﻿CHAPTER 
  II 
  

  

  THE 
  PLANT 
  AS 
  A 
  WORKING 
  MACHINE 
  1 
  

  

  5. 
  The 
  parts 
  of 
  the 
  plant. 
  Ordinary 
  plants 
  are 
  composed 
  

   of 
  routs, 
  stems, 
  leaves, 
  flowers, 
  and 
  seeds. 
  Not 
  infrequently 
  

   sonic 
  of 
  these 
  pails 
  may 
  be 
  absent, 
  or 
  they 
  may 
  be 
  so 
  un- 
  

   usual 
  in 
  form 
  and 
  appearance 
  that 
  their 
  nature 
  is 
  not 
  readily 
  

   seen. 
  Thus, 
  it 
  is 
  not 
  usually 
  evident 
  to 
  others 
  than 
  botanists 
  

   (1) 
  that 
  an 
  onion 
  bulb 
  consists 
  of 
  a 
  very 
  short 
  stem 
  and 
  

   thick, 
  broad 
  leaves, 
  and 
  that 
  when 
  the 
  onion 
  grows, 
  the 
  roots 
  

   descend 
  from 
  the 
  lower 
  part 
  of 
  the 
  stem 
  and 
  green 
  leaves 
  

   and 
  a 
  flower-bearing 
  stem 
  arise 
  from 
  the 
  upper 
  end 
  of 
  the 
  

   stem 
  within 
  the 
  bulb; 
  (2) 
  or 
  that 
  in 
  plants 
  such 
  as 
  turnips 
  

   and 
  carrots 
  the 
  stem 
  and 
  root 
  are 
  not 
  definitely 
  set 
  apart 
  

   from 
  one 
  another; 
  (3) 
  or 
  that 
  the 
  flowers 
  of 
  oak 
  and 
  elm 
  

   trees, 
  so 
  very 
  unlike 
  ilowers 
  as 
  we 
  commonly 
  think 
  of 
  them, 
  

   have 
  nevertheless 
  as 
  good 
  a 
  right 
  to 
  the 
  name 
  as 
  has 
  the 
  

   llouer 
  of 
  an 
  apple 
  tree. 
  

  

  The 
  live 
  parts 
  of 
  a 
  common 
  plant 
  together 
  constitute 
  a 
  

   well-organized 
  unit 
  (fig. 
  3). 
  The 
  pails 
  differ 
  from 
  one 
  an- 
  

   other 
  in 
  structure, 
  in 
  form, 
  and 
  in 
  what 
  they 
  do, 
  but 
  the 
  suc- 
  

   cessful 
  work 
  of 
  each 
  part 
  contributes 
  to 
  the 
  successful 
  work 
  

   of 
  the 
  whole 
  plant. 
  Although 
  we 
  may 
  often 
  be 
  more 
  inter- 
  

   ested 
  in 
  \\hai 
  is 
  being 
  done 
  than 
  in 
  the 
  mechanism 
  which 
  does 
  

   i 
  lie 
  \\ 
  ork. 
  \\ 
  e 
  cannot 
  understand 
  plant 
  work 
  except 
  as 
  we 
  give 
  

   constant, 
  attention 
  to 
  the 
  structures 
  of 
  the 
  parts 
  of 
  plants. 
  

  

  1 
  This 
  chapter 
  gives 
  an 
  outline 
  of 
  plant 
  structure 
  and 
  plant 
  work. 
  Itdoes 
  

   not 
  pivMMii 
  details. 
  Imt 
  -ives 
  a 
  general 
  idea 
  of 
  the 
  nature 
  and 
  functions 
  of 
  

   tin- 
  plant. 
  If 
  tliis 
  ontlin" 
  is 
  presented 
  briefly, 
  it 
  serves 
  to 
  interpret 
  the 
  

   more 
  detailed 
  \vork 
  of 
  later 
  chapters 
  much 
  more 
  profitably 
  than 
  if 
  numerous 
  

   details 
  are 
  presented 
  first. 
  The 
  chapter 
  should 
  be 
  read 
  carefully 
  by 
  every 
  

   member 
  of 
  the 
  class 
  and 
  discussed 
  in 
  one 
  or 
  two 
  recitations, 
  or 
  it 
  may 
  be 
  

   read 
  and 
  discussed 
  by 
  pupils 
  and 
  tea. 
  'her 
  together. 
  

  

  6 
  

  

  