﻿210 
  Retrograde 
  Varieties 
  

  

  are 
  inspected 
  at 
  the 
  time 
  of 
  the 
  fullest 
  display 
  

   of 
  the 
  varietal 
  characters, 
  the 
  obvious 
  hybrids 
  

   will 
  be 
  eliminated, 
  but 
  the 
  hidden 
  ones 
  will 
  of 
  ne- 
  

   cessity 
  be 
  spared, 
  as 
  they 
  are 
  concealed 
  among 
  

   the 
  species 
  by 
  the 
  similarity 
  of 
  their 
  type. 
  

   Hence, 
  the 
  harvest 
  of 
  the 
  variety 
  may 
  be 
  ren- 
  

   dered 
  pure 
  or 
  nearly 
  so, 
  while 
  the 
  harvest 
  of 
  

   the 
  species 
  will 
  retain 
  the 
  seeds 
  of 
  the 
  hybrids. 
  

   Moreover 
  it 
  will 
  contain 
  seeds 
  originated 
  by 
  the 
  

   spontaneous 
  but 
  numerous 
  crosses 
  of 
  the 
  true 
  

   plants 
  with 
  the 
  sparsely 
  intermingled 
  hybrids. 
  

  

  This 
  brings 
  us 
  to 
  the 
  question, 
  as 
  to 
  what 
  will 
  

   be 
  the 
  visible 
  consequences 
  of 
  the 
  occurrence 
  of 
  

   such 
  invisible 
  hybrids 
  in 
  the 
  following 
  gener- 
  

   ation. 
  In 
  opposition 
  to 
  the 
  direct 
  effects 
  just 
  

   described, 
  we 
  may 
  call 
  them 
  indirect. 
  To 
  judge 
  

   of 
  their 
  influence, 
  we 
  must 
  know 
  how 
  hybrid 
  

   seeds 
  of 
  the 
  first 
  generation 
  behave. 
  

  

  In 
  one 
  of 
  our 
  lectures 
  we 
  will 
  deal 
  with 
  the 
  

   laws 
  that 
  show 
  the 
  numerical 
  relations 
  known 
  

   as 
  the 
  laws 
  of 
  Mendel. 
  But 
  for 
  our 
  present 
  

   purpose, 
  these 
  numerical 
  relations 
  are 
  only 
  of 
  

   subordinate 
  importance. 
  What 
  interests 
  us 
  here 
  

   is 
  the 
  fact 
  that 
  hybrids 
  of 
  varieties 
  do 
  not 
  re- 
  

   main 
  constant 
  in 
  the 
  second 
  generation 
  but 
  usu- 
  

   ally 
  split 
  as 
  it 
  is 
  said, 
  remaining 
  hybrid 
  

   only 
  in 
  part 
  of 
  their 
  offspring, 
  the 
  other 
  por- 
  

   tion 
  returning 
  to 
  the 
  parental 
  types. 
  This 
  how- 
  

   ever, 
  will 
  show 
  itself 
  only 
  in 
  those 
  individuals 
  

  

  