﻿MANUAL 
  OF 
  FISH-CULTURE. 
  

  

  49 
  

  

  The 
  water 
  is 
  fed 
  into 
  one 
  end 
  through 
  a 
  wooden 
  or 
  rubber 
  tube 
  

   guarded 
  by 
  a 
  wire 
  screen, 
  and 
  is 
  regulated 
  by 
  a 
  simple 
  swinging 
  

   gate. 
  The 
  outlet 
  is 
  either 
  over 
  a 
  wooden 
  dam 
  or 
  through 
  a 
  hollow 
  

   plug, 
  either 
  of 
  which 
  determines 
  the 
  height 
  of 
  the 
  water 
  in 
  the 
  trough 
  

   which 
  is 
  always 
  maintained 
  just 
  at 
  the 
  top 
  of 
  the 
  covering 
  tray 
  or 
  an 
  

   eighth 
  of 
  an 
  inch 
  above 
  it. 
  

  

  Trough 
  Arranged 
  for 
  EggB. 
  

   Fig. 
  1, 
  plan. 
  Fig. 
  2, 
  longitudinal 
  section. 
  

  

  a, 
  supply 
  -trough 
  

  

  fc, 
  screen. 
  

  

  d. 
  -sujiply-iiipe. 
  

  

  /, 
  egg-trough. 
  

  

  J, 
  down- 
  spout. 
  

  

  r, 
  cleats. 
  

  

  «, 
  stacks 
  of 
  egg-trays. 
  

  

  t, 
  ■waste-pipe. 
  

  

  u, 
  screen. 
  

  

  V, 
  outlet. 
  

  

  w, 
  wooden 
  dam. 
  

  

  X, 
  water 
  surface. 
  

  

  For 
  the 
  regular 
  picking 
  and 
  cleaning, 
  and 
  for 
  other 
  examinations, 
  the 
  

   stacks 
  are 
  removed 
  from 
  the 
  trough 
  to 
  a 
  table, 
  where 
  the 
  trays 
  can 
  be 
  

   taken 
  out 
  one 
  by 
  one, 
  set 
  over 
  into 
  an 
  empty 
  frame, 
  and 
  returned 
  to 
  

   the 
  trough. 
  This 
  can 
  be 
  performed 
  with 
  ordinary 
  caution 
  at 
  any 
  stage 
  

   of 
  the 
  development 
  of 
  the 
  embryo, 
  without 
  doing 
  the 
  slightest 
  injury, 
  

   and 
  after 
  the 
  delicate 
  stage 
  is 
  passed 
  the 
  trays 
  and 
  their 
  burden 
  of 
  

   eggs 
  can 
  be 
  washed 
  at 
  the 
  same 
  time 
  in 
  a 
  pan 
  of 
  water. 
  

  

  WINTER 
  CARE 
  OF 
  EGGS. 
  

  

  The 
  eggs 
  pass 
  the 
  winter 
  in 
  the 
  stacks. 
  They 
  are 
  regularly 
  picked 
  

   over 
  and 
  the 
  dead 
  ones 
  removed 
  once 
  or 
  twice 
  a 
  week 
  — 
  twice 
  during 
  the 
  

   first 
  few 
  weeks, 
  on 
  account 
  of 
  the 
  comparatively 
  high 
  temperature 
  then 
  

   prevailing 
  and 
  the 
  consequent 
  rapid 
  development 
  of 
  decay 
  and 
  growth 
  

   of 
  fungus. 
  It 
  depends, 
  to 
  a 
  considerable 
  extent, 
  on 
  the 
  water 
  tempera 
  

   ture 
  ; 
  the 
  water 
  at 
  the 
  beginning 
  of 
  the 
  spawning 
  season 
  varies 
  from 
  

   50O 
  to 
  55° 
  F., 
  and 
  maintains 
  a 
  mean 
  of 
  43° 
  to 
  45° 
  F. 
  during 
  the 
  mouth 
  

   of 
  November. 
  

  

  The 
  color 
  of 
  a 
  good 
  egg^ 
  or 
  of 
  an 
  unimpregnated 
  egg 
  that 
  still 
  retains 
  

   its 
  vitality, 
  is 
  a 
  translucent 
  salmon 
  pink, 
  with 
  some 
  variations 
  in 
  shade. 
  

  

  F. 
  C. 
  R. 
  1897 
  4 
  

  

  