﻿m 
  

  

  Brown: 
  Apogamy 
  in 
  Osmunda 
  343 
  

  

  in 
  lb 
  and 
  le. 
  In 
  I 
  la 
  the 
  regularity 
  of 
  form 
  was 
  verj- 
  striking. 
  

   However, 
  at 
  the 
  end 
  of 
  eight 
  months 
  the 
  greatest 
  irregularity 
  of 
  

   form 
  was 
  shown 
  by 
  the 
  prothallia 
  of 
  la 
  and 
  Ic. 
  Many 
  of 
  these 
  

   were 
  elongated 
  plates 
  of 
  cells 
  with 
  the 
  margins 
  of 
  the 
  apices 
  

   extremely 
  irregular. 
  Branching 
  of 
  the 
  prothallia 
  occurred 
  in 
  the 
  

   cultures 
  of 
  the 
  following 
  solutions: 
  la, 
  lb, 
  Ic, 
  Id, 
  le 
  and 
  Ig, 
  being 
  

   especially 
  marked 
  in 
  la, 
  lb, 
  Ic 
  and 
  Id. 
  

  

  Sexual 
  organs, 
  both 
  male 
  and 
  female, 
  developed 
  in 
  various 
  

   cultures. 
  That 
  some 
  of 
  these 
  were 
  normal 
  was 
  shown 
  by 
  the 
  

  

  i 
  

  

  presence 
  of 
  young 
  spqrophytes, 
  which 
  developed 
  only 
  in 
  the 
  un- 
  

   modified 
  solutions 
  after 
  the 
  nutrient 
  solution 
  had 
  been 
  renewed. 
  

   Apogamous 
  outgrowths, 
  developed 
  on 
  prothallia 
  in 
  cultures 
  of 
  

   the 
  following 
  solutions, 
  eight 
  months 
  and 
  one 
  week 
  (March 
  9, 
  1917) 
  

   after 
  the 
  spores 
  were 
  sown 
  (Figs. 
  1-6): 
  I, 
  la, 
  lb 
  and 
  le. 
  In 
  

   another 
  attempt 
  to 
  induce 
  apogamy, 
  prothallia 
  were 
  transferred 
  

   from 
  cultures 
  of 
  I 
  (Prantl's 
  unmodified 
  solution) 
  to 
  la 
  four 
  weeks 
  

   after 
  the 
  spores 
  were 
  sown. 
  One 
  case 
  of 
  apogamy 
  in 
  these 
  cul- 
  

   tures 
  was 
  observed 
  (Fig. 
  7). 
  

  

  r 
  

  

  0, 
  Claytoniana, 
  — 
  At 
  the 
  end 
  of 
  three 
  weeks 
  the 
  average 
  size 
  of 
  

   the 
  prothallia 
  of 
  this 
  species 
  In 
  the 
  different 
  cultures 
  varied 
  from 
  

   one 
  to 
  thirty-three 
  cells. 
  As 
  in 
  0. 
  regalis 
  and 
  0. 
  cinnamomea 
  the 
  

   greatest 
  growth 
  occurred 
  in 
  la; 
  least 
  growth 
  occurred 
  in 
  Ic. 
  

   No 
  filamentous 
  stage 
  was 
  present 
  in 
  many 
  of 
  the 
  prothallia 
  of 
  the 
  

   unmodified 
  solutions, 
  a 
  longitudinal 
  wall 
  having 
  been 
  formed 
  in 
  

   the 
  first 
  cell. 
  In 
  other 
  prothallia 
  the 
  filamentous 
  stage 
  varied 
  

   from 
  five 
  cells 
  in 
  Ic 
  and 
  1/ 
  to 
  six 
  cells 
  in 
  Ila, 
  seven 
  cells 
  in 
  Ic 
  and 
  

  

  r 
  

  

  Ila 
  and 
  eight 
  cells 
  in 
  I^. 
  

  

  The 
  yoilng 
  prothallia 
  in 
  the 
  cultures 
  of 
  the 
  unmodified 
  solutions 
  

   I 
  and 
  II 
  and 
  the 
  modified 
  solutions 
  la, 
  lb, 
  Ic, 
  Ig 
  and 
  Ila 
  were 
  

   regular 
  in 
  form, 
  being 
  somewhat 
  elongated. 
  But 
  in 
  Id, 
  le, 
  

   If 
  and 
  Ila 
  the 
  form 
  of 
  the 
  majority 
  of 
  the 
  prothallia 
  was 
  very 
  

   irregular; 
  in 
  some 
  cases 
  they 
  were 
  broad, 
  in 
  others 
  elongated. 
  

   The 
  older 
  prothallia 
  (March 
  19, 
  191 
  7) 
  in 
  the 
  cultures 
  of 
  la, 
  lb, 
  

   Id, 
  Ig 
  and 
  Ila 
  showed 
  the 
  greatest 
  irregularity 
  of 
  size 
  and 
  form. 
  

   Those 
  of 
  Id 
  and 
  Ig 
  were 
  the 
  smallest 
  in 
  size, 
  while 
  those 
  of 
  la 
  and 
  

   lb 
  were 
  the 
  most 
  irregular 
  in 
  form, 
  some 
  of 
  the 
  prothallia 
  of 
  la 
  

  

  being 
  irregular 
  plates 
  of 
  cells. 
  

  

  No 
  branching 
  of 
  the 
  prothallia 
  was 
  observed 
  in 
  the 
  cultures 
  

  

  