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  Vol. 
  47 
  

  

  No. 
  6 
  

  

  BULLETIN 
  

  

  I 
  

  

  r 
  

  

  OF 
  THE 
  

  

  TORREY 
  BOTANICAL 
  CLUB 
  

  

  ■ 
  V 
  

  

  JUNE, 
  1920 
  

  

  Microsporogenesis 
  in 
  Datura 
  Stramonium 
  

  

  Claude 
  E, 
  O'Neal 
  

  

  (with 
  plates 
  8 
  AND 
  9) 
  

  

  It 
  has 
  long 
  been 
  known 
  that 
  the 
  representatives 
  of 
  the 
  genus 
  

   Dahira 
  furnish 
  interesting 
  material 
  easily 
  available 
  for 
  plant 
  

   experimentation. 
  In 
  addition, 
  it 
  has 
  been 
  pointed 
  oiit 
  recently 
  

   (Blakeslee 
  & 
  Avery 
  2, 
  3) 
  that 
  this 
  getius 
  also 
  affords 
  an 
  excellent 
  

   field 
  for 
  the 
  study 
  of 
  Mendelian 
  inheritance 
  and 
  mutative 
  varia- 
  

   tion. 
  The 
  general 
  morphology- 
  of 
  the 
  members 
  of 
  the 
  genus 
  is 
  a 
  

   point 
  of 
  common 
  knowledge, 
  but 
  so 
  far 
  as 
  the 
  writer 
  is 
  aware, 
  no 
  

   careful 
  cytological 
  studies 
  have 
  been 
  made 
  upon 
  the 
  reduction 
  

   divisions 
  of 
  any 
  of 
  its 
  members. 
  Guignard 
  (7) 
  in 
  his 
  now 
  classical 
  

   work 
  treats 
  of 
  double 
  fecundation 
  in 
  D, 
  laevis. 
  Bonicke 
  (4) 
  has 
  

   examined 
  the 
  prophases 
  and 
  counted 
  the 
  chromosomes 
  in 
  D. 
  

   Stramoiniim. 
  Aside 
  from 
  these 
  two 
  investigations, 
  the 
  work 
  

   that 
  has 
  been 
  done 
  upon 
  Datura 
  has 
  been 
  of 
  a 
  pharmaceutical 
  

   or 
  of 
  an 
  experimental 
  character. 
  

  

  The 
  abundance 
  of 
  specimens 
  of 
  D. 
  Stramonnim 
  near 
  at 
  hand 
  

   during 
  the 
  summer 
  of 
  191 
  5 
  led 
  the 
  author 
  to 
  prepare 
  a 
  large 
  number 
  

   of 
  anthers 
  for 
  a 
  study 
  of 
  microsporogenesis 
  in 
  this 
  plant. 
  The 
  

   material 
  was 
  killed, 
  fixed, 
  and 
  embedded 
  in 
  paraffin, 
  in 
  which 
  

   condition 
  it 
  was 
  kept 
  until 
  the 
  summer 
  of 
  1919, 
  when 
  an 
  increased 
  

   interest 
  in 
  the 
  plant 
  as 
  a 
  teaching 
  type 
  induced 
  the 
  belief 
  that 
  a 
  

   completion 
  of 
  the 
  work 
  and 
  a 
  publication 
  of 
  the 
  results 
  would 
  be 
  of 
  

   interest. 
  Accordingly, 
  during 
  the 
  months 
  of 
  June 
  and 
  July, 
  

  

  [The 
  Bulletin' 
  for 
  May 
  (47: 
  199-230, 
  pi. 
  6, 
  7.) 
  was 
  issued 
  June 
  3. 
  1920.) 
  

  

  231 
  

  

  