﻿434 
  Ever-sporting 
  Varieties 
  

  

  termediate 
  forms 
  are 
  very 
  rare, 
  perhaps 
  wholly 
  

   wanting, 
  though 
  in 
  swamps 
  the 
  terrestrial 
  

   plants 
  may 
  often 
  vary 
  widely 
  in 
  the 
  direction 
  of 
  

   the 
  floating 
  type. 
  

  

  That 
  both 
  types 
  sport 
  into 
  each 
  other 
  has 
  

   long 
  been 
  recognized 
  in 
  field-observations, 
  and 
  

   has 
  been 
  the 
  ground 
  for 
  the 
  specific 
  name 
  of 
  

   ampJiibium, 
  though 
  in 
  this 
  respect 
  herbarium- 
  

   material 
  seems 
  usually 
  to 
  be 
  scant. 
  The 
  mat- 
  

   ter 
  has 
  recently 
  been 
  subjected 
  to 
  critical 
  and 
  

   experimental 
  studies 
  by 
  the 
  Belgian 
  botanist 
  

   Massart, 
  who 
  has 
  shown 
  that 
  by 
  transplanting 
  

   the 
  forms 
  into 
  the 
  alternate 
  conditions, 
  the 
  

   change 
  may 
  always 
  be 
  brought 
  about 
  arti- 
  

   ficially. 
  If 
  floating 
  plants 
  are 
  established 
  on 
  

   the 
  shore 
  they 
  make 
  ascending 
  hairy 
  stems, 
  and 
  

   if 
  the 
  terrestrial 
  shoots 
  are 
  submerged, 
  their 
  

   buds 
  grow 
  into 
  long 
  and 
  slack, 
  aquatic 
  stems. 
  

   Even 
  in 
  such 
  experiments, 
  intermediates 
  are 
  

   rare, 
  both 
  types 
  agreeing 
  completely 
  with 
  the 
  

   corresponding 
  models 
  in 
  the 
  wild 
  state. 
  

  

  Among 
  all 
  the 
  previously 
  described 
  cases 
  of 
  

   horticultural 
  plants 
  and 
  monstrosities 
  there 
  is 
  

   no 
  clearer 
  case 
  of 
  an 
  ever-sporting 
  variety 
  than 
  

   this 
  one 
  of 
  the 
  water-persicaria. 
  The 
  var. 
  

   terrestris 
  sports 
  into 
  the 
  var. 
  natans, 
  and 
  

   as 
  often 
  as 
  the 
  changing 
  life 
  conditions 
  may 
  

   require 
  it. 
  It 
  is 
  true 
  that 
  ordinary 
  sports 
  oc- 
  

   cur 
  without 
  our 
  discerning 
  the 
  cause 
  and 
  with- 
  

  

  