﻿T. 
  Holm— 
  Studies 
  in 
  the 
  Gyperacece. 
  

  

  109 
  

  

  the 
  innermost 
  part 
  of 
  the 
  central-cylinder 
  was 
  occupied 
  by 
  

   conjunctive 
  tissue 
  with 
  four 
  large 
  vessels. 
  

  

  The 
  approaching 
  or 
  non-approaching 
  of 
  the 
  proto-hadrorae 
  

   to 
  the 
  endodermis 
  has 
  been 
  very 
  broadly 
  discussed 
  in 
  Klinge's 
  

   classical 
  work, 
  to 
  which 
  we 
  have 
  referred 
  in 
  several 
  of 
  our 
  

   previously 
  published 
  articles. 
  It 
  appears, 
  according 
  to 
  his 
  

   observations, 
  that 
  the 
  most 
  common 
  case 
  in 
  the 
  Cyperaceoe 
  is 
  

   that 
  the 
  proto-hadrome 
  borders 
  immediately 
  on 
  the 
  endodermis 
  ; 
  

   this 
  he 
  observed 
  in 
  a 
  number 
  of 
  European 
  species 
  of 
  Carex^ 
  

   also 
  in 
  some 
  species 
  of 
  Eriophorum^ 
  Scirpus^ 
  Heleochavis 
  and 
  

   of 
  Cyperics, 
  the 
  last 
  having 
  previously 
  been 
  studied 
  by 
  Duval- 
  

   Jouve. 
  However 
  in 
  a 
  few 
  species 
  of 
  Carex 
  : 
  hirta, 
  rJiynco- 
  

   physa 
  and 
  hordeiformis 
  he 
  observed 
  the 
  same 
  peculiarity 
  as 
  

   we 
  have 
  described 
  for 
  C. 
  stipata^ 
  that 
  not 
  all 
  of 
  the 
  proto- 
  

   hadrome 
  vessels 
  showed 
  this 
  position, 
  but 
  that 
  some 
  were 
  

   located 
  inside 
  the 
  pericambium. 
  Furthermore, 
  Klinge, 
  Yan 
  

  

  IK 
  

  

  m 
  

  

  Figs. 
  6 
  and 
  t. 
  Transverse 
  section 
  of 
  root 
  of 
  Carex 
  stipata. 
  B 
  = 
  bark-paren- 
  

   chyma; 
  End. 
  = 
  endodermis; 
  PH 
  = 
  proto-hadrome 
  ; 
  P 
  = 
  pericambium. 
  x 
  560 
  

   and 
  x400. 
  

  

  Tieghem 
  and 
  Duval-Jouve 
  discovered, 
  that 
  in 
  certain 
  species 
  

   of 
  Cyperus 
  and 
  Galilea 
  from 
  the 
  old 
  world 
  none 
  of 
  the 
  proto- 
  

   hadrome 
  vessels 
  bordered 
  on 
  endodermis. 
  In 
  the 
  North 
  

   American 
  Cyperacece, 
  which 
  we 
  have 
  studied 
  so 
  far, 
  we 
  have 
  

   constantly 
  ol3served 
  the 
  proto-hadrome 
  to 
  be 
  in 
  contact 
  with 
  

   endodermis, 
  the 
  only 
  exception 
  being 
  Carex 
  Fraseri, 
  Fim- 
  

   'bristylis 
  castanea, 
  and 
  this 
  particular 
  case, 
  described 
  above, 
  in 
  

   Carex 
  stipata. 
  This 
  is 
  the 
  more 
  interesting 
  since 
  it 
  seems, 
  

   also, 
  to 
  be 
  a 
  very 
  rare 
  case 
  in 
  the 
  old 
  world 
  species 
  of 
  Carex, 
  

   It 
  is 
  stated 
  by 
  Yan 
  Tieghem 
  as 
  characteristic 
  of 
  C. 
  hrizoides, 
  

  

  