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  Elementary 
  Species 
  

  

  they 
  attempted 
  to 
  discredit 
  it. 
  Milde 
  and 
  many 
  

   others 
  have 
  opposed 
  these 
  new 
  ideas 
  with 
  some 
  

   temporary 
  success. 
  Only 
  of 
  late 
  has 
  the 
  school 
  

   of 
  Jordan 
  received 
  due 
  recognition, 
  after 
  

   Thuret, 
  de 
  Bary, 
  Rosen 
  and 
  others 
  tested 
  

   its 
  practices 
  and 
  openly 
  pronounced 
  for 
  them. 
  

   Of 
  late 
  Wittrock 
  of 
  Sweden 
  has 
  joined 
  them, 
  

   making 
  extensive 
  experimental 
  studies 
  concern- 
  

   ing 
  the 
  real 
  units 
  of 
  some 
  of 
  the 
  larger 
  species 
  

   of 
  his 
  country. 
  

  

  From 
  the 
  evidence 
  given 
  by 
  these 
  eminent 
  

   authorities, 
  we 
  may 
  conclude 
  that 
  systematic 
  

   species, 
  as 
  they 
  are 
  accepted 
  nowadays, 
  are 
  as 
  

   a 
  rule 
  compound 
  groups. 
  Sometimes 
  they 
  con- 
  

   sist 
  of 
  two 
  or 
  three, 
  or 
  a 
  few 
  elementary 
  types, 
  

   but 
  in 
  other 
  cases 
  they 
  comprise 
  twenty, 
  or 
  fifty, 
  

   or 
  even 
  hundreds 
  of 
  constant 
  and 
  well 
  differen- 
  

   tiated 
  forms. 
  

  

  The 
  inner 
  constitution 
  of 
  these 
  groups 
  is 
  

   however, 
  not 
  at 
  all 
  the 
  same 
  in 
  all 
  cases. 
  This 
  

   will 
  be 
  seen 
  by 
  the 
  description 
  of 
  some 
  of 
  the 
  

   more 
  interesting 
  of 
  them. 
  The 
  European 
  

   heartsease, 
  from 
  which 
  our 
  garden-pansies 
  have 
  

   been 
  chiefly 
  derived, 
  will 
  serve 
  as 
  an 
  example. 
  

   The 
  garden-pansies 
  are 
  a 
  hybrid 
  race, 
  won 
  by 
  

   crossing 
  the 
  Viola 
  tricolor 
  with 
  the 
  large 
  flow- 
  

   ered 
  and 
  bright 
  yellow 
  V. 
  lutea. 
  They 
  com- 
  

   bine, 
  as 
  everyone 
  knows, 
  in 
  their 
  wide 
  range 
  of 
  

  

  