﻿Occurrence 
  of 
  Multinucleate 
  Cells 
  ire 
  Vegetative 
  Tissues. 
  13 
  

  

  Schurhoff 
  came 
  to 
  our 
  notice. 
  This 
  will 
  necessitate 
  a 
  somewhat 
  fuller 
  

   treatment 
  of 
  this 
  plant 
  than 
  we 
  anticipated, 
  or 
  than 
  could 
  be 
  incorporated 
  

   in 
  the 
  present 
  account. 
  We 
  propose, 
  therefore, 
  to 
  give 
  here 
  only 
  the 
  fore- 
  

   going 
  brief 
  reference 
  to 
  our 
  results 
  and 
  to 
  reserve 
  the 
  description 
  of 
  further 
  

   details, 
  together 
  with 
  a 
  discussion 
  of 
  Schurhoff 
  s 
  work, 
  for 
  a 
  separate 
  com- 
  

   munication. 
  

  

  The 
  Significance 
  of 
  the 
  Multinucleate 
  Phase. 
  

  

  In 
  the 
  foregoing 
  pages 
  we 
  have 
  called 
  attention 
  to 
  a 
  long 
  list 
  of 
  species 
  

   in 
  which 
  multinucleate 
  cells 
  occur, 
  not 
  as 
  a 
  chance 
  phenomenon, 
  but 
  as 
  a 
  

   normal 
  and 
  definite 
  stage 
  in 
  the 
  development 
  of 
  their 
  parenchymatous 
  tissues. 
  

   We 
  may 
  add 
  that 
  not 
  a 
  single 
  species 
  of 
  flowering 
  plant 
  has 
  been 
  met 
  with 
  

   in 
  our 
  work 
  in 
  which, 
  after 
  a 
  careful 
  examination, 
  multinucleate 
  cells 
  have 
  

   not 
  been 
  found 
  to 
  occur 
  to 
  a 
  greater 
  or 
  less 
  extent. 
  We 
  therefore 
  

   feel 
  that 
  we 
  are 
  justified 
  in 
  concluding 
  that 
  the 
  occurrence 
  of 
  a 
  multi- 
  

   nucleate 
  phase 
  is 
  a 
  normal 
  feature 
  in 
  the 
  growth 
  of 
  the 
  majority 
  of 
  the 
  

   higher 
  plants. 
  It 
  is 
  a 
  phase 
  which 
  in 
  general 
  succeeds 
  the 
  meristematic 
  

   activity 
  of 
  the 
  cells, 
  and 
  precedes 
  their 
  period 
  of 
  maximum 
  growth. 
  The 
  

   phase 
  may 
  endure 
  throughout 
  the 
  whole 
  period 
  of 
  growth, 
  and, 
  indeed, 
  

   traces 
  of 
  it 
  may 
  be 
  found 
  in 
  quite 
  old 
  tissues, 
  or 
  it 
  may 
  give 
  place 
  to 
  a 
  

   uninucleate 
  condition 
  at 
  an 
  extremely 
  early 
  stage. 
  From 
  the 
  point 
  

   of 
  view 
  of 
  the 
  development 
  of 
  the 
  individual 
  cell, 
  the 
  multinucleate 
  phase 
  

   may 
  be 
  regarded 
  as 
  a 
  stage 
  at 
  which 
  the 
  cytoplasm 
  has 
  either 
  temporarily 
  

   or 
  permanently 
  lost 
  its 
  ability 
  to 
  divide, 
  whilst 
  this 
  power 
  is 
  still 
  

   retained 
  by 
  the 
  nucleus. 
  A 
  number 
  of 
  cases 
  are 
  already 
  known, 
  both 
  in 
  

   zoological 
  and 
  botanical 
  literature, 
  in 
  which 
  the 
  cytoplasm 
  and 
  nucleus 
  of 
  a 
  

   cell 
  are 
  unequally 
  affected 
  by 
  various 
  agencies- 
  which 
  exert 
  an 
  influence 
  

   upon 
  the 
  course 
  of 
  a 
  mitotic 
  division. 
  Neruec's* 
  well-known 
  work 
  dealing 
  

   with 
  the 
  effect 
  of 
  chloral 
  hydrate 
  and 
  other 
  such 
  substances 
  upon 
  cell 
  

   division 
  is 
  a 
  familiar 
  example, 
  whilst 
  Demoor'sf 
  earlier 
  observations 
  upon 
  

   the 
  effect 
  of 
  chloroform 
  upon 
  the 
  hairs 
  of 
  Tradescantia 
  showed 
  that 
  the 
  

   streaming 
  movements 
  of 
  the 
  cytoplasm 
  are 
  arrested 
  before 
  the 
  mitotic 
  

   division 
  of 
  the 
  nucleus 
  is 
  interfered 
  with. 
  Loeb| 
  has 
  recorded 
  the 
  inter- 
  

   esting 
  fact 
  that, 
  at 
  a 
  certain 
  concentration 
  of 
  sea-water 
  (either 
  with 
  sodium 
  

   chloride, 
  or 
  preferably 
  with 
  magnesium 
  chloride), 
  the 
  cytoplasmic 
  divisions 
  

   are 
  arrested 
  in 
  a 
  freshly 
  fertilised 
  egg 
  of 
  a 
  Sea 
  Urchin, 
  while 
  the 
  nuclear 
  

   divisions 
  continue. 
  

  

  * 
  Nemec, 
  B. 
  ' 
  Das 
  Problem 
  der 
  Befruchtungsvorgange,' 
  Berlin, 
  1910. 
  

  

  t 
  Demoor, 
  J., 
  ' 
  Archives 
  de 
  Biologie,' 
  vol. 
  13, 
  pp. 
  163-244 
  (1895). 
  

  

  \ 
  Loeb, 
  J., 
  ' 
  Archiv 
  f. 
  Entwickelungsmechanik,' 
  vol. 
  2, 
  pp. 
  298-300 
  (1896). 
  

  

  