﻿174 
  Harper: 
  Inheritance 
  of 
  sugar 
  

  

  for 
  plants 
  at 
  least 
  the 
  visible 
  appearance 
  of 
  the 
  synaptic 
  knot 
  and 
  

   the 
  succeeding 
  pachyneme 
  spireme 
  suggest 
  that 
  at 
  this 
  stage 
  the 
  

   chromosome 
  pairs 
  may 
  become 
  very 
  intimately 
  combined 
  (Allen 
  

   '05). 
  On 
  a 
  priori 
  grounds 
  it 
  would 
  seem 
  unlikely 
  that 
  such 
  

   complex 
  and 
  labile 
  compounds 
  as 
  we 
  may 
  suppose 
  constitute 
  the 
  

   germ 
  plasms 
  should 
  enter 
  into 
  such 
  close 
  physical 
  relations 
  of 
  

   fusion 
  without 
  a 
  greater 
  or 
  less 
  amount 
  of 
  mixing 
  and 
  interaction 
  

   which 
  would 
  more 
  or 
  less 
  permanently 
  alter 
  their 
  character. 
  That 
  

   the 
  degree 
  of 
  such 
  interaction 
  should 
  be 
  the 
  same 
  in 
  every 
  case 
  even 
  

   of 
  the 
  same 
  cross 
  would 
  seem 
  to 
  be 
  quite 
  improbable. 
  It 
  would 
  

   be 
  natural 
  enough 
  that 
  many 
  grades 
  of 
  interaction 
  might 
  occur 
  

   in 
  the 
  synaptic 
  stages 
  leading 
  to 
  the 
  formation 
  of 
  the 
  eggs 
  on 
  a 
  

   single 
  ear 
  of 
  corn 
  or 
  the 
  pollen 
  grains 
  of 
  a 
  single 
  anther 
  sac. 
  The 
  

   possible 
  variability 
  suggested 
  by 
  the 
  cytological 
  data 
  as 
  to 
  synapsis 
  

   forms 
  a 
  natural 
  parallel 
  to 
  the 
  variable 
  degrees 
  of 
  mixing 
  of 
  the 
  

   sugar 
  and 
  starch 
  characters 
  shown 
  in 
  the 
  F2 
  hybrid 
  ears, 
  resulting 
  

   from 
  the 
  pairing 
  of 
  gametes 
  from 
  sugar 
  and 
  starch 
  corns 
  in 
  the 
  Fi- 
  

  

  SEXUAL 
  

  

  J 
  

  

  If 
  corn 
  endosperms 
  could 
  be 
  reproduced 
  vegetatively 
  such 
  in- 
  

   tergradations 
  as 
  we 
  are 
  discussing 
  would 
  doubtless 
  occur 
  as 
  bud 
  

   variations, 
  like 
  those 
  Stout 
  has 
  described 
  for 
  Coleus 
  ('15), 
  but 
  it 
  is 
  of 
  

   importance 
  to 
  note 
  that 
  here 
  they 
  regularly 
  follow 
  sexual 
  reproduc- 
  

   tion 
  and 
  it 
  seems 
  to 
  me 
  are 
  to 
  be 
  regarded 
  as 
  the 
  natural 
  expression 
  

   of 
  the 
  likelihood 
  that 
  processes 
  so 
  complex 
  as 
  we 
  now 
  know 
  those 
  

   of 
  sexual 
  reproduction 
  are, 
  should 
  result 
  in 
  a 
  higher 
  percentage 
  of 
  

   variants 
  than 
  results 
  from 
  purely 
  vegetative 
  reproduction 
  in- 
  

   volving 
  In 
  the 
  last 
  analysis 
  only 
  nuclear 
  and 
  cell 
  division. 
  We 
  

   need 
  perhaps 
  further 
  careful 
  statistical 
  studies 
  like 
  those 
  of 
  Stout 
  

   on 
  species 
  like 
  Coleus, 
  which 
  can 
  be 
  propagated 
  In 
  both 
  fashions 
  

   to 
  determine 
  the 
  relative 
  frequency 
  and 
  degree 
  of 
  bud 
  variation 
  

   as 
  compared 
  with 
  variation 
  in 
  sexually 
  reproduced 
  progeny. 
  As 
  

   it 
  is 
  we 
  have 
  the 
  experience 
  of 
  commercial 
  growers 
  that 
  in 
  many 
  

   cases 
  in 
  which 
  seed 
  progenies 
  are 
  quite 
  variable 
  progeny 
  produced 
  

   vegetatively 
  by 
  cuttings, 
  etc., 
  are 
  sufficiently 
  constant 
  to 
  be 
  a 
  

   reliable 
  means 
  of 
  introducing 
  and 
  propagating 
  important 
  types 
  

   of 
  fruits 
  and 
  vegetables. 
  No 
  one 
  questions 
  that 
  It 
  is 
  in 
  general 
  

   regarded 
  as 
  much 
  easier 
  to 
  establish 
  and 
  fix 
  a 
  new 
  variety 
  which 
  

  

  