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  The 
  Genetics 
  of 
  Sex 
  in 
  Funaria 
  hygrometrica. 
  

   By 
  E. 
  J. 
  Collins, 
  M.A. 
  (Cantab.), 
  B.Se. 
  (Loud.). 
  

   (Communicated 
  by 
  W. 
  Bateson, 
  Esq., 
  F.R.S. 
  Beceived 
  September 
  12, 
  1920.) 
  

  

  For 
  dioecious 
  mosses 
  El. 
  and 
  Em. 
  Marchal* 
  have 
  shown 
  that 
  sex 
  segregation 
  

   occurs 
  at 
  the 
  meiotic 
  division 
  of 
  sporogenesis, 
  inasmuch 
  as 
  the 
  individual 
  

   spores 
  which 
  initiate 
  the 
  haploid 
  gametophytic 
  phase 
  are 
  uni-sexual, 
  pro- 
  

   ducing 
  protonemata 
  from 
  which 
  are 
  developed 
  leafy 
  axes 
  all 
  of 
  one 
  sex 
  

   either 
  male 
  or 
  female. 
  

  

  In 
  a 
  former 
  paperf 
  the 
  writer 
  has 
  shown 
  that 
  vegetative 
  cultures 
  

   derived 
  from 
  the 
  antheridia 
  and 
  the 
  surrounding 
  " 
  perigonial 
  " 
  leaves 
  of 
  the 
  

   male 
  " 
  inflorescence 
  " 
  of 
  Funaria 
  hygrometrica 
  — 
  a 
  monoecious 
  type 
  of 
  moss 
  — 
  

   produced 
  male 
  plants 
  only, 
  whilst 
  cultures 
  derived 
  from 
  spores 
  reproduced 
  

   the 
  normal 
  monoecious 
  plants. 
  

  

  From 
  this 
  evidence 
  it 
  appeared 
  probable 
  that 
  at 
  some 
  point 
  in 
  the 
  cell 
  

   divisions 
  by 
  which 
  the 
  axis 
  and 
  its 
  organs 
  are 
  developed, 
  a 
  separation 
  takes 
  

   place 
  such 
  that 
  the 
  element 
  upon 
  which 
  the 
  monoecious 
  condition 
  depends 
  

   is 
  dropped 
  out 
  of 
  those 
  cells 
  from 
  which 
  the 
  male 
  organ 
  with 
  its 
  surrounding 
  

   leaves 
  is 
  formed. 
  

  

  It 
  was 
  therefore 
  highly 
  desirable 
  that 
  vegetative 
  cultures 
  should 
  be 
  made 
  

   from 
  the 
  female 
  sexual 
  organ 
  and 
  the 
  leaves 
  surrounding 
  it, 
  their 
  genetic 
  

   potentialities 
  being 
  unknown. 
  These 
  experiments 
  have 
  now 
  been 
  carried 
  

   out, 
  vegetative 
  cultures 
  having 
  been 
  raised 
  both 
  from 
  the 
  archegonium 
  and 
  

   from 
  the 
  surrounding 
  " 
  perichretial 
  " 
  leaves 
  of 
  Fvnaria 
  h/ygvometriecb. 
  

  

  After 
  the 
  fertilisation 
  of 
  the 
  egg, 
  the 
  flask-shaped 
  archegonium 
  enlarges 
  

   considerably, 
  the 
  basal 
  part 
  (or 
  venter) 
  particularly 
  becoming 
  much 
  inflated. 
  

   In 
  this 
  condition 
  it 
  is 
  quite 
  easy 
  to 
  remove 
  the 
  greater 
  part 
  of 
  the 
  archegonium 
  

   (the 
  venter 
  with 
  the 
  surmounting 
  neck) 
  for 
  the 
  purpose 
  of 
  experiment. 
  

  

  Cultures 
  were 
  made 
  from 
  the 
  inflated 
  venter 
  and 
  neck 
  shortly 
  after 
  its 
  

   appearance 
  above 
  the 
  surrounding 
  perichsetial 
  leaves 
  and 
  also 
  from 
  these 
  leaves. 
  

  

  Four 
  pot 
  cultures 
  in 
  all 
  were 
  established 
  on 
  sterilised 
  soil, 
  two 
  from 
  the 
  

   venter 
  and 
  two 
  from 
  perichuetial 
  leaves. 
  All 
  were 
  placed 
  under 
  a 
  cloche 
  

   upon 
  moist 
  sand 
  in 
  a 
  zinc 
  tray, 
  together 
  with 
  a 
  fifth 
  pot 
  of 
  soil 
  sterilised 
  

   in 
  the 
  same 
  way, 
  but 
  upon 
  which 
  no 
  culture 
  had 
  been 
  sown. 
  The 
  pots 
  were 
  

   watered 
  with 
  boiled 
  distilled 
  water 
  through 
  an 
  opening 
  in 
  the 
  top 
  of 
  the 
  

   cloche. 
  No 
  growth 
  appeared 
  in 
  the 
  control 
  pot. 
  

  

  These 
  cultures 
  have 
  produced 
  typical 
  monoecious 
  plants. 
  

  

  * 
  ' 
  Mem. 
  de 
  l'Acad. 
  Roy. 
  de 
  Belgique,' 
  1906 
  ; 
  ' 
  Bull, 
  de 
  l'Acad 
  ' 
  Roy. 
  da 
  Belgique 
  

   Classe 
  des 
  Sciences,' 
  1907, 
  1909, 
  1911. 
  

   t 
  ' 
  Journal 
  of 
  Genetics,' 
  vol. 
  8, 
  1919. 
  

  

  