﻿156 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  of 
  the 
  eggs 
  from 
  the 
  parent 
  fish 
  and 
  the 
  absorption 
  of 
  the 
  yolk 
  sac. 
  

   Eggs, 
  when 
  transported, 
  were 
  placed 
  on 
  trays 
  and 
  put 
  under 
  melting- 
  

   ice, 
  and 
  later 
  experiments 
  have 
  been 
  conducted 
  inside 
  refrigerator 
  

   boxes. 
  Pathological 
  changes 
  or 
  deformities 
  are 
  induced 
  in 
  the 
  embryos 
  

   when 
  subjected 
  to 
  too 
  low 
  a 
  temperature 
  or 
  when 
  held 
  long 
  enough 
  on 
  

   damp 
  tianuel 
  trays 
  (ordinary 
  air 
  temperatures) 
  to 
  hatch. 
  

  

  It 
  would 
  appear 
  that 
  55° 
  to 
  53° 
  is 
  the 
  lowest 
  temi^erature 
  in 
  which 
  

   ova 
  will 
  safely 
  undergo 
  their 
  normal 
  development 
  and 
  9 
  days 
  is 
  the 
  

   longest 
  period 
  of 
  incubation 
  attainable 
  at 
  that 
  temperature 
  — 
  time 
  suffi- 
  

   cient, 
  when 
  added 
  to 
  the 
  several 
  days 
  required 
  for 
  the 
  young 
  to 
  absorb 
  

   the 
  yolk-sac, 
  to 
  ship 
  them 
  to 
  Europe, 
  which 
  has 
  so 
  far 
  failed. 
  One 
  

   drawback 
  is 
  the 
  rapid 
  development 
  of 
  fungus, 
  which 
  grows 
  over 
  the 
  

   eggs, 
  i^enetrates 
  the 
  membranes, 
  and 
  kills 
  the 
  ova. 
  

  

  Ketardation 
  of 
  the 
  hatching 
  of 
  shad 
  eggs 
  has 
  not 
  been 
  turned 
  to 
  

   practical 
  account, 
  but 
  eggs 
  can 
  be 
  transported 
  hundreds 
  of 
  miles 
  on 
  

   trays, 
  large 
  numbers 
  being 
  moved 
  at 
  a 
  relatively 
  small 
  expense 
  com- 
  

   pared 
  with 
  the 
  same 
  number 
  of 
  fry. 
  

  

  Eggs 
  from 
  the 
  Potomac 
  Eiver 
  are 
  sent 
  to 
  Washington, 
  a 
  distance 
  of 
  

   12 
  miles, 
  by 
  steamer, 
  -and 
  nearly 
  a 
  mile 
  over 
  cobblestone 
  streets 
  in 
  

   Washington. 
  Formerly 
  they 
  were 
  put 
  on 
  the 
  trays 
  soon 
  after 
  being 
  

   taken, 
  but 
  in 
  April, 
  with 
  night 
  air-temi»erature 
  as 
  low 
  as 
  49°, 
  and 
  in 
  

   June, 
  with 
  the 
  relatively 
  high 
  temperature, 
  the 
  quality 
  was 
  bad 
  ; 
  they 
  

   did 
  well 
  between 
  00° 
  and 
  65°, 
  and 
  later 
  they 
  were 
  put 
  into 
  hatching- 
  

   vessels 
  and 
  kept 
  in 
  motion 
  12 
  hours, 
  when 
  they 
  became 
  hard, 
  and 
  went 
  

   forward 
  in 
  better 
  condition. 
  Since 
  1888 
  they 
  have 
  been 
  retained 
  in 
  

   hatching-jars 
  for 
  36 
  hours 
  preceding 
  transfer. 
  

  

  They 
  are 
  shii)ped 
  in 
  crates 
  of 
  20 
  shallow 
  trays, 
  the 
  frames 
  of 
  the 
  

   latter 
  being 
  of 
  wood 
  with 
  bottoms 
  of 
  wire 
  mesh 
  about 
  8 
  to 
  the 
  linear 
  

   inch. 
  Wood 
  and 
  wire 
  are 
  painted 
  with 
  asphaltum. 
  Each 
  tray 
  is 
  

   covered 
  with 
  cheese-cloth, 
  somewhat 
  overlapping 
  the 
  edges, 
  the 
  cloths 
  

   being 
  hemmed, 
  to 
  avoid 
  ravelings. 
  There 
  are 
  two 
  frames 
  of 
  wood, 
  

   connected 
  with 
  leather 
  straps; 
  one 
  the 
  base 
  and 
  the 
  other 
  the 
  cover 
  for 
  

   the 
  stack 
  of 
  trays. 
  The 
  trays, 
  after 
  being 
  filled 
  with 
  eggs, 
  are 
  wrapped 
  

   in 
  a 
  long, 
  cotton-goods 
  apron 
  and 
  strapped 
  together. 
  There 
  is 
  an 
  iron 
  

   handle 
  on 
  the 
  top 
  frame, 
  and 
  the 
  lowermost 
  tray 
  is 
  put 
  down 
  empty 
  

   with 
  the 
  wire 
  surface 
  upward. 
  Then 
  follow 
  the 
  trays 
  containing 
  eggs, 
  

   the 
  uppermost 
  one 
  being 
  put 
  on 
  empty 
  with 
  the 
  wire 
  surface 
  up. 
  The 
  

   top 
  and 
  bottom 
  trays 
  are 
  merely 
  to 
  protect 
  the 
  others. 
  

  

  The 
  greater 
  iDart 
  of 
  the 
  water 
  above 
  the 
  eggs 
  is 
  poured 
  off 
  from 
  the 
  

   jars 
  and 
  the 
  remainder 
  poured 
  into 
  tin 
  jians 
  along 
  with 
  the 
  eggs. 
  

   The 
  cloths, 
  after 
  soaking 
  in 
  water, 
  are 
  arranged 
  one 
  by 
  one 
  on 
  the 
  

   trays 
  and 
  tucked 
  closely 
  into 
  the 
  four 
  corners. 
  The 
  trays 
  are 
  stacked 
  

   up 
  and 
  eggs 
  poured 
  evenly 
  over 
  the 
  surface 
  of 
  the 
  top 
  one 
  with 
  a 
  

   large 
  dipper, 
  and 
  each 
  tray, 
  when 
  filled, 
  is 
  put 
  on 
  the 
  crate 
  base. 
  The 
  

   surplus 
  water 
  drains 
  away 
  to 
  the 
  manipulating 
  table. 
  Tray 
  cloths 
  of 
  

   material 
  too 
  closely 
  woven 
  to 
  let 
  the 
  water 
  through 
  are 
  unsuitable. 
  

   The 
  eggs 
  are 
  bailed 
  up 
  in 
  dippers 
  with 
  the 
  water 
  that 
  they 
  are 
  in, 
  and 
  

  

  