﻿MANUAL 
  OF 
  FISH-CULTURE. 
  47 
  

  

  hours 
  4,400 
  eggs 
  were 
  obtained, 
  of 
  wliich 
  only 
  58 
  J 
  per 
  cent 
  were 
  capable 
  

   of 
  fecuudatiou. 
  In 
  one 
  instance 
  eggs 
  taken 
  from 
  a 
  dead 
  fish 
  and 
  kept 
  

   until 
  the 
  morrow 
  before 
  milting 
  remained 
  so 
  far 
  in 
  normal 
  condition 
  

   that 
  12^ 
  per 
  cent 
  were 
  fecundated. 
  In 
  another 
  case 
  400 
  eggs 
  from 
  a 
  

   fish 
  that 
  had 
  been 
  dead 
  15 
  hours 
  failed 
  totally; 
  and 
  the 
  same 
  result 
  

   was 
  obtained 
  with 
  2,200 
  eggs 
  taken 
  from 
  four 
  specimens 
  killed 
  two 
  days 
  

   before. 
  

  

  The 
  same 
  experiments 
  afford 
  evidence 
  as 
  to 
  the 
  result 
  of 
  keeping 
  eggs 
  

   for 
  various 
  periods 
  of 
  time 
  after 
  they 
  are 
  taken 
  from 
  the 
  fish, 
  and 
  

   eggs 
  exposed 
  to 
  the 
  air 
  and 
  guarded 
  against 
  contact 
  with 
  water 
  appear 
  

   to 
  kee]) 
  better 
  than 
  in 
  the 
  organs 
  of 
  a 
  dead 
  fish. 
  Thus, 
  200 
  eggs 
  were 
  

   kept 
  in 
  a 
  pan 
  without 
  water 
  for 
  12 
  hours 
  after 
  they 
  were 
  taken 
  from 
  

   the 
  fish, 
  and 
  the 
  application 
  of 
  milt 
  then 
  resulted 
  in 
  the 
  impregnation 
  

   of 
  90 
  per 
  cent; 
  of 
  200 
  eggs 
  kept 
  in 
  the 
  same 
  way 
  for 
  30 
  hours 
  and 
  then 
  

   treated 
  with 
  fresh 
  milt, 
  87i 
  per 
  cent 
  were 
  impregnated 
  ; 
  and 
  of 
  100 
  eggs 
  

   kept 
  4 
  days 
  and 
  then 
  treated 
  with 
  fresh 
  milt, 
  12 
  were 
  impregnated. 
  

  

  Milt 
  taken 
  from 
  a 
  living 
  male 
  and 
  kept 
  in 
  an 
  open 
  dish 
  for 
  several 
  

   hours 
  retains 
  its 
  powers 
  fully, 
  but 
  experiments 
  with 
  milt 
  from 
  dead 
  fish 
  

   have 
  given 
  almost 
  wholly 
  negative 
  results. 
  Numerous 
  experiments 
  

   show 
  that 
  if 
  eggs 
  are 
  merely 
  covered 
  by 
  water, 
  without 
  effort 
  to 
  secure 
  

   intermixture 
  or 
  the 
  washing 
  off 
  of 
  the 
  mucus 
  that 
  envelops 
  them 
  when 
  

   pressed 
  from 
  the 
  organs 
  of 
  the 
  mother 
  fish, 
  their 
  susceptibility 
  to 
  fecun- 
  

   dation 
  may 
  not 
  be 
  seriously 
  affected 
  by 
  immersion 
  5 
  or 
  6 
  minutes; 
  but 
  

   if 
  the 
  eggs 
  are 
  stirred, 
  so 
  as 
  to 
  facilitate 
  the 
  washing 
  off" 
  of 
  the 
  mucus 
  

   and 
  the 
  access 
  of 
  jjure 
  water, 
  immersion 
  for 
  1 
  or 
  2 
  minutes 
  may 
  pre- 
  

   vent 
  im])regnation. 
  

  

  When 
  thoroughly 
  diluted 
  with 
  water 
  the 
  milt 
  speedily 
  loses 
  its 
  

   power, 
  the 
  effect 
  being 
  very 
  marked 
  at 
  the 
  end 
  of 
  30 
  seconds; 
  diluted 
  

   with 
  the 
  mucus 
  that 
  accompanies 
  the 
  egg, 
  it 
  will 
  remain 
  effective 
  for 
  a 
  

   long 
  period. 
  Where 
  water 
  has 
  been 
  carefully 
  excluded, 
  milt 
  has 
  been 
  

   used 
  successfully 
  after 
  the 
  lapse 
  of 
  12 
  hours 
  with 
  landlocked 
  salmon, 
  

   and 
  this 
  would 
  probably 
  hold 
  with 
  eggs 
  of 
  all 
  kinds 
  of 
  salmon 
  and 
  

   trout. 
  This 
  property 
  of 
  the 
  mixed 
  mucus 
  and 
  milt 
  has 
  been 
  utilized 
  

   in 
  impregnating 
  masses 
  of 
  eggs 
  when 
  there 
  is 
  a 
  scarcity 
  of 
  males, 
  as 
  

   sometimes 
  occurs 
  toward 
  the 
  close 
  of 
  the 
  spawning 
  season. 
  In 
  strain- 
  

   ing 
  the 
  mixed 
  mucus 
  and 
  milt 
  from 
  the 
  pan 
  of 
  eggs, 
  the 
  lower 
  strata, 
  

   which 
  are 
  richer 
  in 
  milt 
  than 
  the 
  upper, 
  should 
  be 
  especially 
  secured 
  

   and 
  the 
  mixture 
  kept 
  in 
  a 
  convenient 
  receptacle. 
  The 
  upper 
  strata 
  of 
  

   the 
  mixture 
  should 
  not 
  be 
  used, 
  as 
  the 
  milt 
  settles 
  to 
  the 
  bottom. 
  

   Fresh 
  milt 
  should 
  always 
  be 
  preferred 
  when 
  obtainable. 
  

  

  The 
  eggs 
  are 
  washed 
  as 
  soon 
  as 
  the 
  milt 
  is 
  thoroughly 
  diffused 
  among 
  

   them, 
  and 
  this 
  can 
  hardly 
  be 
  done 
  too 
  speedily 
  for 
  the 
  milt 
  to 
  act. 
  A 
  

   careful 
  record 
  of 
  certain 
  lots 
  of 
  eggs 
  that 
  were 
  washed 
  in 
  special 
  haste 
  

   for 
  experimental 
  purposes 
  shows 
  that 
  they 
  were 
  as 
  well 
  impregnated 
  

   as 
  those 
  exposed 
  to 
  the 
  action 
  of 
  the 
  milt 
  for 
  a 
  considerable 
  period. 
  

   Prolonged 
  exposure 
  to 
  the 
  milt 
  has 
  been 
  found 
  to 
  affect 
  the 
  health 
  and 
  

   development 
  of 
  the 
  embryo 
  unfavorably. 
  

  

  