﻿Laws 
  of 
  Fluctuations 
  717 
  

  

  stain 
  from 
  the 
  use 
  of 
  methods 
  which 
  are 
  not 
  

   necessary 
  for 
  the 
  furtherance 
  of 
  experimental 
  

   work. 
  

  

  Fortunately, 
  Quetelet's 
  law 
  is 
  a 
  very 
  clear 
  

   and 
  simple 
  one, 
  and 
  quite 
  sufficient 
  for 
  our 
  con- 
  

   siderations. 
  It 
  claims 
  that 
  for 
  biologic 
  phe- 
  

   nomena 
  the 
  deviations 
  from 
  the 
  average 
  comply 
  

   with 
  the 
  same 
  laws 
  as 
  the 
  deviations 
  from 
  the 
  

   average 
  in 
  any 
  other 
  case, 
  if 
  ruled 
  by 
  chance 
  

   only. 
  The 
  meaning 
  of 
  this 
  assertion 
  will 
  be- 
  

   come 
  clear 
  by 
  a 
  further 
  discussion 
  of 
  the 
  facts. 
  

  

  First 
  of 
  all, 
  fluctuating 
  variability 
  is 
  an 
  al- 
  

   most 
  universal 
  phenomenon. 
  Every 
  organ 
  and 
  

   every 
  quality 
  may 
  exhibit 
  it. 
  Some 
  are 
  very 
  

   variable, 
  while 
  others 
  seem 
  quite 
  constant, 
  

   Shape 
  and 
  size 
  vary 
  almost 
  indefinitely, 
  and 
  the 
  

   chemical 
  composition 
  is 
  subject 
  to 
  the 
  same 
  law, 
  

   as 
  is 
  well 
  known 
  for 
  the 
  amount 
  of 
  sugar 
  in 
  

   sugar-beets. 
  Numbers 
  are 
  of 
  course 
  less 
  liable 
  

   to 
  changes, 
  but 
  the 
  numbers 
  of 
  the 
  rays 
  of 
  um- 
  

   bels, 
  or 
  ray-florets 
  in 
  the 
  composites, 
  of 
  pairs 
  of 
  

   blades 
  in 
  pinnate 
  leaves, 
  and 
  even 
  of 
  stamens 
  

   and 
  carpels 
  are 
  known 
  to 
  be 
  often 
  exceedingly 
  

   variable. 
  The 
  smaller 
  numbers 
  however, 
  are 
  

   more 
  constant, 
  and 
  deviations 
  from 
  the 
  quinate 
  

   structure 
  of 
  flowers 
  are 
  rare. 
  Complicated 
  

   structures 
  are 
  generally 
  capable 
  of 
  only 
  slight 
  

   deviations. 
  

  

  From 
  a 
  broad 
  point 
  of 
  view, 
  fluctuating 
  varia- 
  

  

  