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  The 
  restriction 
  of 
  the 
  ojsters 
  to 
  certain 
  points 
  does 
  not 
  

   appear 
  to 
  depend 
  upon 
  the 
  supply 
  of 
  food, 
  or 
  upon 
  the 
  char- 
  

   acter 
  of 
  the 
  water, 
  but 
  ahnost 
  entirely 
  upon 
  the 
  nature 
  of 
  the 
  

   bottom. 
  The 
  full-grown 
  oyster 
  is 
  able 
  to 
  live 
  and 
  flourish 
  in 
  

   soft 
  mud, 
  as 
  long 
  as 
  it 
  is 
  not 
  buried 
  too 
  deeply 
  for 
  the 
  open 
  

   edge 
  of 
  the 
  shell 
  to 
  reach 
  above 
  the 
  mud, 
  and 
  draw 
  a 
  constant 
  

   supply 
  of 
  water 
  and 
  food 
  onto 
  the 
  gills. 
  The 
  placing 
  of 
  

   adult 
  oysters 
  upon 
  such 
  bottoms 
  at 
  convenient 
  points, 
  to 
  

   ' 
  " 
  fatten 
  " 
  for 
  the 
  market, 
  is 
  a 
  well-known 
  practice. 
  The 
  oys- 
  

   ter 
  embryo 
  would 
  be 
  ingulfed 
  and 
  smothered 
  at 
  once 
  if 
  it 
  

   should 
  settle 
  down 
  upon 
  such 
  a 
  bottom, 
  and 
  in 
  order 
  to 
  have 
  

   the 
  least 
  chance 
  of 
  survival 
  and 
  long 
  life 
  the 
  young 
  oyster 
  

   must 
  find 
  some 
  solid 
  substance 
  to 
  fasten 
  itself 
  to, 
  in 
  order 
  to 
  

   preserve 
  it 
  from 
  sinking 
  in 
  the 
  soft 
  mud 
  or 
  from 
  being 
  covered 
  

   by 
  shifting 
  sand 
  or 
  gravel. 
  As 
  soon 
  as 
  the 
  young 
  oyster 
  finds 
  

   such 
  a 
  solid 
  body, 
  rough 
  and 
  clean, 
  it 
  fastens 
  one 
  valve 
  of 
  its 
  

   shell 
  to 
  it 
  by 
  secreting 
  a 
  cement 
  of 
  shelly 
  matter 
  around 
  the 
  

   growing 
  edge. 
  

  

  The 
  living 
  and 
  dead 
  shells 
  of 
  the 
  adult 
  oysters 
  furnish 
  the 
  

   "best 
  surfaces 
  for 
  the 
  attachment 
  of 
  the 
  young, 
  and 
  for 
  this 
  

   reason 
  the 
  points 
  where 
  oyster 
  beds 
  are 
  already 
  established 
  

   are 
  those 
  where 
  the 
  young 
  have 
  the 
  most 
  favorable 
  surround- 
  

   ino-s 
  and 
  the 
  best 
  chance 
  for 
  life, 
  and 
  the 
  beds 
  thus 
  tend 
  to 
  

   remain 
  permanent 
  and 
  of 
  substantially 
  the 
  same 
  size 
  and 
  

   shape. 
  

  

  At 
  the 
  time 
  of 
  attachment 
  the 
  shell 
  of 
  the 
  young 
  oyster 
  is 
  . 
  

   •still 
  very 
  thin 
  and 
  delicate, 
  and 
  the 
  animal 
  falls 
  an 
  easy 
  vic- 
  

   tim 
  to 
  the 
  numerous 
  enemies 
  which 
  abound 
  upon 
  the 
  ojster 
  

   beds, 
  such 
  as 
  crabs 
  of 
  various 
  sorts, 
  carnivorous 
  gasteropods 
  

   and 
  various 
  fishes. 
  

  

  It 
  is 
  not 
  an 
  uncommon 
  thing 
  for 
  fifty 
  or 
  a 
  hundred 
  young 
  

   "spat" 
  to 
  attach 
  themselves 
  to 
  one 
  full-grown 
  shell. 
  Some 
  

   of 
  these 
  are 
  killed 
  by 
  enemies, 
  and 
  others 
  are 
  crowded 
  out, 
  

   so 
  that 
  only 
  a 
  few 
  grow 
  up 
  at 
  the 
  expense 
  of 
  the 
  others, 
  and 
  

   the 
  number 
  which 
  survive 
  is 
  astonishingly 
  small. 
  Mobius 
  

   has 
  made 
  an 
  attempt 
  to 
  ascertain 
  what 
  chance 
  of 
  survival 
  the 
  

   newly-hatched 
  oyster 
  has. 
  The 
  ratio 
  between 
  half-grown 
  and 
  

   adult 
  oysters 
  in 
  the 
  oyster 
  beds 
  of 
  Schleswig-Holstein 
  has 
  

  

  