﻿T. 
  Holm 
  — 
  Studies 
  in 
  the 
  Cyperacece. 
  127 
  

  

  starch. 
  Considered 
  as 
  a 
  whole, 
  the 
  structure 
  of 
  the 
  rhizome 
  of 
  

   our 
  plant 
  agrees 
  in 
  most 
  respects 
  with 
  that 
  of 
  a 
  number 
  of 
  

   other 
  species, 
  which 
  bj 
  Laux 
  (1. 
  c.) 
  has 
  been 
  classified 
  as 
  repre- 
  

   senting 
  his 
  eighth 
  type. 
  

  

  The 
  roots 
  of 
  Carex 
  Fraseri 
  are 
  numerous 
  and 
  cover 
  the 
  

   short 
  rhizome 
  with 
  a 
  dense 
  mass 
  of 
  long 
  and 
  strong 
  fibers. 
  

   The 
  interior 
  structure 
  of 
  the 
  root 
  in 
  the 
  Cyperacece 
  has 
  long 
  

   since 
  been 
  most 
  ably 
  discussed 
  by 
  Treub 
  (1. 
  c.) 
  and 
  Klinge 
  (1. 
  c), 
  

   whose 
  comparative 
  studies 
  have 
  given 
  us 
  the 
  principal 
  features 
  

   by 
  which 
  the 
  Cyperacece 
  may 
  be 
  distinguished 
  from 
  the 
  

   Graminece 
  and 
  other 
  families 
  of 
  the 
  Monocotyledonece. 
  We 
  

   have 
  learned, 
  for 
  instance, 
  that 
  the 
  inner 
  bark 
  cells 
  in 
  the 
  roots 
  

   of 
  the 
  Grasses 
  collapse 
  radially, 
  while 
  tangentially 
  in 
  the. 
  

   Cyperacece. 
  Another 
  and 
  very 
  distinct 
  character 
  is 
  that 
  in 
  the 
  

   Caricece 
  the 
  protohadrotne 
  borders 
  immediately 
  on 
  the 
  endo- 
  

   dermis, 
  thus 
  interrupting 
  the 
  pericambium. 
  The 
  root 
  of 
  our 
  

   plant 
  shows 
  now 
  the 
  following 
  structure 
  : 
  an 
  epidermis 
  of 
  

   usual 
  form 
  ; 
  a 
  bark-parenchyma 
  of 
  about 
  ten 
  layers 
  of 
  roundish, 
  

   thick- 
  walled 
  cells, 
  some 
  of 
  which 
  collapse 
  tangentially 
  and 
  

   form 
  thereby 
  lacunes 
  of 
  very 
  considerable 
  width. 
  The 
  inner- 
  

   most 
  layer 
  of 
  the 
  bark 
  is 
  differentiated 
  as 
  an 
  endodermis, 
  the 
  

   cells 
  of 
  which 
  are 
  thickened 
  so 
  as 
  to 
  represent 
  a 
  typical 
  U- 
  

   endodermis. 
  We 
  observe, 
  thereupon, 
  the 
  pericambium, 
  which 
  

   in 
  our 
  species 
  forms 
  a 
  completely 
  closed 
  ring, 
  without 
  being 
  

   interrupted 
  by 
  the 
  protohadrome. 
  This 
  fact 
  seems 
  to 
  form 
  a 
  

   very 
  singular 
  character 
  of 
  our 
  plant, 
  thus 
  differing 
  from 
  all 
  

   the 
  other 
  Caricece 
  which 
  have 
  hitherto 
  been 
  examined. 
  

  

  The 
  central 
  cylinder 
  is 
  occupied 
  by 
  six 
  relatively 
  large 
  

   groups 
  of 
  hadrome 
  in 
  alternation 
  with 
  groups 
  of 
  leptome, 
  

   besides 
  the 
  distinct 
  but 
  small 
  elements 
  of 
  the 
  protohadrome, 
  

   situated 
  close 
  to 
  the 
  pericambium. 
  The 
  greater 
  part 
  of 
  the 
  

   central 
  cylinder 
  is, 
  however, 
  occupied 
  by 
  a 
  mass 
  of 
  conjunc- 
  

   tive 
  tissue,* 
  which 
  surrounds 
  the 
  vessels 
  and 
  forms 
  in 
  the 
  

   center 
  of 
  the 
  root 
  a 
  very 
  compact 
  tissue 
  of 
  rather 
  large 
  and 
  

   thick-walled 
  cells, 
  the 
  cell-walls 
  being 
  strongly 
  lignified. 
  

  

  If 
  we 
  will 
  now 
  consider 
  these 
  morphological 
  and 
  anatomical 
  

   characters, 
  which 
  we 
  have 
  observed 
  in 
  Carex 
  Fraseri, 
  it 
  may 
  

   not 
  be 
  denied 
  that 
  this 
  species 
  is 
  one 
  of 
  the 
  most 
  remarkable 
  

   in 
  the 
  whole 
  genus, 
  at 
  least 
  of 
  those 
  which, 
  so 
  far, 
  have 
  been 
  

   examined 
  by 
  the 
  various 
  authors. 
  

  

  The 
  monopodial 
  ramification 
  of 
  its 
  rhizome 
  with 
  its 
  single 
  

   assimilating 
  leaf 
  destitute 
  of 
  sheath, 
  ligule, 
  epidermal 
  expan- 
  

   sions 
  and 
  bulliform-cells 
  in 
  connection 
  with 
  its 
  flat 
  and 
  hollow 
  

   stem, 
  besides 
  the 
  uninterrupted 
  pericambium 
  of 
  the 
  root, 
  con- 
  

   stitute 
  a 
  structure 
  that 
  seems 
  almost 
  unique 
  in 
  the 
  family 
  of 
  

   the 
  Cyperacece. 
  

  

  * 
  Kussow's 
  ■ 
  ' 
  Geleitzellen 
  " 
  (1. 
  a), 
  Klinge's 
  " 
  Leitzellen 
  " 
  (1. 
  c.) 
  and 
  Yan 
  Tieghern's 
  

   "Cellules 
  conjunctives" 
  (1. 
  a). 
  

  

  