The ocean world : being a descriptive history of the sea and its living inhabitants

Front matter

THE OCEAN WORLD.

Plate I. The Argonaut sailing in the open sen.

THE

Preface

“ Our Planet is surrounded by two great oceans,” says Dr. Maury, .the eminent American savant : “ the one visible, the other invisible ; one is under foot, the other over head. One entirely envelopes it, the other covers about two-thirds of its surface.” It is proposed in “ The Ocean World ” to give a brief record of the Natural History of one of those great oceans and its living inhabitants, with as little of the nomenclature of Science, and as few of the repulsive details of Anatomy, as is consistent with clearness of expression ; to describe the ocean in its majestic calm and angry agitation ; to delineate its inhabitants in their many metamorphoses : the cunning with which they attack or evade their enemies : their instructive industry : their quarrels, their combats, and then- loves.

The learned Schleiden eloquently paints the living wonders of the deep: “It we dive into the liquid crystal of the Indian Ocean, the most wondrous enchantments are opened to us, reminding us of the fairy tales of childhood’s dreams. The strangely-branching thickets bear living flowers. Dense masses of Meandrineas and Astreas contrast with the leafy, cup- shaped expansions of the Explanarias, and the variously-branching Madrepores, now spread out like fingers, now

b

VI

PREFACE.

rising in trunk-like branches, and now displaying an elegant array of interlacing tracery. The colouring surpasses everything ; vivid greens alternate with brown and yellow ; rich tints, ranging from purple and deepest blue to a pale reddish-brown. Brilliant rose, yellow, or peachcoloured Nullipores overgrow the decaying masses : they themselves being interwoven with the pearl-coloured plates ot the Rettjjoi es, rivalling the most delicate ivory carvings. Close hy wave the yellow and lilac Sea-fans (Gorgonia), perforated like delicate trellis-work. The bright sand of the bottom is covered with a thousand strange forms of sea-urchins and star-fishes. The leaf-like Flustrx and Eschar se ^ adhere like mosses and lichens to the branches of coral— the yellow, green, and purple-striped limpets clinging to their tiunks. The sea anemones expand their crowns of tentacula upon the lugged rocks or on flat sands, looking like beds of variegated ranunculuses, or sparkling like gigantic cactus blossoms, shining with brightest colours.

« Around the branches of the coral shrubs play the humming-birds of the ocean : little fishes sparkling with red or blue metallic glitter, or gleaming in golden green or brightest silvery lustre ; like spirits of the deep, the delicate milk-white jelly-fishes float softly through the charmed world. Here gleam' the violet and gold-green Isabelle, and the flaming yellow, black, and vermilion-griped Coquette, as they chase their prey; there the band-fish shoots snake-like through the thicket, resembling a silvery ribbon glittering with rose and azure hue. Then come the fabulous cuttle-fishes, in all the diaphanous

colours of the rainbow, but with no definite outline.

“ When day declines, with the shades of night this fantastic garden is lighted up with renewed splendour. Millions of microscopic meins® and crustaceans, like so many glowing sparks, dance through the >| gloom. The Sea-pen waves in a greenish phosphorescent light- Whatever is beautiful or wondrous among fishes, Echmoder ms, je JT fishes and polypi and mdlma, is crowded into the warm and crystai waters of the Tropical ocean. ’

It is stated on the Title-page that

« The Ocean World ” is chiefly translate:! from M. Louis Figuier’s two most recent works. In justice to that gentleman, we must explain this statement. The History of the Ocean is to a large extent, but not wholly, compiled from “ La Terre et les Mers,” one of the volumes of M. Figuier’s “Tableau de la Nature ; but the larger portion ot the work is a free translation of that author s latest work, “ La Vie et les Moeurs des Animaux other chapters, such as “ Life in the Ocean,” the chapter on Crustaceans, and some others, are compiled from various sources ; they will not be found in either of M. Figuier’s volumes ; but in other respects his text has been pretty closely followed.

M. Figuier s plan is to begin the study of animals with the less perfect beings occupying the lower rounds of the Zoological ladder, his reason tor doing so being an impression that the presence of the gradually perfecting animal structure, from the simplest organisms up to the more perfect forms, was specially calculated to attract the reader. “ What can be more curious or more interesting to the mind,” he asks, “ than to examine the successive links in the uninterrupted

chain of living beings which commence with the Infusoria and terminate in Man ?”

The work, he hopes, is not without the impress of a true character ol novelty and originality; at least he knows no work in which t e strange habits and special interests of the Zoophytes and Molluscs can be studied, nor any work in which an attempt is made to represent hem by means of designs at once scientifically correct and attractive rom the picturesque character of the illustrations, most of which mve been made from specimens selected by Monsieur Ch. Bevalet from the various museums in Paris.

One Of these chanmng plain-speaking children we sometimes meet

lately sa,d to M. F.guier, “ They tell me thon art a vulgariser of Science. What is that?” b nser of

He took the child in his arms, and carried if fn fir • , there was a beautiftl rose-tree in blossom, and invited

Vlll

PREFACE.

The child gathered the perfumed flower, not without pricking itself cruelly with the spines ; then, with its little hands still bleeding, it went to distribute roses to others in the room.

“ Thou art now a vulgariser,” said he to the child, “ for thou takest to thyself the thorns, and givest the flowers to others !”

The parallel, although exaggerated, is not without its basis of truth, and was probably suggested by the criticism some of his works have met with : the critics forgetting apparently that these works are an attempt to render scientific subjects popular, and attractive to the general reader.

London. January, 1868.

CHAPTER I. The Ocean

Depth of the Sea . . . .

Colour of the Ocean . . .

Phosphorescence . . . .

Local Colour

CHAPTER If.

Currents of the Ocean . .

Trade-winds

Gulf Stream

Storms

Polar Seas

Antarctic Seas

CHAPTER Ilf.

CHAPTER IT.

Foraminifera

CHAPTER V.

’OLYPIFERA . . . . .

CHAPTER VI.

PAGE

PACK

| Corallines . . .

Tubiporinge

. 122

Gorgon idas

. 123

Isidians ....

CHAPTER YII.

33 !

Zoantharia . .

Madreporidaj . . .

. 151

Porites

. 164

3<

Minyadinians . . . .

. 195

CHAPTER VIII.

AcaLEPHvE . . .

Medusas

. 215

Rhizostoma ....

Vilelladaj

. 231

Ctenophora

. 256

CHAPTER IX.

Echinodkrmata . .

. 261

Asterias .

Crinoidea

272 . 282

107 |

Echinoida? . .

X

C< INTENTS.

MOLLUSCA.

General Definition ....

CHAPTER X.

Tunicata

Ascidians

CHAPTER XI.

Acephalous Mollusca . . .

Ostreadae

CHAPTER XII.

Acephalous Mollusca . . .

Mytilidaa

Cephalous Molluscs . . . .

Their Characteristics . . .

CHAPTER XIII.

Pulmonary Gasteropods . . .

Limneans

CHAPTER XIV.

N on-pulmonary Gasteropods .

Buccinidse

Purpura .......

Pterocera

CHAPTER XV.

PAGE

Molluscous Pterofods . . . 441 CHAPTER XVI.

Cephalopodous Mollusca . . 445

Acetabula 445

Tentaculifera 470

CHAPTER XVII.

I

General Definition .... 473 Crabs and Crayfish . . . 480 Lobsters 490

FISHES.

General Definition .... 493 CHAPTER XVIII.

Cyclostomata 499

Selachia 501

Sturiona 515

CHAPTER XIX.

Osseous, or Bony Fishes . . 521

Plectognathi 522

Lophobranchii 526

Malacopterygii 528

Abdominales 552

Acanthopterygians . . . 578

Pharyngians 584

PAGE

ILLUSTKATIONS.

PLATE

I. The Argonaut Sailing before the Wind .

IT. Sponge Fishing on the Coast of Syria.

III. Coral Fishing on the Coast of Sicily .

IV. Coral Island in the Pomotouan Archipelago .

V. Sea Anemones (I.)

VI. Sea Anemones (II.)

VII. Agalma rubra

VIII. Galeolabla Aurantiaca

IX. Sea Urchins

X. Fishing for Holothuria

XI. Synapta Duverna:a

XII. Dredging for Oysters ....

XIII. Oyster Parks on Lake Fusaro

XIV. Pectinide

XV. SPONDYLU8

XVI. Anodonta ....

XVII. Tridacna gigantea

XVIII. Venus and Cytherea

XIX. Solenide ( Bazor-fish ) ....

XX. .Temple of Serapis

XXI. Conus

XXII. Cyfreade : ... .

PACK

ILLUSTRATIONS.

PLATE PAGE

XXIII. Voluta .423

XXIV. Capture of a Gigantic Cuttle-fish 459

XXV. Shark Fishing 511

XXVI. Sturgeon Fishing on the Volga 518

XXVII. Fishing for Electrical Eels 531

XXVIII. Greenlanders Fishing for Halibut 532

XXIX. The Herring Fishery 568

XXX. A Roman Feast - 582

XXXI. Fishing for Tunny in Provence 587

XXXII. Fishing for Mackerel off the Cornwall Coast . . . 590

CHAPTER I.

THE OCEAN.

Jkpi(TTnv n'ev SSup — " The best of all things is water.”— Pindar.

We have said that the sea covers nearly two-thirds of the surface of the earth The calculation, as given by astronomers, is as follows : The surface of the earth is estimated at 31,625,625* square miles, that portion occupied by the waters being about 23,814,121 square miles, and at consisting or continents, peninsulas, and islands being 7,811 504 m! es; whence it follows that the surface covered witli water is to’ dry

M t0, V2- The waters thua cover a little more than seventenths of the whole surface. “ On the surface of the globe,” Michelet remarks, “ water is the rule, dry land the exception ”

thanl^l^ ^ im“msity an<1 dePth of tlle *“> aids rather n obstacles to the intercourse and commerce of nations ; the maritime routes are now traversed by ships and steamers conveying cargoes

miTrir 7'“ “ —* *■ land routes. One of the feat*

of hdlff I! the ocean .site continuity; for, with the exception

t o rle ’ 7s the CaSpian' the 8«. and some others

whoZrtr °“« n,‘d mdiVi8iMe- As tlW P°et 1* “ it embraces the’ wliole earth with an uninterrupted wave.”

The mean depth of the sea is not very exactly ascertained i * certain phenomena observed in the movement of tides are sun ' 1 7 He incapable of explanation without admitting a mel^K*

B 2

THE OCEAN WORLD.

thousand five hundred fathoms. It is true that a great number of deep sea soundings fall short of that limit ; hut, on the other hand, many others reach seven or eight thousand. Admitting that three thousand fathoms represents the mean depth of the ocean, Sir John Herschel finds that the volume of its waters would exceed three thousand two hundred and seventy-nine million cubic yards.

This vast volume of water is divided by geographers into five great oceans : the Arctic, the Atlantic, Indian, Pacific, and Antarctic Oceans.

The Arctic Ocean extends from the Pole to the Polar Circle ; it is situated between Asia, Europe, and America.

The Atlantic Ocean commences at the Polar Circle and reaches Cape Horn. It is situated between America, Europe, and Africa, a length of about nine thousand miles, with a mean breadth of two thousand seven hundred, covering a surface of about twenty-five million square miles, placed between the Old World and the New. Beyond the Cape of Storms, as Cape Horn may he truly called, it is only separated by an imaginary line from the vast seas of the south, in which the waves, which are the principal source ol tides, have their birth. Here, according to Maury, the young tidal wave, rising in the circumpolar seas of the south, and obedient to the sun and moon, rolls on to the Atlantic, and in twelve hours after passing the parallel of Cape Horn is found pouring its flood into the Bay of Fundy, whence it is projected in great waves across the Atlantic and round the globe, sweeping along its shores and penetrating its gulfs and estuaries, rising and falling in the open sea two or three feet, hut along the shore having a range of ten or twelve feet. Sometimes, as at Fundy on the American coast ; at Brest on the French coast ; and Milford Haven, and the mouth of the Severn in the Bristol Channel, rising and falling thirty or forty feet, “ impetuously rushing against the shores, hut gently stopping at a given line, and flowing hack to its place when the word goes forth, ‘ Thus far shalt thou go, and no farther.’ That which no human power can repel, returns at its appointed time so regularly and surely, that the hour of its approach and the measure of its mass may he predicted with unerring certainty

centuries beforehand.” , . ,

The Indian Ocean, sometimes called Oceania, is hounded on the

north by Asia, on the west by Africa, on the east by the peninsu a o

Molucca, the Sunda Isles, and Australia.

THE SEA.

The Pacific, or Great Ocean, stretches from north to south, from the Arctic to the Antarctic Circle, being bounded on one side by Asia, the island of Sunda, and Australia ; on the other by the west coast of America. This ocean contrasts in a striking manner with the Atlantic: the one has its greatest length from north to south, the other from east to west; the currents of the Pacific are broad and slow, those of the other narrow and rapid ; the waves of this are low, those of the other very high. If we represent the volume of water which falls into the Pacific by one, that received by the Atlantic will be represented by the figure 5. The Pacific is the calmest of seas ; the Atlantic Ocean is the most stormy ocean.

The Antarctic Ocean extends from the Antarctic Polar Circle to the South Pole.

It is remarkable that one half of the globe should be entirely covered with water, whilst the other contains less of water than dry land. Moreover, the distribution of land and water, if, in considerin': the germ of the oceanic basins, we compare the hemispheres separated by the Equator and the northern and southern halves of the globe, is found to be very unequal.

Oceans communicate with continents and islands by coasts, which are said to be scarped when a rocky shore makes a steep and sudden descent to the shore, as in Brittany, Norway, and the west coast of the British islands. In this kind of coast certain rocky indentations encircle it, sometimes above, sometimes under water, forming a labyiintk of islands, as at the Land’s End, Cornwall, where the Scilly Islands form a compact group of from one to two hundred rocky islets, rising out of a deep sea, or, in the case of the Channel, on the opposite coast of France, where the coast makes a sudden descent, forming steep clifls and leaving an open sea. The coast is said to be flat when it consists of soft argillaceous soil descending to the shore with a gentle slope. Of this description of coast there are two, namely, sandy beaches, and hillocks or dunes.

What is the average depth of the sea ? It is difficult to give an exact answer to this question, because of the great difficulty met with in taking soundings, caused chiefly by the deviations of submarine currents. No reliable soundings have yet been made in water over five miles in depth.

THE OCEAN WOULD.

Laplace found, on astronomical consideration, that the mean depth of the ocean could not be more than ten thousand feet. Alexander von Humboldt adopts the same figures. Dr. Young attributes to the Atlantic a mean depth of a thousand yards, and to the Pacific, four thousand. Mr. Airy, the Astronomer Royal, has laid down a formula, that waves of a given breadth will travel with certain velocities at a given depth, from which it is estimated that the average depth of the North Pacific, between Japan and California, is two thousand one hundred and forty-nine fathoms, or two miles and a hall. But these estimates fall far short of the soundings reported by navigators, in which, as we shall see, there are important and only recently discovered elements of error. Du Petit Thouars, during his scientific voyage in the frigate Venus, took some very remarkable soundings in the Southern Pacific Ocean : one, without finding bottom at two thousand four hundred and eleven fathoms ; another, in the equinoctial region, indicated bottom at three thousand seven hundred and ninety.

In his last expedition, in search of a north-west passage, Captain Ross found soundings at five thousand fathoms Lieutenant Walsh, of the American Navy, reports a cast of the deep-sea lead, not far from the American coast, at thirty-four thousand feet without bottom. Lieutenant Berryman reported another unsuccessful attempt to fathom mid ocean with a line thirty-nine thousand feet in length. Captain Denman, of H. M. S. Herald, reported bottom in the South Atlantic at the depth of forty-six thousand feet; and Lieutenant J. P. Parker, of the United States frigate Congress, on attempting soundings near the same region, let go his plummet, after it had run out a line fifty thousand feet long, as though bottom had not been reached. We have the authority of Lieutenant Maury for saying, however, that “ there are no such depths as these.” The under-currents of the deep sea have power to take the line out long after the plummet has ceased to sink, and it was before this fact was discovered that these great soundings were reported. It has also been discovered that the line, once dragged down into the depths of the ocean, runs out unceasingly. This difficulty was finally overcome by the ingenuity of Midshipman Brooke. Under the judicious patronage of the Secretary to the United States Navy, Mr. Brooke invented the simple and ingenious apparatus (Fig. 1), by which soundings are now made, in a manner

DKPTH OF THE OCEAN.

which not only establishes the depth, but brings up specimens of the bottom. The sounding-line in this apparatus is attached to a weighty rod of iron, the lower extremity of which contains a hollow' cup for the reception of tallow or some other soft substance. This rod is passed through a hole in a thirty-two pound spherical shot, being supported in its position by slings a, which are hooked on to the line by the swivels a. When the rod strikes the bottom, the tension on l'ig. I. litookc’s Sounding Apparatus the line ceases, the swivels are reversed, the slings n are thrown out ol the hooks, the ball falls to the ground, and the rod, released from its weight, is easily drawn up, bringing with it portions of the bottom attached to the greasy substance in the cup. By means of this apparatus, specimens of the bottom have been brought up from the depth of four miles.

THE OCEAN WORLD.

The greatest depth at which the bottom has been reached with this plummet is in the North Atlantic between the parallels of thirty-five and forty degrees north, and immediately south of the great bank of rocks off Newfoundland. This does not appear to be more than twenty-five thousand feet deep. “ The basin of the Atlantic,” says Maury, “ according to the deep sea soundings in the accompanying diagram, is a long trough separating the Old World from the New, and extending, probably, from pole to pole. In breadth, it contrasts strongly with the Pacific Ocean. From the top of Chimborazo to the bottom of the Atlantic, at the deepest place yet reached by the plummet in that ocean, the distance in a vertical line is nine miles.”

“ Could the waters of the Atlantic be drawn off, so as to expose to view this great sea gash which separates continents, and extends from the Arctic to the Antarctic Seas, it would present a scene the most rugged, grand, and imposing ; the very ribs of the solid earth with the foundations of the sea would be brought to light, and we should have presented to us in one view, in the empty cradle of the ocean, ‘ a thousand fearful wrecks,’ with the array of ‘ dead men’s skulls, great anchors, heaps of pearls, and inestimable stones,’ which, hi the poet’s eye, lie scattered on the bottom of the sea, making it hideous with the sight of ugly death.”

The depth of the Mediterranean is comparatively inconsiderable. Between Gibraltar and Ceuta, Captain Smith estimates the depth at about five thousand seven hundred feet, and from one to thiee thousand in the narrower parts of the straits. Near Nice, Saussure found bottom at three thousand two hundred and fifty. It is said that the bottom is shallower in the Adriatic, and does not exceed a hundred and forty feet between the coast of Dalmatia and the mouths of the Po.

The Baltic Sea is remarkable for its shallow waters, its maximum rarely exceeding six hundred teet.

It' thus appears that the sea has similar inequalities to those observed on land ; it has its mountains, valleys, hills, and plains.

The Deep Sea Sounding Apparatus of Lieutenant Brooke has already furnished some very remarkable results. Aided by it, Di. Maury has constructed his fine orographic map of the basin of the Atlantic, which is probably as exact as the maps which represent Africa 01 Australia.

DEPTH OF THE OCEAN.

i)

Dr. Maury has also published many charts, giving the depths of the ocean, the substance of which is given in the accompanying map, which represents the configuration of the Atlantic up to the tenth degree of south latitude, not in figures, as in Dr. Maury’s charts, but in tints ; diagonal lines from right to left, representing the shores of both hemispheres, indicate a depth of less than a thousand fathoms ; from left to right, indicate' bottom at one thousand to two thousand; horizontal lines, two to three thousand fathoms ; cross lines show an average depth of three to four thousand fathoms ; finally, the perpendicular lines indicate a depth of four thousand fathoms and upwards. Solid black

Tig. 2. Chart of the Atlantic Ocean.

indicates continents and islands; waving lines, surrounding both con merits at a shoit distance from the shore, indicate the sands which surround the coast line at a little distance from the shore.

The question is sometimes asked, What useful purpose is served bv taking soundings at great depths ? To this we may quote the answer

o ranklin to a similar question, addressed to aeronauts “ What

purpose is served by the birth of a child ?” Every fact in phvsics is interesting m itself ; it forms a rallying point, round which, Liner or later, others will meet, m order to establish some useful truth ; and the

THE OCEAN WORLD.

importance of making and recording deep sea soundings is established by the successful immersion of the transatlantic telegraph.

At the bottom of the Atlantic there exists a remarkable plateau, extending from Cape Eace in Newfoundland, to Cape Clear in Ireland, a distance of over two thousand miles, with a breadth of four hundred and seventy miles : its mean depth along the whole route is estimated at two miles to two miles and a half. It is upon this telegraphic plateau, as it has been called, that the attempt was made to lay down the cable in 1858, and it is on it that the enterprise has been so successfully completed, during the year 1866. The surface of this plateau had been previously explored by means of Brooke’s apparatus, and the bottom was found to be composed chiefly of microscopic calcareous shells ( Foraminijera ), and a few siliceous shells ( Diatomaceee ). These delicate and fragile shells, which seemed to strew the bottom of the sea, in beds of great thickness, were brought up by the sounding-rod in a state of perfect preservation, which proves that the water is remarkably quiet in these depths,— an inference which is fully borne out by the condition in which the cable of 1858 was found, when picked up in 1866.

The first exploration of this plateau was undertaken by the American brig Dolphin , which took a hundred soundings one hundred miles from the coast of Scotland, afterwards taking the direction of the Azores, to the north of which bottom was found, consisting of chalk and yellow sand, at nine thousand six hundred feet. To the south of Newfoundland, the depth was found to be sixteen thousand five hundred feet. In 1856, Lieutenant Berryman, of the American steamer Arctic, completed a line of soundings from St. John, Newfoundland, to Yalentia, off the Irish coast, and in 1857, Lieutenant Dayman, of the English steamship Cyclops, repeated the same operation : this last line of soundings, the result of which is represented in the accompanying section, dil'tered slightly from that followed by Lieutenant Berryman.

DEPTH OP THE OCEAN.

In the Gulf of Mexico, the depth does not seem to exceed seven thousand feet ; the Baltic does not in any place exceed eleven hundred. The depth of the Mediterranean is, as we have said, very variable. At Nice, according to Horace de Saussure, the average depth is three thousand three hundred feet. Between the Dalmatian coast and the mouth of the Po, bottom is found at a hundred and forty feet. Captain Smith found soundings at from one thousand to nine thousand feet in the Straits of Gibraltar, and at ten thousand feet between Gibraltar and Ceuta, where the breadth exceeds sixteen miles. Between Rhodes and Alexandria, the greatest depth is ten thousand feet. Between Alexandria and Candia it is ten thousand three hundred. A hundred and twenty miles east of Malta it is fifteen thousand. The peculiar form of the Mediterranean has led to its being compared to a vast inverted tunnel.

The Arctic Ocean has, probably, no great depth. According to Baron Wrangel, the bottom of the glacial sea, on the north coast of Siberia, forms a gentle slope, and, at the distance of two hundred miles from the shore, it is still only from ninety to a hundred feet. Nevertheless, in Baffin’s Bay, Dr. Kane made soundings at eleven thousand six hundred feet.

The inequalities of the basin of the Pacific Ocean are, comparativelv, unknown to us. The greatest depth observed by Lieutenant Brooke in the great ocean is two thousand seven hundred fathoms, which he found in fifty-nine degrees north latitude and one hundred and sixty-six degrees east longitude. Applying the theory of waves to the billows propelled from the coast of Japan to California, during the earthquake of the 23rd of December, 1854, Professor Bache calculated that the mean depth of this part ot the Pacific is fourteen thousand four hundred feet. In the Pacific Ocean, latitude sixty degrees south and one hundred and sixty degrees east longitude, he found soundings at fourteen thousand six hundred feet— about two miles and a half. Another cast of the lead in the Indian Ocean was made in seven thousand and forty fathoms, but without bringing up any soil from the bottom. Among the fragments brought up from the bottom of the Coral Sea, a remarkable absence of calcareous shells was noted, whilst "he siliceous fragments ot sponges were found in great quantities. Other soundings made in the Pacific, at a depth of four or five miles, were 3xamined by Ehrenberg, who found a hundred and thirty-five different

THE OCEAN WORLD.

forms of infusoria represented, and among them twenty-two species new to him. Generally speaking, the composition of the infusoria ol the Atlantic are calcareous ; those of the Pacific, siliceous. These animalcules draw from the sea the mineral matter with which it is charged — that is, the lime or silica which form their shell. These ! shells accumulate after the death of the animal, and lorm the bottom of the ocean. The animals construct their habitations near the surface ; when they die, they fall into the depths of the ocean, where they accumulate in myriads, forming mountains and plains in mid ocean. In this manner, we may remark, en passant, many of the existing continents had their birth in geological times. The horizontal beds of marine deposits, which are called sedimentary rocks, and especially the cretaceous rocks and calcareous beds of the J urassic and Tertiary periods, all result from such remains.*

The sea level is, in general, the same everywhere. It represents > the spherical form of our planet, and is the basis for calculating all . terrestrial heights ; but many gulfs and inlands open on the east are • supposed to be exceptions to this’ rule : the accumulation of waters, , pressed into these receptacles by the general movement ol the sea t from east to west, it is alleged, may pile up the waters, in some cases, to a greater height than the general level.

It had long been admitted, on the faith of inexact observation, that : the level of the Eed Sea was higher than that of the Mediterranean. . It has also been said that the level of the Pacific Ocean at Panama ishigher by about forty inches than the mean level of the Atlantic at! Chagres, and that, at the moment of high water, this difference wasincreased to about thirteen feet, while at low it is over six feet in the? opposite direction. This has been proved, so far as the evidence goes, . to he error in what concerns the difference in level of the Eed Sea and! Mediterranean, and the opening of the Suez Canal, which is near att hand, will probably furnish still more convincing proofs. It is probable that errors, of measurement have also occurred, so far as the Pacific! and Atlantic are concerned.

It has been calculated that all the waters of the several seas; gathered together would form a sphere of fifty or sixty leagues im diameter, and, supposing the surface of the globe perfectly level, that: