﻿LECTURE 
  IX 
  

  

  CROSSES 
  OF 
  SPECIES 
  AND 
  VARIETIES 
  

  

  In 
  the 
  foregoing 
  lectures 
  I 
  have 
  tried 
  to 
  show 
  

   that 
  there 
  is 
  a 
  real 
  difference 
  between 
  element- 
  

   ary 
  species 
  and 
  varieties. 
  The 
  first 
  are 
  of 
  

   equal 
  rank, 
  and 
  together 
  constitute 
  the 
  col- 
  

   lective 
  or 
  systematic 
  species. 
  The 
  latter 
  are 
  

   usually 
  derived 
  from 
  real 
  and 
  still 
  existing 
  

   types. 
  Elementary 
  species 
  are 
  in 
  a 
  sense 
  inde- 
  

   pendent 
  of 
  each 
  other, 
  while 
  varieties 
  are 
  of 
  a 
  

   derivative 
  nature. 
  

  

  Furthermore 
  I 
  have 
  tried 
  to 
  show 
  that 
  the 
  

   ways 
  in 
  which 
  elementary 
  or 
  minor 
  species 
  must 
  

   have 
  originated 
  from 
  their 
  common 
  ancestor 
  

   must 
  be 
  quite 
  different 
  from 
  the 
  mode 
  of 
  origin 
  

   of 
  the 
  varieties. 
  We 
  have 
  assumed 
  that 
  the 
  

   first 
  come 
  into 
  existence 
  by 
  the 
  production 
  of 
  

   something 
  new, 
  by 
  the 
  acquirement 
  of 
  a 
  char- 
  

   acter 
  hitherto 
  unnoticed 
  in 
  the 
  line 
  of 
  their 
  an- 
  

   cestors. 
  On 
  the 
  contrary, 
  varieties, 
  in 
  most 
  

   cases, 
  evidently 
  owe 
  their 
  origin 
  to 
  the 
  loss 
  of 
  

   an 
  already 
  existing 
  character, 
  or 
  in 
  other 
  less 
  

   frequent 
  cases, 
  to 
  the 
  re-assumption 
  of 
  a 
  quality 
  

  

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