﻿AND 
  STARCH 
  CHARACTERS 
  IN 
  CORN 
  139 
  

  

  retic 
  provision 
  

  

  breed 
  

  

  these 
  simple 
  hypotheses 
  allowed. 
  Among 
  Mendelians 
  as 
  well 
  as 
  

   others 
  there 
  is 
  now 
  coming 
  to 
  be 
  rather 
  general 
  agreement 
  that 
  

   visible 
  characters 
  are 
  due 
  to 
  several 
  or 
  even 
  numerous 
  more 
  or 
  less 
  

   independently 
  modifiable 
  or 
  varying 
  units 
  in 
  the 
  germ 
  plasm- 
  This 
  

   change 
  of 
  viewpoint 
  is 
  due 
  to 
  the 
  increasing 
  number 
  of 
  cases 
  which 
  

   show 
  more 
  complicated 
  results 
  from 
  crossing 
  individuals 
  differing 
  

   m 
  a 
  single 
  visible 
  character 
  than 
  are 
  provided 
  for 
  in 
  the 
  so-called 
  

   monohybrid 
  formula. 
  The 
  visible 
  data 
  in 
  many 
  such 
  cases 
  are 
  

   a 
  large 
  number 
  of 
  individuals 
  in 
  the 
  F^ 
  which 
  do 
  not 
  show 
  the 
  

   character 
  in 
  question 
  in 
  sharply 
  differentiated 
  form, 
  that 
  is, 
  the 
  

   occurrence 
  of 
  intermediates 
  as 
  the 
  older 
  authors 
  would 
  have 
  de- 
  

   scribed 
  them. 
  

  

  It 
  . 
  has 
  been 
  universally 
  shown 
  by 
  the 
  actual 
  data 
  that 
  in 
  

   crossing 
  sweet 
  corns 
  with 
  flints 
  in 
  certain 
  cases 
  at 
  least 
  inter- 
  

   mediate 
  kernels 
  appear 
  in 
  the 
  F2 
  which 
  are 
  not 
  so 
  plump 
  as 
  flints 
  

   and 
  not 
  so 
  wrinkled 
  as 
  a 
  good 
  quality 
  of 
  sugar 
  kernels, 
  but 
  there 
  

   has 
  been 
  a 
  general 
  tendency 
  to 
  disregard 
  these 
  facts 
  in 
  the 
  interest 
  

   of 
  maintaining 
  simple 
  Mendelian 
  expressions 
  for 
  the 
  results 
  of 
  

   such 
  crosses. 
  Whether 
  there 
  are 
  any 
  races 
  in 
  which 
  these 
  inter- 
  

   mediates 
  do 
  not 
  appear 
  is 
  not 
  altogether 
  clear. 
  

  

  Sturtevant 
  ( 
  '99) 
  reports 
  three 
  varieties 
  of 
  what 
  is 
  apparently 
  

   a 
  similar 
  intermediate 
  type 
  of 
  corn, 
  based 
  on 
  three 
  ears 
  sent 
  him 
  

   from 
  the 
  San 
  Padro 
  Indian 
  collection 
  of 
  Dr. 
  Palmer. 
  He 
  proposes 
  

   the 
  binomial 
  Zea 
  amyleasaccharata, 
  "Starchy-sweet 
  corn," 
  for 
  

   such 
  types 
  and 
  states 
  that 
  he 
  also 
  obtained 
  kernels 
  of 
  similar 
  ap- 
  

   pearance 
  from 
  Peru 
  in 
  1895. 
  Sturtevant 
  describes 
  all 
  these 
  

   types 
  as 
  having 
  the 
  upper 
  portion 
  of 
  the 
  kernel 
  sweet 
  and 
  the 
  

   lower 
  portion 
  starchy, 
  an 
  interesting 
  special 
  case 
  in 
  the 
  Inter- 
  

  

  gradi 
  

  

  Collins 
  and 
  Kempton 
  ('13 
  and 
  '14) 
  

  

  believe 
  that 
  in 
  the 
  offspring 
  of 
  crosses 
  bet^veen 
  sweet 
  and 
  waxy 
  

   varieties 
  irregularities 
  in 
  the 
  expected 
  Mendelian 
  ratios 
  are 
  due 
  

   to 
  a 
  "failure 
  of 
  some 
  sweet 
  seeds 
  to 
  develop 
  a 
  wrinkled 
  exterior." 
  

   Correns 
  ('01) 
  made 
  the 
  investigation 
  of 
  the 
  starch 
  and 
  sugar 
  

   characters 
  one 
  of 
  the 
  main 
  objects 
  of 
  his 
  classic 
  study 
  of 
  heredity 
  

   in 
  corn 
  and 
  has 
  recorded 
  his 
  observations 
  of 
  the 
  degree 
  of 
  wrinkling 
  

   of 
  the 
  kernels 
  in 
  the 
  Fi 
  and 
  F^ 
  generations 
  with 
  considerable 
  

   completeness. 
  But 
  Correns's 
  conclusions 
  and 
  interpretations 
  have 
  

  

  