illu.
of each region down to the seventh, which lies between the depths of 80 and
105 fathoms, all the inhabited space below this being included in the eighth
province, where no less than 65 species of Testacea have been taken.” In
describing the “ imbedding of the remains of marine plants and animals,”
he writes as follows I have already stated that at a depth of 950 fathoms,
between Gibraltar and Ceuta, Captain Smith found a gravelly bottom, with fragments
of broken shells, carried thither probably from the comparatively shallow
parts of the neighbouring straits, through which a powerful current flows.
Beds of shelly sand might here, in the course of ages, be accumulated several
thousand feet thick. But, without the aid of the drifting-power of a current,
shells may accumulate iu the spot where they live and die, at great depths from
the surface, if sediment be thrown down upon them ; for, even in our own colder
latitudes, the depths at which living marine animals abound is considerable.
Captain Vidal ascertained, by soundings off Tory Island, on the north-west coast
of Ireland, that Crustacea, Star-fish, and Testacea occurred at various depths
between 50 and 100 fathoms; and he drew up Dentalia from the mud of
Galway Bay, in 230 and fathoms water.”
Mr. Page, in ‘ The Advanced Text-Book of Geology*,’ says that, “ according
to experiment, water at the depth of 1000 feet is compressed ^ t h of its own
bulk ; and at this rate of compression we know that at great depths animal and
vegetable life, as known to us, cannot possibly exist,—the extreme depressions of
seas being thus, like the extreme elevations of the land, barren and lifeless solitudes.
Further, at great depths, sand, mud, and all loose debris will be
compressed and consolidated ; and, according to the experiments of Sir James
Hall, even limestone could be fused without the loss of its carbonic acid. The
effect of depth in regulating the distribution of species is one of the prettiest
problems in zoology, every zone from the shore seawards being characterized by
different specific forms ; and, as will hereafter be seen, the comparative depths
of seas of deposit may be ascertained with considerable certainty by a study of
the fossils found in such deposits.”
According to Messrs. Agassiz and Gouldf, “ The depths of the ocean are quite
• ‘ Advanced Text-Book of Geology, Descriptive and Industrial,’ by David Page, F.G.S. London
1866 ; p. 20.
t ‘ Outlines of Comparative Physiology,' by Professors Agassiz and Gould. London, 1851; p. 365.
THE BATHYMETRICAL LIMITS OP LIFE IN THE OCEAN. 77
as impassable for marine species as high mountains are for terrestrial animals.
I t would be quite as difficult for a fish or a mollusk to cross from the coast of
Europe to the coast of America, as it would be for a reindeer to pass from the
Arctic to the Antarctic regions across the torrid zone. Experiments of dredging
in very deep water have also taught us that the abyss of the ocean is nearly
a desert. Not only are no materials found there for sustenance, but it is
doubtful if animals could sustain the pressure of so great a column of water,
although many of them are provided with a system of pores which enable them to
sustain a much greater pressure than terrestrial animals.”
The same distinguished authorities have, at a still more recent date, expressed
similar opinions. Mr. Maroou, a member of the Boston Society of Natural
History (U.S.), having informed that Society that he had read in an English
journal an account of the capture of the star-fishes (as given by me in my
published notes, and also in a lecture at the Eoyal Institution of Great Britain,
in February 1861), Messrs. Agassiz and Gould intimated their doubts of the
creatures having been brought up from the depth stated, and suggested that
they might have become attached to the line at a point far nearer to the surface.
The following passages, quoted from the invaluable work written by Sir Henry
De la Beche thirty years ago*, when the researches of Sir John Eoss were
comparatively speaking of recent date, clearly show the opinions then entertained
on the subject:—“ AVe have hitherto considered marine animal life witli
reference to creatures living in particular depths of water, and which, when we
regard those of the ocean, are comparatively shallow. The surface of the deep
ocean teems with animal life, and is probably not less well proportionably
tenanted down to depths where, from the want of the necessary conditions, it
ceases to exist AVhat the actual depth may be beneath which animal life
does not exist in the ocean, we have yet no good data for ascertaining; but that
there must be such a limit, to at least any kind of life analogous to that witli
which we are acquainted, there can be little doubt.”
Professor Loven, in discussing the bathymetrical limits of submarine life in
the Scandinavian seasf, alludes to three forms of Echinoderms living in tlie
• ‘Researches in Theoretical Geologj-,’ by H. T. De la Beche, F.E.S., &e. &c. London, ISiM-
pp. 262, 263.
t British Association Reports, 1844, vol. xiii. p. 50.