﻿126 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  If 
  the 
  egg 
  be 
  exainiued 
  6 
  or 
  8 
  hours 
  after 
  it 
  is 
  fertilized, 
  the 
  germinal 
  

   disk 
  will 
  be 
  found 
  to 
  have 
  contracted 
  to 
  a 
  saucer-shaped 
  cap 
  extending 
  

   over 
  about 
  a 
  lifth 
  of 
  the 
  surface 
  of 
  the 
  yolk. 
  It 
  is 
  smooth 
  and 
  even, 
  

   gradually 
  thinning 
  to 
  a 
  sharp 
  outer 
  rim, 
  with 
  a 
  thickness 
  iu 
  the 
  center 
  

   of 
  the 
  cap 
  of 
  about 
  a 
  fifth 
  of 
  its 
  diameter. 
  At 
  this 
  stage 
  — 
  segmentation 
  

   not 
  having 
  commenced 
  — 
  the 
  impregnated 
  eggs 
  can 
  not 
  be 
  told 
  from 
  the 
  

   unimpregnated 
  ones. 
  At 
  18 
  hours 
  segmentation 
  will 
  be 
  well 
  advanced 
  

   and 
  the 
  disk 
  will 
  have 
  contracted 
  into 
  six 
  or 
  eight 
  rounded 
  nodules 
  of 
  

   uneven 
  size, 
  with 
  well 
  defined 
  valleys 
  between, 
  there 
  being 
  no 
  longer 
  

   a 
  sharp 
  rim 
  to 
  the 
  disk. 
  At 
  24 
  hours 
  — 
  the 
  best 
  time 
  to 
  determine 
  

   the 
  percentage 
  of 
  live 
  eggs 
  — 
  the 
  disk 
  presents 
  a 
  somewhat 
  similar 
  

   appearance, 
  except 
  that 
  it 
  will 
  be 
  divided 
  into 
  25 
  or 
  more 
  segments, 
  

   easily 
  seen 
  under 
  the 
  glass; 
  the 
  disk 
  of 
  the 
  unimj)regnated 
  egg 
  of 
  

   the 
  same 
  age 
  forms 
  an 
  almost 
  exact 
  hemisphere, 
  is 
  perfectly 
  smooth 
  

   in 
  appearance, 
  and 
  is 
  therefore 
  easily 
  distinguished 
  from 
  the 
  live 
  egg. 
  

   Segmentation 
  now 
  goes 
  on 
  rapidly, 
  and 
  at 
  72 
  hours 
  the 
  cells 
  look 
  under 
  

   a 
  1-inch 
  objective 
  — 
  a 
  suitable 
  power 
  to 
  use 
  in 
  this 
  work 
  — 
  about 
  the 
  

   size 
  of 
  a 
  mustard 
  seed, 
  the 
  disk 
  having 
  in 
  the 
  meantime 
  assumed 
  an 
  

   hemis])herical 
  shape. 
  

  

  During 
  the 
  entire 
  period 
  of 
  incubation, 
  but 
  more 
  especially 
  during 
  

   the 
  early 
  stages 
  of 
  growth, 
  the 
  eggs 
  should 
  be 
  worked 
  as 
  gently 
  as 
  

   possible; 
  that 
  is, 
  only 
  sufhcieut 
  water 
  should 
  be 
  used 
  to 
  keep 
  them 
  in 
  

   slow 
  motion 
  and 
  to 
  prevent 
  "banking." 
  At 
  the 
  commencement 
  they 
  

   require 
  about 
  6 
  quarts 
  of 
  water 
  per 
  minute 
  to 
  the 
  jar, 
  but 
  later 
  they 
  will 
  

   run 
  with 
  a 
  quart 
  less 
  per 
  miuute. 
  The 
  eggs 
  require 
  constant 
  watching 
  

   for 
  the 
  first 
  week 
  or 
  more, 
  and 
  although 
  not 
  considered 
  an 
  adhesive 
  egg, 
  

   agglutination 
  takes 
  place 
  occasionally 
  wheu 
  the 
  water 
  becomes 
  roily. 
  

   Unless 
  the 
  "banks" 
  so 
  formed 
  are 
  separated 
  by 
  gently 
  stirring 
  them 
  

   with 
  a 
  long 
  feather 
  (the 
  long 
  wing 
  feathers 
  of 
  a 
  turkey 
  are 
  suitable), 
  

   the 
  eggs 
  forming 
  the 
  pack 
  soon 
  die 
  and 
  form 
  a 
  mass 
  in 
  the 
  jar. 
  

  

  In 
  a 
  few 
  days, 
  varying 
  with 
  the 
  temi)erature 
  of 
  the 
  water, 
  the 
  unim- 
  

   pregnated 
  and 
  other 
  dead 
  eggs 
  begin 
  to 
  "fungus" 
  — 
  that 
  is, 
  a 
  growth 
  

   makes 
  its 
  appearance 
  on 
  them 
  and 
  they 
  rise 
  to 
  the 
  top 
  of 
  the 
  egg 
  mass 
  — 
  

   wheu 
  they 
  must 
  be 
  removed 
  by 
  the 
  use 
  of 
  a 
  siphon, 
  and 
  if 
  live 
  eggs 
  are 
  

   among 
  those 
  drawn 
  ofi^', 
  they 
  must 
  be 
  set 
  up 
  in 
  what 
  are 
  called 
  " 
  hospital 
  

   jars," 
  where 
  the 
  live 
  and 
  dead 
  ones 
  are 
  more 
  readily 
  separated. 
  

  

  The 
  dead 
  eggs 
  are 
  drawn 
  off 
  every 
  day, 
  otherwise 
  they 
  are 
  liable 
  to 
  

   become 
  loaded 
  with 
  silt 
  from 
  the 
  water 
  and 
  sink, 
  mixing 
  with 
  the 
  live 
  

   eggs 
  and 
  making 
  it 
  difficult 
  to 
  separate 
  them. 
  

  

  For 
  the 
  removal 
  of 
  dead 
  eggs 
  from 
  the 
  jars 
  a 
  long-distance 
  siphou 
  is 
  

   used 
  at 
  Put-in 
  Bay 
  station, 
  which 
  saves 
  much 
  labor. 
  It 
  is 
  constructed 
  

   thus: 
  To 
  the 
  short 
  end 
  of 
  the 
  ordinary 
  siphon, 
  which 
  consists 
  of 
  a 
  thiu 
  

   quarter-inch 
  brass 
  tube 
  about 
  a 
  foot 
  long 
  bent 
  into 
  the 
  form 
  of 
  a 
  goose 
  

   neck, 
  is 
  attached 
  a 
  piece 
  of 
  common 
  rubber 
  tubing 
  3 
  or 
  4 
  feet 
  long 
  with 
  

   a 
  |-inch 
  interior 
  diameter. 
  This 
  is 
  connected 
  with 
  a 
  rubber 
  tube 
  of 
  the 
  

   same 
  size 
  and 
  long 
  enough 
  to 
  reach 
  the 
  whole 
  row 
  of 
  jars 
  or 
  all 
  in 
  the 
  

  

  