﻿344 
  INTRODUCTION 
  TO 
  BOTANY 
  

  

  C 
  II, 
  O 
  c 
  , 
  and 
  in 
  making 
  this 
  unit 
  of 
  starch 
  there 
  li;is 
  been 
  used 
  

  

  6 
  10 
  5 
  

  

  all 
  of 
  tin- 
  carbon, 
  all 
  of 
  the 
  hydrogen, 
  and 
  live 
  units 
  of 
  the 
  

   oxygen, 
  thus 
  leaving 
  twelve 
  units 
  of 
  oxygen 
  to 
  be 
  set 
  tree 
  or 
  

   to 
  be 
  used 
  by 
  the 
  plant 
  in 
  some 
  other 
  \vay. 
  Some 
  of 
  this 
  free 
  

   oxygen 
  passes 
  into 
  the 
  air, 
  though 
  some 
  of 
  it 
  is 
  used 
  by 
  the 
  

   plant 
  in 
  a 
  later 
  process. 
  

  

  The 
  compounds 
  thus 
  constructed, 
  such 
  as 
  starch 
  and 
  su^ar, 
  

   are 
  called 
  carbohydrates, 
  the 
  name 
  indicating 
  that 
  they 
  are 
  

   compounds 
  of 
  carbon 
  and 
  water. 
  

  

  