The morning news. [volume] (Savannah, Ga.) 1887-1900, 1897-07-01
CORAL AND CORAL ISLANDS.
Facts and Theories About Them, and
the Part Coral Plays.

From the New York Times.
Dr. Benjamin Sharpe, corresponding
secretary of the Academy of Natural Sci
enees, recently delivered at that institu-
ton in Philadelphia a lecture from which
the following excerpts are taken:
COrals have played a very large part
in the history of the earth and are to-
day still contributing very extensive ad-
ditions to the continents. The corals are
widely distributed from the cold regions
of the north through the equator and to
the colder regions of the south. Among
the corals of the colder waters the single
polyp form generally obtains.
The Red Sea is very rich in corals. as
are the waters aroud Ceylon and NADIA
gascar and the north of Australia. while
the South Pacific may be said to be the
home Of the reef-building corals-extend-
ing as far as the Sandwich Islands.
In the West Indies we have the coral
group extending from the Bahamas
through the Caribs and the coast Of
South America
The single polyp forms are not more
than half an inch in hight and this is
the one found on the cable at a depth of
1900 fathoms.
NAAAn VIC NbAAt ~ STUDY the lemDerdNurG
of the surface of the ocean we find. by
taking certain points and running a
line through the points of equal tenn
perature, the so-called isotherms. The Is
otherm OF 6S degrees Fahrenheit win ex-
tend little north of the tropical region
that is 2S degrees north; but as we get
toward the continent IL varies a good
| deal according to the season and accord
ing TO the current-running further up
on the United States and japanese side.
while running further down on the Afri-
can and western coast Of America
No reef corals exist above 6S degrees
Fahrenheit except in the Bermudas, which
Is due to the warmth OF the gulf stream.
The lsotherm Of 6S degrees divides the
| Pacific regions into tropical and sub-tropi-
| cal. lying 10 degrees to Is degrees north
and south of the equator; and here we find
| the temperature never less chan "a degrees
| Fahrenheit. In the West Indies and South
| Pacific the surface water comes up as
high as so degrees or 81 degrees
l. Between the isotherms Of "A degrees an
| the principal reof-building corals are
found that are known to science and we
| have also a very rich coral fauna. The
most northern reef we have In the Pa.
| elflc h the Hawaiian Islands
| The West Indian region Is extremely rich
In corals, owing largely to the Caribbean
current, which comes up around the
| HHoIes OF south America sweeping into
the bay called the Caribbean sea and the
| Gulf OF Mexico
There are no coral reefs whatever on
the western shore OF tho continent OF eth.
| or Europe or Africa. nor on the western
coast Of America from the northern TO Tho
most southern limit. We have the Guit
| OF Panama w the torrid region. with TEN.
pcrature above "a degrees Fahrenheit al
the time, and we san have no corals ir
this rcgion-due probably to certain actor
OF oceanic currents. We have a current
sweeping from Africa &C che eastern shore,
OF the American continent northwarf
through a cold region, then back agar
to the African coast, and we have "A air,i
lar state OF affairs on the south. In IA,
same way we have the currents IN IN,
Pacific, running across the Aslatic shor
northward 10 the Aleutlan Islands. with ,
return sweep; so that Is one of the rea
sons why We find no corals IN those places
The currents also-apart from the fac
that they pass into other colder regions
are not capable OF carrying the embryos
in the life history Of the common 10,
coral. after the egg is seemontod an,
formed, We have a little embryo. which a
covered with ella, and this swlms aroun,
freely In the water ana develops later
curious. lobcd arrangement which adds d
JOS power and looomotlon but for som
time This little animal viii swim arounl
IN the water, and, OF course II subjcctel