﻿11 
  

  

  If 
  the 
  point 
  of 
  a 
  knife 
  be 
  pushed 
  into 
  the 
  reproductive 
  or- 
  

   gan 
  a 
  milk-like 
  fluid 
  will 
  ooze 
  out 
  of 
  the 
  cut, 
  and 
  a 
  little 
  of 
  

   it 
  may 
  be 
  taken 
  upon 
  a 
  knife 
  blade 
  and 
  transferred 
  to 
  a 
  glass 
  

   slide 
  for 
  examination. 
  The 
  drop 
  of 
  fluid 
  should 
  be 
  thoroughly 
  

   mixed 
  with 
  a 
  drop 
  of 
  sea 
  water 
  and 
  placed 
  on 
  the 
  slide, 
  and 
  

   gently 
  covered 
  with 
  a 
  cover-glass, 
  and 
  examined 
  with 
  a 
  mag- 
  

   nifying 
  power 
  of 
  about 
  one 
  hundred 
  diameters. 
  If 
  the 
  speci- 
  

   men 
  is 
  a 
  female, 
  this 
  power 
  will 
  show 
  that 
  the 
  white 
  fluid 
  is 
  

   almost 
  entirely 
  made 
  up 
  of 
  irregular 
  pear-shaped 
  ovarian 
  

   eggs 
  (Figure 
  49), 
  each 
  of 
  which 
  contains 
  a 
  large 
  circular 
  

   transparent 
  germinative 
  vesicle 
  surrounded 
  by 
  a 
  layer 
  of 
  

   granular 
  slightly 
  opaque 
  yolk. 
  It 
  is 
  almost 
  impossible 
  to 
  de- 
  

   scribe 
  the 
  slight 
  differences 
  which 
  distinguish 
  the 
  perfectly 
  

   ripe 
  egg 
  from 
  those 
  which 
  are 
  nearly 
  ripe 
  but 
  not 
  capable 
  of 
  

   fertilization, 
  although 
  a 
  very 
  little 
  experience 
  will 
  enable 
  one 
  

   to 
  tell 
  whether 
  it 
  is 
  worth 
  while 
  to 
  attempt 
  the 
  fertilization, 
  

   of 
  the 
  eggs 
  of 
  any 
  given 
  female. 
  

  

  When 
  the 
  drop 
  of 
  fluid 
  is 
  thoroughly 
  mixed 
  with 
  the 
  sea 
  

   water, 
  the 
  eggs 
  should 
  appear 
  clean, 
  sharply 
  defined, 
  separate 
  

   from 
  each 
  other, 
  and 
  pretty 
  uniformly 
  distributed 
  through 
  the 
  

   drop, 
  as 
  shown 
  in 
  the 
  figure. 
  If 
  they 
  adhere 
  to 
  each 
  other, 
  

   or 
  if 
  their 
  outlines 
  are 
  indistinct, 
  or 
  if 
  there 
  is 
  much 
  fine 
  

   granular 
  matter 
  scattered 
  between 
  the 
  eggs, 
  it 
  is 
  probable 
  that 
  

   the 
  attempt 
  at 
  artificial 
  fertilization 
  will 
  at 
  best 
  be 
  only 
  par- 
  

   tially 
  successful. 
  

  

  When 
  a 
  perfectly 
  ripe 
  female 
  is 
  found, 
  it 
  should 
  be 
  set 
  aside 
  

   and 
  the 
  search 
  continued 
  for 
  a 
  male. 
  The 
  question 
  of 
  the 
  

   sex 
  of 
  the 
  oyster 
  has 
  long 
  been 
  a 
  matter 
  of 
  dispute, 
  and 
  the 
  

   subject 
  will 
  be 
  fully 
  discussed 
  in 
  another 
  place. 
  All 
  that 
  

   concerns 
  us 
  now 
  is 
  to 
  know 
  that 
  for 
  all 
  practical 
  purposes 
  the 
  

   sexes 
  are 
  separate 
  in 
  the 
  European 
  as 
  well 
  as 
  the 
  American 
  

   oyster. 
  At 
  the 
  breeding 
  season 
  each 
  individual 
  is 
  either 
  ex- 
  

   clusively 
  a 
  male 
  or 
  exclusively 
  a 
  female. 
  Out 
  of 
  several 
  

   thousand 
  which 
  I 
  examined, 
  I 
  have 
  not 
  found 
  one 
  which 
  con- 
  

   tained 
  both 
  eggs 
  and 
  male 
  cells, 
  and 
  all 
  the 
  best 
  authorities 
  

   upon 
  the 
  European 
  oyster 
  make 
  the 
  same 
  statement, 
  although 
  

   there 
  is 
  some 
  reanon 
  for 
  the 
  belief 
  that 
  an 
  oyster 
  may 
  give 
  • 
  

  

  