﻿436 
  T. 
  Holm 
  — 
  Shcdies 
  in 
  the 
  Cyperacece. 
  

  

  the 
  leptome 
  is 
  partly 
  surrounded 
  by 
  the 
  hadrome. 
  This 
  form 
  

   of 
  bundle, 
  the 
  perihadromatic, 
  is 
  not 
  uncommon 
  in 
  monoco- 
  

   tyledonous 
  plants, 
  while 
  the 
  perileptomatic 
  type 
  is 
  especially 
  

   characteristic 
  of 
  the 
  Ferns. 
  

  

  The 
  mestome-bundles, 
  the 
  collateral 
  and 
  the 
  concentric, 
  

   show 
  a 
  still 
  more 
  advanced 
  development 
  in 
  the 
  rhizome 
  than 
  

   in 
  the 
  stem 
  above-ground, 
  viz., 
  the 
  hadrome 
  has 
  a 
  greater 
  

   number 
  of 
  pitted-ducts 
  and 
  the 
  leptome-groups 
  are 
  much 
  

   larger. 
  

  

  The 
  innermost 
  part 
  of 
  the 
  central- 
  cylinder 
  is, 
  as 
  stated 
  above, 
  

   occupied 
  by 
  a 
  mass 
  of 
  starch-bearing 
  fundamental 
  tissue. 
  The 
  

   stereome 
  is 
  rather 
  poorly 
  developed 
  in 
  the 
  rhizome 
  and 
  its 
  

   cells 
  are 
  rather 
  thin-walled. 
  It 
  is 
  here 
  restricted 
  to 
  the 
  mes- 
  

   tome-bundles 
  which 
  it 
  partly 
  surrounds, 
  and 
  it 
  seems 
  to 
  be 
  

   strongest 
  developed 
  on 
  the 
  hadrome 
  side, 
  the 
  inner 
  face 
  of 
  the 
  

   bundles. 
  Numerous 
  tannin-reservoirs 
  were 
  observed 
  to 
  be 
  

   scattered 
  around 
  in 
  the 
  groups 
  of 
  this 
  tissue, 
  the 
  stereome. 
  

  

  We 
  have 
  now 
  pointed 
  out 
  the 
  principal 
  anatomical 
  charac- 
  

   teristics 
  of 
  the 
  leaf 
  and 
  the 
  stem 
  with 
  their 
  various 
  modifica- 
  

   tions, 
  such 
  as 
  they 
  are 
  represented 
  in 
  our 
  genus, 
  and 
  we 
  might 
  

   finally 
  give 
  a 
  brief 
  sketch 
  of 
  the 
  root, 
  although 
  this 
  was 
  not 
  

   observed 
  to 
  possess 
  any 
  peculiarities 
  so 
  as 
  to 
  be 
  distinguished 
  

   from 
  that 
  of 
  the 
  majority 
  of 
  the 
  other 
  CyperacecB. 
  There 
  is, 
  

   inside 
  the 
  epidermis, 
  a 
  single 
  layer 
  of 
  very 
  thick-walled 
  

   cells, 
  which 
  form 
  a 
  closed 
  ring 
  around 
  the 
  broad 
  bark- 
  

   parenchyma, 
  in 
  which 
  a 
  few 
  tannin-reservoirs 
  are 
  to 
  be 
  seen. 
  

   The 
  bark 
  shows 
  the 
  characteristic 
  tangential 
  collapsing 
  of 
  

   some 
  of 
  the 
  cells, 
  and 
  its 
  innermost 
  layer 
  is 
  differentiated 
  as 
  an 
  

   endodermis. 
  The 
  pericambium 
  consists 
  merely 
  of 
  one 
  layer 
  

   of 
  cells, 
  which 
  are 
  interrupted 
  here 
  and 
  there 
  by 
  the 
  protoha 
  

   drome. 
  The 
  center 
  of 
  the 
  root 
  is 
  occupied 
  by 
  two 
  very 
  large 
  

   vessels, 
  which 
  alternate 
  with 
  the 
  corresponding 
  groups 
  of 
  

   leptome. 
  

  

  Washington, 
  D. 
  C, 
  December, 
  1896. 
  

  

  EXPLANATION 
  OF 
  FIGURES. 
  

   Anatomy 
  of 
  Dulichium. 
  

  

  Figure 
  1. 
  — 
  Transverse 
  section 
  of 
  the 
  median 
  part 
  of 
  the 
  leaf-blade, 
  showing 
  

   the 
  bulliform-cells 
  above 
  the 
  median 
  mestome-bundie. 
  x 
  320. 
  

  

  Figure 
  2. 
  — 
  Transverse 
  section 
  of 
  epidermis 
  of 
  leaf, 
  showing 
  a 
  siliciou3 
  cone 
  

   inside 
  one 
  of 
  the 
  epidermis-cells, 
  x 
  400. 
  

  

  Figure 
  3. 
  — 
  Tannin- 
  reservoirs 
  in 
  the 
  mesophyll 
  and 
  in 
  the 
  stereome 
  from 
  a 
  trans- 
  

   verse 
  section 
  of 
  the 
  leaf-blade, 
  the 
  upper 
  face. 
  The 
  black 
  -painted 
  

   cells 
  indicate 
  the 
  tannin-reservoirs 
  in 
  this 
  as 
  well 
  as 
  in 
  the 
  other 
  

   figures, 
  x 
  240. 
  

  

  Figure 
  4. 
  — 
  Tannin-reservoir 
  in 
  a 
  group 
  of 
  stereome 
  from 
  the 
  superior 
  face 
  of 
  

   the 
  leaf-blade, 
  x 
  400. 
  

  

  Figure 
  5. 
  — 
  A 
  large 
  mestome-bundie 
  from 
  the 
  leaf-blade, 
  transverse 
  section. 
  

   Three 
  of 
  the 
  epidermis-cells 
  contain 
  cones, 
  and 
  tanain-reservoirs 
  are 
  

   observable 
  in 
  the 
  mesophyll. 
  x 
  320. 
  

  

  