Evening star. [volume] (Washington, D.C.) 1854-1972, 1954-08-30
Coral Isles Are Made
By Worm-Like Bugs
u. S. Studies Little Insects
Thut Build in the Sea
BY Thomos R. Henry

By Thomas R. Henry
Worm-like bugs I'LL tropic seas with
white islands of fronded palms.
They build titanic, ip-wrecking
stone walls in the way of roaring tides
and create orchards and thorny jungles
Of faerie. pervaded by an indescrib-
able. ethereal. blue twilight and haunted
by nightmare monsters, on shallow
ocean floors.
The United States now has under
its custody. heritage of war, about>a
hundred islands created by these strange
little worms over many milleniumS.
Their ways of life and manner of their
workmanship have become of vital in
terest to the Government agencies upon
which has fallen the custodianship.
There are approximately 400 coral
islands scattered through the seas. This
is the estimate prepared by the Pacific
Science Board of the National Research
council which is carrying out extensive
researches on the biology and geology
OF these curious worm made Specks of
land, scenes of some Of the last wars
bloodiest battles.
hungry StOmacnS.
These bodybuilding "worms"-actu-
ally they are somewhat below worms in
the geological scale, but they have
worm-like structures and habits. are
the Madreporaria. 1.-THE coral insects"
and host of their kin. They are
voraciously hungry "stomachs" That is
about all.
The bloodless, brainless, sightless.
heartlesS little empty bags are among
the simplest of multi-celled animals.
They are organized only for catching.
eating and digesting living creatures
and for making lands soon drenched
With the blood OF war-waging higher
organisms.
The Madreporaria are related to the
white, singing umbrella-shaped Jelly
f1sh, Scourge of summer beaches. and
OF the brilliantly red and purple Portu-
guese man-of-war, one of the terrors
OF tropic seas. The worm shaped bags
are NEUTRALITY-SUSPICIOUS., or skin. on
the outside and endoderm, or stomach.
on the inside. On one end is a slit
shaped mouth surrounded by from five
to twenty writhing tentacles which
hurl lassoes tipped with poison arrows.
The inside OF the bag is divided into
compartments. Each tentacle is an ex-
tension OF compartment, by means of
which 1T captures its prey. The builder
worms are strictly carnivorouS. Their
food consists of the microscopic crab
like copepods. lice of the seas, and the
larvae of mollusks, starfish and other
minute organisms.
Like Plant and Animal Life.
The Madreporaria and their stone
building relatives constitute a major di-
vision of the Coelentera, creatures quite
close to the rootStock of animal life.
They seem hardly to have decided
whether to be animals or plants. and
share characters of both the Kingdoms
OF life on earth. These worms start life
as "lum," microscopic organisms pro-
duced in the seas in enormous GUAM
titles from germ cells released by the
mature coral bugs AS such, like the
larvae OF oysters and clans. they are
free-SWimming animals for periods of
from two or three days to two or three
weeks. During this time they perish in
enormous numbers. perhaps fortunately
for map makers. At the end of the brief
episode OF freedom, the bug, or polyp as
1t henceforth Is known, attaches itself
to rock or some other hard object on
the sea bottom, stands upright, and
starts its life work of eating and build
ing. 1t has the ability to extract from
material OF limestone. and secreting It
sea water carbonate of lime. the basic
TO form cylindrical shell around its
worm-like body. Out of this shell pro-
trude only the mouth and >tentacles.
Tentacles Snare Victims.
1t captures it's prey by one of the
most remarkable contrivances in nature.
The tentacles are provided with mic
roscoplcaly fine threads coiled tightly
in gelatinous balls. This thread, as
much as foot long, can be shot out
at lightning speed in the direction of
minute organisms whose presence is
indicated by movements in the water
detected by the tentacles. Some threads
carry darts. like the singing darts of
sea urchins. Others have at their ends
tiny balls of some glue-like substance
which adheres firmly to any creature
which is hit. The victim Is Immediately
drawn to the tentacle and swallowed.
The lasso is recoiled to be used again.
The coral worm, like all Coelentera,
has two ways of reproduction - by
throwing out germ cells to become free
swimming lum and by budding like q
tree. The latter is by far the most i'm
portant, so far as rock building is
concerned. A bud is put out from the
free head surface, near the mouth, and
grows into complete polyp. This in
turn builds limestone shell around
itself and repeats the budding process.
This is repeated thousands of times SO
that from one little worm may arise a
shrub-like structure or, since the bud
ding can be at almost any angle, q
disk or platform. When countless
millions of polyps which have settled
down close together build such colonies
a reef is started.
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