﻿178 
  Harper: 
  Jnherttance 
  of 
  sugar 
  

  

  L 
  

  

  r 
  

  

  to 
  the 
  nuclear 
  membrane 
  is 
  coming 
  to 
  be 
  recognized 
  as 
  a 
  problem 
  

   of 
  fundamental 
  cytological 
  Importance. 
  These 
  interrelations 
  of 
  

   the 
  cell 
  structures 
  constitute 
  as 
  I 
  have 
  pointed 
  out 
  a 
  sort 
  of 
  internal 
  

   environment 
  for 
  the 
  germ 
  plasm 
  but 
  an 
  environment 
  from 
  which 
  

   In 
  my 
  opinion 
  it 
  Is 
  inseparable 
  and 
  which 
  determines 
  continuously 
  

   in 
  a 
  considerable 
  degree 
  its 
  constitution. 
  With 
  the 
  recognition 
  

   that 
  all 
  protoplasmic 
  cell 
  structures 
  are 
  phases 
  of 
  a 
  complex 
  of 
  

   colloidal 
  systems 
  the 
  question 
  as 
  to 
  whether 
  all 
  change 
  must 
  not 
  

   of 
  necessity 
  originate 
  in 
  environmental 
  influence 
  largely 
  loses 
  its 
  

   point. 
  That 
  the 
  position 
  of 
  the 
  chromosomes 
  with 
  reference 
  to 
  

   the 
  plasma 
  membrane 
  may 
  be 
  of 
  significance, 
  has 
  been 
  already 
  

  

  theory 
  

  

  That 
  

  

  such 
  conceptions 
  seem 
  far 
  less 
  fanciful, 
  as 
  our 
  evidence 
  for 
  the 
  

   individuality 
  of 
  the 
  chromosomes 
  and 
  the 
  reality 
  of 
  their 
  paired 
  

   positions 
  in 
  the 
  diploid 
  cells 
  becomes 
  more 
  positive, 
  cannot 
  be 
  

   questioned. 
  During 
  the 
  period 
  of 
  the 
  maturation 
  and 
  fertilization 
  

   processes 
  the 
  germ 
  plasm 
  Is 
  best 
  protected 
  from, 
  because 
  it 
  is 
  least 
  

   dependent 
  on, 
  the 
  general 
  external 
  environment 
  and 
  in 
  view 
  of 
  

   the 
  complexity 
  of 
  these 
  processes 
  the 
  claim 
  that 
  all 
  change 
  must 
  

   be 
  initiated 
  by 
  influences 
  from 
  outside 
  the 
  organism 
  can 
  have 
  

   little 
  weight. 
  Changes 
  resulting 
  from 
  the 
  functioning 
  of 
  the 
  

   mechanism 
  of 
  chromosome 
  pairing 
  and 
  reduction, 
  and 
  gametic 
  

   fusions 
  may 
  well 
  be 
  characterized 
  as 
  due 
  to 
  the 
  normal 
  capacity 
  of 
  

   the 
  germ 
  plasm 
  for 
  congenital 
  variation. 
  I 
  

  

  any 
  doctrine 
  of 
  spontaneous 
  or 
  self-caused 
  change, 
  but 
  anT 
  only 
  

   pointing 
  out 
  that 
  the 
  stages 
  of 
  embryo 
  initiation, 
  from 
  their 
  

   obscurity 
  and 
  our 
  ignorance 
  of 
  them, 
  have 
  been 
  either 
  re- 
  

   garded 
  as 
  of 
  no 
  significance 
  (Lamarckian 
  emphasis 
  on 
  Influence 
  

  

  am 
  

  

  environmen 
  

  

  strictly 
  theoretically 
  conceived 
  importance 
  (doctrines 
  of 
  germinal 
  

   variation) 
  In 
  initiating 
  variation 
  and 
  even 
  evolutionary 
  advance. 
  

   With 
  our 
  better 
  knowledge, 
  we 
  now 
  see, 
  from 
  the 
  very 
  complexity 
  

   of 
  the 
  mechanisms 
  concerned 
  and 
  the 
  fundamentally 
  new 
  relations 
  

   into 
  which 
  the 
  gametic 
  cells 
  enter 
  in 
  the 
  act 
  of 
  fusion, 
  there 
  may 
  

   well 
  result 
  at 
  least 
  what 
  we 
  may 
  perhaps 
  properly 
  call 
  with 
  Meehan 
  

   and 
  Cook 
  ('19) 
  the 
  normal 
  fluctuating 
  variation 
  of 
  the 
  organism. 
  

   We 
  realize 
  more 
  fully 
  now 
  than 
  Darwin 
  did 
  that 
  the 
  question 
  

   as 
  to 
  whether 
  sexual 
  reproduction 
  is 
  in 
  itself 
  a 
  source 
  of 
  variation 
  

  

  