﻿INTRODUCTORY 
  5 
  

  

  in 
  length. 
  Some 
  very 
  pure 
  natural 
  waters 
  contain 
  no 
  plants 
  

   readily 
  visible 
  to 
  the 
  eye, 
  while 
  the 
  foul 
  drainage 
  of 
  a 
  barn- 
  

   yard 
  in 
  warm 
  weather 
  may 
  be 
  of 
  a 
  uniform 
  bright-green 
  color 
  

   from 
  the 
  presence 
  of 
  many 
  thousands 
  of 
  microscopic 
  plants 
  

   in 
  every 
  drop 
  of 
  the 
  water. 
  Plants 
  occur 
  in 
  all 
  the 
  seas 
  as 
  

   well 
  as 
  in 
  all 
  the 
  fresh 
  waters, 
  on 
  every 
  kind 
  of 
  soil 
  from 
  the 
  

   wettest 
  swamps 
  to 
  arid 
  deserts, 
  on 
  rocky 
  cliffs, 
  and 
  on 
  

   branches 
  and 
  leaves 
  of 
  trees. 
  

  

  4. 
  Structures 
  and 
  habits 
  of 
  plants. 
  Although 
  the 
  relations 
  

   of 
  plants 
  to 
  human 
  life 
  and 
  the 
  life 
  of 
  the 
  lower 
  animals 
  are 
  

   of 
  the 
  highest 
  importance, 
  it 
  is 
  not 
  this 
  aspect 
  of 
  botany 
  which 
  

   is 
  of 
  largest 
  concern 
  to 
  the 
  beginner. 
  We 
  have 
  no 
  reason 
  to 
  

   suppose 
  that 
  plants 
  exist 
  for 
  the 
  benefit 
  of 
  man. 
  Plant 
  struc- 
  

   tures 
  and 
  processes 
  are 
  of 
  importance 
  primarily 
  in 
  maintaining 
  

   the 
  life 
  of 
  plants 
  themselves, 
  and 
  their 
  use 
  by 
  men 
  is 
  a 
  by- 
  

   product 
  of 
  plant 
  life. 
  In 
  order 
  to 
  gain 
  any 
  scientific 
  knowl- 
  

   edge 
  of 
  elementary 
  botany, 
  it 
  is 
  necessary 
  to 
  try 
  to 
  find 
  out 
  

   what 
  are 
  the 
  forms 
  and 
  internal 
  structures 
  of 
  plants, 
  how 
  they 
  

   carry 
  on 
  their 
  life 
  processes, 
  and 
  what 
  relations 
  exist 
  between 
  

   them 
  and 
  the 
  external 
  conditions 
  of 
  soil 
  and 
  climate. 
  To 
  these 
  

   studies 
  may 
  be 
  added 
  some 
  consideration 
  of 
  the 
  relations 
  be- 
  

   tween 
  the 
  plant 
  and 
  its 
  plant 
  and 
  animal 
  neighbors, 
  and 
  other 
  

   studies 
  about 
  what 
  plants 
  have 
  done 
  for 
  man 
  and 
  what 
  he 
  is 
  

   trying 
  to 
  do 
  with 
  plants. 
  But 
  it 
  must 
  be 
  clearly 
  understood 
  

   that 
  the 
  study 
  of 
  plant 
  structures 
  and 
  functions 
  -- 
  what 
  

   plants 
  are 
  and 
  how 
  they 
  live 
  - 
  - 
  is 
  fundamental 
  to 
  any 
  other 
  

   study 
  of 
  plants. 
  

  

  