﻿Taxonomic 
  Anomalies 
  667 
  

  

  seein 
  to 
  be 
  also 
  more 
  inconstant 
  when 
  propa- 
  

   gated 
  sexually. 
  The 
  difference 
  is 
  so 
  striking 
  

   and 
  affords 
  such 
  a 
  reliable 
  feature 
  that 
  Koch 
  

   proposed 
  to 
  make 
  two 
  distinct 
  varieties 
  of 
  them, 
  

   calling 
  the 
  pure 
  type 
  Fraxinus 
  excelsior 
  mono- 
  

   phylla, 
  and 
  the 
  varying 
  trees 
  F. 
  excel, 
  exhetero- 
  

   phylla. 
  Some 
  writers, 
  and 
  among 
  them 
  Will- 
  

   denow, 
  have 
  preferred 
  to 
  separate 
  the 
  " 
  one- 
  

   leaved 
  " 
  forms 
  from 
  the 
  species, 
  and 
  to 
  call 
  

   them 
  Fraxinus 
  simplici 
  folia. 
  

  

  According 
  to 
  Smith 
  and 
  to 
  Loudon, 
  the 
  ' 
  ' 
  one- 
  

   leaved 
  ' 
  ' 
  ashes 
  are 
  found 
  wild 
  in 
  different 
  dis- 
  

   tricts 
  in 
  England. 
  Intermediate 
  forms 
  have 
  not 
  

   been 
  recorded 
  from 
  these 
  localities. 
  This 
  

   mode 
  of 
  origin 
  is 
  that 
  already 
  detailed 
  for 
  the 
  

   laciniate 
  varieties 
  of 
  alders 
  and 
  so 
  many 
  other 
  

   trees. 
  Hence 
  it 
  may 
  be 
  assumed 
  that 
  the 
  " 
  one- 
  

   leaved 
  " 
  ashes 
  have 
  sprung 
  suddenly 
  but 
  fre- 
  

   quently 
  from 
  the 
  original 
  pinnate 
  species. 
  The 
  

   pure 
  type 
  of 
  Willdenow 
  should, 
  in 
  this 
  case, 
  

   be 
  considered 
  as 
  due 
  to 
  a 
  slightly 
  different 
  

   mutation, 
  perhaps 
  as 
  a 
  pure 
  retrograde 
  variety, 
  

   while 
  the 
  varying 
  strains 
  may 
  only 
  be 
  ever- 
  

   sporting 
  forms. 
  This 
  would 
  likewise 
  explain 
  

   part 
  of 
  their 
  observed 
  inconstancy. 
  

  

  In 
  this 
  respect 
  the 
  historic 
  dates, 
  as 
  collected 
  

   by 
  Korshinsky, 
  are 
  not 
  very 
  convincing. 
  Vi- 
  

   cinism 
  has 
  of 
  course, 
  almost 
  never 
  been 
  exclud- 
  

   ed, 
  and 
  part 
  of 
  the 
  multiformity 
  of 
  the 
  offspring 
  

  

  