﻿Laws 
  of 
  Fluctuations 
  719 
  

  

  the 
  whole 
  method 
  of 
  statistical 
  investigation. 
  

   It 
  is 
  equally 
  important 
  for 
  the 
  discussion 
  of 
  the 
  

   contrast 
  between 
  fluctuations 
  and 
  mutations, 
  

   and 
  for 
  the 
  appreciation 
  of 
  their 
  part 
  in 
  the 
  

   general 
  progress 
  of 
  organization. 
  Mutations 
  

   are 
  going 
  on 
  in 
  all 
  directions, 
  producing, 
  if 
  they 
  

   are 
  progressive, 
  something 
  quite 
  new 
  every 
  

   time. 
  Fluctuations 
  are 
  limited 
  to 
  increase 
  and 
  

   decrease 
  of 
  what 
  is 
  already 
  available. 
  They 
  

   may 
  produce 
  plants 
  with 
  higher 
  stems, 
  more 
  

   petals 
  in 
  the 
  flowers, 
  larger 
  and 
  more 
  palatable 
  

   fruits, 
  but 
  obviously 
  the 
  first 
  petal 
  and 
  the 
  first 
  

   berry 
  cannot 
  have 
  originated 
  by 
  the 
  simple 
  in- 
  

   crease 
  of 
  some 
  older 
  quality. 
  Intermediates 
  

   may 
  be 
  found, 
  and 
  they 
  may 
  mark 
  the 
  limit, 
  but 
  

   the 
  demonstration 
  of 
  the 
  absence 
  of 
  a 
  limit 
  is 
  

   quite 
  another 
  question. 
  It 
  would 
  require 
  the 
  

   two 
  extremes 
  to 
  be 
  shown 
  to 
  belong 
  to 
  one 
  unit, 
  

   complying 
  with 
  the 
  simple 
  law 
  of 
  Quetelet. 
  

  

  Nourishment 
  is 
  the 
  potent 
  factor 
  of 
  fluctuat- 
  

   ing 
  variability. 
  Of 
  course 
  in 
  thousands 
  of 
  cases 
  

   our 
  knowledge 
  is 
  not 
  sufficient 
  to 
  allow 
  us 
  to 
  ana- 
  

   lyze 
  this 
  relation, 
  and 
  a 
  number 
  of 
  phases 
  of 
  the 
  

   phenomenon 
  have 
  been 
  discovered 
  only 
  quite 
  

   recently. 
  But 
  the 
  fact 
  itself 
  is 
  thoroughly 
  mani- 
  

   fest, 
  and 
  its 
  appreciation 
  is 
  as 
  old 
  as 
  horticul- 
  

   tural 
  science. 
  Knight, 
  who 
  lived 
  at 
  the 
  begin- 
  

   ning 
  of 
  the 
  last 
  century, 
  has 
  laid 
  great 
  stress 
  

   upon 
  it, 
  and 
  it 
  has 
  since 
  influenced 
  practice 
  in 
  a 
  

  

  