﻿106 
  Elementary 
  Species 
  

  

  ical 
  culture 
  of 
  cereals 
  of 
  his 
  time. 
  In 
  his 
  poein 
  

   Georgics 
  (I. 
  197) 
  the 
  following 
  lines 
  are 
  found: 
  

  

  Vidi 
  lecta 
  diu, 
  et 
  rnulto 
  spectata 
  labore 
  

   Degenerare 
  tamen, 
  ni 
  vis 
  humana 
  quotannis 
  

   Maxima 
  quaeque 
  nianu 
  legeret. 
  

   (The 
  chosen 
  seed, 
  through 
  years 
  and 
  labor 
  

  

  improved, 
  

  

  Was 
  seen 
  to 
  run 
  back, 
  unless 
  yearly 
  

   Man 
  selected 
  by 
  hand 
  the 
  largest 
  and 
  fullest 
  

   of 
  ears.) 
  

  

  Elsewhere 
  Virgil 
  and 
  also 
  some 
  lines 
  of 
  

   Columella 
  and 
  Varro 
  go 
  to 
  prove 
  in 
  the 
  same 
  

   way 
  that 
  selection 
  was 
  applied 
  by 
  the 
  Romans 
  

   to 
  their 
  cereals, 
  and 
  that 
  it 
  was 
  absolutely 
  

   necessary 
  to 
  keep 
  their 
  races 
  pure. 
  There 
  is 
  

   little 
  doubt, 
  but 
  that 
  it 
  was 
  the 
  same 
  principle 
  

   as 
  that 
  which 
  has 
  led, 
  after 
  many 
  centuries, 
  to 
  

   the 
  complete 
  isolation 
  and 
  improvement 
  of 
  the 
  

   very 
  best 
  races 
  of 
  the 
  mixed 
  varieties. 
  It 
  fur- 
  

   ther 
  proves 
  that 
  the 
  mixed 
  conditions 
  of 
  the 
  

   cereals 
  was 
  known 
  to 
  man 
  at 
  that 
  time, 
  al- 
  

   though 
  distinct 
  ideas 
  of 
  specific 
  marks 
  and 
  dif- 
  

   ferences 
  were 
  of 
  course 
  still 
  wholly 
  lacking. 
  It 
  

   is 
  proof 
  also 
  that 
  cultivated 
  cereals 
  from 
  the 
  

   earliest 
  times 
  must 
  have 
  been 
  built 
  up 
  of 
  num- 
  

   erous 
  elementary 
  forms. 
  Moreover 
  it 
  is 
  very 
  

   probable, 
  that 
  in 
  the 
  lapse 
  of 
  centuries 
  a 
  good- 
  

   ly 
  number 
  of 
  such 
  types 
  must 
  have 
  disap- 
  

  

  