a considerable degree determined by the nature of the rocks and their detritus, it follows that each part of this coast will have its more or less distinct Flora and Fauna. What now must result from the action of the waves in the course of a geologic epoch? As the sea makes slow inroads on the land, the place at which each group of strata crops out on the beach will gradually move towards the west: its distinctive fish, mollusks, crustaceans, and sea-weeds, migrating with it. ”

“ The hard sand which the tide has left is pitted with tiny holes, the lairs of a million crabs and sea insects. The beaches are covered with a wondrous diversity of animal and vegetable growths thrown up and discarded by the tide. Seaweed of strange varieties, and of every fantastic shape and texture, the round balls of fibrous grass, like gigantic thistledowns, which scurry before the light breeze, as though endued with life, the white oval shells of the cuttle-fish, and the shapeless hideous masses of dead medusæ, all lie about in extricable confusion on the sandy shores of the East Coast. ”

“ Freshwater plants and animals.—The remains of species belonging to those genera of the animal and vegetable kingdoms which are more or less exclusively confined to fresh water are for the most part preserved in the beds of lakes or estuaries, but they are oftentimes swept down by rivers into the sea, and there intermingled with the exuviæ of marine races. ”

“ The transportation of seeds of plants by water requires very little notice; every one is familiar with the mode in which coral islands, which gradually rise out of the sea, become covered with vegetation. "If new lands are formed, the organic forces are ever ready to cover the naked rock with life.—Lichens form the first covering of the barren {75}rocks, where afterwards lofty forest trees wave their airy summits. The successive growth of mosses, grasses, herbaceous plants and shrubs or bushes, occupies the intervening period of long but undetermined duration." ”

“ Another immediate effect of ocean streams arises where their currents of warm water come against shores or shallows of the sea. At these points, if the water have a tropical temperature, we invariably find a vast and rapid development of marine animals and plants, of which the coral-making polyps are the most important. In such positions the growth of forms which secrete solid skeletons is so rapid that great walls of their remains accumulate next the shore, the mass being built outwardly by successive growths until the realm of the land may be extended for scores of miles into the deep. ”

“ Still other variations, as of strength of currents, salinity, etc., exert an influence in this realm and lead to great diversity in its living organisms. Throughout its entire extent, however, the continental shelf abounds in both plant and animal life.
The plant life of the sea, as has been shown in recent years by the use of the dredge and net, is most abundant at the surface and is practically absent at the bottom where the water is over 100 fathoms deep. The animals of the sea, like those of the land, are dependent primarily on plants for their food. ”

“ Among the many conditions which have produced great diversity in numbers and distribution of marine organisms during geologic time are temperature, depth of water, clearness of water, nature of sea bottom, degree of salinity, and food supply. River and lake deposits also not uncommonly contain remains of organisms which inhabited the waters, but also others which were carried in. “Surrounding trees drop their leaves, flowers, and fruit upon the mud flats, insects fall into the quiet waters, while quadrupeds are mired in mud or quicksand and soon buried out of sight. ”

“ Single leaves are rarely transported far from their place of origin, and when of good preservation in geologic deposits, give decisive evidence of the nearness of the shore. On the other hand, tough palm leaves have been seen in the sea 70 miles from land and rafts of leaves are often met with 200 or more miles beyond the mouths of the Kongo and the Amazon. Proximity to shore is also indicated by the presence in marine faunas of land molluscs, insects and bones of land vertebrates. ”

“ Then these die off, and a third kind plants itself upon their remains and carries the structure to the top, near the surface of the sea, where many surface-corals, corallines, and various other limy and flinty plants and animals help to erect a dry reef, upon which land vegetation can find a root-hold, and where, after a while, men may dwell. When these coral-built islands are ring-shaped they are called atolls, and are believed to be living crowns about the summits of submerged mountains. ”

“ The color of seawater varies according to the thickness through which we observe it, on account of the unequal absorption of the different rays; hence a marine plant will find itself in a condition more or less favorable, and be better or less equipped for the struggle for existence, according to the depth of the soil on which it rests. ”

“ And once more, the comparatively-varied shores, presenting physical conditions that change from mile to mile, will furnish suitable habitats for more numerous species. So that as the elevation proceeds, three causes conspire to introduce additional marine plants and animals. To what classes will the increasing Fauna be for a long period confined? Of course, to classes of which individuals, or their germs, are most liable to be carried far away from their native shores by floating sea-weed or drift-wood ”

“ Its bottom is carpeted or paved with marine plants, with zoophytes and with shells, while its waters are teeming with infinitely varied forms of moving life. Most of its vegetables and its animals, no doubt, are confined by the laws of their organization to a warmer temperature than that of the Mediterranean, but among them there must be many whose habitat is of a wider range, many whose powers of accommodation would enable them to acclimate themselves in a colder sea. ”