﻿Retrograde 
  Varieties 
  123 
  

  

  by 
  cutting, 
  and 
  this 
  leads 
  to 
  the 
  distinction 
  of 
  

   ' 
  ' 
  seed- 
  varieties 
  : 
  and 
  ' 
  ' 
  vegetative 
  varieties. 
  ' 
  

   In 
  the 
  first 
  case 
  the 
  inheritance 
  of 
  the 
  special 
  

   characters 
  through 
  the 
  seeds 
  decides 
  the 
  status 
  

   of 
  the 
  variety, 
  in 
  the 
  latter 
  case 
  this 
  point 
  is 
  left 
  

   wholly 
  out 
  of 
  consideration. 
  

  

  Leaving 
  aside 
  all 
  these 
  different 
  types, 
  we 
  

   are 
  concerned 
  here 
  only 
  with 
  the 
  " 
  seed-varie- 
  

   ties 
  : 
  ' 
  of 
  pure 
  origin, 
  or 
  at 
  least 
  with 
  those, 
  that 
  

   are 
  supposed 
  to 
  be 
  so. 
  Hybridization 
  and 
  

   vegetative 
  multiplication 
  of 
  the 
  hybrids 
  no 
  

   doubt 
  occur 
  in 
  nature, 
  but 
  they 
  are 
  very 
  rare, 
  

   when 
  compared 
  with 
  the 
  ordinary 
  method 
  of 
  

   propagation 
  by 
  seed. 
  " 
  Seed-varieties 
  " 
  may 
  

   further 
  be 
  divided 
  into 
  constant 
  and 
  inconstant 
  

   ones. 
  The 
  difference 
  is 
  very 
  essential, 
  but 
  the 
  

   test 
  is 
  not 
  always 
  easy 
  to 
  apply. 
  Constant 
  

   varieties 
  are 
  as 
  sharply 
  defined 
  and 
  as 
  narrowly 
  

   limited 
  as 
  are 
  the 
  best 
  wild 
  species, 
  while 
  in- 
  

   constant 
  types 
  are 
  cultivated 
  chiefly 
  on 
  account 
  

   of 
  their 
  wide 
  range 
  of 
  form 
  and 
  color. 
  This 
  

   diversity 
  is 
  repeated 
  yearly, 
  even 
  from 
  the 
  

   purest 
  seed. 
  We 
  will 
  now 
  discuss 
  the 
  constant 
  

   seed-varieties, 
  leaving 
  the 
  inconstant 
  and 
  ever- 
  

   sporting 
  types 
  to 
  a 
  subsequent 
  lecture. 
  

  

  In 
  this 
  way 
  we 
  may 
  make 
  an 
  exact 
  inquiry 
  

   into 
  the 
  departures 
  from 
  the 
  species 
  which 
  are 
  

   ordinarily 
  considered 
  to 
  constitute 
  the 
  essential 
  

   character 
  of 
  such 
  a 
  constant 
  and 
  pure 
  seed- 
  

  

  