New-York tribune., 1907-06-09
MAY FORCE OYSTERS TO BREED PEARLS

oysters could be discovered and measures taken
- P'o'ei' tHiS disappearance. then the future OF
.'e pearl HsheFy would be secured. The matter
mas been for some time under examination at tto
hAhds OF marine biologists who may be trusted
10 md n solution Of the mystery ~ n ,s lieco,,
erspie' most careful survey OF the banks is nov-
4'iua4'y Hlade' ana tho beds which are to be fshed
oach year are Systematically examined and the
oysters roughly counted Boats moving I'm circIes
Iouhd given points send down divers whose take
ID carefully recorded a chart with the average
age or the oysters As 1t IS known that a good
ui'or Gun Clear from two and a half to three
square yaFds at Il dive, the number OF million
oysters upon n bank be approximately arrived
at Nor is this computa ton found from, Tho asbn,
results TO be Inaccurate. Various causes lead 10
the disappearance of the oysters from banks upon
"hlch they have been seen and counted. 1t IS be
Ieved by some that they occasionally detach them
serves from their hold and move away but though
this may be the case when young. it is doubtful
II they do so when mature The shifting Of the
sand' owing to the storms and currents probably
accounts for their disappearance in many cases
where they are gradually siItcd over. lie buried
oeheath the sea floor. and perish. Boring
sponges which pierce the shell responsible for
much disease and many deaths: while the oysters
are as susceptible all other creatures to the evil
effects OF overcrowding which lowers vitality
arrests the shell growth and causes Widespread
mortality The young spat IS washed away into
unfavorable places and so lost while the old oyster
is liable TO the attacks OF its greatest enemy the
huge ray which with its teeth OF great crushing
power Is able to crunch the strongest shells
Shoals OF these fish, many of five feet across
pass along the banks annihilating the oysters and
destroy whole beds within a short time
These are probably the chief causes of the IN
certainty which has always hung over the banks
from year 10 year. And if these are responsible
for the frequent failure of the fishery It is pos
slble that this failure may be prevented bv de-
posting large quantities cf broken stone upon the
bottom. These stones prevent some extent the
drifting Of the sand, they afford a holding ground
for the oysters, and ward off the attacks Of the
ray, who unable to differentiate between the ov-
ster5 and the stones. becomes discouraged and
moves OFF. Experiments have already been tried
in the transportation Of young oysters about nine
months old from unfavorable ground Ten millions
were dTedged from q small area, and so great
was the number found that. after these had been
numbers brought up. and far the divers report
that they have suffered no mortality An oyster
OF from three and half to four and a half years
old may Yield fine pearls that if these exnert-
ments succeed in maintaining constant supply
a fine return may be expected before many years
1t Is Of course possible that investigation NAV ar
any time tnrow light upon the pearl forming para
site The host of the adult parasite Is not known
but as oysters from neighboring areas vary enor-
mously in pearl infection 1t is supposed that GER
tain conditions attract this host whatever II may
be The pearl production of one generation of
oysters is little indication of the yield OF the fol-
lowing generation upon the same beds-a fact
which Increases the mystery. Should the history
of this parasite be discovered it Will probably be
possible to increase the infection at will The
question Is being most carefully investigated and
a solution s not beyond the bounds of possibility
Nlnsteenth Century,