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  through 
  a 
  siphon, 
  reaching 
  nearly 
  but 
  not 
  quite 
  down 
  to 
  the 
  

   eggs. 
  A 
  fresh 
  supply 
  of 
  sea 
  water 
  should 
  then 
  be 
  added, 
  and 
  

   the 
  eggs 
  stirred 
  and 
  allowed 
  to 
  settle, 
  and 
  the 
  water 
  drawn 
  

   off 
  as 
  before, 
  and 
  this 
  should 
  be 
  repeated 
  until 
  the 
  water, 
  

   after 
  the 
  eggs 
  have 
  settled 
  to 
  the 
  bottom, 
  remains 
  clear. 
  

  

  The 
  beaker 
  may 
  now 
  be 
  set 
  aside 
  where 
  it 
  will 
  not 
  be 
  ex- 
  

   posed 
  to 
  sudden 
  changes 
  of 
  temperature, 
  and 
  the 
  eggs 
  will 
  

   require 
  no 
  further 
  attention 
  until 
  the 
  embryos 
  begin 
  to 
  swim, 
  

   which 
  will 
  be 
  in 
  from 
  two 
  to 
  six 
  hours, 
  according 
  to 
  the 
  tem- 
  

   perature. 
  The 
  little 
  oysters 
  must 
  of 
  course 
  be 
  supplied 
  with 
  

   fresh 
  sea 
  water 
  from 
  time 
  to 
  time 
  during 
  their 
  development, 
  

   an-d 
  as 
  they 
  are 
  so 
  small 
  that 
  the 
  w'ater 
  cannot 
  be 
  drawn 
  off 
  

   after 
  they 
  begin 
  to 
  swim, 
  they 
  must 
  be 
  supplied 
  with 
  fresh 
  

   water 
  by 
  transferring 
  them 
  from 
  time 
  to 
  time 
  to 
  larger 
  and 
  

   larger 
  beakers. 
  In 
  two 
  hours 
  or 
  so 
  after 
  the 
  eggs 
  are 
  fertil- 
  

   ized 
  the 
  embryos 
  begin 
  to 
  swim, 
  and 
  crowd 
  to 
  the 
  surface 
  of 
  

   the 
  water 
  in 
  great 
  numbers, 
  and 
  form 
  a 
  thin 
  stratum 
  close 
  to 
  

   the 
  surface. 
  This 
  layer 
  of 
  embryos 
  may 
  be 
  carefully 
  siphoned 
  

   off 
  into 
  a 
  very 
  small 
  beaker, 
  and 
  a 
  little 
  fresh 
  sea 
  water 
  

   added. 
  In 
  an 
  hour 
  or 
  so 
  there 
  will 
  be 
  a 
  new 
  layer 
  of 
  em- 
  

   bryos 
  at 
  the 
  surface 
  of 
  beaker 
  No. 
  1, 
  and 
  these 
  should 
  also 
  

   be 
  siphoned 
  into 
  No. 
  2, 
  and 
  this 
  should 
  be 
  repeated 
  as 
  long 
  

   as 
  the 
  embryos 
  continue 
  to 
  rise 
  to 
  the 
  surface 
  of 
  the 
  first 
  

   beaker. 
  Every 
  five 
  or 
  six 
  hours 
  a 
  little 
  fresh 
  sea 
  water 
  should 
  

   be 
  poured 
  from 
  a 
  height 
  of 
  a 
  foot 
  or 
  more 
  into 
  beaker 
  No. 
  2, 
  

   until 
  it 
  is 
  filled. 
  The 
  contents 
  should 
  then 
  be 
  poured 
  into 
  a 
  

   larger 
  beaker, 
  and 
  sea 
  water 
  added 
  four 
  or 
  five 
  times 
  a 
  day 
  as 
  

   before. 
  In 
  this 
  way 
  the 
  embryos 
  may 
  be 
  kept 
  alive 
  for 
  a 
  

   week, 
  although 
  they 
  have 
  by 
  this 
  time 
  got 
  into 
  such 
  a 
  large 
  

   vessel 
  that 
  it 
  is 
  almost 
  impossible 
  to 
  find 
  any 
  of 
  them 
  for 
  

   microscopic 
  examination. 
  

  

  t 
  

  

  THE 
  DEVELOPMENT 
  OF 
  THE 
  EGGS. 
  

  

  I 
  will 
  now 
  attempt 
  a 
  brief 
  popular 
  account 
  of 
  the 
  changes 
  

   through 
  which 
  the 
  fertilized 
  egg 
  is 
  gradually 
  converted 
  into 
  

   the 
  complex 
  body 
  of 
  the 
  adult 
  oyster. 
  

  

  