﻿180 
  Harper: 
  Inheritance 
  of 
  sugar 
  

  

  processes. 
  The 
  congenital 
  characteristics 
  of 
  a 
  series 
  of 
  hybrid 
  

  

  r 
  

  

  offspring 
  from 
  the 
  same 
  pure 
  bred 
  parents 
  and 
  produced 
  at 
  the 
  

   same 
  time 
  are 
  not 
  to 
  be 
  expected 
  to 
  be 
  identical. 
  Offspring 
  from 
  

   inbreeding 
  or 
  from 
  selfing 
  in 
  a 
  so-called 
  pure 
  race 
  may 
  also 
  show 
  

   congenital 
  fluctuating 
  variations 
  due 
  to 
  the 
  inherent 
  nature 
  of 
  the 
  

   sexual 
  processes 
  and 
  quite 
  independent 
  of 
  the 
  so-called 
  racial 
  

   purity 
  of 
  the 
  parents 
  as 
  fixed 
  by 
  carefully 
  controlled 
  inbreeding. 
  

  

  The 
  endosperm 
  characters 
  of 
  corn 
  are 
  as 
  noted 
  especially 
  favor- 
  

   able 
  for 
  the 
  detection 
  of 
  such 
  phenomena 
  since 
  we 
  have 
  here 
  in 
  

   the 
  hundreds 
  of 
  kernels 
  from 
  the 
  middle 
  region 
  of 
  a 
  good-sized 
  

   selfed 
  or 
  inbred 
  ear 
  a 
  series 
  of 
  offspring 
  from 
  independent 
  

   matings 
  developed 
  to 
  maturity 
  under 
  practically 
  identical 
  environ- 
  

   mental 
  conditions 
  except 
  perhaps 
  for 
  a 
  slight 
  progressive 
  diminu- 
  

   tion 
  in 
  food 
  and 
  water 
  supply 
  as 
  we 
  proceed 
  from 
  the 
  butt 
  of 
  the 
  

   ear 
  to 
  its 
  tip 
  and 
  a 
  little 
  more 
  crowding 
  due 
  to 
  the 
  narrowing 
  of 
  

   the 
  ear 
  in 
  some 
  races. 
  The 
  effect 
  of 
  these 
  factors 
  on 
  endosperm 
  

   characters 
  is 
  apparently 
  so 
  slight 
  as 
  to 
  be 
  negligible. 
  Variations 
  

   between 
  the 
  kernels 
  under 
  these 
  conditions 
  are 
  to 
  be 
  characterized 
  

   from 
  their 
  time 
  of 
  origin 
  as 
  congenital 
  and 
  are 
  to 
  be 
  expected 
  to 
  

   be 
  more 
  or 
  less 
  fully 
  heritable 
  as 
  my 
  results 
  from 
  selecting 
  and 
  

   selfing 
  intermediate 
  kernels 
  between 
  the 
  sugar 
  and 
  starch 
  char- 
  

   acters 
  show 
  that 
  they 
  are.' 
  

  

  It 
  is 
  easy 
  to 
  assign 
  differences 
  between 
  flowers 
  or 
  leaves 
  on 
  

   the 
  same 
  plant 
  or 
  between 
  peas 
  or 
  beans 
  from 
  different 
  pods 
  or 
  

   from 
  the 
  ends 
  of 
  the 
  pods 
  as 
  compared 
  with 
  their 
  middle 
  region 
  to 
  

   the 
  effects 
  of 
  environment, 
  but 
  differences 
  between 
  peas 
  or 
  beans 
  

   from 
  the 
  middle 
  region 
  of 
  the 
  same 
  well-developed 
  pod 
  or 
  between 
  

   kernels 
  from 
  the 
  middle 
  region 
  of 
  a 
  large, 
  well-filled 
  ear 
  of 
  corn 
  

   must 
  be 
  congenital. 
  In 
  the 
  corn 
  especially 
  it 
  is 
  possible 
  to 
  obtain 
  

   numbers 
  large 
  enough 
  from 
  the 
  same 
  ear 
  to 
  study 
  such 
  variations 
  

   statistically 
  as 
  I 
  have 
  done 
  and 
  arrive 
  at 
  the 
  certainty 
  of 
  their 
  fluc- 
  

   tuating 
  and 
  none 
  the 
  less 
  more 
  or 
  less 
  fully 
  heritable 
  value. 
  

  

  A 
  further 
  advantage 
  afforded 
  by 
  corn 
  for 
  the 
  study 
  of 
  these 
  

   fluctuating 
  variations 
  is 
  found 
  in 
  the 
  practical 
  fact 
  that 
  these 
  

   endosperm 
  characters 
  are 
  permanent 
  and 
  the 
  ears 
  are 
  easily 
  

   stored 
  and 
  preserved 
  for 
  comparison 
  with 
  the 
  new 
  data 
  obtained 
  

   in 
  each 
  succeeding 
  year. 
  No 
  other 
  material 
  I 
  know 
  of 
  is 
  so 
  favor- 
  

   able 
  in 
  all 
  these 
  respects 
  for 
  the 
  careful 
  and 
  quantitative 
  study 
  of 
  

   the 
  inheritance 
  of 
  variations. 
  

  

  