﻿MANUAL 
  OF 
  FISH-CULTUEE. 
  6t 
  

  

  more 
  eagerly 
  devoured, 
  and 
  apparently 
  no 
  other 
  food 
  has 
  contributed 
  

   more 
  to 
  the 
  growth 
  of 
  the 
  fish; 
  but 
  the 
  time 
  expended 
  in 
  collecting 
  is 
  

   out 
  of 
  all 
  proportion 
  to 
  the 
  quantity 
  of 
  food 
  secured. 
  Perhaps 
  a 
  series 
  

   of 
  breeding-tanks 
  arranged 
  in 
  proximity 
  to 
  the 
  fish-troughs, 
  into 
  which 
  

   the 
  water 
  containing 
  the 
  larvw 
  might 
  be 
  drawn 
  when 
  desirable 
  by 
  the 
  

   simple 
  opening 
  of 
  a 
  faucet, 
  would 
  reduce 
  the 
  labor 
  involved. 
  

  

  Middlings 
  and 
  flour 
  have 
  been 
  tried 
  in 
  combination 
  with 
  blood 
  from 
  

   the 
  shambles, 
  but 
  did 
  not 
  appear 
  to 
  satisfy 
  the 
  fish 
  so 
  well 
  as 
  the 
  vari- 
  

   ous 
  forms 
  of 
  meat, 
  and 
  their 
  use 
  has, 
  therefore, 
  not 
  been 
  continued. 
  

   They 
  were 
  fed 
  in 
  the 
  form 
  of 
  a 
  pudding 
  composed 
  of 
  two 
  parts 
  blood 
  

   and 
  one 
  psbrt 
  flour 
  or 
  middlings, 
  cooked 
  carefully 
  to 
  avoid 
  burning, 
  

   and 
  the 
  mixture 
  was 
  then 
  passed 
  through 
  a 
  meat-chopper 
  and 
  ladled 
  

   out 
  with 
  a 
  spoon, 
  like 
  other 
  chopped 
  food. 
  

  

  The 
  growth 
  of 
  live 
  food 
  in 
  the 
  ponds 
  themselves 
  in 
  which 
  the 
  fish 
  are 
  

   maintained 
  has 
  been 
  the 
  subject 
  of 
  study. 
  Ponds 
  several 
  years 
  old 
  

   and 
  well 
  stocked 
  with 
  vegetation 
  were 
  at 
  one 
  time 
  devoted 
  to 
  these 
  

   experiments. 
  They 
  had 
  been 
  empty 
  during 
  the 
  preceding 
  winter, 
  and 
  

   in 
  the 
  spring 
  were 
  fertilized 
  with 
  various 
  sorts 
  of 
  animal 
  and 
  vegetable 
  

   refuse. 
  They 
  were 
  stocked 
  with 
  diflerent 
  species 
  of 
  Crustacea 
  native- 
  

   to 
  the 
  region, 
  including 
  shrimps 
  {Gammarus) 
  and 
  entomostraca, 
  of 
  the 
  

   genera 
  Daphnia^ 
  Ceriodaphnia, 
  Sida, 
  Cyclops, 
  Polyphemus, 
  etc., 
  which 
  

   were 
  systematically 
  collected 
  from 
  open 
  waters 
  by 
  nets 
  and 
  other 
  appa- 
  

   ratus 
  and 
  placed 
  in 
  the 
  ponds. 
  These 
  forms 
  all 
  multiplied 
  there, 
  some 
  

   of 
  them 
  enormously, 
  but 
  no 
  means 
  was 
  found 
  of 
  inducing 
  continuous 
  

   or 
  frequent 
  reproduction 
  of 
  them, 
  and 
  the 
  young 
  fish 
  soon 
  exhausted 
  

   the 
  supply. 
  

  

  In 
  serving 
  the 
  food 
  the 
  attendant 
  carries 
  it 
  with 
  the 
  left 
  hand 
  — 
  in 
  a 
  

   2-quart 
  dipper 
  if 
  chopped 
  meat, 
  in 
  a 
  larger 
  vessel 
  if 
  maggots 
  — 
  and, 
  

   dipping 
  it 
  out 
  with 
  a 
  large 
  spoon, 
  strews 
  it 
  the 
  whole 
  length 
  of 
  the 
  

   trough, 
  being 
  careful 
  to 
  put 
  the 
  greater 
  portion 
  at 
  the 
  head, 
  where 
  the 
  

   fish 
  nearly 
  always 
  congregate. 
  Finely 
  chopped 
  food, 
  for 
  very 
  young 
  

   fish, 
  is 
  slightly 
  thinned 
  with 
  water 
  before 
  feeding. 
  

  

  It 
  is 
  usual 
  to 
  feed 
  the 
  meat 
  raw 
  except 
  the 
  lights, 
  which 
  chop 
  better 
  

   if 
  boiled 
  first; 
  but 
  occasional 
  lots 
  of 
  meat, 
  on 
  the 
  point 
  of 
  becoming, 
  

   tainted, 
  are 
  boiled 
  to 
  save 
  them. 
  All 
  meats 
  fed 
  directly 
  to 
  the 
  fish 
  are 
  

   first 
  passed 
  through 
  a 
  chopping-machine. 
  To 
  fish 
  just 
  beginning 
  to 
  

   eat, 
  food 
  is 
  given 
  four 
  times 
  a 
  day, 
  or 
  in 
  some 
  cases 
  even 
  six 
  times, 
  but 
  

   as 
  the 
  season 
  progresses 
  the 
  number 
  of 
  rations 
  is 
  gradually 
  reduced 
  

   to 
  two 
  daily." 
  In 
  winter 
  such 
  fish 
  as 
  are 
  carried 
  through 
  are 
  fed 
  but 
  

   once 
  a 
  day. 
  

  

  CLEANING- 
  THE 
  TROTtgHS. 
  

  

  The 
  troughs 
  are 
  all 
  cleaned 
  daily. 
  When 
  the 
  hollow 
  plug 
  is 
  drawn 
  

   the 
  water 
  rushes 
  out 
  rapidly 
  and 
  carries 
  most 
  of 
  the 
  debris 
  against 
  the 
  

   screen. 
  The 
  fishes 
  are 
  excited, 
  and, 
  scurrying 
  about, 
  loosen 
  nearly 
  all 
  

   the 
  dirt 
  from 
  the 
  bottom; 
  what 
  will 
  not 
  otherwise 
  yield 
  is 
  started 
  with 
  

   a 
  brush, 
  but 
  after 
  the 
  first 
  few 
  weeks 
  the 
  brush 
  has 
  rarely 
  to 
  be 
  usedi 
  

  

  