﻿34S 
  Rickett: 
  Sphaerocarpos 
  Doxxellii 
  

  

  thallus, 
  especially 
  the 
  involucres, 
  are 
  broken 
  off 
  or 
  partly 
  broken 
  

   off, 
  and 
  are 
  in 
  contact 
  with 
  the 
  soil. 
  Regeneration 
  is 
  most 
  easily 
  

   observed 
  if 
  separated 
  portions 
  of 
  the 
  involucres 
  are 
  cultivated 
  in 
  

  

  r 
  

  

  water. 
  Shoots 
  may 
  be 
  produced 
  either 
  on 
  the 
  inside 
  or 
  on 
  the 
  

   outside 
  of 
  the 
  involucre, 
  and 
  rhizoids 
  are 
  produced 
  at 
  the 
  same 
  

   time, 
  especially 
  in 
  the 
  neighborhood 
  of 
  the 
  shoots. 
  When 
  shoots 
  

   develop 
  on 
  the 
  inside 
  of 
  the 
  involucre, 
  it 
  is 
  necessary 
  for 
  them 
  to 
  

   curve 
  about 
  so 
  as 
  to 
  emerge; 
  if 
  formed 
  on 
  the 
  outside 
  of 
  the 
  

   involucre, 
  they 
  grow 
  straight 
  outward. 
  A 
  shoot 
  is 
  formed 
  as 
  a 
  cell 
  

   mass 
  arising 
  from 
  a 
  single 
  cell. 
  At 
  the 
  tip 
  of 
  this 
  body 
  is 
  formed 
  

   the 
  growing 
  point. 
  Right 
  and 
  left 
  from 
  this, 
  flat 
  wings 
  develop. 
  

   Sometimes 
  a 
  long 
  germ-tube 
  is 
  first 
  formed, 
  consisting 
  of 
  many 
  

   cells. 
  In 
  such 
  a 
  case, 
  the 
  whole 
  structure 
  resembles 
  a 
  sporeling, 
  

   except 
  that 
  the 
  formation 
  of 
  the 
  flat 
  plate 
  at 
  the 
  end 
  of 
  the 
  germ- 
  

   tube 
  is 
  not 
  at 
  right 
  angles 
  to 
  the 
  germ-tube, 
  but 
  simply 
  a 
  spreading 
  

   out 
  and 
  flattening 
  of 
  the 
  latter. 
  The 
  history, 
  except 
  in 
  a 
  few 
  

   cases, 
  is 
  not 
  so 
  simple 
  as 
  that 
  described 
  by 
  Leitgeb, 
  the 
  wings 
  not 
  

   necessarily 
  lying 
  in 
  one 
  plane, 
  and 
  the 
  formation 
  of 
  the 
  flat 
  plate 
  

   resulting 
  from 
  the 
  spreading 
  out 
  of 
  the 
  first 
  cylindrical 
  body. 
  

   Sometimes 
  one 
  of 
  the 
  wings 
  goes 
  on 
  to 
  develop 
  into 
  a 
  thallus, 
  

   apparently 
  because 
  the 
  development 
  of 
  the 
  growing 
  region 
  between 
  

   the 
  two 
  wings 
  was 
  arrested. 
  Goebel 
  compares 
  the 
  formation 
  of 
  

   these 
  adventitious 
  shoots 
  with 
  spore 
  germination, 
  and 
  emphasizes 
  

   the 
  fact 
  that 
  they 
  may 
  develop 
  either 
  almost 
  exactly 
  as 
  does 
  a 
  

   sporeling, 
  namely 
  by 
  the 
  formation 
  of 
  a 
  flat 
  plate 
  of 
  cells 
  from 
  the 
  

   terminal 
  group 
  of 
  cells 
  of 
  the 
  germ-tube, 
  or 
  by 
  a 
  direct 
  and 
  simple 
  

   flattening 
  out 
  of 
  the 
  primary 
  cell 
  mass, 
  which 
  fact 
  shows 
  of 
  how 
  

   little 
  value 
  is 
  any 
  sharp 
  distinction 
  between 
  these 
  two 
  methods 
  in 
  

   a 
  discussion 
  of 
  spore 
  germination. 
  

  

  I 
  first 
  noticed 
  the 
  occurrence 
  of 
  regeneration 
  in 
  searching 
  for 
  

   germinating 
  spores 
  In 
  soil 
  cultures 
  of 
  S. 
  Donnellii 
  Aust. 
  Many 
  

   small 
  plants 
  which 
  I 
  picked 
  up 
  proved 
  to 
  have 
  no 
  spore 
  wall 
  

   attached 
  at 
  the 
  basal 
  end, 
  and 
  In 
  some 
  cases 
  were 
  found 
  instead 
  

   to 
  be 
  attached 
  to 
  old 
  dead 
  portions 
  of 
  tissue. 
  In 
  these 
  cases 
  the 
  

   plants 
  were 
  of 
  a 
  ribbon-like 
  form, 
  broadening 
  out 
  a 
  little 
  at 
  the 
  

   anterior 
  end. 
  In 
  cultures 
  made 
  later 
  for 
  the 
  purpose 
  of 
  obtaining 
  

   regeneration, 
  the 
  young 
  plants 
  were 
  broader 
  and 
  less 
  ribbon- 
  

   shaped. 
  The 
  light 
  conditions 
  under 
  which 
  these 
  latter 
  plants 
  

  

  