﻿98 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  After 
  the 
  incubation 
  bas 
  reached 
  a 
  stage 
  where 
  the 
  fish 
  are 
  begin- 
  

   ning 
  to 
  break 
  their 
  shells, 
  the 
  hatching-box 
  is 
  taken 
  out 
  and 
  reversed, 
  

   the 
  open 
  end 
  being 
  fixed 
  snugly 
  against 
  the 
  lower 
  wall 
  of 
  the 
  compart- 
  

   ment. 
  The 
  closed 
  end 
  of 
  the 
  box 
  being 
  thus 
  placed 
  upstream, 
  the 
  

   water 
  is 
  prevented 
  from 
  entering 
  except 
  through 
  its 
  former 
  exit, 
  the 
  

   holes 
  in 
  the 
  bottom 
  of 
  the 
  box, 
  and 
  is 
  thus 
  forced 
  up 
  through 
  the 
  box, 
  

   with 
  an 
  exit 
  at 
  the 
  top 
  which 
  prevents 
  the 
  sacs 
  of 
  the 
  batching 
  fish 
  

   from 
  being 
  forced, 
  by 
  pressure 
  from 
  above, 
  down 
  through 
  the 
  screen, 
  

   as 
  would 
  be 
  the 
  case 
  if 
  the 
  box 
  were 
  left 
  in 
  its 
  former 
  position. 
  

  

  When 
  the 
  process 
  of 
  hatching 
  is 
  nearly 
  completed 
  the 
  trays 
  are 
  

   removed 
  and 
  emptied 
  into 
  a 
  large 
  pan 
  filled 
  with 
  water, 
  where 
  the 
  dead 
  

   shells 
  and 
  other 
  refuse, 
  being 
  of 
  low 
  specific 
  gravity, 
  rise 
  to 
  the 
  top 
  

   and 
  can 
  be 
  easily 
  poured 
  off. 
  This 
  is 
  called 
  washing 
  the 
  fisb. 
  The 
  fish 
  

   are 
  then 
  replaced 
  upon 
  the 
  trays 
  and 
  returned 
  to 
  the 
  hatching-boxes, 
  

   where 
  they 
  remain 
  until 
  the 
  food-sac 
  is 
  nearly 
  absorbed, 
  a 
  period 
  of 
  from 
  

   25 
  to 
  40 
  days, 
  according 
  as 
  the 
  temperature 
  varies 
  from 
  50° 
  to 
  38° 
  F. 
  

  

  The 
  young 
  fry, 
  deprived 
  of 
  their 
  food 
  supply 
  by 
  the 
  absorption 
  of 
  

   this 
  sac, 
  must 
  soon 
  be 
  jilaced 
  where 
  they 
  can 
  get 
  their 
  sustenance 
  else- 
  

   where. 
  They 
  may 
  be 
  planted 
  in 
  waters 
  suitable 
  to 
  their 
  nature, 
  or 
  

   reared 
  for 
  breeding 
  or 
  other 
  purposes 
  at 
  the 
  station. 
  

  

  PLANTING 
  THE 
  FRY. 
  

  

  In 
  their 
  natural 
  state, 
  as 
  soon 
  as 
  the 
  weight 
  of 
  the 
  food-sac 
  has 
  

   diminished 
  by 
  absorption 
  enough 
  to 
  permit 
  their 
  rising, 
  the 
  fish 
  begin 
  

   to 
  take 
  food, 
  and 
  by 
  the 
  time 
  the 
  sac 
  is 
  entirely 
  gone 
  they 
  are 
  probably 
  

   taking 
  it 
  regularly. 
  When 
  very 
  young 
  fry 
  are 
  transferred 
  to 
  outside 
  

   waters 
  where 
  there 
  is 
  natural 
  food 
  only, 
  it 
  should 
  be 
  done 
  8 
  or 
  10 
  days 
  

   before 
  the 
  sac 
  is 
  entirely 
  absorbed, 
  for, 
  if 
  delayed 
  till 
  after 
  the 
  sac 
  dis- 
  

   appears, 
  many 
  will 
  die 
  before 
  they 
  become 
  accustomed 
  to 
  finding 
  food 
  

   in 
  their 
  new 
  home. 
  

  

  Brook 
  trout 
  fry 
  are 
  usually 
  transported 
  in 
  ordinary 
  round-shouldered 
  

   cans 
  of 
  10 
  gallons 
  capacity, 
  the 
  number 
  of 
  fish 
  per 
  can 
  depending 
  

   entirely 
  upon 
  the 
  distance 
  they 
  are 
  to 
  be 
  carried 
  and 
  the 
  facilities 
  for 
  

   taking 
  care 
  of 
  them 
  en 
  route, 
  such 
  as 
  opportunities 
  for 
  changing 
  the 
  

   water, 
  supplying 
  fresh 
  ice, 
  etc. 
  For 
  a 
  short 
  trip 
  of 
  from 
  5 
  to 
  10 
  hours 
  

   duration, 
  between 
  4,000 
  and 
  5,000 
  are 
  carried 
  in 
  each 
  can, 
  but 
  where 
  

   they 
  are 
  to 
  be 
  on 
  the 
  road 
  from 
  1 
  to 
  5 
  days, 
  it 
  is 
  hardly 
  safe 
  to 
  attempt 
  

   carrying 
  more 
  than 
  2,500. 
  The 
  United 
  States 
  Fish 
  Commission 
  dis- 
  

   tributes 
  fry 
  by 
  means 
  of 
  its 
  cars, 
  built 
  especially 
  for 
  the 
  purpose, 
  in 
  

   whicb 
  either 
  running 
  water 
  is 
  kept 
  upon 
  them 
  or 
  fresh 
  air 
  introduced 
  

   into 
  the 
  water 
  to 
  make 
  it 
  life-sustaining. 
  Small 
  shipments 
  are 
  made 
  

   by 
  a 
  special 
  messenger 
  in 
  a 
  baggage 
  car, 
  the 
  railway 
  companies 
  usually 
  

   offering 
  every 
  available 
  opportunity 
  for 
  changing 
  water, 
  etc. 
  The 
  fish, 
  

   upon 
  arrival 
  at 
  the 
  railway 
  point 
  nearest 
  their 
  destination, 
  are 
  carried 
  

   thence 
  by 
  wagon 
  to 
  the 
  stream 
  M'here 
  they 
  are 
  to 
  be 
  planted, 
  by 
  dis- 
  

   tributing 
  them 
  in 
  small 
  lots 
  in 
  different 
  places 
  where 
  there 
  is 
  shallow 
  

   water 
  and 
  a 
  good 
  bottom. 
  

  

  