﻿Theories 
  of 
  Evolution 
  9 
  

  

  row 
  limits 
  as 
  far 
  as 
  the 
  present 
  methods 
  of 
  

   selection 
  go. 
  But 
  the 
  question 
  remains 
  to 
  be 
  

   solved, 
  whether 
  our 
  methods 
  are 
  truly 
  the 
  right 
  

   ones, 
  and 
  whether 
  by 
  the 
  use 
  of 
  new 
  princi- 
  

   ples, 
  new 
  results 
  might 
  not 
  cause 
  the 
  balance 
  of 
  

   opinion 
  to 
  favor 
  the 
  opposite 
  side. 
  

  

  Of 
  late, 
  a 
  thorough 
  and 
  detailed 
  discussion 
  of 
  

   the 
  opposing 
  views 
  has 
  been 
  given 
  by 
  Morgan 
  

   in 
  his 
  valuable 
  book 
  on 
  evolution 
  and 
  adapta- 
  

   tion. 
  He 
  has 
  subjected 
  all 
  the 
  proposed 
  theo- 
  

   ries 
  to 
  a 
  severe 
  criticism 
  both 
  on 
  the 
  ground 
  of 
  

   facts 
  and 
  on 
  that 
  of 
  their 
  innate 
  possibility 
  and 
  

   logical 
  value. 
  He 
  decides 
  in 
  favor 
  of 
  the 
  mu- 
  

   tation-theory. 
  His 
  arguments 
  are 
  incisive 
  and 
  

   complete 
  and 
  wholly 
  adapted 
  to 
  the 
  compre- 
  

   hension 
  of 
  all 
  intelligent 
  readers, 
  so 
  that 
  his 
  

   book 
  relieves 
  me 
  entirely 
  of 
  the 
  necessity 
  of 
  

   discussing 
  these 
  general 
  questions, 
  as 
  it 
  could 
  

   not 
  be 
  done 
  in 
  a 
  better 
  or 
  in 
  a 
  clearer 
  way. 
  

  

  I 
  intend 
  to 
  give 
  a 
  review 
  of 
  the 
  facts 
  obtained 
  

   from 
  plants 
  which 
  go 
  to 
  prove 
  the 
  assertion, 
  

   that 
  species 
  and 
  varieties 
  have 
  originated 
  by 
  

   mutation, 
  and 
  are, 
  at 
  present, 
  not 
  known 
  to 
  orig- 
  

   inate 
  in 
  any 
  other 
  way. 
  This 
  review 
  consists 
  

   of 
  two 
  parts. 
  One 
  is 
  a 
  critical 
  survey 
  of 
  the 
  

   facts 
  of 
  agricultural 
  and 
  horticultural 
  breed- 
  

   ing, 
  as 
  they 
  have 
  accumulated 
  since 
  the 
  time 
  of 
  

   Darwin. 
  This 
  body 
  of 
  evidence 
  is 
  to 
  be 
  com- 
  

   bined 
  with 
  some 
  corresponding 
  experiments 
  

  

  