and the researches of Professor Loven, in the Norwegian and Lapland seas,
have borne out their correctness The first two of the regions above
mentioned had been previously noticed by Lamoureux, in his account of the
distribution (vertically) of sea-weeds, by Audouin and Milne Edwards in
their _Observations on the Natural History of the coast of France_, and
by Sars in the preface to his _Beskrivelser og Jagttayelser_."]
On the coasts of the British Islands, Forbes distinguishes four zones or
regions, the Littoral (between tide marks), the Laminarian (between
lowwater-mark and 15 fathoms), the Coralline (from 15 to 50 fathoms), and
the Deep sea or Coral region (from 50 fathoms to beyond 100 fathoms).
But, in the deeper waters of the Aegean Sea, between the shore and a depth
of 300 fathoms, Forbes was able to make out no fewer than eight zones of
life, in the course of which the number and variety of forms gradually
diminished until, beyond 300 fathoms, life disappeared altogether. Hence
it appeared as if descent in the sea had much the same effect on life, as
ascent on land. Recent investigations appear to show that Forbes was
right enough in his classification of the facts of distribution in depth
as they are to be observed in the Aegean; and though, at the time he
wrote, one or two observations were extant which might have warned him
not to generalize too extensively from his Aegean experience, his own
dredging work was so much more extensive and systematic than that of any
other naturalist, that it is not wonderful he should have felt justified
in building upon it. Nevertheless, so far as the limit of the range of
life in depth goes, Forbes' conclusion has been completely negatived, and
the greatest depths yet attained show not even an approach to a "zero of
life":--
"During the several cruises of H.M. ships _Lightning_ and _Porcupine_ in
the years 1868, 1869, and 1870," says Dr. Wyville Thomson, "fifty-seven
hauls of the dredge were taken in the Atlantic at depths beyond 500
fathoms, and sixteen at depths beyond 1,000 fathoms, and, in all cases,
life was abundant. In 1869, we took two casts in depths greater than
2,000 fathoms. In both of these life was abundant; and with the deepest
cast, 2,435 fathoms, off the month of the Bay of Biscay, we took living,
well-marked and characteristic examples of all the five invertebrate sub-
kingdoms. And thus the question of the existence of abundant animal life
at the bottom
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