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  Fluctuations 
  

  

  tigation 
  of 
  true 
  double 
  races, 
  or 
  ever-sporting 
  

   varieties. 
  The 
  striped 
  snapdragon 
  shows 
  a 
  

   curve 
  of 
  its 
  stripes 
  with 
  two 
  summits, 
  one 
  cor- 
  

   responding 
  to 
  the 
  average 
  striped 
  flowers, 
  and 
  

   the 
  other 
  to 
  the 
  pure 
  red 
  ones. 
  Such 
  cases 
  may 
  

   be 
  discovered 
  by 
  means 
  of 
  curves, 
  but 
  the 
  con- 
  

   stituents 
  cannot 
  be 
  separated 
  by 
  culture-exper- 
  

   iments. 
  

  

  A 
  curious 
  peculiarity 
  is 
  afforded 
  by 
  half- 
  

   curves. 
  The 
  number 
  of 
  petals 
  is 
  often 
  seen 
  

   to 
  vary 
  only 
  in 
  one 
  direction 
  from 
  what 
  should 
  

   be 
  expected 
  to 
  be 
  the 
  mean 
  condition. 
  With 
  

   buttercups 
  and 
  brambles 
  and 
  many 
  others 
  there 
  

   is 
  only 
  an 
  increase 
  above 
  the 
  typical 
  five; 
  

   quaternate 
  flowers 
  are 
  wanting 
  or 
  at 
  least 
  are 
  

   very 
  rare. 
  With 
  weigelias 
  and 
  many 
  others 
  the 
  

   number 
  of 
  the 
  tips 
  of 
  the 
  corolla 
  varies 
  down- 
  

   wards, 
  going 
  from 
  five 
  to 
  four 
  and 
  three. 
  Hun- 
  

   dreds 
  of 
  flowers 
  show 
  the 
  typical 
  five, 
  and 
  de- 
  

   termine 
  the 
  summit 
  of 
  the 
  curve. 
  This 
  drops 
  

   down 
  on 
  one 
  side 
  only, 
  indicating 
  unilateral 
  

   variability, 
  which 
  in 
  many 
  cases 
  is 
  due 
  to 
  a 
  

   very 
  intimate 
  connection 
  of 
  a 
  concealed 
  sec- 
  

   ondary 
  summit 
  and 
  the 
  main 
  one. 
  In 
  the 
  

   case 
  of 
  the 
  bulbous 
  buttercup, 
  Ranunculus 
  bul- 
  

   bosus, 
  I 
  have 
  succeeded 
  in 
  isolating 
  this 
  second- 
  

   ary 
  summit, 
  although 
  not 
  in 
  a 
  separate 
  variety, 
  

   but 
  only 
  in 
  a 
  form 
  corresponding 
  to 
  the 
  type 
  

   of 
  ever-sporting 
  varieties. 
  

  

  