﻿96 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  and 
  the 
  operation 
  repeated 
  till 
  all 
  the 
  eggs 
  are 
  extruded. 
  The 
  eggs 
  

   are 
  immediately 
  impregnated 
  with 
  milt, 
  which 
  is 
  obtained 
  from 
  the 
  male 
  

   in 
  similar 
  manner, 
  except 
  that 
  more 
  force 
  is 
  necessary 
  and 
  the 
  pressure 
  

   is 
  made 
  at 
  a 
  point 
  about 
  midway 
  between 
  the 
  ventral 
  and 
  anal 
  fins. 
  

  

  The 
  contents 
  of 
  the 
  pan 
  are 
  next 
  lightly 
  stirred 
  with 
  a 
  feather 
  to 
  

   insure 
  impregnation 
  of 
  all 
  the 
  eggs 
  possible. 
  They 
  now 
  present 
  a 
  

   milky 
  appearance 
  and 
  are 
  washed 
  in 
  as 
  many 
  changes 
  of 
  water 
  as 
  is 
  

   necessary 
  to 
  thoroughly 
  cleanse 
  them 
  from 
  the 
  milt 
  and 
  other 
  refuse, 
  

   when 
  the 
  pan, 
  left 
  half 
  filled 
  with 
  fresh 
  water, 
  is 
  placed 
  in 
  running 
  

   water 
  to 
  keep 
  the 
  eggs 
  at 
  a 
  low 
  temperature. 
  After 
  from 
  30 
  to 
  60 
  min- 
  

   utes, 
  according 
  to 
  the 
  temperature 
  of 
  the 
  water, 
  the 
  separation 
  of 
  the 
  

   eggs 
  ensues. 
  

  

  In 
  the 
  work 
  on 
  the 
  An 
  Sable 
  Eiver, 
  the 
  eggs, 
  after 
  separating, 
  are 
  

   laid 
  on 
  gravel 
  placed 
  i 
  inch 
  deep 
  in 
  the 
  boxes 
  of 
  the 
  troughs. 
  Here 
  they 
  

   remain 
  till 
  the 
  eye-spots 
  begin 
  to 
  appear, 
  when 
  they 
  are 
  prepared 
  for 
  

   shipment. 
  During 
  this 
  iuterval 
  of 
  about 
  thirty 
  days 
  the 
  principal 
  care 
  

   consists 
  in 
  sorting 
  out 
  bad 
  eggs, 
  and, 
  with 
  a 
  feather, 
  gently 
  changing 
  

   the 
  position 
  of 
  good 
  ones 
  to 
  prevent 
  sediment 
  from 
  collecting 
  on 
  them. 
  

  

  SHIPPING 
  GREEN 
  EGGS. 
  

  

  Green 
  eggs 
  can 
  be 
  safely 
  moved 
  at 
  auy 
  time 
  up 
  to 
  and 
  including 
  the 
  

   eighth 
  day. 
  They 
  are 
  shipped 
  from 
  the 
  field 
  station 
  to 
  the 
  hatchery 
  in 
  

   cubical 
  boxes 
  constructed 
  from 
  ^-inch 
  pine 
  lumber, 
  just 
  large 
  enough 
  

   to 
  admit, 
  with 
  a 
  surrounding 
  air-space 
  of 
  ^ 
  inch, 
  19 
  canton-flannel 
  trays, 
  

   18 
  inches 
  square 
  on 
  the 
  inside, 
  the 
  frames 
  of 
  which 
  are 
  made 
  from 
  |-inch 
  

   square 
  white 
  pine. 
  The 
  eggs 
  are 
  drawn 
  by 
  means 
  of 
  a 
  siphon 
  from 
  the 
  

   gravel 
  boxes 
  into 
  a 
  tub 
  or 
  bucket 
  which 
  has 
  been 
  half 
  filled 
  with 
  water 
  

   to 
  prevent 
  them 
  from 
  injury. 
  Using 
  a 
  graduated 
  dipper 
  for 
  the 
  pur- 
  

   pose 
  of 
  ascertaining 
  approximately 
  the 
  number 
  of 
  eggs 
  necessary 
  to 
  

   make 
  them 
  about 
  two 
  deep 
  on 
  the 
  tray, 
  the 
  packer 
  pours 
  them 
  upon 
  

   the 
  flannel 
  and 
  spreads 
  them 
  as 
  evenly 
  as 
  possible 
  with 
  a 
  feather. 
  The 
  

   tray 
  is 
  then 
  placed 
  in 
  the 
  box 
  and 
  the 
  operation 
  repeated 
  until 
  eighteen 
  

   trays 
  are 
  filled 
  with 
  eggs. 
  The 
  nineteenth, 
  or 
  top 
  tray, 
  is 
  usually 
  left 
  

   empty, 
  but 
  if 
  the 
  weather 
  is 
  very 
  warm 
  it 
  is 
  filled 
  with 
  fine 
  ice. 
  The 
  

   cover 
  is 
  then 
  fastened 
  down, 
  the 
  box 
  marked, 
  and 
  the 
  eggs 
  are 
  ready 
  

   for 
  shipment 
  to 
  the 
  hatchery. 
  

  

  THE 
  HATCHING 
  APPARATUS. 
  

  

  After 
  a 
  period 
  of 
  about 
  thirty 
  days 
  on 
  the 
  gravel, 
  the 
  eggs 
  are 
  taken 
  

   up 
  and 
  placed 
  in 
  the 
  (Jlark 
  hatching-box, 
  for 
  here 
  they 
  may 
  be 
  held 
  

   without 
  any 
  appreciable 
  loss 
  through 
  the 
  escape 
  of 
  fish 
  when 
  hatching. 
  

   This 
  apparatus 
  as 
  used 
  at 
  Northville 
  is 
  arranged 
  as 
  follows: 
  A 
  tank 
  15 
  

   feet 
  long, 
  with 
  a 
  partition 
  running 
  its 
  entire 
  length, 
  is 
  so 
  placed 
  that 
  

   its 
  lower 
  end 
  rests 
  upon 
  the 
  upper 
  end 
  of 
  a 
  similar 
  one 
  13 
  feet 
  long, 
  

   which 
  differs 
  from 
  the 
  upper 
  one 
  only 
  in 
  that 
  it 
  contains 
  two 
  boxes 
  less. 
  

   Nine 
  partitions, 
  placed 
  crosswise 
  of 
  the 
  tank, 
  form, 
  with 
  the 
  lengthwise 
  

   partitions, 
  a 
  double 
  row 
  of 
  eight 
  compartments, 
  each 
  of 
  which 
  is 
  19A 
  

  

  