﻿Experimental 
  Pedigree-Cultures 
  549 
  

  

  I 
  have 
  made 
  four 
  such 
  experiments, 
  each 
  com- 
  

   prising 
  the 
  handling 
  of 
  many 
  thousands 
  of 
  in- 
  

   dividual 
  plants, 
  and 
  lasting 
  through 
  five 
  to 
  nine 
  

   generations. 
  At 
  the 
  beginning 
  the 
  plants 
  were 
  

   biennial, 
  as 
  in 
  the 
  native 
  locality, 
  but 
  later 
  I 
  

   learned 
  to 
  cultivate 
  them 
  in 
  annual 
  genera- 
  

   tions. 
  They 
  have 
  been 
  started 
  from 
  different 
  

   plants 
  and 
  seeds, 
  introduced 
  from 
  the 
  original 
  

   field 
  into 
  my 
  garden 
  at 
  Amsterdam. 
  

  

  It 
  seems 
  sufficient 
  to 
  describe 
  here 
  one 
  of 
  

   these 
  pedigree-cultures, 
  as 
  the 
  results 
  of 
  all 
  four 
  

   were 
  similar. 
  In 
  the 
  fall 
  of 
  1886 
  I 
  took 
  nine 
  

   large 
  rosettes 
  from 
  the 
  field, 
  planted 
  them 
  to- 
  

   gether 
  on 
  an 
  isolated 
  spot 
  in 
  the 
  garden, 
  and 
  

   harvested 
  their 
  seeds 
  the 
  next 
  year. 
  These 
  nine 
  

   original 
  plants 
  are 
  therefore 
  to 
  be 
  considered 
  

   as 
  constituting 
  the 
  first 
  generation 
  of 
  my 
  race. 
  

   The 
  second 
  generation 
  was 
  sown 
  in 
  1888 
  and 
  

   flowered 
  in 
  1889. 
  It 
  at 
  once 
  yielded 
  the 
  ex- 
  

   pected 
  result. 
  15000 
  seedlings 
  were 
  tested 
  

   and 
  examined, 
  and 
  among 
  them 
  10 
  showed 
  

   diverging 
  characters. 
  They 
  were 
  properly 
  

   protected, 
  and 
  proved 
  to 
  belong 
  to 
  two 
  new 
  

   types. 
  5 
  of 
  them 
  were 
  lata 
  and 
  5 
  nanella. 
  

   They 
  flowered 
  next 
  year 
  and 
  displayed 
  all 
  the 
  

   characters 
  as 
  described 
  in 
  our 
  preceding 
  lec- 
  

   ture. 
  Intermediates 
  between 
  them 
  and 
  the 
  gen- 
  

   eral 
  type 
  were 
  not 
  found, 
  and 
  no 
  indication 
  of 
  

   their 
  appearance 
  was 
  noted 
  in 
  their 
  parents. 
  

  

  