﻿13 
  

  

  The 
  number 
  of 
  male 
  cells 
  which 
  a 
  single 
  male 
  will 
  yield 
  is 
  

   great 
  beyond 
  all 
  power 
  of 
  expression, 
  but 
  the 
  number 
  of 
  eggs 
  

   which 
  an 
  average 
  female 
  will 
  furnish 
  may 
  be 
  estimated 
  with 
  

   sufficient 
  exactness. 
  A 
  single 
  ripe 
  egg 
  measures 
  about 
  one 
  

   five 
  hundredth 
  of 
  an 
  inch 
  in 
  diameter, 
  or 
  five 
  hundred 
  laid 
  in 
  a 
  

   row, 
  touching 
  each 
  other, 
  would 
  make 
  one 
  inch 
  ; 
  and 
  a 
  square 
  

   inch 
  would 
  contain 
  five 
  hundred 
  such 
  rows, 
  or 
  500 
  x 
  500 
  = 
  

   250,000 
  eggs. 
  ISTearly 
  all 
  the 
  eggs 
  of 
  a 
  perfectly 
  ripe 
  female 
  

   may 
  be 
  washed 
  out 
  of 
  the 
  ovary 
  into 
  a 
  beaker 
  of 
  sea 
  water, 
  

   and 
  as 
  they 
  are 
  heavier 
  than 
  the 
  sea 
  water, 
  they 
  soon 
  sink 
  to 
  

   the 
  bottom, 
  and 
  the 
  eggs 
  of 
  a 
  medium 
  sized 
  female 
  will 
  cover 
  

   the 
  bottom 
  of 
  a 
  beaker 
  two 
  inches 
  in 
  diameter 
  with 
  a 
  layer 
  

   of 
  eggs 
  one-twentieth 
  of 
  an 
  inch 
  deep. 
  The 
  area 
  of 
  the 
  bot- 
  

   tom 
  of 
  a 
  beaker 
  two 
  inches 
  in 
  diameter 
  is 
  a 
  little 
  more 
  than 
  

   three 
  square 
  inches, 
  and 
  a 
  layer 
  of 
  eggs 
  one-tw^entieth 
  of 
  an 
  

   inch 
  deep, 
  covering 
  three 
  square 
  inches, 
  is 
  equal 
  to 
  one 
  three- 
  

   twentieths 
  of 
  an 
  inch 
  deep 
  and 
  two 
  square, 
  and 
  as 
  a 
  single 
  layer 
  

   of 
  eggs 
  is 
  one-five-hundredth 
  of 
  an 
  inch 
  thick, 
  a 
  layer 
  three- 
  

   twentieths 
  of 
  an 
  inch 
  thick 
  will 
  contain 
  seventy-five 
  layers 
  of 
  

   eggs, 
  with 
  250,000 
  eggs 
  in 
  each 
  layer, 
  or 
  1 
  8,750,000 
  eggs. 
  It 
  

   is 
  difficult 
  to 
  get 
  the 
  eggs 
  perfectly 
  pure, 
  and 
  if 
  we 
  allow 
  one- 
  

   half 
  for 
  foreign 
  matter 
  and 
  errors 
  of 
  measurement, 
  and 
  for 
  

   imperfect 
  contact 
  between 
  the 
  eggs, 
  we 
  shall 
  have 
  more 
  than 
  

   nine 
  millions 
  as 
  the 
  number 
  of 
  eggs 
  laid 
  by 
  an 
  oyster 
  of 
  av- 
  

   erage 
  size, 
  a 
  number 
  which 
  is 
  probably 
  less 
  than 
  the 
  true 
  

   number. 
  

  

  JVlobius 
  estimates 
  the 
  number 
  of 
  eggs 
  laid 
  by 
  an 
  average 
  

   European 
  oyster 
  at 
  1,012,925, 
  or 
  only 
  one-ninth 
  the 
  num- 
  

   ber 
  laid 
  by 
  an 
  ordinary 
  American 
  oyster, 
  but 
  the 
  Ameri- 
  

   can 
  oyster 
  is 
  very 
  much 
  larger 
  than 
  the 
  European, 
  while 
  its 
  

   eggs 
  are 
  less 
  than 
  one-third 
  as 
  large, 
  so 
  the 
  want 
  of 
  agree- 
  

   ment 
  betw'een 
  these 
  estimates 
  does 
  not 
  indicate 
  that 
  either 
  of 
  

   them 
  is 
  incorrect.* 
  Another 
  estimate 
  of 
  the 
  number 
  of 
  eggs 
  

  

  *Mobins' 
  measurement, 
  from 
  .15 
  to 
  .18 
  millimeters, 
  is 
  given 
  (Austern 
  unci 
  

   Austern-wirtscliaft, 
  1877), 
  as 
  the 
  diameter, 
  not 
  of 
  the 
  esrg, 
  hut 
  of 
  the 
  em- 
  

   br^'o, 
  hut 
  his 
  figures 
  show 
  that 
  the 
  European 
  oyster, 
  like 
  the 
  American, 
  

   does 
  not 
  grow 
  much 
  during 
  the 
  early 
  stages 
  of 
  development, 
  but 
  remains 
  of 
  

   about 
  the 
  same 
  size 
  as 
  the 
  egg. 
  

  

  