﻿50 
  

  

  surround 
  tlie 
  uiillions 
  of 
  eo^s 
  matured 
  l)ya 
  single 
  female, 
  

   that 
  only 
  the 
  most 
  tritiino- 
  fraction 
  ever 
  develop 
  as 
  illus- 
  

   trated 
  by 
  the 
  above 
  calculation. 
  The 
  egg 
  of 
  the 
  oyster 
  

   being 
  exceedingly 
  small 
  and 
  h<^avier 
  than 
  water, 
  imme- 
  

   diately 
  falls 
  to 
  the 
  bottom 
  upon 
  being 
  set 
  free 
  by 
  the 
  

   parent. 
  Should 
  the 
  bottom 
  be 
  oozy 
  or 
  composed 
  of 
  sedi- 
  

   ment 
  its 
  chances 
  of 
  development 
  are 
  meagre 
  indeed. 
  Ir- 
  

   recoverably 
  buried, 
  the 
  eggs 
  do 
  not 
  in 
  all 
  probability 
  

   have 
  the 
  chance 
  to 
  begin 
  to 
  develop 
  at 
  all. 
  The 
  chances 
  

   of 
  impregnation 
  are 
  also 
  reduced, 
  because 
  the 
  male 
  and 
  

   female 
  oj^sters 
  empty 
  their 
  generative 
  products 
  directly 
  

   into 
  the 
  surrounding 
  water, 
  whereby 
  the 
  likelihood 
  of 
  

   the 
  eggs 
  meeting 
  with 
  tlie 
  male 
  cells 
  becomes 
  diminished. 
  

   What 
  with 
  falling 
  into 
  the 
  mud 
  and 
  what 
  with 
  a 
  lessen- 
  

   ed 
  chance 
  of 
  bec<miing 
  impregnated, 
  it 
  is 
  not 
  unlikely 
  

   that 
  M5bius" 
  estimate 
  is 
  very 
  nearly 
  correct, 
  but 
  the 
  

   American 
  oyster 
  whose 
  yield 
  of 
  eggs 
  is 
  much 
  greater,^ 
  

   not 
  only 
  on 
  account 
  of 
  its 
  larger 
  size, 
  but 
  also 
  because 
  

   the 
  eggs 
  are 
  smaller 
  than 
  those 
  of 
  the 
  European, 
  has 
  

   probably 
  still 
  fewer 
  chances 
  of 
  survival." 
  The 
  vigorous 
  

   growth 
  of 
  small 
  oi-ganisms 
  on 
  surfaces 
  fitted 
  for 
  the 
  at- 
  

   tachment 
  of 
  young 
  oysters 
  also 
  tends 
  to 
  cause 
  sediment 
  

   to 
  gather 
  in 
  such 
  places 
  in 
  the 
  interstices 
  of 
  the 
  little 
  

   organic 
  forest 
  where 
  the 
  eggs 
  of 
  the 
  oyster 
  no 
  doubt 
  

   often 
  become 
  entombed 
  or 
  smothered 
  by 
  the 
  crowded 
  

   growth 
  suriounding 
  them. 
  

  

  INTEKFP:KEXrE 
  OF 
  nTIIKR 
  AXIMAL 
  LIFE. 
  

  

  AVe 
  have 
  called 
  attention 
  above 
  to 
  the 
  probal)le 
  inter- 
  

   ference 
  (^f 
  small 
  organic 
  growths 
  to 
  the 
  fixation 
  of 
  the 
  

   young 
  fry 
  ; 
  in 
  j^ractice 
  it 
  is 
  found 
  thjat 
  the 
  larger 
  organic 
  

   growths 
  which 
  establish 
  themselvos 
  on 
  the 
  collectors, 
  al- 
  

   so 
  become 
  injurious. 
  The 
  two 
  most 
  conspicuous 
  types 
  

   are 
  the 
  sessile 
  Ascidians 
  or 
  tunicates 
  and 
  the 
  barnacles. 
  

   I 
  have 
  frequently 
  found 
  fully 
  one-half 
  of 
  the 
  surface 
  of 
  a 
  

  

  *According 
  to 
  estimates 
  which 
  I 
  have 
  made 
  based 
  on 
  the 
  i'gures 
  of 
  the 
  eggs 
  of 
  Oitrea 
  eduUs 
  

   given 
  by 
  M. 
  Davair.e, 
  they 
  are 
  1-130 
  of 
  an 
  inch 
  in 
  diameter. 
  Estimates 
  based 
  on 
  the 
  figures 
  of 
  

   Lacaze-Duthiers 
  give 
  1-270 
  of 
  an 
  inch, 
  while 
  M 
  bins 
  estimates 
  the 
  size 
  of 
  the 
  yourig 
  fry 
  at 
  1-156 
  

   of 
  an 
  inch. 
  

  

  