﻿508 
  J. 
  BRETLAND 
  PARMER 
  AND 
  J. 
  E. 
  8. 
  MOORE. 
  

  

  is 
  connected 
  with 
  changes 
  in 
  the 
  nucleoli. 
  The 
  linin 
  frame- 
  

   work 
  becomes 
  more 
  and 
  more 
  clear, 
  but 
  at 
  first 
  it 
  is 
  impossible 
  

   to 
  make 
  out 
  in 
  it 
  anything 
  suggesting 
  a 
  continuous 
  thread. 
  

   Rather 
  it 
  appears 
  as 
  a 
  large 
  number 
  of 
  fibrils 
  irregularly 
  

   arranged 
  in 
  groups 
  (fig. 
  1). 
  Attempts 
  were 
  made, 
  though 
  

   without 
  decisive 
  results, 
  to 
  ascertain 
  Avhether 
  the 
  number 
  

   of 
  these 
  groups 
  bore 
  any 
  definite 
  relation 
  to 
  the 
  number 
  

   of 
  cliromosomes. 
  In 
  some 
  cases 
  there 
  appeared 
  to 
  be 
  such 
  

   a 
  correspondence. 
  The 
  outline 
  of 
  the 
  individual 
  linin 
  fila- 
  

   ments 
  is 
  irregular, 
  and 
  stainiug 
  droplets 
  of 
  a 
  chromatin-like 
  

   substance, 
  possibly 
  of 
  nucleolar 
  origiu, 
  are 
  often 
  found 
  

   adheriug 
  to 
  them. 
  Perhaps 
  this 
  substance 
  maybe 
  regai'ded 
  

   as 
  equivalent 
  to 
  the 
  " 
  basichromatin 
  " 
  of 
  some 
  authors.^ 
  The 
  

   general 
  appearance 
  exhibited 
  by 
  the 
  nucleus 
  at 
  this 
  stage 
  is 
  

   that 
  of 
  a 
  sphere 
  containing, 
  besides 
  the 
  more 
  or 
  less 
  numerous 
  

   nucleoli, 
  a 
  grumous 
  precipitate 
  which 
  tends 
  to 
  become 
  

   aggregated 
  in 
  delicate 
  fibrils. 
  

  

  From 
  these 
  fibrils 
  the 
  linin 
  spireme 
  arises. 
  It 
  appears, 
  in 
  

   uninjured 
  nuclei, 
  to 
  form 
  a 
  continuous 
  thread, 
  although 
  it 
  is 
  

   diflBcult, 
  owing 
  to 
  the 
  numerous 
  convolutions 
  of 
  the 
  skein, 
  to 
  be 
  

   quite 
  certain 
  of 
  this. 
  It 
  is 
  of 
  course 
  impossible, 
  save 
  from 
  the 
  

   continuity 
  of 
  stainable 
  substance, 
  to 
  form 
  any 
  valid 
  judgment 
  

   as 
  to 
  the 
  nature 
  of 
  the 
  spireme 
  as 
  to 
  whether 
  it 
  is 
  continuous 
  

   or 
  otherwise, 
  and 
  it 
  may 
  be 
  that 
  the 
  appearance 
  of 
  isolated 
  

   fibi'ils 
  in 
  the 
  previous 
  stage 
  is 
  really 
  due 
  to 
  lack 
  of 
  equidistance 
  

   in 
  the 
  arrangement 
  of 
  the 
  chromatin. 
  In 
  other 
  words, 
  it 
  

   may 
  be 
  that 
  a 
  continuous 
  thread 
  of 
  linin 
  does 
  really 
  exist 
  in 
  

   this 
  earlier 
  stage, 
  although 
  we 
  have 
  not 
  been 
  able 
  to 
  identify 
  

   it 
  as 
  such, 
  and 
  for 
  the 
  present 
  do 
  not 
  feel 
  disposed 
  to 
  

   assume 
  more 
  than 
  the 
  appearance 
  observed 
  seems 
  to 
  warrant. 
  

   Perhaps 
  the 
  matter 
  is 
  not 
  one 
  of 
  great 
  importance, 
  for 
  it 
  is 
  

   at 
  any 
  rate 
  certain 
  that 
  at 
  the 
  close 
  of 
  the 
  previous 
  di 
  aster 
  

   no 
  such 
  continuous 
  filament 
  was 
  present. 
  

  

  But 
  the 
  definite 
  spireme 
  thread 
  can 
  be 
  distinguished 
  very 
  

   cleai'ly 
  at 
  an 
  early 
  period 
  in 
  karyokinetic 
  activity, 
  certainly 
  

   long 
  before 
  the 
  spore 
  mother-cells 
  dissolve 
  their 
  union 
  with 
  

   * 
  Heidenhain, 
  ' 
  Ueber 
  Kern 
  and 
  Protoplasma,' 
  1893. 
  

  

  