﻿Systematic 
  Atavism 
  643 
  

  

  for 
  each 
  stem 
  and 
  each 
  branch, 
  but 
  as 
  a 
  rule, 
  

   the 
  stronger 
  axes 
  are 
  more 
  liable 
  to 
  furnish 
  

   anomalies 
  than 
  the 
  weaker. 
  

  

  Exactly 
  the 
  same 
  thing 
  is 
  true 
  of 
  double 
  

   adaptations. 
  Every 
  bud 
  of 
  the 
  water-persi- 
  

   caria 
  may 
  develop 
  either 
  into 
  an 
  erect 
  or 
  into 
  a 
  

   floating 
  stem, 
  according 
  as 
  it 
  is 
  surrounded 
  by 
  

   water 
  or 
  by 
  relatively 
  dry 
  soil. 
  In 
  other 
  cases 
  

   utility 
  is 
  often 
  less 
  manifest, 
  but 
  some 
  use 
  may 
  

   either 
  be 
  proved, 
  or 
  shown 
  to 
  be 
  very 
  probable. 
  

   At 
  all 
  events 
  the 
  term 
  adaptation 
  includes 
  the 
  

   idea 
  of 
  utility, 
  and 
  obviously 
  useless 
  contriv- 
  

   ances 
  could 
  hardly 
  be 
  brought 
  under 
  the 
  same 
  

   head. 
  

  

  We 
  have 
  also 
  dealt 
  with 
  the 
  question 
  of 
  

   heredity. 
  It 
  is 
  obvious 
  that 
  from 
  the 
  flowers 
  of 
  

   the 
  floating 
  and 
  erect 
  stems 
  of 
  the 
  water-persi- 
  

   caria 
  seeds 
  will 
  result, 
  each 
  capable 
  of 
  yielding 
  

   both 
  forms. 
  Quite 
  the 
  same 
  thing 
  was 
  the 
  case 
  

   with 
  the 
  teasels. 
  Some 
  40# 
  of 
  the 
  progeny 
  pro- 
  

   duce 
  beautifully 
  twisted 
  stems, 
  but 
  whether 
  the 
  

   seed 
  was 
  saved 
  from 
  the 
  most 
  completely 
  

   twisted 
  specimens 
  or 
  from 
  the 
  straight 
  plants 
  

   of 
  the 
  race 
  was 
  of 
  no 
  importance. 
  

  

  This 
  phenomenon 
  of 
  twisting 
  may 
  now 
  be 
  

   considered 
  from 
  quite 
  another 
  point 
  of 
  view. 
  

   It 
  is 
  a 
  case 
  of 
  systematic 
  atavism, 
  or 
  of 
  the 
  re- 
  

   acquirement 
  of 
  some 
  ancient 
  and 
  long-lost 
  qual- 
  

   ity. 
  This 
  quality 
  is 
  the 
  alternate 
  position 
  of 
  

  

  