﻿626 
  Mutations 
  

  

  means 
  of 
  the 
  crossing 
  of 
  the 
  offspring 
  of 
  a 
  

   single 
  mutant 
  with 
  previously 
  existing 
  sorts, 
  is 
  

   a 
  very 
  common 
  feature 
  in 
  horticultural 
  prac- 
  

   tice. 
  It 
  warns 
  us 
  that 
  only 
  a 
  small 
  part 
  of 
  the 
  

   novelties 
  introduced 
  yearly 
  are 
  due 
  to 
  real 
  mu- 
  

   tations. 
  Further 
  instances 
  of 
  novelties 
  with 
  

   such 
  a 
  common 
  origin 
  are 
  the 
  purple-leaved 
  

   dahlias, 
  the 
  gooseberries 
  without 
  prickles, 
  the 
  

   double 
  petunias, 
  erect 
  gloxinias 
  and 
  many 
  

   others. 
  Accumulation 
  of 
  characters, 
  acquired 
  

   in 
  different 
  races 
  of 
  a 
  species, 
  may 
  easily 
  be 
  

   effected 
  in 
  this 
  way 
  ; 
  in 
  fact 
  it 
  is 
  one 
  of 
  the 
  im- 
  

   portant 
  factors 
  in 
  the 
  breeding 
  of 
  horticultural 
  

   novelties. 
  

  

  I 
  have 
  alluded 
  more 
  than 
  once 
  in 
  this 
  lecture 
  

   to 
  the 
  question, 
  whether 
  it 
  is 
  probable 
  that 
  mu- 
  

   tations 
  occur 
  in 
  one 
  individual 
  or 
  in 
  more. 
  

   The 
  common 
  belief 
  among 
  horticulturists 
  is 
  

   that, 
  as 
  a 
  rule, 
  they 
  appear 
  in 
  a 
  single 
  plant. 
  

   This 
  belief 
  is 
  so 
  widespread 
  that 
  whenever 
  a 
  

   novelty 
  is 
  seen 
  for 
  the 
  first 
  time 
  in 
  two 
  or 
  more 
  

   specimens 
  it 
  is 
  at 
  once 
  suggested 
  that 
  it 
  might 
  

   have 
  originated 
  and 
  been 
  overlooked 
  in 
  a 
  previ- 
  

   ous 
  generation. 
  Not 
  caring 
  to 
  confess 
  a 
  lack 
  

   of 
  close 
  observation, 
  the 
  number 
  of 
  mutants 
  

   in 
  such 
  cases 
  is 
  usually 
  kept 
  secret. 
  At 
  least 
  

   this 
  statement 
  has 
  been 
  made 
  to 
  me 
  by 
  some 
  of 
  

   the 
  horticulturists 
  at 
  Erfurt, 
  whom 
  I 
  visited 
  

   some 
  years 
  ago 
  in 
  order 
  to 
  learn 
  as 
  much 
  as 
  

  

  