﻿T. 
  Holm 
  — 
  Studies 
  in 
  the 
  Cyperacece. 
  125 
  

  

  face 
  of 
  the 
  blade 
  to 
  that 
  of 
  the 
  inferior. 
  This 
  parenchyma- 
  

   sheath 
  is 
  not 
  green 
  in 
  our 
  plant, 
  but 
  colorless. 
  

  

  The 
  mestome-bundles 
  are, 
  furthermore, 
  surrounded 
  by 
  a 
  

   rather 
  thick-walled 
  mestome-sheath 
  (M. 
  S. 
  in 
  fig. 
  7) 
  which 
  

   forms 
  an 
  uninterrupted 
  ring 
  all 
  around 
  the 
  leptome 
  and 
  

   hadrome. 
  The 
  group 
  of 
  leptome 
  is 
  very 
  well 
  differentiated 
  

   and 
  the 
  hadrome 
  contains 
  a 
  larger 
  number 
  of 
  vessels, 
  especially 
  

   ring-vessels, 
  than 
  is 
  usually 
  observed 
  in 
  Carex. 
  On 
  both 
  faces 
  

   of 
  the 
  mestome-bundles 
  are 
  groups 
  of 
  stereome 
  (St. 
  in 
  fig. 
  7) 
  

   which 
  show 
  the 
  same 
  structure 
  as 
  generally 
  known 
  in 
  this 
  

   genus. 
  This 
  tissue, 
  the 
  stereome, 
  forms 
  also 
  an 
  isolated 
  group 
  

   in 
  the 
  leaf-margin 
  itself. 
  

  

  One 
  feature 
  seems, 
  however, 
  somewhat 
  striking, 
  when 
  we 
  

   consider 
  a 
  number 
  of 
  transverse 
  sections 
  from 
  the 
  entire 
  width 
  

   of 
  the 
  blade, 
  viz 
  : 
  the 
  uniformity 
  in 
  size 
  and 
  development 
  of 
  

   the 
  mestome-bundles, 
  at 
  the 
  same 
  time 
  as 
  we 
  observe 
  the 
  

   equality 
  in 
  thickness 
  of 
  the 
  mesophyll 
  between 
  the 
  mestome- 
  

   bundles. 
  There 
  is, 
  generally, 
  in 
  the 
  broad-leaved 
  species 
  of 
  

   Carex 
  a 
  distinct 
  difference 
  to 
  be 
  found 
  in 
  regard 
  to 
  the 
  size 
  of 
  

   the 
  mestome-bundles, 
  besides 
  that 
  the 
  mesophyll 
  often 
  becomes 
  

   constricted 
  in 
  certain 
  places 
  so 
  as 
  to 
  leave 
  room 
  for 
  groups 
  of 
  

   bulliform-cells, 
  which 
  as 
  stated 
  above 
  are 
  absent 
  in 
  our 
  plant. 
  

   The 
  sections 
  of 
  the 
  leaf, 
  as 
  described 
  above, 
  were 
  all 
  taken 
  

   from 
  the 
  middle 
  of 
  the 
  blade, 
  and 
  we 
  will 
  now 
  examine 
  the 
  

   very 
  base 
  of 
  the 
  same 
  leaf, 
  which 
  in 
  the 
  other 
  Carices 
  forms 
  a 
  

   closed 
  sheath, 
  but 
  which 
  is 
  free 
  and 
  merely 
  convolute 
  in 
  our 
  

   plant. 
  Such 
  sections, 
  taken 
  from 
  the 
  base 
  of 
  the 
  leaf, 
  show 
  a 
  

   structure 
  much 
  like 
  that 
  we 
  have 
  described 
  for 
  the 
  broad 
  part 
  

   of 
  the 
  blade. 
  We 
  merely 
  note 
  that 
  the 
  groups 
  of 
  stereome 
  

   are 
  longer 
  and 
  much 
  more 
  narrow, 
  besides 
  tbat 
  their 
  cells 
  have 
  

   a 
  considerably 
  larger 
  lumen. 
  The 
  mestome-bundles 
  themselves 
  

   show 
  a 
  somewhat 
  weaker 
  development, 
  and 
  the 
  lacunes 
  are 
  

   much 
  reduced 
  in 
  size 
  from 
  what 
  we 
  have 
  observed 
  higher 
  up 
  

   in 
  the 
  leaf. 
  

  

  The 
  structure 
  of 
  the 
  utriculus 
  may 
  be 
  described 
  in 
  this 
  place. 
  

   Its 
  thin, 
  bladderlike 
  texture 
  (fig. 
  8) 
  is 
  due 
  to 
  the 
  extraordinary 
  

   thin 
  cell-walls 
  of 
  not 
  only 
  the 
  epidermis, 
  but 
  also 
  of 
  the 
  meso- 
  

   phyll 
  underneath 
  this. 
  A 
  few 
  mestome-bundles 
  are 
  observable, 
  

   all 
  of 
  which 
  are 
  very 
  weakly 
  developed, 
  especially 
  in 
  regard 
  to 
  

   the 
  hadrome-part, 
  and 
  the 
  cells 
  of 
  the 
  supporting 
  stereome 
  are 
  

   relatively 
  very 
  thin-walled. 
  Utriculus, 
  so 
  far, 
  corresponds 
  to 
  

   "Wilczek's 
  second 
  type 
  (1. 
  c), 
  characterized 
  by 
  its 
  thin 
  structure 
  

   and 
  the 
  non-differentiation 
  of 
  the 
  mesophyll. 
  

  

  The 
  pericarp 
  shows 
  a 
  similar 
  thin 
  texture 
  and 
  is 
  composed 
  

   of 
  three 
  tissues, 
  viz 
  : 
  a 
  very 
  thin-walled 
  epidermis, 
  a 
  stratum 
  

   of 
  three 
  rows 
  of 
  relatively 
  thick-walled 
  sclereids, 
  and 
  finally 
  a 
  

   layer 
  of 
  horizontally 
  stretched 
  cells, 
  which 
  form 
  the 
  inner 
  

  

  