The St. Mary banner. (Franklin, Parish of St. Mary, La.) 1889-1931, 1904-10-29
iECRET OF ORIENT PEARL
DISCOVERED TO BE MERELY SEP
III cHRES OF DEAD PARASITES.

UNCOVERED TO BE MERELY SEP
uLcHRES OF DEAD PARASITES.
The Gulf Of Manaar, on the COAST VI
CeyIon, is the Chief Source-F'sheo
Up by Native Divers OF
Baby Tape Worms.
For more than 1000 years the Gun
II Manaar, on the northwest coast ..
Ceylon, has been noted as the ch'ei
source of Orient pearls, wnlcu 1Ao
found in the bodies Of pearl oysters
(Margaritifera vulgaris), more 'iuiS
described, however, as pearl musse'0'
The mollusks are fished up by ma
tive divers, though recourse Will PROV
ably be made to dredging in the lu-
ture. The alarming decline in TINS
Important fishery, the proceeds OF
! which, amounting to hundreds VI
I thousands of rupees annually, nave
Tong been an important asset ID 'he
revenue of the Ceylon government
recently resulted in Prof. Herdman OF
! Liyerpool being sent out to ascertain
the cause, and, If possible. to suggest
q remedy.
The first volume Of his report mas
Just appeared, and the beneficial re-
suit of his valuable suggestions -
already being felt. Mr.. James Hor-
nell a well known naturalist. mas
been associated with Prof. Herdman
in the matter, and is continuing the
work under the auspices of the Colo
! NAL Government. The most interest
ing outcome Of the whole thing ID
the fascinating story which these ex'
perts tell us about the mode OF origin
of .oysters' tears" Mr.. Hornell has
Just ascertained the facts which make
the story complete.
For nearly half a century It mas
been known that river pearls, Wnlch
once were the object OF important
British fisheries, are caused by the
Irritation set up by parasitic worms,
and forty years ago Kelaart proved
that this is also true of the marine
| pearls cf Ceylon But 1t has been re-
served for Herdman and Horne.i to
work out in detail the story Of the
parasite infesting the pearl oyster
adding one more romance to the fatty
tale book of modern science.
Living in Indian seas is vorsc!ors
stingray (Trygon), the intestines OF
which afford food and lodging to go
culiar little tape worm (Teirarhyo'
chus). This unwe!come guest holds
on for dear life to the lining OF tho
intestine by means Of two suckers
and eour long hooked tubes, project
ing from its head. AS in tape worms
generally, the hind end is made ur
Of series Of fiat joints, within which
innumerable eggs are developed. The
ripe joints pass out Of the body o1
the fish, and from the eggs minute
free-swimming embryos hatch out
Some of these pass between the
shells Of pearl oysters, bur7ow into
the bodies of the unfortunate inmates
and there develop heads. But many
other things must happen II they arc
to get the chance OF growing int
adult worms. One Of the hereditary
foes Of pearl oysters is the rough
skinned trigger fish (balistes) which
feeds on the sluggish bivalves, easily
crushing their hard shells with its
powerful chiselended teeth. II ONT
! OF these fishes happens to devour al
infested oyster the little parasite
bore through the walls OF its stom
J ach and imbed themselves In its flesh
making 1t "measily." But the para
site has yet to reach the interior OF
stingray before it can become adult
and the transfer is often effected, TO
} the trigger fish is a favorite item II
the bill of fare of the stranger ray.
: But what has all this to do witt
: pearls9 Here is the answer. Man.
Of the Juvenile tape worms that infes
the oyster die, and then become
: source Of irritation. To allay the tick
J ling, layer after layer Of pearly sub
/ stance is formed around them, and Il
due course we have pearls. Long-in
tested oysters, OF course, yield tn
, finest. The economic bearing OF thes
} facts is clear. Stingrays and trigge
7 fishes alike must be carefully "pre
J served" otherwise the tape Worr
Will become extinct, and then n
pearls, or, at least, none Of the bes
: sort. Some varieties are very poss
! bly, caused by parasites Of othe
kinds. And small, inferior pearls ma
be formed round sand grains or m
} mute, hard particles due to milan
! matory disease. In ignorance of tn
facts related, 1t was proposed no
lcng ago to wage war a. Ioutranc
i against the trigger fishes because the
devour pearl oysters. II the step ma
T been taken the government pocke
' would have been sorely depleted. 81
after all, natural history has its use
for practical men," and it is pit
that our government does not gel
erously endow scientific research
this important subject.
n The secret OF the Orient pearl, q