﻿MATURATION, 
  ETC., 
  OF 
  THE 
  EGG 
  OF 
  THE 
  AXOLOTI.. 
  417 
  

  

  slightly 
  flattened^ 
  rounded 
  mass, 
  tbongli 
  much 
  less 
  flattened 
  

   and 
  much 
  smaller 
  than 
  the 
  first 
  polar 
  body. 
  Like 
  the 
  latter 
  

   it 
  contains 
  some 
  pigment 
  and 
  yolk-granules. 
  The 
  narrow 
  stalk 
  

   by 
  which 
  it 
  is 
  connected 
  to 
  the 
  egg 
  contains 
  the 
  remains 
  of 
  

   the 
  spindle 
  fibres, 
  but 
  I 
  have 
  not 
  observed 
  any 
  thickenings 
  of 
  

   these 
  which 
  could 
  be 
  identified 
  as 
  '^Zwischenkorper." 
  The 
  

   chromosomes 
  retain 
  for 
  a 
  time 
  the 
  arrangement 
  described 
  in 
  

   the 
  last 
  stagv. 
  

  

  The 
  second 
  polar 
  body 
  is 
  formed 
  below 
  or 
  near 
  the 
  de- 
  

   pression 
  in 
  which 
  the 
  first 
  is 
  lodged. 
  It 
  protrudes 
  a 
  little 
  

   above 
  the 
  surface 
  of 
  the 
  egg; 
  the 
  vitelline 
  membrane 
  is 
  

   correspondingly 
  pushed 
  out. 
  

  

  3. 
  Further 
  history 
  of 
  the 
  polar 
  bodies. 
  

  

  In 
  the 
  first 
  polar 
  body 
  the 
  V-shaped 
  chromosomes 
  are 
  

   united 
  in 
  pairs 
  by 
  their 
  apices. 
  At 
  first 
  they 
  are 
  closely 
  

   grouped 
  togethei', 
  but 
  later 
  they 
  become 
  scattered, 
  and 
  each 
  

   pair 
  assumes 
  a 
  cruciform 
  shape 
  (fig. 
  9). 
  It 
  is 
  now 
  impossible 
  

   to 
  decide 
  which 
  of 
  the 
  four 
  arms 
  of 
  the 
  cross 
  belong 
  to 
  which 
  

   of 
  the 
  two 
  constituent 
  chromosomes, 
  for 
  all 
  four 
  arms 
  are 
  

   equally 
  separated 
  by 
  constrictions 
  from 
  one 
  another 
  at 
  the 
  

   point 
  of 
  union. 
  The 
  surface 
  of 
  the 
  chromosomes 
  is 
  produced 
  

   at 
  intervals 
  into 
  little 
  tooth-like 
  projections. 
  

  

  In 
  one 
  case 
  only 
  have 
  I 
  observed 
  the 
  reconstitution 
  of 
  a 
  

   nucleus 
  in 
  the 
  first 
  polar 
  body 
  (fig. 
  10). 
  The 
  chromosomes 
  

   are 
  still 
  distinct 
  and 
  still 
  in 
  pairs, 
  but 
  they 
  lie 
  in 
  a 
  circum- 
  

   scribed 
  oval 
  area 
  which 
  seems 
  to 
  contain 
  an 
  achromatic 
  

   reticulum, 
  staining 
  dissimilarly^ 
  to 
  the 
  cytoplasm. 
  I 
  ought 
  

   to 
  say, 
  perhaps, 
  that 
  there 
  is 
  no 
  doubt 
  that 
  this 
  is 
  a 
  first 
  and 
  

   not 
  a 
  second 
  polar 
  body, 
  for 
  a 
  second 
  polar 
  spindle 
  is 
  present 
  

   in 
  the 
  same 
  egg. 
  At 
  the 
  same 
  time 
  it 
  is 
  possible 
  that 
  the 
  

   cell 
  just 
  described 
  is 
  one 
  of 
  the 
  two 
  products 
  of 
  the 
  division 
  

   of 
  the 
  first 
  polar 
  body 
  ; 
  its 
  small 
  size 
  is 
  in 
  favour 
  of 
  this 
  

   view. 
  Fick 
  saw 
  one 
  case 
  of 
  such 
  division. 
  

  

  The 
  first 
  polar 
  body 
  always 
  contains 
  some 
  pigment 
  and 
  

   yolk-granules 
  ; 
  the 
  latter 
  tend 
  to 
  become 
  aggregated 
  into 
  

  

  