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  INTRODUCTION 
  TO 
  BOTANY 
  

  

  f.ix 
  

  

  chlorophyll-containing 
  tissues 
  in 
  such 
  a 
  position 
  that 
  they 
  

   may 
  receive 
  light 
  ; 
  at 
  the 
  same 
  time, 
  through 
  the 
  fibrovascu- 
  

   lar 
  bundles 
  of 
  the 
  leafstock 
  and 
  the 
  rhi/ome, 
  soil 
  water 
  and 
  

  

  substances 
  in 
  solution 
  may 
  be 
  

   transported 
  to 
  the 
  chlorophyll 
  

   tissue. 
  The 
  root 
  system 
  an- 
  

   chors 
  the 
  plant 
  in 
  the 
  earth 
  

   and 
  absorbs 
  the 
  water 
  needed 
  

   in 
  food 
  manufacture. 
  

  

  In 
  general, 
  plants 
  that 
  rise 
  

   above 
  the 
  soil 
  and 
  into 
  the 
  air 
  

   must 
  be 
  supported 
  and 
  must 
  

   secure 
  water 
  from 
  some 
  source. 
  

   The 
  climbing 
  vines 
  which 
  are 
  

   dependent 
  upon 
  other 
  plants 
  

   are 
  supported 
  chiefly 
  by 
  these 
  

   other 
  plants. 
  Most 
  vines 
  pro- 
  

   cure 
  their 
  supply 
  of 
  water 
  

   from 
  the 
  soil 
  and 
  transport 
  it 
  

   by 
  means 
  of 
  their 
  own 
  vascular 
  

   tissue. 
  Fibrovascular 
  tissue, 
  

   by 
  reason 
  of 
  its 
  strength, 
  

   makes 
  possible 
  the 
  upright 
  

   position 
  and 
  is 
  essential 
  (as 
  

   is 
  also 
  the 
  absorbing 
  and 
  an- 
  

   choring 
  root 
  system) 
  alike 
  to 
  

   the 
  iields 
  of 
  upright 
  grain 
  and 
  

   to 
  the 
  forests. 
  The 
  importance 
  

   of 
  vascular 
  tissue 
  in 
  ferns 
  

   and 
  higher 
  plants 
  can 
  hardly 
  

   be 
  over-estimated. 
  

   261. 
  Types 
  of 
  ferns. 
  Ferns 
  are 
  usually 
  distinguished 
  from 
  

   one 
  another 
  by 
  the 
  leaves, 
  the 
  sori, 
  and 
  the 
  sporangia. 
  There 
  

   is 
  much 
  variation 
  in 
  position 
  and 
  arrangement 
  of 
  sori 
  in 
  dif- 
  

   ferent 
  ferns 
  (fig. 
  215). 
  In 
  some 
  the 
  sori 
  are 
  dots 
  placed 
  regu- 
  

   larly 
  upon 
  the 
  leaf. 
  In 
  others 
  they 
  are 
  like 
  slits 
  or 
  blistery 
  

  

  FIG. 
  215. 
  Types 
  of 
  fern 
  leaflets 
  

  

  A, 
  bracken 
  fern; 
  /.', 
  shield 
  fern; 
  C, 
  

   spleemvort 
  ; 
  1>, 
  tin 
  1 
  iii:ii<li'iili:iir 
  fern. 
  In 
  

   the 
  different 
  specimens 
  the 
  sporangia 
  

   are 
  at.s, 
  the 
  indnsinm 
  at 
  i, 
  and 
  the 
  false 
  

   indusi 
  inn 
  at 
  /./' 
  

  

  