﻿264 
  Retrograde 
  Varieties 
  

  

  the 
  mixed 
  characters. 
  Both 
  parents 
  bear 
  large 
  

   capsules 
  with 
  an 
  abundance 
  of 
  seed, 
  but 
  in 
  the 
  

   hybrids 
  the 
  capsules 
  remain 
  narrow 
  and 
  weak, 
  

   ripening 
  not 
  more 
  than 
  one-tenth 
  the 
  usual 
  

   quantity 
  of 
  seed. 
  Both 
  parents 
  are 
  easily 
  

   cultivated 
  in 
  annual 
  generations 
  and 
  the 
  same 
  

   holds 
  good 
  for 
  the 
  hybrid. 
  But 
  whereas 
  the 
  

   hybrid 
  of 
  muricata 
  and 
  biennis 
  is 
  a 
  stout 
  plant, 
  

   this 
  type 
  is 
  weak 
  with 
  badly 
  developed 
  foliage, 
  

   and 
  very 
  long 
  strict 
  spikes. 
  Perhaps 
  it 
  was 
  

   not 
  able 
  to 
  withstand 
  the 
  bad 
  weather 
  of 
  the 
  

   last 
  few 
  years. 
  

  

  A 
  goodly 
  number 
  of 
  constant 
  hybrids 
  are 
  de- 
  

   scribed 
  in 
  literature, 
  or 
  cultivated 
  in 
  fields 
  and 
  

   gardens. 
  In 
  such 
  cases 
  the 
  essential 
  question 
  

   is 
  not 
  whether 
  they 
  are 
  now 
  constant, 
  but 
  

   whether 
  they 
  have 
  been 
  so 
  from 
  the 
  beginning, 
  

   or 
  whether 
  they 
  prove 
  to 
  be 
  constant 
  whenever 
  

   the 
  original 
  cross 
  is 
  repeated. 
  For 
  constant 
  

   hybrids 
  may 
  also 
  be 
  the 
  issue 
  of 
  incipient 
  split- 
  

   tings, 
  as 
  we 
  shall 
  soon 
  see. 
  

  

  Among 
  other 
  examples 
  we 
  may 
  begin 
  with 
  

   the 
  hybrid 
  alfalfa 
  or 
  hybrid 
  lucerne 
  (Medicago 
  

   media). 
  It 
  often 
  originates 
  spontaneously 
  be- 
  

   tween 
  the 
  common 
  purple 
  lucerne 
  or 
  alfalfa 
  

   and 
  its 
  wild 
  ally 
  with 
  yellow 
  flowers 
  and 
  pro- 
  

   cumbent 
  stems, 
  the 
  Medicago 
  falcata. 
  This 
  

   hybrid 
  is 
  cultivated 
  in 
  some 
  parts 
  of 
  Germany 
  

   on 
  a 
  large 
  scale, 
  as 
  it 
  is 
  more 
  productive 
  than 
  

  

  