﻿Origin 
  of 
  Peloric 
  Toadflax 
  471 
  

  

  tation, 
  it 
  seems 
  worth 
  while 
  to 
  give 
  some 
  details 
  

   regarding 
  their 
  fertilization. 
  

  

  Isolated 
  plants 
  of 
  Linaria 
  vulgaris 
  do 
  not 
  

   produce 
  seed, 
  even 
  if 
  freely 
  pollinated 
  by 
  bees. 
  

   Pollen 
  from 
  other 
  plants 
  is 
  required. 
  This 
  re- 
  

   quirement 
  is 
  not 
  at 
  all 
  restricted 
  to 
  the 
  genus 
  

   Linaria, 
  as 
  many 
  instances 
  are 
  known 
  to 
  occur 
  

   in 
  different 
  families. 
  It 
  is 
  generally 
  assumed 
  

   that 
  the 
  pollen 
  of 
  any 
  other 
  individual 
  of 
  the 
  

   same 
  species 
  is 
  capable 
  of 
  producing 
  fertiliza- 
  

   tion, 
  although 
  it 
  is 
  to 
  be 
  said 
  that 
  a 
  critical 
  

   examination 
  has 
  been 
  made 
  in 
  but 
  few 
  instances. 
  

  

  This, 
  however, 
  is 
  not 
  the 
  case, 
  at 
  least 
  not 
  in 
  

   the 
  present 
  instance. 
  I 
  have 
  pollinated 
  a 
  num- 
  

   ber 
  of 
  plants, 
  grown 
  from 
  seed 
  of 
  the 
  same 
  

   strain 
  and 
  combined 
  them 
  in 
  pairs, 
  and 
  ex- 
  

   cluded 
  the 
  visits 
  of 
  insects, 
  and 
  pollen 
  other 
  

   than 
  that 
  of 
  the 
  plant 
  itself 
  and 
  that 
  of 
  the 
  spec- 
  

   imen 
  with 
  which 
  it 
  was 
  paired. 
  The 
  result 
  was 
  

   that 
  some 
  pairs 
  were 
  fertile 
  and 
  others 
  barren. 
  

   Counting 
  these 
  two 
  groups 
  of 
  pairs, 
  I 
  found 
  

   them 
  nearly 
  equal 
  in 
  number, 
  indicating 
  there- 
  

   by 
  that 
  for 
  any 
  given 
  individual 
  the 
  pollen 
  of 
  

   half 
  of 
  the 
  others 
  is 
  potent, 
  but 
  that 
  of 
  the 
  other 
  

   half 
  impotent. 
  From 
  these 
  facts 
  we 
  may 
  con- 
  

   clude 
  the 
  presence 
  of 
  a 
  curious 
  case 
  of 
  dimor- 
  

   phy, 
  analogous 
  to 
  that 
  proposed 
  for 
  the 
  prim- 
  

   roses, 
  but 
  without 
  visible 
  differentiating 
  marks 
  

   in 
  the 
  flowers. 
  At 
  least 
  such 
  opposite 
  charac- 
  

  

  