﻿34 
  MUSSEL 
  RESOUECES 
  OF 
  THE 
  ILLINOIS 
  RIVER. 
  

  

  POSITION 
  OF 
  PEARLS 
  IN 
  MUSSEL 
  SHELL. 
  

  

  Pearls 
  are 
  usually 
  found 
  in 
  the 
  mantle 
  near 
  the 
  tip 
  or 
  posterior 
  

   end 
  of 
  the 
  mussel, 
  while 
  slugs 
  and 
  other 
  pieces 
  may 
  be 
  found 
  in 
  

   various 
  parts 
  of 
  the 
  body, 
  along 
  the 
  lateral 
  hinge, 
  at 
  the 
  cardinal 
  

   teeth, 
  in 
  the 
  adductor 
  muscles, 
  and 
  in 
  the 
  shell 
  itself, 
  etc. 
  

  

  Sometimes 
  a 
  pearl 
  becomes 
  attached 
  to 
  the 
  shell, 
  after 
  which 
  

   it 
  may 
  be 
  covered 
  over 
  by 
  deposits 
  or 
  layers 
  of 
  nacre 
  and 
  is 
  then 
  

   said 
  to 
  be 
  embedded. 
  These 
  pearls 
  can 
  be 
  recovered 
  by 
  sawing 
  

   the 
  shell 
  around 
  the 
  observed 
  protuberance 
  or 
  by 
  carefully 
  removing 
  

   the 
  inclosing 
  layers. 
  Many 
  shells 
  have 
  what 
  are 
  commonly 
  called 
  

   ''blisters," 
  which 
  are 
  successive 
  pearly 
  deposits 
  over 
  mud, 
  muddy 
  

   water, 
  organic 
  matter, 
  or 
  some 
  foreign 
  substance 
  finding 
  its 
  way 
  

   into 
  the 
  mussel. 
  It 
  illustrates 
  a 
  method 
  the 
  animal 
  uses 
  to 
  remedy 
  

   a 
  distm^bance 
  within. 
  Blisters, 
  as 
  found 
  in 
  the 
  Unios, 
  have 
  no 
  

   commercial 
  value. 
  There 
  are 
  found 
  occasionally 
  in 
  the 
  meats 
  of 
  the 
  

   mussels 
  cartilaginous 
  formations 
  which 
  are 
  denominated 
  by 
  the 
  

   fishermen 
  as 
  "soft 
  pearls 
  undergoing 
  the 
  process 
  of 
  formation 
  into 
  

   true 
  pearls." 
  It 
  is 
  claimed 
  that 
  soft 
  pearls 
  are 
  caused 
  by 
  a 
  grain 
  

   of 
  sand 
  or 
  other 
  foreign 
  body. 
  

  

  PEELING 
  A 
  PEARL. 
  

  

  As 
  pearls 
  are 
  composed 
  of 
  thin 
  concentric 
  layers 
  of 
  nacre 
  and 
  coii- 
  

   cliioHn 
  or 
  animal 
  substance, 
  each 
  separate 
  and 
  distinct, 
  peeling 
  or 
  

   removing 
  some 
  of 
  the 
  outer 
  layers 
  of 
  the 
  various 
  forms 
  of 
  pearls 
  to 
  

   improve 
  the 
  gems 
  is 
  often 
  done 
  successfully 
  by 
  one 
  versed 
  in 
  this 
  

   line 
  of 
  work. 
  Pearls 
  having 
  a 
  dark 
  spot, 
  stain, 
  or 
  chalky 
  appear- 
  

   ance 
  over 
  the 
  entire 
  surface, 
  or 
  even 
  a 
  part 
  of 
  it, 
  are 
  greatly 
  dimin- 
  

   ished 
  in 
  value. 
  When 
  such 
  is 
  the 
  case 
  it 
  is 
  often 
  worth 
  while 
  to 
  try 
  

   the 
  experiment 
  of 
  peehng, 
  as 
  the 
  result 
  wiU 
  probably 
  be 
  satisfactory 
  

   and 
  a 
  good 
  pearl 
  obtained 
  from 
  witliin. 
  However, 
  it 
  may 
  be 
  stated 
  

   that 
  fairly 
  good 
  pearls 
  have 
  been 
  damaged 
  rather 
  than 
  improved 
  by 
  

   peehng, 
  as 
  the 
  inner 
  layers 
  were 
  in 
  a 
  worse 
  condition 
  than 
  those 
  at 
  

   the 
  original 
  surface. 
  A 
  fine, 
  pink, 
  high-button 
  pearl 
  of 
  40 
  grains 
  

   and 
  worth 
  $800 
  was 
  seen 
  this 
  summer. 
  The 
  pearl 
  had 
  a 
  small 
  spot 
  

   on 
  the 
  side 
  and 
  might 
  have 
  been 
  benefited 
  by 
  peeling, 
  but 
  the 
  owner, 
  

   considering 
  its 
  present 
  value 
  and 
  the 
  uncertainty 
  of 
  the 
  result 
  of 
  

   peeling, 
  would 
  not 
  take 
  the 
  risk. 
  

  

  CRIPPLED 
  SHELLS. 
  

  

  Occasionally 
  tlio 
  various 
  mussel 
  beds 
  of 
  the 
  Illinois 
  produce 
  a 
  few 
  

   examples 
  of 
  distorted 
  or 
  injured 
  mussels, 
  commonly 
  called 
  "ciippled 
  

   sliells." 
  They 
  are 
  legarded 
  by 
  the 
  pearler 
  as 
  excellent 
  fmds 
  and 
  

   are 
  generally 
  opened 
  at 
  once 
  without 
  waiting 
  for 
  tlie 
  cooking-out 
  

   process, 
  with 
  the 
  hope 
  that 
  a 
  piece 
  of 
  some 
  value 
  may 
  be 
  present. 
  

  

  