﻿197 
  

  

  the 
  end 
  of 
  that 
  montli, 
  as 
  far 
  as 
  I 
  could 
  ascertain 
  the 
  condi- 
  

   tion 
  of 
  both 
  ova 
  and 
  spermatozoa 
  depended 
  upon 
  the 
  depth 
  

   of 
  water, 
  though 
  the 
  rule 
  was 
  not 
  invariable. 
  

  

  The 
  generative 
  products 
  of 
  the 
  deep 
  water 
  oysters 
  reached 
  

   a 
  state 
  most 
  favorable 
  for 
  reproduction 
  several 
  weeks 
  after 
  the 
  

   same 
  had 
  occurred 
  in 
  the 
  shoal 
  water 
  ; 
  and, 
  in 
  general 
  terms, 
  

   neither 
  ova 
  nor 
  spermatozoa 
  in 
  most 
  of 
  the 
  oysters 
  in 
  either 
  

   deep 
  or 
  shoal 
  water 
  after 
  the 
  middle 
  of 
  August 
  was 
  in 
  a 
  state 
  

   favorable 
  for 
  fertilization. 
  

  

  Large 
  numbers 
  of 
  oysters 
  in 
  all 
  depths 
  passed 
  through 
  the 
  

   spawning 
  season 
  without 
  expelling 
  the 
  contents 
  of 
  the 
  genera- 
  

   tive 
  organs. 
  I 
  found 
  this 
  the 
  case 
  especially 
  on 
  the 
  beds 
  on 
  

   the 
  western 
  side 
  of 
  Tangier 
  Sound, 
  abov^e 
  Kedge's 
  Straits, 
  

   where, 
  on 
  the 
  8th 
  and 
  9th 
  of 
  October, 
  we 
  found 
  many 
  oysters 
  

   fattening 
  with 
  the 
  generative 
  matter 
  unexpelled. 
  I 
  was 
  in- 
  

   formed 
  that 
  this 
  was 
  not 
  unusual, 
  and 
  that 
  it 
  injured 
  the 
  oys- 
  

   ter 
  for 
  marketable 
  purposes. 
  

  

  As 
  late 
  as 
  the 
  8th 
  I 
  found 
  oysters 
  with 
  the 
  generative 
  mat- 
  

   ter 
  in 
  good 
  condition, 
  and 
  on 
  the 
  Tth 
  of 
  October 
  I 
  succeeded 
  

   in 
  securing 
  from 
  oysters 
  taken 
  from 
  Kedge's 
  Straits 
  a 
  suifi- 
  

   cient 
  amount 
  of 
  ova 
  and 
  spermatozoa 
  to 
  make 
  experiments 
  in 
  

   artificial 
  impregnation, 
  and 
  was 
  successful 
  in 
  producing 
  one 
  

   embryo 
  oyster. 
  

  

  Probably 
  had 
  I 
  used 
  greater 
  care 
  a 
  larger 
  number 
  would 
  

   have 
  resulted. 
  

  

  During 
  the 
  season 
  of 
  1878 
  we 
  observed 
  large 
  numbers 
  of 
  

   asty7'is 
  in 
  the 
  shells 
  of 
  the 
  mature 
  oysters, 
  and 
  attached 
  to 
  

   those 
  of 
  the 
  young. 
  In 
  many 
  cases 
  they 
  were 
  found 
  in 
  the 
  

   holes 
  which 
  had 
  been 
  bored 
  in 
  the 
  shells 
  of 
  the 
  latter. 
  

  

  As 
  we 
  could 
  not 
  lind 
  any 
  known 
  enemy 
  of 
  the 
  oyster 
  in 
  

   sufficient 
  numbers 
  to 
  account 
  for 
  the 
  evident 
  damage 
  done, 
  

   and 
  as 
  so 
  many 
  circumstances 
  pointed 
  to 
  the 
  astyris 
  as 
  the 
  

   cause, 
  I 
  concluded 
  that 
  the 
  boring 
  must 
  be 
  done 
  by 
  that 
  ani- 
  

   mal, 
  and 
  alluded 
  to 
  it 
  in 
  my 
  previous 
  report. 
  The 
  specimens 
  

   preserved 
  were 
  described 
  by 
  Mr. 
  AV. 
  H. 
  Dal], 
  and 
  the 
  descrip- 
  

   tion 
  appended 
  to 
  that 
  report. 
  

  

  During 
  the 
  past 
  summer 
  we 
  have 
  found 
  a 
  much 
  larger 
  num- 
  

   ber 
  of 
  the 
  rough 
  welks 
  {urosalpinx 
  cinereiis) 
  than 
  during 
  the 
  

  

  