﻿272 
  Retrograde 
  Varieties 
  

  

  lings 
  myself, 
  many 
  of 
  which 
  have 
  already 
  flow- 
  

   ered, 
  bearing 
  the 
  leaves 
  and 
  flowers 
  of 
  the 
  com- 
  

   mon 
  species. 
  Seeds 
  of 
  the 
  purple 
  reversions 
  

   have 
  also 
  been 
  sown, 
  and 
  also 
  yielded 
  the 
  

   parental 
  type 
  only. 
  

  

  Why 
  this 
  most 
  curious 
  hybrid 
  sports 
  so 
  reg- 
  

   ularly 
  and 
  why 
  others 
  always 
  remain 
  true 
  to 
  

   their 
  type 
  is 
  as 
  yet 
  an 
  open 
  question. 
  

  

  But 
  recalling 
  our 
  former 
  consideration 
  of 
  

   this 
  subject 
  the 
  supposition 
  seems 
  allowable 
  

   that 
  the 
  tendency 
  to 
  revert 
  is 
  not 
  connected 
  

   with 
  the 
  type 
  of 
  the 
  hybrid, 
  but 
  is 
  apt 
  to 
  occur 
  

   in 
  some 
  rare 
  individuals 
  of 
  every 
  type. 
  But 
  

   since 
  most 
  of 
  the 
  sterile 
  hybrids 
  are 
  only 
  known 
  

   to 
  us 
  in 
  a 
  single 
  individual 
  and 
  its 
  vegetative 
  

   offspring, 
  this 
  surmise 
  offers 
  an 
  explanation 
  of 
  

   the 
  rare 
  occurrence 
  of 
  sports. 
  

  

  Finally, 
  we 
  must 
  consider 
  some 
  of 
  the 
  so- 
  

   called 
  hybrid 
  races 
  or 
  strains 
  of 
  garden-plants. 
  

   Dahlia, 
  Gladiolus, 
  Amaryllis, 
  Fuchsia, 
  Pelar- 
  

   gonium 
  and 
  many 
  other 
  common 
  flowers 
  afford 
  

   the 
  best 
  known 
  instances. 
  Immeasurable 
  

   variability 
  seems 
  here 
  to 
  be 
  the 
  result 
  of 
  

   crossing. 
  But 
  on 
  a 
  closer 
  inspection 
  the 
  range 
  

   of 
  characters 
  is 
  not 
  so 
  very 
  much 
  wider 
  in 
  these 
  

   hybrid 
  races 
  than 
  in 
  the 
  groups 
  of 
  parent- 
  

   species 
  which 
  have 
  contributed 
  to 
  the 
  origin 
  of 
  

   the 
  hybrids. 
  Our 
  tuberous 
  begonias 
  owe 
  their 
  

   variability 
  to 
  at 
  least 
  seven 
  original 
  parent 
  spe- 
  

  

  