﻿50 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  iND 
  FISHERIES. 
  

  

  It 
  is 
  possible, 
  by 
  placing 
  it 
  in 
  a 
  favorable 
  light, 
  to 
  get 
  a 
  fairly 
  good 
  

   interior 
  view, 
  including 
  the 
  detailed 
  anatomy 
  of 
  the 
  embryo. 
  When 
  

   the 
  egg 
  dies 
  it 
  turns 
  chalky 
  white, 
  becomes 
  wholly 
  opaque, 
  and 
  in 
  a 
  few 
  

   days, 
  depending 
  on 
  the 
  temperature, 
  decay 
  sets 
  in, 
  and 
  sometimes 
  a 
  

   white 
  water-mold 
  or 
  fungus 
  begins 
  to 
  grow 
  upon 
  it. 
  The 
  mere 
  decay 
  

   of 
  the 
  egg 
  would 
  foul 
  the 
  water, 
  thereby 
  injuring 
  the 
  neighboring 
  eggs, 
  

   and 
  the 
  fungus 
  established 
  on 
  the 
  dead 
  eggs 
  may 
  spread 
  to 
  the 
  living 
  

   ones. 
  It 
  is 
  therefore 
  essential 
  that 
  the 
  white 
  eggs 
  be 
  removed 
  before 
  

   they 
  have 
  time 
  to 
  do 
  any 
  injury. 
  

  

  For 
  egg-picking 
  a 
  homemade 
  pair 
  of 
  tweezers, 
  about 
  6 
  inches 
  long, 
  is 
  

   used, 
  made 
  of 
  any 
  convenient 
  wood 
  and 
  tipped 
  with 
  a 
  pair 
  of 
  wire 
  

   loops 
  of 
  a 
  size 
  to 
  conveniently 
  grasp 
  the 
  egg. 
  The 
  oj)erator 
  lifts 
  the 
  

   stack 
  of 
  trays 
  carefully 
  from 
  the 
  trough 
  and, 
  to 
  save 
  dripping, 
  carries 
  

   it 
  on 
  a 
  wooden 
  waiter 
  to 
  a 
  well-lighted 
  table 
  of 
  convenient 
  height, 
  on 
  

   which 
  stands 
  an 
  oblong 
  pan, 
  14 
  by 
  18 
  inches, 
  holding 
  about 
  an 
  inch 
  of 
  

   water. 
  

  

  The 
  stack 
  of 
  eggs 
  to 
  be 
  picked 
  is 
  placed 
  at 
  one 
  end 
  of 
  the 
  pan 
  and 
  

   at 
  the 
  other 
  end 
  is 
  an 
  empty 
  stack-frame. 
  The 
  trays 
  are 
  examined 
  one 
  

   by 
  one, 
  dipj)ed 
  in 
  the 
  pan 
  of 
  water, 
  picked 
  (or 
  cleaned 
  by 
  agitation 
  

   when 
  the 
  eggs 
  are 
  in 
  condition 
  to 
  endure 
  the 
  disturbance), 
  and 
  j)laced 
  

   in 
  the 
  emj^ty 
  frame. 
  The 
  air 
  of 
  the 
  room 
  is 
  kept 
  at 
  a 
  low 
  temperature 
  

   during 
  this 
  process, 
  and 
  the 
  water 
  in 
  the 
  pan 
  is 
  often 
  changed. 
  

  

  The 
  eggs 
  when 
  first 
  impregnated 
  are 
  very 
  sensitive 
  to 
  rude 
  shocks 
  and 
  

   are 
  handled 
  with 
  great 
  care. 
  Within 
  a 
  few 
  hours 
  the 
  germ 
  begins 
  to 
  

   develop; 
  in 
  10 
  days, 
  at 
  a 
  temperature 
  of 
  about 
  40'^ 
  F., 
  the 
  germ-disk 
  

   appears 
  as 
  a 
  ring 
  of 
  color 
  on 
  the 
  uj^per 
  side 
  of 
  the 
  yolk. 
  At 
  this 
  date 
  

   the 
  unimpregnated 
  egg 
  presents 
  the 
  same 
  appearance 
  and 
  does 
  not 
  

   change 
  much 
  until 
  its 
  death, 
  however 
  long 
  that 
  may 
  be 
  deferred. 
  In 
  

   the 
  impregnated 
  eggj 
  however, 
  the 
  germ-disk 
  continually 
  enlarges 
  upon 
  

   the 
  surface 
  of 
  the 
  yolk; 
  the 
  ring 
  of 
  color 
  that 
  marks 
  its 
  edge 
  advances 
  

   before 
  it, 
  passing 
  quite 
  round 
  the 
  yolk, 
  and 
  closing 
  up 
  on 
  the 
  posterior 
  

   side. 
  

  

  As 
  early 
  as 
  the 
  thirteenth 
  day 
  the 
  difference 
  between 
  the 
  imi^regnated 
  

   and 
  unimpregnated 
  egg 
  is 
  quite 
  plain 
  to 
  the 
  unaided 
  eye 
  after 
  a 
  very 
  

   little 
  experience, 
  and 
  three 
  or 
  four 
  days 
  later 
  the 
  good 
  egg 
  is 
  marked 
  

   by 
  a 
  distinct 
  line 
  of 
  color 
  passing 
  around 
  the 
  very 
  middle 
  of 
  the 
  yolk, 
  

   a 
  phenomenon 
  never 
  appearing 
  in 
  an 
  unimpregnated 
  egg. 
  During 
  

   this 
  stage, 
  while 
  the 
  embryonic 
  disk 
  is 
  spreading 
  around 
  the 
  yolk, 
  

   the 
  egg 
  grows 
  constantly 
  more 
  and 
  more 
  delicate, 
  and 
  liable 
  to 
  rupture 
  

   of 
  its 
  tissues 
  and 
  consequent 
  death 
  on 
  very 
  slight 
  disturbance; 
  but 
  

   later 
  the 
  tissues 
  grow 
  stronger, 
  and 
  when, 
  about 
  the 
  thirty-fifth 
  or 
  

   fortieth 
  day, 
  the 
  eyes 
  of 
  the 
  embryo 
  have 
  assumed 
  enough 
  color 
  to 
  

   appear 
  as 
  two 
  dark 
  dots, 
  the 
  egg 
  has 
  attained 
  hardiness 
  enough 
  to 
  

   endure 
  rougher 
  handling. 
  Thenceforward, 
  until 
  the 
  near 
  approach 
  of 
  

   the 
  time 
  for 
  hatching, 
  the 
  work 
  consists 
  simply 
  in 
  picking 
  out 
  the 
  dead 
  

   ones, 
  occasionally 
  rinsing 
  out 
  the 
  sediment, 
  and 
  sometimes 
  removing 
  

   the 
  unimpregnated 
  eggs. 
  

  

  