﻿414 
  REPORT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  The 
  early 
  stages 
  in 
  the 
  maturation 
  of 
  the 
  genital 
  glands 
  appear 
  to 
  

   progress 
  slowly. 
  There 
  is 
  a 
  gradual 
  increase 
  in 
  the 
  size 
  of 
  the 
  organs, 
  

   and 
  in 
  the 
  case 
  of 
  the 
  ovaries 
  this 
  is 
  accompanied 
  by 
  a 
  great 
  increase 
  

   in 
  the 
  size 
  of 
  the 
  individual 
  eggs. 
  After 
  they 
  have 
  reached 
  full 
  or 
  

   nearly 
  full 
  size 
  there 
  is 
  a 
  period 
  of 
  quiescence, 
  followed 
  by 
  a 
  rapid 
  

   completion 
  of 
  the 
  final 
  i)rocesses. 
  The 
  testes 
  become 
  soft 
  and 
  the 
  milt 
  

   will 
  flow 
  when 
  they 
  are 
  ruptured, 
  while 
  the 
  eggtii 
  become 
  clear 
  and 
  loose 
  

   in 
  the 
  cavity 
  of 
  the 
  ovary. 
  The 
  clearing 
  of 
  the 
  eggs 
  does 
  not 
  take 
  

   place 
  throughout 
  the 
  whole 
  ovary 
  at 
  once, 
  but 
  usually, 
  although 
  not 
  

   always, 
  begins 
  at 
  the 
  posterior 
  end 
  and 
  along 
  the 
  outer 
  side 
  next 
  to 
  the 
  

   body 
  wall; 
  it 
  then 
  i^rogresses 
  forward 
  and 
  inward 
  until 
  api)arently 
  

   the 
  whole 
  ovary 
  is 
  involved, 
  the 
  last 
  stages 
  being 
  the 
  loosening 
  of 
  the 
  

   eggs 
  in 
  the 
  follicles 
  and 
  their 
  dropping 
  into 
  the 
  lumen 
  of 
  the 
  organ 
  

   preceding 
  their 
  discharge 
  from 
  the 
  fish. 
  

  

  The 
  rapid 
  develoi)ment 
  of 
  the 
  genital 
  organs, 
  which, 
  as 
  before 
  stated, 
  

   when 
  ripe 
  constitute 
  about 
  one-fifth 
  of 
  the 
  total 
  weight 
  of 
  the 
  indi- 
  

   vidual, 
  makes 
  a 
  heavy 
  drain 
  upon 
  the 
  substance 
  and 
  energy 
  of 
  the 
  

   fish. 
  Any 
  fat 
  which 
  may 
  bave 
  been 
  stored 
  up 
  prior 
  to 
  this 
  period 
  

   tends 
  to 
  disappear, 
  its 
  substance 
  furnishing, 
  in 
  part, 
  the 
  material 
  and 
  

   energy 
  required 
  in 
  the 
  maturation 
  of 
  the 
  ova 
  and 
  spermatozoa. 
  This 
  

   calling 
  npon 
  the 
  reserve, 
  and 
  the 
  additional 
  circumstance 
  that 
  the 
  ripe 
  

   fish 
  take 
  but 
  little 
  or 
  no 
  food, 
  causes 
  the 
  spent 
  herring 
  to 
  be 
  poor 
  and 
  

   lean, 
  but 
  after 
  spawning 
  they 
  rapidly 
  fatten 
  if 
  an 
  abundant 
  food 
  supply 
  

   be 
  available. 
  

  

  It 
  appears 
  that 
  herring 
  8 
  inches 
  in 
  length 
  are 
  commonly 
  found 
  with 
  

   ripe 
  spawn 
  and 
  milt 
  upon 
  the 
  coast 
  of 
  Norway 
  and 
  Sweden, 
  but 
  there 
  

   is 
  a 
  wide 
  difference 
  of 
  opinion 
  concerning 
  the 
  age 
  of 
  such 
  fish, 
  the 
  esti- 
  

   mates 
  of 
  different 
  naturalists 
  varying 
  from 
  one 
  to 
  six 
  years. 
  Ljungman 
  

   estimates 
  their 
  age 
  at 
  three 
  years; 
  Huxley 
  thought 
  the 
  age 
  at 
  which 
  

   spawning 
  begins 
  to 
  be 
  not 
  more 
  than 
  sixteen 
  to 
  eighteen 
  months, 
  while 
  

   G. 
  O. 
  Sars 
  thinks 
  that 
  the 
  minimum 
  in 
  most 
  cases 
  is 
  five 
  or 
  six 
  years. 
  

  

  From 
  a 
  large 
  number 
  of 
  herring 
  examined 
  at 
  Eastport 
  in 
  1893 
  and 
  

   1895, 
  I 
  am 
  led 
  to 
  conclude 
  that 
  ripe 
  fish 
  under 
  9^ 
  inches, 
  measured 
  from 
  

   tip 
  of 
  snout 
  to 
  fork 
  of 
  tail, 
  are 
  very 
  rare, 
  and 
  that 
  usually 
  they 
  do 
  not 
  

   mature 
  genital 
  products 
  before 
  they 
  are 
  10 
  or 
  10^ 
  inches 
  long, 
  while 
  

   most 
  of 
  the 
  spawn 
  fish 
  observed 
  at 
  Grand 
  Manan 
  and 
  Machias, 
  as 
  well 
  

   as 
  those 
  brought 
  from 
  Moosabec 
  to 
  Eastport 
  in 
  1893 
  and 
  1895, 
  were 
  

   about 
  12 
  or 
  13 
  inches 
  long. 
  These 
  statements 
  apply 
  to 
  the 
  autumn 
  

   spawning 
  fish 
  only, 
  as 
  no 
  opportunity 
  was 
  had 
  of 
  exasmining 
  the 
  fish 
  of 
  

   the 
  spring 
  school, 
  although 
  the 
  fishermen 
  state 
  that 
  the 
  latter 
  are 
  good- 
  

   sized 
  fish. 
  I 
  believe 
  that 
  the 
  first 
  spawning 
  takes 
  place 
  when 
  the 
  fish 
  

   is 
  between 
  two 
  and 
  tliree 
  years 
  of 
  age. 
  

  

  The 
  period 
  of 
  incubation 
  of 
  the 
  eggs 
  varies 
  according 
  to 
  the 
  tempera- 
  

   ture, 
  cold 
  water 
  regarding 
  and 
  warmer 
  accelerating 
  the 
  period 
  required 
  

   fM^ 
  the 
  development 
  of 
  the 
  embryo. 
  From 
  experiments 
  made 
  by 
  the 
  

   United 
  States 
  Fish 
  Commission, 
  it 
  appears 
  that 
  upon 
  the 
  coast 
  of 
  

   Massachusetts 
  from 
  ten 
  to 
  twelve 
  days 
  elapse 
  between 
  fertilization 
  and 
  

  

  