﻿208 
  Stork: 
  Studies 
  in" 
  the 
  genus 
  Taraxacum 
  

  

  These 
  thickened 
  parts 
  soon 
  separate 
  from 
  one 
  another 
  (Figs. 
  

   5 
  and 
  6) 
  and 
  are 
  presently 
  seen 
  as 
  irregular 
  isodiametrlc 
  chromo- 
  

  

  m 
  

  

  somes 
  distributed 
  throughout 
  the 
  nuclear 
  cavity 
  (Figs. 
  7-9). 
  

   At 
  this 
  stage 
  counts 
  are 
  possible 
  in 
  thick 
  optical 
  sections. 
  These 
  

   counts 
  vary 
  from 
  26 
  to 
  30. 
  No 
  bodies 
  are 
  here 
  observable 
  that 
  

  

  gradually 
  

  

  Juel 
  

  

  — 
  *— 
  ^ 
  — 
  W 
  - 
  - 
  ^ 
  — 
  ^ 
  ^ 
  ^^ 
  

  

  this 
  elongation, 
  the 
  chromosomes 
  undergo 
  the 
  remarkable 
  change 
  

   that 
  Juel 
  has 
  described 
  for 
  T. 
  vulgare, 
  stating 
  that 
  it 
  is 
  a 
  departure 
  

   from 
  all 
  normal 
  rules. 
  This 
  change 
  consists 
  in 
  an 
  elongation 
  

   again 
  of 
  the 
  chromosomes 
  into 
  irregular 
  rod-shaped 
  forms 
  (FiGS. 
  

   10 
  and 
  II, 
  the 
  latter 
  from 
  a 
  thin 
  section.) 
  These 
  might 
  be 
  sup- 
  

   posed 
  to 
  belong 
  to 
  earlier 
  stages, 
  like 
  those 
  shown 
  in 
  Figs. 
  5 
  and 
  6, 
  

   but 
  the 
  nature 
  of 
  the 
  nucellus 
  and 
  the 
  elongated 
  form 
  of 
  the 
  

   nucleus 
  indicate 
  that 
  without 
  a 
  doubt 
  this 
  is 
  a 
  secondary 
  elon- 
  

   gation 
  of 
  the 
  chromosomes 
  after 
  they 
  had 
  once 
  assumed 
  a 
  more 
  

   or^ 
  less 
  isodiametric 
  form. 
  The 
  chromosomes 
  here 
  cannot 
  be 
  

   said 
  to 
  be 
  in 
  pairs 
  except 
  in 
  so 
  far 
  as 
  is 
  brought 
  about 
  by 
  chance, 
  

   contrary 
  to 
  what 
  Osawa 
  reports 
  for 
  T. 
  albidum. 
  Nor 
  does 
  It 
  

   seem 
  possible 
  that 
  a 
  splitting 
  of 
  the 
  chromosomes 
  here 
  takes 
  place, 
  

   for 
  there 
  are 
  certainly 
  not 
  upwards 
  of 
  60 
  chromosomes 
  In 
  the 
  

   nucleus 
  at 
  this 
  time. 
  

  

  At 
  this 
  point 
  the 
  nucleus 
  has 
  become 
  so 
  much 
  elongated 
  that 
  

   the 
  larger 
  dimension 
  may 
  be 
  five 
  times 
  as 
  great 
  as 
  the 
  shorter 
  

   (Fig. 
  12). 
  The 
  chromosomes 
  again 
  return 
  to 
  an 
  Isodiametric 
  

   form 
  and 
  appear 
  to 
  be 
  smaller 
  and 
  possibly 
  denser 
  bodies 
  than 
  

   when 
  they 
  first 
  assumed 
  this 
  form. 
  In 
  the 
  preparation 
  from 
  

   which 
  Fig. 
  12 
  is 
  drawn 
  31 
  chromosomes 
  can 
  be 
  distinguished, 
  

   though 
  not 
  with 
  certainty. 
  At 
  this 
  point 
  the 
  nucleolus 
  and 
  the 
  

   nuclear 
  membrane 
  disappear, 
  and 
  one 
  sees 
  the 
  spindle 
  fibers 
  make 
  

   their 
  appearance. 
  The 
  spindle 
  is 
  always 
  regularly 
  bipolar 
  and 
  in 
  

   some 
  cases 
  is 
  observed 
  to 
  lie 
  at 
  a 
  considerable 
  angle 
  In 
  the 
  cell 
  

   (Fig. 
  16). 
  The 
  wall 
  between 
  the 
  resulting 
  daughter 
  cells 
  is 
  often 
  

   also 
  more 
  or 
  less 
  oblique 
  but 
  never 
  to 
  so 
  great 
  a 
  degree 
  as 
  was 
  

   observed 
  in 
  the 
  case 
  of 
  the 
  spindle. 
  Whether 
  an 
  abnormal 
  shifting 
  

   of 
  the 
  spindle 
  was 
  produced 
  in 
  some 
  cases 
  by 
  fixation 
  or 
  other 
  

   manipulation 
  or 
  whether 
  the 
  wall 
  has 
  a 
  tendency 
  to 
  form 
  in 
  a 
  

   position 
  more 
  nearly 
  at 
  right 
  angles 
  to 
  the 
  long 
  axis 
  of 
  the 
  cell 
  is 
  

   not 
  known. 
  The 
  chromosomes 
  are 
  at 
  first 
  loosely 
  scattered 
  

  

  