﻿61 
  

  

  The 
  spermatozoa 
  or 
  male 
  elements 
  are 
  very 
  numerous 
  in 
  

   the 
  milt, 
  and 
  present 
  an 
  appearance 
  very 
  much 
  resembling 
  

   grains 
  of 
  wheat, 
  Fig, 
  6, 
  PI. 
  I, 
  rolling 
  and 
  jerking 
  across 
  

   the 
  field 
  of 
  the 
  microscope. 
  In 
  some 
  of 
  the 
  spermatozoa 
  I 
  

   discovered 
  a 
  very 
  slight 
  prolongation 
  at 
  one 
  end, 
  bat 
  other 
  

   than 
  this, 
  could 
  see 
  no 
  indication, 
  cither 
  Avhen 
  in 
  motion 
  or 
  

   still, 
  of 
  any 
  tail, 
  or 
  long, 
  slender, 
  filamentous 
  appendage 
  such 
  

   as 
  is 
  found 
  in 
  all 
  other 
  vertebrate 
  spermatozoa, 
  so 
  far 
  as 
  my 
  

   knowledge 
  extends. 
  The 
  spermatozoa 
  are 
  very 
  small, 
  how- 
  

   ever_, 
  and 
  as 
  I 
  had 
  no 
  means 
  of 
  viewing 
  them 
  with 
  greater 
  

   magnitude 
  than 
  950 
  diameters 
  ; 
  and 
  as 
  they 
  then 
  appeared 
  

   mere 
  specks 
  upon 
  the 
  field, 
  this 
  observation 
  in 
  regard 
  to 
  the 
  

   tail 
  is 
  far 
  from 
  reliable. 
  How 
  and 
  where 
  the 
  spermatozoa 
  

   pass 
  through 
  the 
  vitelline 
  membrane 
  into 
  the 
  ovum, 
  and 
  

   impregnate 
  it, 
  has 
  long 
  been 
  a 
  mooted 
  question. 
  That 
  in 
  

   this 
  species 
  they 
  pass 
  in 
  through 
  the 
  opening 
  in 
  the 
  micro- 
  

   pyle, 
  however, 
  and 
  are 
  drawn 
  in 
  with 
  the 
  water 
  whicli 
  tlie 
  

   ovum 
  absorbs, 
  cannot, 
  I 
  think, 
  be 
  questioned. 
  

  

  At 
  least 
  this 
  much 
  is 
  known, 
  that 
  if 
  the 
  dry 
  method 
  of 
  

   milting 
  the 
  spawn 
  is 
  adopted 
  : 
  that 
  is, 
  putting 
  the 
  milt 
  and 
  

   spawn 
  together 
  before 
  any, 
  or 
  when 
  very 
  little 
  water 
  has 
  

   been 
  i)laced 
  with 
  the 
  spawn, 
  and 
  afterwards 
  placing 
  them 
  

   in 
  water 
  and 
  shaking 
  together 
  gently^ 
  the 
  proportion 
  of 
  eggs 
  

   which 
  fail 
  to 
  be 
  impregnated, 
  or 
  to 
  do 
  well, 
  is 
  very 
  small 
  

   indeed 
  ; 
  but 
  if 
  the 
  spawn 
  be 
  allowed 
  to 
  remain 
  in 
  water 
  for 
  

   even 
  a 
  vei-y 
  sliort 
  time 
  before 
  the 
  milt 
  is 
  added, 
  in 
  fact, 
  until 
  

   by 
  absorption 
  the 
  micropyle 
  lias 
  become 
  obliterated, 
  the 
  pro- 
  

   portion 
  of 
  eggs 
  which 
  turn 
  out 
  unimpregnated 
  and 
  bad 
  is 
  

   very 
  large 
  indeed. 
  To 
  test 
  the 
  question 
  as 
  to 
  whether 
  s^ier- 
  

   matozoa 
  were 
  actually 
  taken 
  into 
  the 
  ovum 
  during 
  this 
  season 
  

   of 
  water 
  absorption, 
  I 
  took 
  a 
  Smelt 
  egg 
  whicli 
  had 
  had 
  milt 
  

   shed 
  over 
  it, 
  and 
  as 
  soon 
  as 
  it 
  had 
  ceased 
  absorbing 
  water, 
  

   or 
  as 
  soon 
  as 
  it 
  was 
  apparently 
  full 
  of 
  water, 
  carefully 
  

   removed 
  the 
  mucous 
  and 
  washed 
  it 
  in 
  six 
  waters, 
  so 
  as 
  to 
  

   remove 
  any 
  spermatozoa 
  which 
  might 
  be 
  upon 
  the 
  outside. 
  

   I 
  then 
  took 
  off 
  the 
  vitelline 
  membrane, 
  and 
  allowed 
  the 
  yolk 
  

  

  