﻿62 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  except 
  to 
  rub 
  the 
  debris 
  through 
  the 
  outlet 
  screen. 
  Owing 
  to 
  the 
  incli- 
  

   nation 
  of 
  the 
  trough, 
  the 
  water 
  recedes 
  from 
  the 
  upper 
  end 
  until 
  the 
  

   lishes 
  lying 
  there 
  are 
  almost 
  wholly 
  out 
  of 
  water, 
  but, 
  although 
  they 
  are 
  

   left 
  in 
  that 
  position 
  sometimes 
  for 
  10 
  or 
  15 
  minutes, 
  no 
  harm 
  has 
  ever 
  

   been 
  known 
  to 
  result. 
  

  

  TRANSPORTATION 
  AND 
  LIBERATION 
  OF 
  YOUNO 
  SALMON. 
  

  

  The 
  salmon 
  produced 
  at 
  the 
  station 
  have, 
  with 
  few 
  exceptions, 
  been 
  

   liberated 
  in 
  the 
  Penobscot 
  Eiver 
  or 
  its 
  tributaries, 
  and 
  more 
  than 
  90 
  

   per 
  cent 
  of 
  them 
  in 
  small 
  tributaries 
  within 
  10 
  miles 
  of 
  the 
  station. 
  

   They 
  have 
  been 
  spread 
  about 
  in 
  streams 
  and 
  lakes, 
  at 
  all 
  accessible 
  

   points. 
  They 
  are 
  transferred 
  in 
  tin 
  cans, 
  holding 
  about 
  8 
  gallons, 
  with 
  

   an 
  extreme 
  height, 
  including 
  neck, 
  of 
  17 
  or 
  18 
  inches, 
  and 
  a 
  body 
  15^ 
  

   inches 
  in 
  diameter 
  and 
  10 
  inches 
  deep, 
  making 
  a 
  very 
  broad 
  and 
  low 
  

   can, 
  well 
  adapted 
  to 
  the 
  use 
  to 
  which 
  it 
  is 
  put. 
  Its 
  great 
  width 
  favors 
  

   aeration 
  at 
  the 
  surface, 
  and 
  a 
  good 
  deal 
  of 
  dashing 
  about 
  of 
  the 
  water 
  

   when 
  on 
  the 
  road. 
  The 
  cans 
  are 
  filled 
  to 
  within 
  about 
  an 
  inch 
  from 
  the 
  

   shoulder, 
  giving 
  opportunity 
  for 
  the 
  water 
  to 
  swash 
  about 
  and 
  aerate 
  

   itself. 
  Into 
  such 
  a 
  can 
  are 
  put 
  from 
  200 
  to 
  400 
  Atlantic 
  salmon 
  seven 
  

   months 
  old, 
  more 
  or 
  less, 
  according 
  to 
  the 
  size 
  of 
  the 
  fish, 
  the 
  tempera- 
  

   ture 
  of 
  the 
  air, 
  and 
  the 
  weather. 
  The 
  ordinary 
  load 
  is 
  about 
  300 
  when 
  

   the 
  temperature 
  of 
  the 
  water 
  is 
  52° 
  to 
  51° 
  F., 
  making 
  37 
  fish 
  per 
  gallon. 
  

   Such 
  loads 
  are 
  entirely 
  safe 
  for 
  the 
  conditions 
  attending 
  the 
  work. 
  

   The 
  motion 
  of 
  the 
  wagon 
  in 
  which 
  they 
  are 
  carried 
  keeps 
  up 
  the 
  aera- 
  

   tion 
  of 
  the 
  water, 
  so 
  that 
  the 
  fish 
  can 
  not 
  exhaust 
  the 
  air. 
  Should 
  the 
  

   cans 
  stand 
  still 
  a 
  very 
  long 
  time 
  aeration 
  is 
  effected 
  by 
  a 
  force-pump 
  

   which 
  draws 
  the 
  water 
  from 
  the 
  can 
  and 
  returns 
  it 
  through 
  a 
  tube 
  so 
  

   that 
  it 
  strikes 
  upon 
  a 
  deflector 
  by 
  which 
  it 
  is 
  broken 
  and 
  scattered 
  in 
  

   spray. 
  The 
  suction 
  hose 
  is 
  covered 
  with 
  a 
  roomy 
  wire 
  strainer, 
  so 
  that 
  

   the 
  fish 
  are 
  not 
  drawn 
  in. 
  

  

  DISEASES. 
  

  

  Salmon 
  in 
  all 
  their 
  stages 
  of 
  growth 
  are 
  subject 
  to 
  a 
  variety 
  of 
  dis- 
  

   eases. 
  White 
  spots 
  sometimes 
  occur 
  on 
  the 
  eggs 
  attached 
  to 
  the 
  shell, 
  

   but 
  have 
  no 
  hold 
  on 
  the 
  embryos, 
  so 
  that 
  when 
  the 
  shell 
  is 
  torn 
  off 
  the 
  

   white 
  spot 
  is 
  seen 
  as 
  a 
  cluster 
  of 
  globular 
  white 
  masses 
  on 
  its 
  inner 
  

   surface. 
  These 
  appear 
  to 
  be 
  vegetable 
  parasites, 
  perhaps 
  fungoid 
  in 
  

   their 
  relations, 
  and 
  are 
  never 
  seriously 
  abundant. 
  Other 
  white 
  spots 
  

   are 
  connected 
  with 
  the 
  yolk-sac 
  itself. 
  These 
  are 
  more- 
  serious, 
  but 
  

   while 
  they 
  result 
  in 
  the 
  death 
  of 
  many 
  embryos, 
  they 
  are 
  by 
  no 
  means 
  

   always 
  fatal. 
  In 
  1896 
  there 
  were 
  hatched 
  at 
  the 
  station 
  some 
  rainbow 
  

   trout 
  that 
  were 
  badly 
  spotted 
  on 
  the 
  sac. 
  A 
  portion 
  of 
  the 
  fry 
  were 
  

   divided 
  into 
  three 
  lots 
  for 
  experiment: 
  {a) 
  Without 
  spots 
  j 
  (6) 
  moder- 
  

   ately 
  spotted; 
  (c) 
  badly 
  spotted. 
  They 
  were 
  kept 
  separate 
  through 
  the 
  

   season, 
  and 
  a 
  fair 
  percentage 
  survived, 
  as 
  follows: 
  Of 
  lot 
  a, 
  55 
  per 
  

   cent; 
  of 
  lot 
  b, 
  59 
  per 
  cent; 
  of 
  lot 
  c, 
  43 
  per 
  cent. 
  In 
  the 
  fall 
  they 
  were 
  

  

  