﻿17 
  

  

  Another 
  female 
  may 
  now 
  be 
  cut 
  up, 
  and 
  the 
  eggs 
  may 
  be 
  

   added 
  to 
  the 
  contents 
  of 
  the 
  same 
  beaker, 
  but 
  if 
  the 
  females 
  

   are 
  large, 
  and 
  yield 
  many 
  eggs, 
  it 
  is 
  not 
  best 
  to 
  use 
  more 
  than 
  

   one, 
  for 
  although 
  there 
  are 
  enough 
  male 
  cells 
  to 
  fertilize 
  a 
  

   very 
  jrreat 
  number 
  of 
  C";2;s, 
  the 
  e^gs 
  arc 
  heavier 
  than 
  water 
  

   and 
  soon 
  sink 
  to 
  the 
  bottom, 
  and 
  if 
  they 
  form 
  a 
  very 
  thick 
  

   layer, 
  only 
  those 
  which 
  lie 
  near 
  the 
  surface 
  have 
  room 
  to 
  

   develop. 
  

  

  The 
  beaker 
  should 
  now 
  be 
  allowed 
  to 
  stand 
  for 
  aboiit 
  ten 
  

   minutes, 
  and 
  in 
  the 
  meantime 
  some 
  of 
  the 
  eggs 
  maybe 
  picked 
  

   out 
  with 
  a 
  dipping 
  tube 
  for 
  examination 
  under 
  the 
  micro- 
  

   scope. 
  In 
  using 
  the 
  dipping 
  tube, 
  cover 
  the 
  large 
  end 
  with 
  

   the 
  tip 
  of 
  the 
  finger, 
  and 
  run 
  the 
  small 
  end 
  down 
  close 
  to 
  

   the 
  bottom 
  of 
  the 
  beaker, 
  and 
  then 
  take 
  the 
  finger 
  off 
  the 
  

   top, 
  and 
  as 
  the 
  water 
  runs 
  in 
  at 
  the 
  bottom 
  it 
  will 
  carry 
  

   some 
  of 
  the 
  eggs 
  with 
  it. 
  "When 
  the 
  tube 
  is 
  filled, 
  place 
  the 
  

   finger 
  on 
  the 
  top 
  again, 
  and 
  draw 
  it 
  out 
  of 
  the 
  water, 
  and, 
  

   holding 
  it 
  perpendicularly 
  on 
  the 
  centre 
  of 
  a 
  glass 
  slide, 
  and 
  

   taking 
  the 
  finger 
  off 
  the 
  top, 
  allow 
  a 
  good 
  sized 
  drop 
  to 
  run 
  

   out 
  into 
  the 
  slide. 
  

  

  If 
  things 
  are 
  working 
  properly, 
  each 
  a^^ 
  should 
  now 
  have 
  

   a 
  number 
  of 
  male 
  cells 
  attached 
  by 
  their 
  heads 
  to 
  its 
  outer 
  

   surface, 
  with 
  their 
  tails 
  radiating 
  from 
  it 
  in 
  all 
  directions, 
  a& 
  

   shown 
  in 
  Figure 
  51. 
  

  

  It 
  is 
  not 
  necessary 
  that 
  more 
  than 
  one 
  male 
  cell 
  should 
  

   fasten 
  onto 
  each 
  Q'^'g^ 
  but 
  they 
  usually 
  cover 
  them 
  in 
  such 
  

   numbers 
  that 
  the 
  lashing 
  of 
  their 
  tails 
  causes 
  the 
  eggs 
  to 
  ro- 
  

   tate 
  and 
  move 
  through 
  the 
  water. 
  

  

  As 
  soon 
  as 
  all 
  the 
  eggs 
  have 
  male 
  cells 
  attached 
  to 
  them, 
  it 
  

   is 
  necessary 
  to 
  get 
  rid 
  of 
  the 
  superfluous 
  male 
  fluid, 
  for 
  it 
  

   would 
  soon 
  decay 
  and 
  pollute 
  the 
  water 
  if 
  it 
  were 
  allowed 
  to 
  

   remain, 
  and 
  if 
  it 
  is 
  not 
  drawn 
  off 
  from 
  the 
  eggs 
  while 
  ^they 
  

   are 
  at 
  the 
  bottom, 
  it 
  is 
  almost 
  impossible 
  to 
  remove 
  it 
  after 
  

   the 
  embryos 
  have 
  begun 
  to 
  swim, 
  without 
  loosing 
  them 
  as 
  well. 
  

  

  After 
  a 
  final 
  stirring, 
  the 
  beaker 
  should 
  be 
  allowed 
  to 
  stand 
  

   for 
  about 
  five 
  minutes, 
  to 
  allow 
  the 
  eggs 
  to 
  settle 
  to 
  the 
  bot- 
  

   tom, 
  and 
  the 
  fluid 
  above 
  them 
  should 
  then 
  be 
  drawn 
  off 
  

  

  