﻿268 
  REPOKT 
  OF 
  COMMISSIONER 
  OF 
  FISH 
  AND 
  FISHERIES. 
  

  

  streaks 
  if 
  the 
  water 
  be 
  agitated, 
  and 
  witli 
  no 
  particles 
  distinguishable 
  

   by 
  the 
  naked 
  eye. 
  

  

  Another 
  test 
  is 
  to 
  spread 
  out 
  a 
  drop 
  of 
  the 
  genital 
  fluid, 
  mixed 
  with 
  

   a 
  drop 
  of 
  water, 
  in 
  a 
  thin 
  film 
  upon 
  a 
  piece 
  of 
  glass, 
  such 
  as 
  a 
  micro- 
  

   scope 
  slide. 
  If 
  the 
  specimen 
  be 
  a 
  female, 
  an 
  examination 
  with 
  a 
  strong 
  

   hand 
  lens 
  will 
  reveal 
  many 
  minute 
  pear-shaped 
  or 
  oval 
  bodies 
  or 
  eggs, 
  

   each 
  with 
  a 
  clear 
  spot, 
  the 
  nucleus 
  or 
  so-called 
  germinal 
  vesicle. 
  If 
  the 
  

   specimen 
  be 
  a 
  male, 
  the 
  film 
  can 
  not 
  be 
  resolved 
  into 
  distinguishable 
  

   particles 
  when 
  viewed 
  with 
  the 
  lens, 
  but 
  consists 
  of 
  a 
  milk-white 
  mass, 
  

   having 
  a 
  quivering 
  appearance 
  owing 
  to 
  the 
  effect 
  of 
  the 
  combined 
  

   movements 
  of 
  the 
  indistinguishable 
  spermatozoa. 
  

  

  The 
  histological 
  characters 
  which 
  distinguish 
  the 
  testes 
  and 
  ovary 
  

   are 
  considered 
  under 
  the 
  head 
  of 
  anatomy. 
  

  

  According 
  to 
  Professor 
  Schiedt, 
  an 
  hermaphroditic 
  oyster 
  occurs 
  on 
  

   our 
  northwest 
  coast, 
  the 
  specimens 
  examined 
  coming 
  from 
  the 
  State 
  of 
  

   Washington, 
  the 
  exact 
  locality 
  not 
  being 
  mentioned. 
  Sexually, 
  there- 
  

   fore, 
  this 
  species 
  resembles 
  the 
  common 
  oyster 
  of 
  Europe. 
  

  

  RIPENING 
  OF 
  THE 
  GENERATIVE 
  ORGANS. 
  

  

  In 
  spring, 
  when 
  the 
  water 
  begins 
  to 
  warm, 
  certain 
  changes 
  begin 
  to 
  

   manifest 
  themselves 
  in 
  the 
  generative 
  organs, 
  preparatory 
  to 
  the 
  act 
  

   of 
  spawning. 
  In 
  the 
  female 
  some 
  of 
  the 
  minute 
  eggs 
  in 
  the 
  ovaries 
  

   increase 
  in 
  size 
  and 
  become 
  loosened 
  in 
  the 
  follicles 
  or 
  little 
  pockets 
  of 
  

   tissue 
  in 
  which 
  they 
  have 
  undergone 
  their 
  early 
  development. 
  All 
  of 
  

   the 
  eggs 
  which 
  are 
  to 
  be 
  discharged 
  in 
  any 
  one 
  year 
  do 
  not 
  ripen 
  at 
  the 
  

   same 
  time, 
  so 
  that 
  the 
  spawning 
  of 
  each 
  individual 
  extends 
  over 
  a 
  

   greater 
  or 
  less 
  j^eriod. 
  An 
  examination 
  of 
  the 
  ovary 
  at 
  any 
  time 
  will 
  

   always 
  show 
  great 
  numbers 
  of 
  minute 
  immature 
  eggs, 
  most 
  of 
  these 
  

   being 
  ova 
  which 
  will 
  ripen 
  and 
  be 
  discharged 
  during 
  some 
  subsequent 
  

   year. 
  Other 
  changes, 
  which 
  it 
  is 
  not 
  necessary 
  to 
  mention 
  here, 
  take 
  

   place 
  in 
  the 
  eggs 
  and 
  tissues, 
  but 
  the 
  ultimate 
  result 
  is 
  that 
  the 
  ovary 
  

   becomes 
  enlarged 
  by 
  the 
  growth 
  of 
  the 
  ripening 
  eggs 
  and 
  the 
  latter 
  

   pass 
  into 
  the 
  oviducts, 
  which 
  stand 
  out 
  as 
  milky-white 
  and 
  much- 
  

   branched 
  vessels 
  on 
  each 
  side 
  of 
  the 
  body. 
  

  

  The 
  spermatozoa 
  develop 
  in 
  somewhat 
  the 
  same 
  manner, 
  but 
  the 
  

   generative 
  cells, 
  instead 
  of 
  developing 
  into 
  eggs, 
  undergo 
  rapid 
  divi- 
  

   sion, 
  each 
  into 
  a 
  number 
  of 
  minute 
  active 
  bodies, 
  which 
  pass 
  into 
  the 
  

   sperm 
  ducts 
  and 
  gorge 
  them 
  with 
  a 
  white 
  fluid, 
  the 
  milt, 
  m 
  general 
  

   naked-eye 
  appearance 
  closely 
  resembling 
  the 
  ovarian 
  fluid. 
  

  

  SPAWNING. 
  

  

  The 
  act 
  of 
  spawning 
  consists 
  m 
  the 
  discharge 
  of 
  the 
  ripe 
  genital 
  

   products 
  into 
  the 
  surrounding 
  water, 
  where 
  fertilization 
  is 
  left 
  to 
  chance. 
  

  

  The 
  genital 
  ducts, 
  one 
  on 
  each 
  side, 
  open 
  into 
  the 
  chambers 
  above 
  

   the 
  gills, 
  and 
  the 
  ova 
  in 
  the 
  one 
  sex 
  and 
  the 
  spermatozoa 
  in 
  the 
  other, 
  

   gradually 
  oozing 
  out 
  of 
  the 
  openings, 
  are 
  caught 
  up 
  by 
  the 
  currents 
  

   of 
  water 
  passing 
  through 
  the 
  gill-canals 
  and 
  expelled 
  from 
  the 
  body, 
  

  

  