﻿Laivs 
  of 
  Fluctuations 
  721 
  

  

  the 
  following 
  day 
  the 
  weather 
  may 
  be 
  unfavor- 
  

   able 
  and 
  greatly 
  retard 
  growth. 
  The 
  individual 
  

   differences 
  seem 
  to 
  be 
  due, 
  at 
  least 
  in 
  a 
  very 
  

   great 
  measure, 
  to 
  such 
  apparent 
  trifles. 
  

  

  On 
  the 
  other 
  hand 
  partial 
  differences 
  are 
  

   often 
  manifestly 
  due 
  to 
  similar 
  causes. 
  Con- 
  

   sidering 
  the 
  various 
  stems 
  of 
  plants, 
  which 
  mul- 
  

   tiply 
  themselves 
  by 
  runners 
  or 
  by 
  buds 
  on 
  the 
  

   roots, 
  the 
  assertion 
  is 
  in 
  no 
  need 
  of 
  further 
  

   proof. 
  The 
  same 
  holds 
  good 
  for 
  all 
  cases 
  of 
  

   artificial 
  multiplication 
  by 
  cuttings, 
  or 
  by 
  other 
  

   vegetative 
  methods. 
  But 
  even 
  if 
  we 
  limit 
  our- 
  

   selves 
  to 
  the 
  leaves 
  of 
  a 
  single 
  tree, 
  or 
  the 
  

   branches 
  of 
  a 
  shrub, 
  or 
  the 
  flowers 
  on 
  a 
  plant, 
  

   the 
  same 
  rule 
  prevails. 
  The 
  development 
  of 
  

   the 
  leaves 
  is 
  dependent 
  on 
  their 
  position, 
  wheth- 
  

   er 
  inserted 
  on 
  strong 
  or 
  weak 
  branches, 
  exposed 
  

   to 
  more 
  or 
  less 
  light, 
  or 
  nourished 
  by 
  strong 
  or 
  

   weak 
  roots. 
  The 
  vigor 
  of 
  the 
  axillary 
  buds 
  

   and 
  of 
  the 
  branches 
  which 
  they 
  may 
  produce 
  is 
  

   dependent 
  upon 
  the 
  growth 
  and 
  activity 
  of 
  the 
  

   leaves 
  to 
  which 
  the 
  buds 
  are 
  axillary. 
  

  

  This 
  dependency 
  on 
  local 
  nutrition 
  leads 
  to 
  

   the 
  general 
  law 
  of 
  periodicity, 
  which, 
  broadly 
  

   speaking, 
  governs 
  the 
  occurrence 
  of 
  the 
  fluctuat- 
  

   ing 
  deviations 
  of 
  the 
  organs. 
  This 
  law 
  of 
  pe- 
  

   riodicity 
  involves 
  the 
  general 
  principle 
  that 
  

   every 
  axis, 
  as 
  a 
  rule, 
  increases 
  in 
  strength 
  when 
  

  

  