﻿es 
  of 
  Davaine, 
  Salensky 
  and. 
  others, 
  who, 
  however, 
  have 
  

   failed 
  to 
  see 
  the 
  earliest 
  stages. 
  

  

  The 
  note 
  on 
  tlie 
  development 
  of 
  Mya 
  arenaria 
  is 
  

   added 
  merely 
  to 
  establish 
  the 
  time 
  of 
  the 
  spawning 
  sea- 
  

   son 
  ; 
  to 
  show 
  that 
  it 
  is 
  possible 
  to 
  impregnate 
  the 
  eggs 
  

   artificially, 
  and 
  to 
  indicate 
  to 
  some 
  extent 
  the 
  nature 
  of 
  

   the 
  process 
  of 
  development, 
  the 
  study 
  of 
  which 
  I 
  could 
  

   not 
  complete 
  owing 
  to 
  illness. 
  

  

  The 
  histology 
  of 
  the 
  ovaries 
  of 
  both 
  the 
  oyster 
  and 
  

   clam 
  remains 
  to 
  be 
  studied, 
  since 
  it 
  is 
  possible 
  only 
  by 
  

   that 
  means 
  to 
  ascertain 
  whether 
  the 
  whole 
  of 
  the 
  eggs 
  

   are 
  mature 
  at 
  one 
  time. 
  The 
  researches 
  of 
  Flemming 
  

   and 
  Von 
  Jhering 
  show 
  that 
  such 
  is 
  not 
  the 
  case 
  in 
  Unio 
  

   and 
  SGrohicularia. 
  Much 
  of 
  the 
  success 
  of 
  future 
  

   attempts 
  at 
  artiticial 
  incubation 
  depends 
  upon 
  a 
  decisive 
  

   answer 
  to 
  this 
  question. 
  My 
  own 
  experience 
  in 
  investi- 
  

   gating 
  the 
  ovaries 
  of 
  Ostrea 
  and 
  Mya^ 
  countenances 
  the 
  

   belief 
  in 
  my 
  mind, 
  that 
  the 
  time 
  of 
  maturity 
  for 
  nearly 
  

   all 
  the 
  ovarian 
  eggs 
  is 
  about 
  the 
  same. 
  

  

  The 
  questi(^n 
  as 
  to 
  the 
  exact 
  age 
  of 
  the 
  fry 
  of 
  the 
  oyster 
  

   at 
  the 
  time 
  of 
  fixation, 
  as 
  well 
  as 
  the 
  age 
  of 
  the 
  fry 
  of 
  

   Mya 
  at 
  the 
  time 
  it 
  buries 
  itself 
  in 
  the 
  sand, 
  also 
  awaits 
  

   an 
  answer 
  ; 
  but 
  it 
  is 
  the 
  hope 
  of 
  the 
  writer 
  that, 
  with 
  an 
  

   incubating 
  apparatus 
  which 
  he 
  has 
  lately 
  devised 
  as 
  an 
  

   adjunct 
  to 
  his 
  microscope, 
  he 
  may 
  in 
  the 
  course 
  of 
  another 
  

   season's 
  work, 
  reach 
  a 
  satisfactory 
  conclusion 
  in 
  regard 
  

   to 
  this, 
  as 
  well 
  as 
  many 
  other 
  important 
  matters. 
  

  

  