﻿LECTURE 
  VI 
  

  

  STABILITY 
  AND 
  REAL 
  ATAVISM 
  

  

  It 
  is 
  generally 
  believed 
  that 
  varieties 
  are 
  

   principally 
  distinguished 
  from 
  species 
  by 
  their 
  

   inconstancy. 
  This 
  conception 
  is 
  derived 
  from 
  

   some 
  special 
  cases 
  and 
  transferred 
  to 
  others, 
  

   and 
  in 
  its 
  common 
  form 
  this 
  belief 
  must 
  have 
  

   originated 
  from 
  the 
  confusion 
  which 
  exists 
  as 
  

   to 
  the 
  meaning 
  of 
  the 
  term 
  variety. 
  It 
  is 
  

   true 
  that 
  vegetative 
  varieties 
  as 
  a 
  rule 
  run 
  back, 
  

   when 
  propagated 
  by 
  seeds 
  ; 
  they 
  are 
  an 
  obvious 
  

   instance 
  of 
  inconstancy. 
  In 
  the 
  second 
  place 
  

   we 
  have 
  considered 
  the 
  group 
  of 
  inconstant 
  or 
  

   sporting 
  varieties, 
  which 
  of 
  course 
  we 
  must 
  ex- 
  

   clude 
  when 
  studying 
  the 
  stability 
  of 
  other 
  types. 
  

   However, 
  even 
  these 
  sporting 
  varieties 
  are 
  un- 
  

   stable 
  only 
  to 
  a 
  certain 
  degree, 
  and 
  in 
  a 
  broader 
  

   sense 
  will 
  prove 
  to 
  be 
  as 
  true 
  to 
  their 
  character 
  

   as 
  the 
  most 
  constant 
  types. 
  

  

  Having 
  separated 
  these 
  two 
  groups, 
  which 
  

   include 
  also 
  the 
  wide 
  range 
  of 
  hybrid 
  forms, 
  we 
  

   may 
  next 
  consider 
  only 
  those 
  varieties 
  of 
  pure 
  

   origin, 
  and 
  ordinarily 
  propagated 
  by 
  seeds, 
  

  

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