﻿Unbalanced 
  Crosses 
  255 
  

  

  find 
  their 
  mates 
  in 
  the 
  cross, 
  so 
  these 
  two 
  will 
  

   also 
  meet 
  one 
  another. 
  They 
  will 
  unite 
  just 
  as 
  

   well 
  as 
  though 
  they 
  were 
  both 
  active 
  or 
  both 
  

   dormant. 
  For 
  essentially 
  they 
  are 
  the 
  same, 
  

   only 
  differing 
  in 
  their 
  degree 
  of 
  activity. 
  From 
  

   this 
  we 
  can 
  infer, 
  that 
  in 
  the 
  crossing 
  of 
  varie- 
  

   ties, 
  no 
  unpaired 
  remainder 
  is 
  left, 
  all 
  units 
  

   combining 
  in 
  pairs 
  exactly 
  as 
  in 
  ordinary 
  fertil- 
  

   ization. 
  

  

  Setting 
  aside 
  the 
  contrast 
  between 
  activity 
  

   and 
  latency 
  in 
  this 
  single 
  pair, 
  the 
  procedure 
  in 
  

   the 
  inter-crossing 
  of 
  varieties 
  is 
  the 
  same 
  as 
  in 
  

   ordinary 
  normal 
  fertilization. 
  

  

  Summarizing 
  this 
  discussion 
  we 
  may 
  con- 
  

   clude 
  that 
  in 
  normal 
  fertilization 
  and 
  in 
  the 
  

   inter-crossing 
  of 
  varieties 
  all 
  characters 
  are 
  

   paired, 
  while 
  in 
  crosses 
  between 
  elementary 
  

   species 
  the 
  differentiating 
  marks 
  are 
  not 
  mated. 
  

  

  In 
  order 
  to 
  distinguish 
  these 
  two 
  great 
  types 
  

   of 
  fertilization 
  we 
  will 
  use 
  the 
  term 
  bisexual 
  for 
  

   the 
  one 
  and 
  unisexual 
  for 
  the 
  other. 
  The 
  term 
  

   balanced 
  crosses 
  then 
  conveys 
  the 
  idea 
  of 
  com- 
  

   plete 
  bisexuality, 
  all 
  unit-characters 
  combining 
  

   in 
  pairs. 
  Unbalanced 
  crosses 
  are 
  those 
  in 
  which 
  

   one 
  or 
  more 
  units 
  do 
  not 
  find 
  their 
  mates 
  and 
  

   therefore 
  remain 
  unpaired. 
  This 
  distinction 
  

   was 
  proposed 
  by 
  Macfarlane 
  when 
  studying 
  

   the 
  minute 
  structure 
  of 
  plant-hybrids 
  in 
  com- 
  

   parison 
  with 
  that 
  of 
  their 
  parents 
  (1892). 
  

  

  