﻿False 
  Atavism 
  195 
  

  

  yellow 
  ones, 
  and 
  from 
  the 
  variety 
  " 
  Delila 
  

   of 
  the 
  same 
  species 
  two 
  red 
  ones, 
  a 
  single 
  white 
  

   and 
  two 
  belonging 
  to 
  another 
  variety 
  called 
  

   " 
  Firefly.' 
  Calllopsis 
  tinctoria 
  has 
  three 
  va- 
  

   rieties, 
  the 
  ordinary 
  type, 
  a 
  brown-flowered 
  

   one 
  and 
  one 
  with 
  tubular 
  rays. 
  Seeds 
  of 
  each 
  

   of 
  these 
  three 
  sorts 
  ordinarily 
  contain 
  a 
  few 
  

   belonging 
  to 
  the 
  others. 
  Iberis 
  umbellata 
  rosea 
  

   often 
  gives 
  some 
  white 
  and 
  violet 
  examples. 
  

   The 
  li 
  Swan 
  " 
  variety 
  of 
  the 
  opium-poppy, 
  a 
  

   dwarfish 
  double-flowered 
  form 
  of 
  a 
  pure 
  white, 
  

   contained 
  some 
  single-flowered 
  and 
  some 
  red- 
  

   flowered 
  plants, 
  when 
  sown 
  from 
  commercial 
  seed 
  

   are 
  said 
  to 
  be 
  pure. 
  But 
  these 
  were 
  only 
  occa- 
  

   sional 
  admixtures, 
  since 
  after 
  artificial 
  fertiliza- 
  

   tion 
  of 
  the 
  typical 
  specimens 
  the 
  strain 
  at 
  once 
  

   became 
  absolutely 
  pure, 
  and 
  remained 
  so 
  for 
  a 
  

   series 
  of 
  generations, 
  as 
  long 
  as 
  the 
  experiment 
  

   was 
  continued. 
  Seeds 
  of 
  trees 
  often 
  contain 
  

   large 
  quantities 
  of 
  impurities, 
  and 
  the 
  laciniated 
  

   varieties 
  of 
  birch, 
  elder 
  and 
  walnut 
  have 
  often 
  

   been 
  observed 
  to 
  come 
  true 
  only 
  in 
  a 
  small 
  

   number 
  of 
  seedlings. 
  

  

  In 
  the 
  case 
  of 
  new 
  or 
  young 
  varieties, 
  seed- 
  

   merchants 
  often 
  warn 
  their 
  customers 
  as 
  to 
  the 
  

   probable 
  degree 
  of 
  purity 
  of 
  the 
  seeds 
  offered, 
  

   in 
  order 
  to 
  avoid 
  complaints. 
  For 
  example 
  the 
  

   snow-white 
  variety 
  of 
  the 
  double 
  daisy, 
  Bellis 
  

   perennis 
  plena, 
  was 
  offered 
  at 
  the 
  start 
  as 
  con- 
  

  

  