I Cannot Refrain From Once Again Remarking On The
Singularity Of These Complex Structures - A Great Sandy And
Generally Concave
Disk rises abruptly from the unfathomable
ocean, with its central expanse studded, and its edge
symmetrically bordered with oval basins
Of coral-rock just
lipping the surface of the sea, sometimes clothed with
vegetation, and each containing a lake of clear water!
One more point in detail: as in the two neighbouring
archipelagoes corals flourish in one and not in the other, and
as so many conditions before enumerated must affect their
existence, it would be an inexplicable fact if, during the
changes to which earth, air, and water are subjected, the
reef-building corals were to keep alive for perpetuity on any
one spot or area. And as by our theory the areas including
atolls and barrier-reefs are subsiding, we ought occasionally to
find reefs both dead and submerged. In all reefs, owing to the
sediment being washed out of the lagoon-channel to leeward,
that side is least favourable to the long-continued vigorous
growth of the corals; hence dead portions of reef not
unfrequently occur on the leeward side; and these, though still
retaining their proper wall-like form, are now in several
instances sunk several fathoms beneath the surface. The
Chagos group appears from some cause, possibly from the
subsidence having been too rapid, at present to be much less
favourably circumstanced for the growth of reefs than formerly:
one atoll has a portion of its marginal reef, nine miles
in length, dead and submerged; a second has only a few
quite small living points which rise to the surface, a third
and fourth are entirely dead and submerged; a fifth is a
mere wreck, with its structure almost obliterated.
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Words from 196468 to 196762
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