disposal, he made a series of observations on the British,
Scandinavian, and Danish coasts, and explored also with the same
object the shores of the Mediterranean. Not content with sounding the
present ocean, he sunk his daring plummet in the seas of past
geological ages, and by comparing the nature and position of their
fossil remains with those of living marine faunæ, he measured the
depths of the water along their shores. He collected a vast amount of
material, and the results of his labors have formed the basis of all
subsequent generalizations upon this subject. Nevertheless he arrived
at some erroneous conclusions, which, had he lived, he would no doubt
have been the first to correct. Dredging from low-water-mark outward,
he found that, from the Laminarian and Coralline zone, the animals
began gradually to decrease in number, and that, at a depth of two or
three hundred fathoms, the dredge always came up nearly empty. He
inferred that at a certain depth the weight of water became too great
to be endured by animals, and that the ocean beyond this line, like
the land beyond the line of perpetual snow, was barren of life. This
result seemed the more probable on account of the immense pressure to
which animals are subjected, even at a comparatively moderate depth. A
column of water thirty-two feet high is equal to one atmosphere in
weight; this pressure being increased to the same amount for every
thirty-two feet of depth, it follows that a fish one hundred and
twenty-eight feet, or some twenty fathoms below the surface, is under
the pressure of almost four atmospheres plus that of the air outside.
Wherever tides run high, as in the Bay of Fundy, for instance, where
an animal is under the pressure of one atmosphere at low tide, and of
three atmospheres at high tide, we see that marine animals are
uninjured by great changes of pressure. Yet it seems natural to
suppose that there is a limit to this power of resistance; and that
there must exist barren areas at the bottom of the ocean, as destitute
of life as the regions on the earth which are above the line of
perpetual snow. No doubt pressure does influence the distribution of
life in the ocean; but it would seem, from subsequent observations,
that the boundaries assigned by Forbes were far too narrow, and that
the structure of many marine animals enables them to live under a
weight, the one hundredth part of which would be fatal to any
terrestrial animal.
For some years Forbes's theory was very generally accepted, and the
results of Darwin's and Dana's investigations, showing that corals
could not live beyond a depth of fifteen fathoms, seemed to confirm
it. But, quite recently, facts derived from new and unlooked-for
sources of information have given a check to this theory. Commerce has
come to the aid of science (rewarding her for the gift first received
at her hands), and the telegraph cables, alive with the secrets of sea
and land, have brought us tidings from the deep. Dr. Wallich, the
naturalist who in 1860 accompanied the expedition to explore the bed
of the Atlantic, previous to laying the telegraphic cable, first
called attention again to this subject. He brought up various animals,
highly organized, from a depth of about nineteen hundred fathoms.
Yet, in spite of this positive evidence added to the former
observations of Ehrenberg, and to those of Sir James Ross, who, in the
Antarctic Sea, brought up an Euryale on a sounding-line from a depth
of eight hundred to a thousand fathoms, naturalists were slow to
believe that the distribution of animal life in the ocean was not
limited to the shallow depths assigned by Edward Forbes. In the
Mediterranean and in the Red Sea, from depths of eighteen hundred to
two thousand fathoms, living animals have been brought up on the
telegraph wires, not of doubtful infusorial character, hovering on the
border-land between animal and vegetable life, but of considerable
size, as, for instance, one or two kinds of Crustacea, Cockles, stocks
of Bryozoa and tubes of Annelids. When the cable between France and
Algiers was taken up from a depth of eighteen hundred fathoms, there
came with it an Oyster, Cockle-shells, Annelid tubes, Bryozoa and
Sea-fans. As these animals were growing upon it, there could be no
doubt that they had their normal life and development at this depth,
and since they are carnivorous, they tell also of the existence of
other animals with them on which they feed.
The dredge, which thus far has played an important part in zoölogical
researches, is destined to revolutionize many of our accepted
theories, if we can judge of its future by the brilliant results of
the last few years.
From 1861 to the present time the Swedish government has sent several
expeditions to Spitzbergen and Greenland. They carried on dredging
operations most successfully to a depth of twenty-six hundred fathoms.
For some years past Lovén, Koren, and Danielssen, the elder and
younger Sars, and other Scandinavian naturalists, have made systematic
dredgings along the coast of Norway, which, though not extending below
four hundred fathoms or thereabouts, have yet furnished most
astounding results.
The United States Coast Survey has, in connection with an exploration
of the Gulf Stream, been the first to establish a systematic series of
dredgings at great depths, continued during several years. The results
have proved conclusively that there exists everywhere, in the deep
sea, modified, of course, according to the nature of the bottom and
the temperature, a most varied fauna, totally distinct from that
characteristic of the shores and of shallower waters. Since 1867 Count
Pourtales has had charge of these investigations, first established
many years ago by Professor Bache and continued by his successor
Professor Peirce. He has dredged across the Gulf Stream between
Florida and Cuba to a depth of about seven hundred fathoms, collecting
an immense number of marine animals entirely unknown before, and
characteristic of the different belts of depth, having a most
extraordinary geographical distribution, many of the species being
found in Florida, the Azores, the Faroe Islands, and the west coast of
Norway.
The English Admiralty has for two summers detailed a vessel admirably
fitted for such purposes, intrusting the scientific direction of the
expedition to Dr. Carpenter, Professor Thomson, and Mr. Jeffreys.
Their dredgings, carried on to the enormous depth of two thousand four
hundred and thirty-five fathoms, have in every respect corroborated
the conclusions drawn from the collections made by Count Pourtales and
the Scandinavian naturalists, who, not content with so thoroughly
exploring their own coast, have even sent a ship of war to dredge
across the whole Atlantic.
These discoveries only show how much yet remains to be done before we
shall fully understand the laws of marine life. But we already have
ample evidence that the same beneficent order controls the
distribution of animals in the ocean as on land, appointing to all its
inhabitants their fitting home in the dim waste of waters.
* * * * *
SYSTEMATIC TABLE OF THE ANIMALS DESCRIBED IN THIS VOLUME
RADIATA CUV.
CLASS I.--POLYPI LAM.
ORDER I.--ACTINARIA EDW.
_Metridium marginatum_ EDW. _Rhodactinia Davisii_ AG. _Bicidium
parasiticum_ AG. _Arachnactis brachiolata_ A. AG. _Halcampa albida_ AG.
ORDER II.--MADREPORIA AG.
_Astrangia Danæ_ AG.
ORDER III.--HALCYONARIA EDW.
_Halcyonium carneum_ AG.
CLASS II.--ACALEPHÆ CUV.
ORDER I.--HYDROIDEA JOHNST.
_Velella mutica_ BOSC. _Physalia Arethusa_ TIL. _Nanomia cara_ A. AG.
_Millepora alcicornis_ LIN. _Hydractinia polyclina_ AG. _Tubularia
Couthouyi_ AG. _Hybocodon prolifer_ AG. _Coryne mirabilis_ AG. _Turris
vesicaria_ A. AG. _Bougainvillia superciliaris_ AG. _Dysmorphosa
fulgurans_ A. AG. _Dynamena pumila_ LAMX. _Dyphasia rosacea_ AG. _Lafoea
cornuta_ LAMX. _Melicertum campanula_ PÉR. et LES. _Ptychogena lactea_
A. AG. _Laomedea amphora_ AG. _Zygodactyla groenlandica_ AG. _Tima
formosa_ AG. _Eucope diaphana_ AG. _Clytia bicophora_ AG. _Oceania
languida_ A. AG.
ORDER II.--DISCOPHORÆ ESCH.
_Haliclystus auricula_ CLARK. _Trachynema digitale_ A. AG. _Campanella
pachyderma_ A. AG. _Cyanea arctica_ PÉR. et LES. _Aurelia flavidula_
PÉR. et LES.
ORDER III.--CTENOPHORÆ ESCH.
_Idyia roseola_ AG. _Pleurobrachia rhododactyla_ AG. _Bolina alata_ AG.
CLASS III.--ECHINODERMATA KLEIN.
ORDER I.--CRINOIDEA MILL.
_Pentacrinus,_ _Alecto Eschrichtii_ M. & T. _Alecto meridionalis_ AG.
ORDER II.--OPHIURIDEA FORBES.
_Amphiura squamata_ SARS. _Ophiopholis bellis_ LYM. _Astrophyton
Agassizii_ STIMP.
ORDER III.--ASTERIDEA FORBES.
_Ctenodiscus crispatus_ D. & K. _Hippasteria phrygiana_ AG. _Cribrella
oculata_ FORBES. _Solaster endeca_ FORBES. _Crossaster papposa_ M. & T.
_Astracanthion pallidus_ AG. _Astracanthion berylinus_ AG.
ORDER IV.--ECHINIDEA LAM.
_Toxopneustes drobachiensis_ AG. _Echinarachnius parma_ GRAY.
ORDER V.--HOLOTHURIDEA BRANDT.
_Caudina arenata_ STIMP. _Synapta tenuis_ AYRES. _Cuvieria squamata_ D.
& K. _Pentacta frondosa_ JÄG.
* * * * *
INDEX.
PAGE
Abbreviations of authors' names, xii
Acalephs, 21
Actinia, 7
Actinoids, 7
Alecto Eschrichtii, 121
Alecto meridionalis, 121
Amphiura squamata, 115
Arachnactis brachiolata, 14
Astracanthion berylinus, 108
Astracanthion pallidus, 112
Astrangia Danæ, 16
Astrophyton Agassizii, 117
Aurelia flavidula, 42
Bicidium parasiticum, 15
Bolina alata, 31
Bougainvillia superciliaris, 69
Campanella pachyderma, 44
Campanularians, 49
Caudina arenata, 97
Circe, 45
Clytia bicophora, 56
Comatula, 121
Coryne mirabilis, 68
Cribrella oculata, 112
Crinoids, 120
Crossaster papposa, 114
Ctenodiscus crispatus, 113
Ctenophoræ, 26
Cuvieria squamata, 98
Cyanea aretica, 38
Development of Melicertum, 64
'' '' Tima, 64
Discophoræ, 37
Distribution of Life in the Ocean, 141
Dynamena pumila, 66
Dyphasia rosacea, 67
Dysmorphosa fulgurans, 75
Echinarachnius parma, 106
Echinoderms, 91
Echinoids, 101
Embryology of Astracanthion, 124
'' '' Ctenophoræ, 34
'' '' Echinoderms, 123
'' '' Ophiurans, 135
'' '' Sea-urchins, 130
'' '' Star-fishes, 124
Eucope diaphana, 50
Halcampa albida, 16
Halcyonium carneum, 19
Halcyonoids, 19
Haliclystus auricula, 46
Hippasteria phrygiana, 113
Holothurians, 95
Hybocodon prolifer, 74
Hydractinia polyclina, 73
Hydroids, 49
Idyia roseola, 32
Lafoea cornuta, 67
Laomedea amphora, 65
Lucernaria, 46
Madreporians, 16
Melicertum campanula, 63
Metridium marginatum, 7
Millepora alcicornis, 22
Mode of catching Jelly-fishes, 85
Nanomia cara, 76
Oceania languida, 53
Ophiurans, 115
Ophiopholis bellis, 115
Pentacrinus, 121
Pentacta frondosa, 99
Pleurobrachia rhododactyla, 27
Polyps, 5
Ptychogena lactea, 86
Physalia Arethusa, 83
Radiates, 1
Rhodactinia Davisii, 13
Sarsia, 68
Sea-urchin, 101
Sertularians, 66
Solaster endeca, 114
Star-fishes, 108
Synapta tenuis, 95
Systematic Table, 152
Tima formosa, 60
Toxopneustes drobachiensis, 101
Trachynema digitale, 45
Tubularia Couthouyi, 72
Tubularians, 67
Turris vesicaria, 69
Velella mutica, 84
Zygodactyla groenlandica, 57
THE END.
___________________________________________________________
Cambridge: Stereotyped and Printed by Welch, Bigelow, & Co.
* * * * *
Transcriber's Notes
With the exception of the corrections detailed below and some
minor corrections (missing periods, commas, etc.) which were made
but are not listed, the text presented is that in the original
printed version. The illustration labels were originally presented
at the bottom of the containing page; but have been moved beneath
the illustrations.
Typographical Corrections
Page xi: Ophiopolis => Ophiopholis
Page 4: diferent => different
Page 21, 101, 127, 131, 148: so called => so-called
* * * * *