﻿362 
  Weatherwax: 
  Structure 
  

  

  contrary 
  

  

  g 
  results 
  were 
  ob- 
  

  

  tained 
  with 
  an 
  ear 
  having 
  ten 
  rows 
  at 
  one 
  end 
  and 
  eighteen 
  at 
  

   the 
  other 
  (Fig. 
  i). 
  The 
  evidence 
  is 
  conclusive 
  that 
  the 
  difference 
  

   in 
  number 
  of 
  rows 
  is 
  due 
  to 
  the 
  discontinuance 
  of 
  a 
  row 
  of 
  pairs 
  

   of 
  spikelets 
  and 
  not 
  to 
  the 
  abortion 
  of 
  the 
  pedicelled 
  spikelets 
  of 
  

   two 
  such 
  row^s. 
  

  

  Figs. 
  4-6 
  show, 
  in 
  a 
  composite 
  camera 
  lucida 
  drawing, 
  a 
  

   belt 
  around 
  an 
  ear, 
  covering 
  the 
  point 
  of 
  transition 
  from 
  twelve 
  

   rows 
  to 
  ten. 
  The 
  structure 
  of 
  the 
  ear 
  shows 
  that 
  i 
  and 
  2, 
  3 
  and 
  4, 
  

   5 
  and 
  6, 
  etc., 
  are 
  respective 
  pairs 
  of 
  rows. 
  Fig. 
  5 
  shows 
  Collins 
  's 
  

   interpretation 
  of 
  the 
  loss 
  of 
  rows, 
  if 
  this 
  is 
  a 
  case 
  where 
  the 
  location 
  

   of 
  rows 
  can 
  be 
  determined 
  with 
  what 
  he 
  calls 
  "reasonable 
  cer- 
  

   tainty" 
  (p. 
  134); 
  rows 
  3 
  and 
  10, 
  representing 
  the 
  pedicelled 
  spike- 
  

   lets 
  of 
  their 
  respective 
  pairs, 
  are 
  dropped. 
  But 
  the 
  method 
  here 
  

   described 
  removes 
  all 
  doubt 
  and 
  is 
  applicable 
  to 
  all 
  ears 
  regardless 
  

   of 
  their 
  external 
  aspect. 
  It 
  shows, 
  as 
  in 
  Fig. 
  6, 
  that 
  the 
  two 
  

   rows 
  lost 
  constitute 
  one 
  pair. 
  

  

  It 
  is 
  probably 
  incorrect 
  to 
  speak 
  of 
  the 
  "loss" 
  of 
  rows 
  except 
  

   as 
  an 
  event 
  mcident 
  to 
  our 
  progress 
  in 
  examing 
  the 
  ear 
  from 
  one 
  

   end 
  to 
  the 
  other, 
  for 
  the 
  actual 
  loss 
  of 
  rows 
  in 
  this 
  case 
  is 
  probably 
  

   not^ 
  a 
  fact 
  of 
  either 
  phylogeny 
  or 
  ontogeny. 
  There 
  is 
  nothing 
  to 
  

   mdicate 
  that 
  the 
  short 
  rows 
  represent 
  long 
  rows 
  partially 
  aborted. 
  

   In 
  fact 
  the 
  abortion 
  of 
  spikelets 
  or 
  of 
  rows 
  in 
  the 
  ear 
  seems 
  to 
  be 
  

   much 
  more 
  constant 
  as 
  a 
  characteristic 
  of 
  theories 
  demanding 
  it 
  

   for 
  consistency 
  than 
  of 
  real 
  ears 
  of 
  corn; 
  and 
  the 
  integrity 
  of 
  the 
  

   pair 
  of 
  pistillate 
  spikelets 
  seems 
  to 
  be 
  maintained 
  quite 
  as 
  con- 
  

   stantly 
  in 
  maize 
  as 
  is 
  the 
  abortion 
  of 
  one 
  of 
  the 
  pair 
  in 
  teosinte. 
  

  

  Unuersity 
  of 
  Georgia, 
  

   Athens. 
  Georgia 
  

  

  