﻿176 
  

  

  BOTANICAL 
  GAZETTE. 
  

  

  [ 
  J^^iy^ 
  

  

  the 
  newer 
  walls. 
  Tlie 
  process 
  

  

  of 
  grow^th 
  

  

  soon 
  obliterates 
  

  

  the 
  regular 
  arrangement 
  of 
  cill 
  but 
  the 
  first 
  tw^o 
  walls. 
  

  

  There 
  is 
  no 
  division 
  of 
  the 
  root-cap 
  segments 
  parallel 
  to 
  

  

  the 
  outer 
  surface 
  as 
  figured 
  by 
  GoebeP. 
  In 
  Equisetum 
  arvense 
  

  

  there 
  is 
  no 
  hypodermal 
  layer 
  as 
  

   in 
  Marsilia. 
  The 
  endodermis"^(d. 
  fig. 
  

   2) 
  divides 
  into 
  two 
  layers 
  at 
  about 
  

   the 
  5th 
  or 
  6th 
  segment^. 
  These 
  two 
  

   layers 
  are 
  not 
  further 
  divided 
  by 
  

   tangential 
  w^alls. 
  The 
  root-cap 
  di- 
  

   vides 
  for 
  a 
  wdiile, 
  in 
  the 
  same 
  way 
  as 
  

   in 
  Marsilia. 
  But 
  now 
  a 
  new 
  sort 
  of 
  

  

  ^^^^^ 
  .«.v^o 
  place. 
  This 
  is 
  not 
  

  

  noted 
  in 
  anv 
  of 
  the 
  authors 
  to 
  which 
  I 
  

  

  division 
  takes 
  

  

  have 
  access. 
  A 
  

  

  formed, 
  in 
  

  

  part 
  or 
  all 
  the 
  cells 
  of 
  the 
  root-cap 
  

   parallel 
  to 
  its 
  outer 
  surface 
  (fig- 
  i< 
  

   r" 
  and 
  r''') 
  . 
  As 
  growth 
  continues 
  and 
  

   the 
  cells 
  of 
  the 
  root-cap 
  diverge 
  from 
  

   the 
  apical 
  cell, 
  their 
  connection 
  

   with 
  each 
  other 
  becomes 
  looser 
  

   They 
  also 
  lose 
  

   somewhat 
  radial 
  

   the 
  first 
  the 
  

  

  their 
  regular 
  

  

  and 
  

   position. 
  From 
  

   _ 
  root-cap 
  is 
  distinctly 
  

   different 
  from 
  the 
  dermatogen, 
  and 
  

   in 
  a 
  less 
  degree 
  the 
  dermatogen, 
  pei; 
  

   iblem 
  and 
  plerome 
  are 
  differenti- 
  

   ated. 
  

  

  ^^rlll 
  P'^I^^.ffi" 
  imbedding 
  process 
  was 
  used 
  in 
  making 
  the 
  

   .fnin?rf/ 
  • 
  7 
  . 
  ^^Si? 
  ''^^^ 
  '^'^^ 
  '^^"m 
  cochineal 
  for 
  Equisetum. 
  

   ihXt! 
  "\ 
  i'-i 
  V'^ 
  ^'^^t^ 
  «^ 
  Equisetum 
  were 
  hardened 
  m 
  

  

  ■iorx 
  Wh' 
  ?^' 
  f'^'^'^S^' 
  chromic 
  acid 
  was 
  also 
  satisfac- 
  

   tor}. 
  When 
  hardened 
  in 
  nh.-r.r^:^ 
  „„:j 
  .u„ 
  „.„:„ 
  vvashes 
  

  

  is 
  

  

  Fig. 
  2. 
  

  

  out 
  -.nrl^Ilr 
  T"'*^'''''' 
  ^" 
  Chromic 
  acid, 
  the 
  stain 
  

   Tlt!!!li'''^'f''^'^' 
  .staining 
  on 
  the 
  slide. 
  

  

  HOUR*' 
  

  

  •I 
  form,, 
  In 
  ^o 
  .---—" 
  ,-"""'iiy 
  on 
  me 
  Slide. 
  The 
  following 
  

   a 
  tormula 
  of 
  the 
  methods 
  employed 
  : 
  

  

  Harden 
  in 
  absolute 
  alcohol 
  or 
  chromic 
  acid 
  3-S 
  

  

  Melted 
  paraffin 
  ""'^^ 
  (^'^^"rated 
  solution) 
  f 
  

  

  Imbed. 
  ^^^ 
  

  

  '^see 
  preceding 
  note. 
  

  

  .acfis. 
  Text-book, 
  p. 
  i2V>d 
  English 
  edition. 
  

  

  DeBary, 
  l.cpp. 
  122, 
  351, 
  -IH. 
  

  

  