﻿MANUAL 
  OF 
  FISH-CULTURE. 
  155 
  

  

  was 
  added 
  to 
  from 
  day 
  to 
  day 
  for 
  nearly 
  a 
  week, 
  when 
  it 
  was 
  brought 
  

   up 
  to 
  1.018, 
  or 
  the 
  same 
  specific 
  gravity 
  as 
  the 
  water 
  used 
  in 
  the 
  marine 
  

   aquaria. 
  At 
  the 
  time 
  these 
  were 
  placed 
  in 
  the 
  brackish 
  water 
  others 
  

   were 
  put 
  into 
  fresh-water 
  aquaria, 
  but 
  the 
  latter 
  died 
  within 
  three 
  

   days. 
  Those 
  in 
  salt 
  water 
  began 
  in 
  two 
  or 
  three 
  days 
  to 
  take 
  food, 
  

   consisting 
  of 
  chopped 
  oysters, 
  clams, 
  and 
  beef, 
  the 
  preference 
  being 
  

   for 
  oysters. 
  At 
  first 
  they 
  would 
  take 
  food 
  only 
  when 
  it 
  was 
  sinking, 
  

   later 
  they 
  began 
  taking 
  it 
  off' 
  plants 
  where 
  it 
  had 
  lodged, 
  and 
  finally 
  

   from 
  the 
  bottom. 
  Nearly 
  all 
  remained 
  healthy, 
  plump, 
  and 
  active 
  for 
  

   six 
  months, 
  some 
  living 
  until 
  about 
  midsummer. 
  

  

  For 
  ten 
  years 
  past 
  two 
  or 
  three 
  million 
  shad 
  fry 
  have 
  been 
  reared 
  

   annually 
  at 
  tlie 
  Fish 
  Ponds, 
  Washington, 
  D. 
  C. 
  A 
  G-acre 
  pond 
  is 
  used, 
  

   the 
  water 
  supply 
  being 
  taken 
  from 
  the 
  city 
  water-works. 
  The 
  dej)th 
  

   varies 
  from 
  2 
  to 
  3 
  feet, 
  and 
  throughout 
  the 
  whole 
  extent 
  there 
  is 
  a 
  dense 
  

   growth 
  of 
  water-plants, 
  among 
  which 
  crustacean 
  food 
  multiplies 
  — 
  new 
  

   supplies 
  being 
  brought 
  in 
  from 
  the 
  water-pipes. 
  Fingerling 
  shad 
  are 
  

   so 
  tender 
  that 
  the 
  numbers 
  annually 
  liberated 
  can 
  not 
  be 
  ascertained 
  ; 
  

   they 
  can 
  not 
  withstand 
  the 
  handling 
  consequent 
  upon 
  counting 
  them, 
  

   not 
  even 
  undergoing 
  transfer 
  in 
  dippers 
  of 
  water, 
  and 
  their 
  scales 
  drop 
  

   off" 
  on 
  being 
  touched 
  ; 
  consequently 
  at 
  high 
  tide 
  they 
  are 
  liberated 
  into 
  

   the 
  Potomac 
  through 
  a 
  sluice-gate 
  with 
  an 
  outlet 
  pipe 
  about 
  2 
  feet 
  in 
  

   diameter. 
  They 
  require 
  some 
  days 
  to 
  make 
  their 
  escape. 
  By 
  couserva 
  

   tive 
  estimate 
  50 
  to 
  60 
  per 
  cent 
  are 
  held 
  safely 
  until 
  about 
  October. 
  

  

  Rearing 
  has 
  been 
  experimentally 
  tested 
  at 
  Wytheville 
  and 
  Neosho 
  

   with 
  good 
  results. 
  At 
  Neosho 
  on 
  the 
  3d 
  of 
  June, 
  1892, 
  700,000 
  fry 
  were 
  

   received 
  from 
  Gloucester, 
  N. 
  J.; 
  their 
  growth 
  was 
  satisfactory. 
  In 
  

   l)reparing 
  for 
  their 
  release 
  the 
  hatchery 
  branch 
  was 
  cleared 
  of 
  shoals, 
  

   drifts, 
  and 
  aquatic 
  plants 
  for 
  three-quarters 
  of 
  a 
  mile, 
  and 
  early 
  in 
  

   November, 
  when 
  the 
  branch 
  was 
  swollen 
  with 
  rain 
  water, 
  200,000 
  

   G-months-old 
  fish 
  were 
  allowed 
  to 
  pass 
  through 
  open 
  gates; 
  they 
  were 
  

   some 
  hours 
  in 
  escaping, 
  in 
  a 
  continuous 
  silvery 
  mass. 
  These 
  were 
  the 
  

   first 
  fingerling 
  shad 
  planted 
  in 
  waters 
  tributary 
  to 
  the 
  Gulf 
  of 
  Mexico. 
  

  

  TRANSPORTATION. 
  

  

  Good, 
  healthy 
  fry 
  will 
  pass 
  from 
  the 
  jar 
  to 
  the 
  collector-tank 
  as 
  fast 
  

   as 
  hatched, 
  and 
  unless 
  too 
  thick 
  will 
  not 
  lie 
  on 
  the 
  bottom 
  of 
  the 
  tank, 
  

   although 
  they 
  sometimes 
  crowd 
  on 
  the 
  side 
  nearest 
  the 
  strongest 
  rays 
  

   of 
  light. 
  As 
  many 
  as 
  500,000 
  to 
  800,000 
  are 
  collected 
  in 
  each 
  tank. 
  

   In 
  transporting, 
  they 
  must 
  be 
  kept 
  in 
  vessels 
  with 
  smooth 
  surfaces, 
  

   preferably 
  tin-lined 
  cans. 
  Zinc 
  vessels 
  are 
  destructive, 
  and 
  galvanized 
  

   cans 
  are 
  not 
  recommended. 
  

  

  About 
  2,000 
  to 
  3,000 
  fry 
  are 
  put 
  to 
  a 
  gallon 
  of 
  water, 
  which 
  must 
  be 
  

   pure 
  enough 
  for 
  ordinary 
  drinking 
  purposes 
  and 
  well 
  aerated. 
  The 
  

   water 
  in 
  the 
  cans 
  must 
  be 
  kept 
  at 
  58° 
  to 
  G5°, 
  though 
  in 
  rivers 
  and 
  

   ponds 
  the 
  fry 
  endure 
  a 
  temperature 
  of 
  90° 
  F. 
  

  

  As 
  early 
  as 
  1874, 
  experiments 
  were 
  carried 
  on 
  to 
  retard 
  the 
  develo]) 
  

   ment 
  of 
  eggs, 
  in 
  order 
  to 
  provide 
  a 
  longer 
  period 
  between 
  the 
  delivery 
  

  

  