﻿202 
  Stork: 
  Studies 
  in 
  the 
  genus 
  Taraxacum 
  

  

  such 
  a 
  case. 
  The 
  term 
  apogamy, 
  so 
  far 
  as 
  its 
  inherent 
  meaning 
  

   goes, 
  applies, 
  but 
  this 
  term 
  has 
  received 
  a 
  special 
  significance 
  by 
  

   being 
  applied 
  to 
  embryo-origin 
  from 
  a 
  vegetative 
  cell. 
  Both 
  

   terms 
  are 
  therefore 
  objectionable, 
  and 
  the 
  diifficulty 
  is 
  due 
  to 
  the 
  

   fact 
  that 
  the 
  embryo 
  starts 
  from 
  a 
  cell 
  that 
  partakes 
  of 
  some 
  of 
  

   the 
  characters 
  of 
  an 
  egg 
  and 
  some 
  of 
  the 
  characters 
  of 
  a 
  vegetative 
  

   sporophyte 
  cell, 
  more 
  especially 
  its 
  diploid 
  chromosome 
  number. 
  

   An 
  arbitrary 
  compromise 
  was 
  therefore 
  reached 
  by 
  Winkler 
  (12) 
  in 
  

   the 
  adoption 
  of 
  the 
  expression, 
  "somatic 
  parthenogenesis." 
  It 
  

   would 
  seem 
  to 
  the 
  writer 
  much 
  more 
  logical 
  to 
  qualify 
  the 
  mean- 
  

   ing 
  of 
  the 
  term 
  parthenogenesis 
  by 
  the 
  use 
  of 
  the 
  more 
  specific 
  

   adjective, 
  diploid, 
  instead 
  of 
  by 
  the 
  general 
  adjective, 
  somatic, 
  

   for 
  it 
  is 
  only 
  that 
  one 
  character 
  of 
  a 
  somatic 
  cell, 
  the 
  possession 
  of 
  

   a 
  diploid 
  chromosome 
  number, 
  which 
  one 
  wishes 
  to 
  emphasize 
  in 
  

   connection 
  with 
  this 
  type 
  of 
  apomlxy. 
  In 
  all 
  its 
  other 
  characters 
  

   it 
  certainly 
  is 
  not 
  somatic. 
  Sears 
  (11) 
  has 
  coined 
  the 
  expression 
  

   amiotic 
  parthenogenesis,'* 
  The 
  writer 
  would 
  characterize 
  the 
  

  

  ti 
  

  

  condition 
  either 
  by 
  the 
  term 
  ''parthenogenesis" 
  modified 
  by 
  an 
  

   adjective, 
  as 
  "diploid" 
  or 
  "amiotic" 
  or 
  by 
  the 
  term, 
  "ooapo- 
  

   gamy." 
  The 
  latter 
  term 
  *has 
  been 
  used, 
  but 
  the 
  writer 
  is 
  at 
  

   present 
  unable 
  to 
  determine 
  who 
  is 
  responsible 
  for 
  the 
  expression* 
  

   Since 
  the 
  embryos 
  of 
  the 
  two 
  species 
  of 
  Taraxacum 
  in 
  question 
  

   arise 
  through 
  ooapogamy, 
  the 
  reduced 
  chromosome 
  number 
  does 
  

   not 
  enter 
  into 
  the 
  life 
  cycle 
  of 
  these 
  plants 
  and 
  amphimixis 
  is 
  

   wanting. 
  For 
  this 
  reason 
  they 
  suggested 
  themselves 
  as 
  good 
  

   objects 
  for 
  the 
  study 
  of 
  certain 
  genetical 
  problems. 
  Here 
  the 
  

   question 
  of 
  hybridization 
  is 
  completely 
  shut 
  out 
  at 
  the 
  present 
  

   stage 
  in 
  their 
  evolution. 
  It 
  is 
  possible 
  that 
  there 
  was 
  consider- 
  

   able 
  hybridization 
  at 
  one 
  time 
  in 
  the 
  phylogeny 
  of 
  the 
  genus. 
  

   We 
  must 
  accept 
  such 
  a 
  conclusion 
  if 
  we 
  believe 
  that 
  poly- 
  

   morphy 
  is 
  the 
  result 
  of 
  early 
  hybridization. 
  Did 
  the 
  ooapo- 
  

   gamous 
  species 
  lose 
  their 
  normal 
  sexuality 
  independently 
  of 
  one 
  

   another 
  after 
  they 
  had 
  arisen 
  through 
  hybridization, 
  or 
  did 
  this 
  

   loss 
  occur 
  in 
  a 
  single 
  species, 
  which 
  is 
  then 
  the 
  parent 
  species 
  from 
  

   which 
  were 
  evolved 
  the 
  present-day 
  ooapogamous 
  species? 
  

   Perhaps 
  the 
  latter 
  of 
  the 
  two 
  alternatives 
  would 
  seem 
  the 
  more 
  

   likely, 
  which 
  would 
  then 
  mean 
  that 
  mutation 
  had 
  played 
  a 
  part 
  

   In 
  their 
  production 
  in 
  the 
  absence 
  of 
  hybridization. 
  Dahlstedt 
  

  

  