﻿aulas 
  mlit 
  

  

  JUN 
  2 
  719 
  

  

  Mother-Cells 
  and 
  Tapetum 
  of 
  Lettuce 
  (Lactuca 
  satr 
  

  

  well 
  as 
  of 
  those 
  which 
  seem 
  to 
  fall 
  into 
  the 
  usual 
  order 
  of 
  events. 
  Doubtless, 
  

   some 
  organisms 
  show 
  much 
  greater 
  variation 
  in 
  these 
  respects 
  than 
  others, 
  

   and 
  this 
  also 
  is 
  not 
  without 
  its 
  significance 
  for 
  genetics. 
  

  

  In 
  connection 
  with 
  this 
  work, 
  I 
  am 
  greatly 
  indebted 
  to 
  my 
  research 
  

   assistant, 
  Miss 
  E. 
  M. 
  Kees, 
  B.Sc, 
  the 
  accuracy 
  of 
  whose 
  drawings 
  has 
  added 
  

   a 
  great 
  deal 
  to 
  the 
  value 
  of 
  the 
  results. 
  

  

  BIBLIOGRAPHY. 
  

  

  1. 
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  Jean 
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  sur 
  revolution 
  cles 
  cellules-nourricieres 
  du 
  pollen 
  chez 
  

  

  les 
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  2. 
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  in 
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  3. 
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  5. 
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  6. 
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  0. 
  (1915), 
  " 
  Untersuchungen 
  iiber 
  die 
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  der 
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  in 
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  Pollensacken 
  der 
  Angiospermen," 
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  Wiss. 
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  vol. 
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   Plates 
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  7. 
  Moore, 
  J. 
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  (1895), 
  " 
  On 
  the 
  structural 
  changes 
  in 
  the 
  reproductive 
  cells 
  during 
  

  

  spermatogenesis 
  of 
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  ' 
  Quart. 
  Journ. 
  Micro. 
  Sci.,' 
  vol. 
  38, 
  

   pp. 
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  Plates 
  13-16, 
  figs. 
  4. 
  

  

  8. 
  Morgan, 
  T. 
  H., 
  Sturtevant, 
  A. 
  H., 
  Muller, 
  H. 
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  C. 
  B. 
  (1915), 
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  Mechanism 
  of 
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  Heredity,' 
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  York. 
  

  

  9. 
  JVilson, 
  E. 
  B. 
  (1912), 
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  Studies 
  on 
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  VIII 
  : 
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  on 
  the 
  

  

  maturation 
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  in 
  certain 
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  and 
  other 
  forms, 
  with 
  considerations 
  

   on 
  synapsis 
  and 
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  ' 
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  VOL. 
  XCI. 
  — 
  B. 
  

  

  