﻿494 
  J. 
  BRETLAND 
  FARMER 
  AND 
  J. 
  E. 
  S. 
  MOOEE. 
  

  

  chromosomes 
  of 
  each 
  of 
  the 
  four 
  nuclei 
  that 
  result 
  from 
  the 
  

   two 
  maiotic 
  divisions. 
  

  

  But 
  such 
  an 
  interpretation 
  involves 
  important 
  conclusions, 
  

   not 
  only 
  as 
  to 
  the 
  nature 
  of 
  reduction, 
  but 
  also 
  as 
  to 
  the 
  kind 
  

   of 
  importance 
  to 
  be 
  attached 
  to 
  the 
  chromosomes 
  themselves. 
  

   For 
  if 
  it 
  be 
  really 
  valid, 
  it 
  becomes 
  impossible 
  to 
  consistently 
  

   retain 
  a 
  belief 
  in 
  the 
  permanence 
  of 
  the 
  chromosomes 
  from 
  

   one 
  life-cycle 
  to 
  another. 
  It 
  is 
  obvious 
  that 
  if 
  their 
  number 
  

   is 
  thus 
  periodically 
  reduced 
  to 
  one 
  half, 
  and 
  if 
  the 
  resulting 
  

   chromatic 
  elements 
  are 
  distributed 
  to 
  the 
  daughter 
  nuclei 
  

   solely 
  after 
  duplication 
  by 
  means 
  of 
  longitudinal 
  fission, 
  the 
  

   individual 
  chromosomes 
  that 
  arise 
  during 
  the 
  maiotic 
  phase 
  

   could 
  not 
  possibly 
  correspond 
  to 
  any 
  that 
  existed 
  in 
  the 
  

   nuclei 
  of 
  the 
  cells 
  previous 
  to 
  the 
  incidence 
  of 
  this 
  phase 
  of 
  

   reduction. 
  The 
  only 
  hypothesis 
  consistent 
  with 
  such 
  a 
  

   view 
  would 
  demand 
  the 
  previous 
  longitudinal 
  fusion 
  in 
  

   pairs 
  of 
  the 
  original 
  chromosomes, 
  a 
  view 
  that 
  has 
  not 
  been 
  

   seriously 
  held 
  by 
  any 
  who 
  have 
  maintained 
  the 
  existence 
  of 
  

   two 
  longitudinal 
  fissions 
  during 
  the 
  heterotype 
  prophase. 
  

  

  Hence 
  it 
  would 
  follow 
  that 
  during 
  the 
  prophase 
  of 
  the 
  

   heterotype 
  mitosis 
  the 
  chromosomes 
  for 
  the 
  next 
  generation 
  

   must, 
  so 
  to 
  speak, 
  be 
  formed 
  afresh. 
  That 
  is, 
  they 
  are 
  entirely 
  

   reconstituted 
  — 
  out 
  of 
  the 
  original 
  matter 
  perhaps, 
  but 
  with 
  a 
  

   complete 
  rearrangement 
  of 
  substance 
  that 
  would 
  preclude 
  any 
  

   idea 
  of 
  continuity 
  in 
  their 
  organisation. 
  And 
  this 
  is 
  equiva- 
  

   lent 
  to 
  a 
  denial 
  of 
  the 
  permanence 
  of 
  the 
  chromosomes 
  from 
  

   one 
  generation 
  to 
  another. 
  

  

  Such 
  a 
  view 
  does 
  not, 
  of 
  course, 
  necessarily 
  involve 
  a 
  

   similar 
  denial 
  of 
  the 
  equivalence 
  of 
  the 
  somatic 
  chromosomes, 
  

   in 
  which 
  there 
  is 
  no 
  numerical 
  reduction, 
  but 
  it 
  relegates 
  the 
  

   whole 
  question 
  to 
  a 
  position 
  of 
  subordinate 
  importance. 
  It 
  is 
  

   obvious 
  that 
  such 
  a 
  result 
  must 
  profoundly 
  affect 
  any 
  con- 
  

   ceptions 
  as 
  to 
  the 
  nature 
  of 
  the 
  relation 
  that 
  may 
  be 
  supposed 
  

   to 
  exist 
  between 
  the 
  chromosomes 
  and 
  the 
  mechanism 
  of 
  

   heredity. 
  For 
  if 
  the 
  inherited 
  and 
  other 
  qualities 
  of 
  an 
  

   organism 
  are 
  to 
  be 
  associated 
  in 
  any 
  way 
  with 
  the 
  chromo- 
  

   somes, 
  and 
  if 
  these 
  structures 
  have 
  no 
  persistent 
  organisation 
  

  

  