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  when 
  it 
  is 
  iiuitilated. 
  I 
  have 
  known 
  this 
  milky 
  ai)pear- 
  

   ance 
  of 
  tlie 
  mutilated 
  mantle 
  of 
  the 
  oyster 
  to 
  lead 
  per- 
  

   sons 
  to 
  mistake 
  it 
  for 
  the 
  reproductive 
  organ 
  ; 
  a 
  mistake 
  

   easily 
  made 
  by 
  the 
  inexperienced. 
  

  

  The 
  preceding 
  account 
  of 
  the 
  physiology 
  of 
  the 
  so- 
  

   called 
  fattening 
  process 
  will 
  serve 
  to 
  prove 
  how 
  little 
  

   philosophy 
  there 
  is 
  in 
  the 
  doctrine 
  that 
  oysters 
  may 
  be 
  

   fattened 
  by 
  putting 
  them 
  for 
  a 
  day 
  or 
  two 
  in 
  water 
  less 
  

   salt 
  than 
  that 
  from 
  which 
  they 
  were 
  first 
  taken, 
  in 
  order 
  

   that 
  they 
  may 
  be 
  water-swollen 
  by 
  the 
  action 
  of 
  osmose 
  

   so 
  as 
  to 
  give 
  them 
  a 
  plump 
  appearance. 
  

  

  Upon 
  making 
  an 
  examination 
  of 
  some 
  oysters 
  to-day 
  

   (Dec. 
  6th,) 
  to 
  learn 
  something 
  in 
  regard 
  to 
  the 
  nature 
  of 
  

   the 
  so-called 
  fatty 
  material 
  contained 
  in 
  the 
  thickened 
  

   mantle, 
  I 
  tind 
  that 
  it 
  is 
  made 
  up 
  of 
  nucleated 
  cells 
  com- 
  

   posed 
  of 
  a 
  fine 
  corpuscular 
  material. 
  The 
  protoplasmic 
  

   granules 
  are 
  so 
  tine 
  that 
  they 
  remind 
  one, 
  when 
  exam- 
  

   ined 
  under 
  a 
  i:)ower 
  of 
  200 
  diameters, 
  of 
  the 
  corpuscles 
  

   found 
  in 
  milk, 
  though 
  they 
  are 
  probably 
  quite 
  different 
  

   in 
  nature. 
  They 
  manifest 
  the 
  dancing 
  motion 
  when 
  

   highly 
  magnified, 
  which 
  is 
  known 
  as 
  pedesis 
  or 
  the 
  

   Brownian 
  movement, 
  and 
  appear 
  to 
  be 
  perfectly 
  spheri- 
  

   cal 
  with 
  considerable 
  variation 
  in 
  size. 
  V^on 
  examining 
  

   another 
  specimen 
  I 
  found 
  the 
  principal 
  ducts 
  of 
  the 
  

   testes 
  already 
  defined, 
  and 
  upon 
  microscopic 
  examination 
  

   an 
  abundance 
  of 
  active, 
  though 
  not 
  perfectly 
  mature, 
  

   spermatozoa 
  were 
  noticed. 
  The 
  spermaries 
  in 
  this 
  case 
  

   may 
  no 
  doubt 
  be 
  considered 
  as 
  a 
  jjart 
  of 
  the 
  fat, 
  but 
  the 
  

   case 
  is 
  most 
  interesting 
  as 
  showing 
  how 
  very 
  early 
  in 
  the 
  

   season 
  the 
  generative 
  products 
  commence 
  to 
  develop. 
  

  

  I-OOI) 
  OF 
  THE 
  OYSTEK. 
  

  

  The 
  food 
  of 
  this 
  mollusk, 
  as 
  is 
  well 
  known, 
  consists 
  

   entirely 
  of 
  microscopic 
  beings 
  and 
  fragments 
  of 
  organic 
  

   matter, 
  which 
  are 
  carried 
  by 
  currents 
  from 
  the 
  palps 
  and 
  

   gills, 
  which 
  have 
  been 
  already 
  described, 
  to 
  the 
  large 
  

   mouth 
  of 
  the 
  animal 
  at 
  the 
  hinge 
  end 
  of 
  the 
  shell. 
  The 
  

   inside 
  of 
  the 
  gullet 
  and 
  stomach, 
  like 
  some 
  other 
  parts 
  of 
  

  

  