﻿False 
  Atavism 
  203 
  

  

  of 
  the 
  same 
  species, 
  if 
  cultivated 
  at 
  small 
  dis- 
  

   tances 
  apart, 
  say 
  40 
  - 
  50 
  meters 
  or 
  even 
  more. 
  

  

  Vicinism 
  therefore, 
  may 
  play 
  a 
  part 
  in 
  all 
  

   such 
  cultures, 
  enough 
  to 
  account 
  for 
  all 
  the 
  

   impurities 
  observed 
  in 
  the 
  nurseries 
  or 
  in 
  com- 
  

   mercial 
  seed-samples. 
  

  

  Of 
  course 
  this 
  whole 
  discussion 
  is 
  limited 
  to 
  

   such 
  species 
  as 
  are 
  not 
  only 
  as 
  a 
  rule 
  visited 
  by 
  

   insects, 
  but 
  are 
  dependent 
  on 
  these 
  visits 
  for 
  

   their 
  fertilization. 
  Most 
  of 
  our 
  garden-flowers 
  

   are 
  included 
  in 
  this 
  category. 
  If 
  not 
  then 
  we 
  

   may 
  expect 
  to 
  find 
  the 
  cultures 
  and 
  seeds 
  pure, 
  

   irrespective 
  of 
  the 
  distances 
  between 
  allied 
  va- 
  

   rieties, 
  as 
  for 
  instance 
  with 
  peas, 
  which 
  are 
  

   known 
  to 
  be 
  self-fertilizing. 
  Another 
  instance 
  

   is 
  given 
  by 
  the 
  barley. 
  One 
  of 
  the 
  most 
  curious 
  

   anomalous 
  varieties 
  of 
  this 
  cereal, 
  is 
  the 
  

   " 
  Nepaul-barley," 
  with 
  its 
  small 
  adventitious 
  

   flowers 
  on 
  the 
  palets 
  or 
  inner 
  scales. 
  It 
  is 
  a 
  

   very 
  old, 
  widely 
  cultivated 
  sort, 
  which 
  always 
  

   comes 
  true 
  from 
  seed, 
  and 
  which 
  has 
  been 
  

   tested 
  in 
  repeated 
  experiments 
  in 
  my 
  garden. 
  

   The 
  spikelets 
  of 
  this 
  curious 
  plant 
  are 
  one- 
  

   flowered 
  and 
  provided 
  with 
  two 
  linear 
  glumes 
  

   or 
  outer 
  scales. 
  Of 
  the 
  inner 
  scales 
  or 
  palets, 
  

   the 
  outer 
  one 
  is 
  three-lobed 
  at 
  the 
  summit, 
  hence 
  

   the 
  varietal 
  name 
  of 
  Horde 
  nm 
  vulgar 
  e 
  trifur- 
  

   catum. 
  The 
  central 
  lobe 
  is 
  oblong 
  and 
  hollow, 
  

   covering 
  a 
  small 
  supernumerary 
  floret 
  inserted 
  

  

  