﻿OYSTERS 
  AND 
  METHODS 
  OF 
  OYSTER-CULTURE, 
  335 
  

  

  to 
  be 
  covered 
  by 
  too 
  large 
  a 
  number 
  of 
  spermatozoa; 
  thousands 
  more 
  than 
  are 
  

   required 
  if 
  too 
  muck 
  is 
  used. 
  These 
  8ui)erfiuou3 
  spermatozoa 
  simply 
  become 
  the 
  

   cause 
  of 
  a 
  putresceut 
  action, 
  which 
  is 
  injurious 
  to 
  the 
  healthy 
  development 
  of 
  the 
  

   eggs. 
  A 
  drop 
  of 
  milt 
  to 
  20 
  drops 
  of 
  eggs 
  is 
  quite 
  sufficient. 
  

  

  Immediately 
  after 
  the 
  ova 
  have 
  been 
  fertilized 
  it 
  is 
  best 
  to 
  put 
  them 
  into 
  clean 
  

   sea 
  -water 
  at 
  once, 
  iising 
  water 
  of 
  the 
  same 
  density 
  as 
  that 
  in 
  which 
  the 
  adults 
  grew. 
  

   If 
  the 
  attempt 
  is 
  made 
  to 
  impregnate 
  the 
  eggs 
  in 
  water 
  much 
  denser 
  than 
  that 
  in 
  

   which 
  the 
  adults 
  lived, 
  it 
  is 
  probable 
  that 
  the 
  milt 
  will 
  be 
  killed 
  at 
  once. 
  This 
  

   singular 
  fact, 
  which 
  was 
  accidentally 
  discovered 
  by 
  Colonel 
  McDonald 
  and 
  myself, 
  

   shoAvs 
  how 
  very 
  careful 
  we 
  should 
  be 
  to 
  take 
  into 
  consideration 
  every 
  variation 
  in 
  the 
  

   conditions 
  affecting 
  a 
  biological 
  experiment. 
  If 
  sufficient 
  water 
  is 
  used 
  no 
  trouble 
  

   will 
  be 
  experienced 
  from 
  the 
  pollution 
  of 
  the 
  water 
  by 
  dangerous 
  micro-organisms, 
  

   which 
  are 
  able 
  to 
  destroy 
  the 
  oyster 
  embryos. 
  From 
  50 
  to 
  200 
  volumes 
  of 
  fresh, 
  

   clean 
  water 
  may 
  be 
  added 
  to 
  the 
  volume 
  in 
  which 
  the 
  eggs 
  were 
  first 
  fertilized. 
  

   This 
  may 
  be 
  added 
  graduallj' 
  during 
  the 
  first 
  twenty-four 
  hours, 
  so 
  as 
  to 
  assist 
  

   aeration 
  and 
  prevent 
  the 
  suffocation 
  of 
  the 
  embryos. 
  * 
  

  

  ARTIFICIAL 
  FEEDING. 
  

  

  There 
  is 
  no 
  practical 
  way 
  now 
  known 
  of 
  furnishing 
  oysters 
  with 
  an 
  

   artificial 
  food 
  supply. 
  

  

  Experiments 
  have 
  been 
  made 
  with 
  a 
  view 
  to 
  feeding 
  the 
  adult 
  oysters 
  

   upon 
  corn-meal 
  or 
  some 
  similar 
  substance, 
  but 
  such 
  attempts 
  have 
  been 
  

   of 
  no 
  practical 
  value. 
  There 
  is 
  no 
  doubt 
  that 
  they 
  would 
  eat 
  corn-meal 
  

   or 
  any 
  other 
  substance 
  in 
  a 
  sufliciently 
  fine 
  state 
  of 
  division 
  to 
  be 
  acted 
  

   upon 
  by 
  the 
  cilia. 
  The 
  oyster 
  is 
  incaijable 
  of 
  making 
  a 
  selection 
  of 
  its 
  

   food, 
  and 
  probably 
  any 
  substance, 
  nutritious, 
  inert, 
  or 
  injimous, 
  would 
  

   be 
  swept 
  into 
  the 
  mouth 
  with 
  complete 
  indifference 
  except 
  as 
  to 
  the 
  

   result. 
  Corn-meal 
  and 
  similar 
  substances 
  would 
  doubtless 
  be 
  nutri- 
  

   tious, 
  but 
  their 
  use 
  must 
  be 
  so 
  wasteful 
  that 
  the 
  value 
  of 
  the 
  meal 
  

   would 
  be 
  greater 
  than 
  that 
  of 
  the 
  oyster 
  produced. 
  

  

  The 
  only 
  way 
  in 
  which 
  the 
  amount 
  of 
  oyster 
  food 
  can 
  be 
  increased 
  is 
  

   by 
  so 
  regulating 
  the 
  conditions 
  in 
  ponds 
  or 
  parks 
  that 
  the 
  natural 
  food 
  

   may 
  grow 
  in 
  greater 
  luxuriance. 
  In 
  artificial 
  propagation 
  the 
  life 
  of 
  

   the 
  young 
  has 
  been 
  prolonged 
  beyond 
  tbe 
  early 
  embryonic 
  stages 
  by 
  

   feeding 
  upon 
  certain 
  marine 
  alga> 
  reduced 
  to 
  a 
  powder 
  by 
  pounding 
  

   them 
  in 
  a 
  mortar, 
  but 
  such 
  successes 
  have 
  been 
  purely 
  experimental 
  

   and 
  are 
  of 
  no 
  significance 
  from 
  a 
  practical 
  standpoint. 
  Even 
  if 
  artificial 
  

   propagation 
  were 
  to 
  obtain 
  a 
  place 
  in 
  practical 
  oyster-culture, 
  the 
  fry 
  

   would 
  doubtless 
  be 
  liberated 
  before 
  resort 
  to 
  artificial 
  feeding 
  would 
  

   become 
  necessary. 
  

  

  * 
  Fisheries 
  Industries, 
  Sec. 
  I, 
  jtp. 
  723, 
  724, 
  725. 
  

  

  