﻿T. 
  Holm 
  — 
  Studies 
  in 
  the 
  Cyperacece. 
  361 
  

  

  cylindric 
  with 
  a 
  mediane 
  groove 
  in 
  C. 
  elynoides, 
  and 
  condupli- 
  

   cate 
  in 
  the 
  others. 
  There 
  are 
  no 
  furrows 
  on 
  the 
  dorsal 
  face 
  of 
  

   the 
  blade 
  and 
  no 
  papillae 
  from 
  epidermis 
  protect 
  the 
  stomata 
  ; 
  

   short, 
  but 
  pointed 
  prickle-like 
  projections 
  from 
  epidermis 
  

   occur 
  along 
  the 
  keel 
  and 
  the 
  leaf-margins, 
  but 
  they 
  are 
  rela- 
  

   tively 
  few 
  in 
  number. 
  The 
  cuticle 
  is 
  very 
  distinct, 
  but 
  not 
  

   very 
  thick, 
  and 
  it 
  is 
  perfectly 
  smooth. 
  Epidermis 
  is 
  thick- 
  

   walled 
  with 
  the 
  exception 
  of 
  the 
  cone-cells, 
  and 
  viewed 
  

   superficially 
  we 
  notice 
  quite 
  a 
  considerable 
  difference 
  in 
  the 
  

   respective 
  length 
  of 
  the 
  cells 
  outside 
  the 
  stereome 
  and 
  the 
  

   palisade-tissue. 
  In 
  Oarex 
  elynoides 
  and 
  C. 
  oreocharis 
  the 
  cells 
  

   of 
  epidermis 
  outside 
  the 
  stereome 
  are 
  almost 
  quadrangular 
  

   with 
  nearly 
  straight 
  radial 
  walls, 
  while 
  they 
  are 
  rectangular 
  

   with 
  undulate 
  walls 
  in 
  those 
  strata 
  which 
  cover 
  the 
  mesophyll. 
  

   Similar 
  structure 
  of 
  epidermis 
  is, 
  as 
  we 
  remember, 
  especially 
  

   characteristic 
  of 
  the 
  Gramineod, 
  in 
  which, 
  however, 
  the 
  short 
  

   cells 
  show 
  often 
  a 
  stronger 
  silicification 
  than 
  the 
  others, 
  besides 
  

   they 
  are 
  frequently 
  more 
  or 
  less 
  fusiform 
  in 
  outline. 
  In 
  C. 
  

   filifolia 
  epidermis 
  shows 
  no 
  such 
  modification. 
  Stomata 
  are 
  

   present 
  on 
  the 
  lower 
  surface 
  outside 
  the 
  mesophyll 
  and 
  near 
  

   the 
  margins 
  on 
  the 
  upper 
  ; 
  they 
  show 
  the 
  same 
  structure 
  as 
  

   described 
  above 
  for 
  the 
  stem. 
  The 
  upper 
  face 
  of 
  the 
  blade 
  

   shows 
  an 
  epidermis 
  of 
  larger 
  cells, 
  and 
  one 
  row 
  of 
  true 
  bulli- 
  

   form 
  cells 
  were 
  observed 
  in 
  C. 
  oreocharis, 
  just 
  above 
  the 
  mid- 
  

   rib 
  ; 
  in 
  the 
  two 
  other 
  species 
  the 
  epidermis-cells 
  are 
  uniformly 
  

   developed, 
  none 
  being 
  bulliform, 
  but 
  we 
  find 
  in 
  these 
  two 
  

   species 
  a 
  secondary 
  epidermis 
  of 
  small 
  cells, 
  which 
  is 
  especially 
  

   distinct 
  above 
  the 
  midrib. 
  

  

  The 
  mesophyll 
  is 
  developed 
  in 
  a 
  very 
  different 
  manner 
  in 
  

   these 
  species. 
  In 
  C. 
  oreocharis 
  it 
  shows 
  a 
  distinct 
  palisade- 
  

   tissue, 
  the 
  cells 
  of 
  which 
  are 
  vertical 
  on 
  the 
  blade; 
  lacunes 
  are 
  

   to 
  be 
  found 
  between 
  the 
  mestome-bundles, 
  but 
  they 
  are 
  not 
  

   very 
  wide 
  and 
  do 
  not 
  extend 
  to 
  epidermis. 
  In 
  C. 
  filifolia 
  the 
  

   palisade-tissue 
  is 
  compact 
  and 
  borders 
  on 
  a 
  large 
  colorless 
  tissue, 
  

   which 
  occupies 
  the 
  upper 
  part 
  of 
  the 
  leaf, 
  and 
  which 
  is 
  broken 
  

   down 
  into 
  two 
  large 
  lacunes, 
  separated 
  from 
  each 
  other 
  by 
  a 
  

   narrow 
  layer 
  of 
  green 
  mesophyll 
  above 
  the 
  midrib. 
  In 
  the 
  

   leaf 
  of 
  C. 
  elynoides 
  Ave 
  find 
  a 
  relatively 
  narrow 
  palisade-tissue 
  

   on 
  the 
  lower 
  face 
  of 
  which 
  several 
  cells 
  radiate 
  towards 
  the 
  

   center 
  of 
  the 
  mestome-bundles 
  ; 
  the 
  greater 
  part 
  of 
  the 
  upper 
  

   face 
  is 
  occupied 
  by 
  an 
  enormous 
  mass 
  of 
  colorless 
  tissue, 
  which 
  

   is 
  partly 
  broken 
  down 
  into 
  a 
  continuous, 
  wide 
  lacune. 
  The 
  

   stereome 
  is 
  more 
  thick-walled 
  in 
  C. 
  filifolia 
  than 
  in 
  the 
  other 
  

   two 
  species. 
  It 
  occurs 
  as 
  hypodermal 
  groups 
  on 
  both 
  faces 
  of 
  

   the 
  blade, 
  accompanying 
  the 
  larger 
  mestome-bundles 
  in 
  C. 
  

   oreocharis, 
  w 
  T 
  hile 
  the 
  smaller 
  bundles 
  are 
  only 
  supported 
  by 
  a 
  

  

  Am. 
  Jour. 
  Sci.— 
  Fourth 
  Series, 
  Vol. 
  IX, 
  No. 
  53.— 
  May, 
  1900. 
  

   25 
  

  

  