﻿168 
  Retrograde 
  Varieties 
  

  

  seems 
  to 
  be 
  propagated 
  only 
  by 
  cuttings 
  or 
  by 
  

   grafting. 
  If 
  this 
  is 
  true, 
  all 
  specimens 
  must 
  be 
  

   considered 
  as 
  constituting 
  together 
  only 
  one 
  

   individual, 
  notwithstanding 
  their 
  wide 
  distribu- 
  

   tion 
  in 
  the 
  gardens 
  and 
  parks 
  of 
  so 
  many 
  coun- 
  

   tries. 
  This 
  induces 
  me 
  to 
  suppose, 
  that 
  the 
  

   tendency 
  to 
  reversion 
  is 
  not 
  a 
  character 
  of 
  the 
  

   variety 
  as 
  such, 
  but 
  rather 
  a 
  peculiarity 
  of 
  this 
  

   one 
  individual. 
  In 
  other 
  words 
  it 
  seems 
  prob- 
  

   able 
  that 
  when 
  the 
  whitish 
  variety 
  arises 
  a 
  sec- 
  

   ond 
  time 
  from 
  the 
  red 
  species, 
  it 
  is 
  not 
  at 
  all 
  

   necessary 
  that 
  it 
  should 
  exhibit 
  this 
  same 
  tend- 
  

   ency 
  to 
  revert. 
  Or 
  to 
  put 
  it 
  still 
  in 
  another 
  

   way, 
  I 
  think 
  that 
  we 
  may 
  suppose 
  that 
  a 
  variety, 
  

   which 
  might 
  be 
  produced 
  repeatedly 
  from 
  the 
  

   same 
  original 
  stock, 
  would 
  only 
  in 
  rare 
  indi- 
  

   viduals 
  have 
  a 
  tendency 
  to 
  revert, 
  and 
  in 
  most 
  

   cases 
  would 
  be 
  as 
  absolutely 
  constant 
  as 
  the 
  

   species 
  itself. 
  

  

  Such 
  a 
  conception 
  would 
  give 
  us 
  a 
  distinct 
  

   insight 
  into 
  the 
  cause 
  of 
  the 
  rarity 
  of 
  these 
  

   reversions. 
  Many 
  varieties 
  of 
  shrubs 
  and 
  trees 
  

   have 
  originated 
  but 
  once 
  or 
  twice. 
  Most 
  of 
  

   them 
  must 
  therefore, 
  if 
  our 
  supposition 
  is 
  cor- 
  

   rect, 
  be 
  expected 
  to 
  be 
  stable 
  and 
  only 
  a 
  few 
  

   may 
  be 
  expected 
  to 
  be 
  liable 
  to 
  reversions. 
  

  

  Among 
  the 
  conifers 
  many 
  very 
  good 
  cases 
  of 
  

   reversions 
  by 
  buds 
  are 
  to 
  be 
  found 
  in 
  gardens 
  

   and 
  glasshouses. 
  They 
  behave 
  exactly 
  like 
  the 
  

   whitish 
  currant. 
  But 
  as 
  the 
  varietal 
  characters 
  

  

  