﻿PLANT 
  INDUSTRIES 
  

  

  311 
  

  

  maple 
  sap 
  and, 
  as 
  ordinarily 
  used, 
  it 
  contains 
  from 
  30 
  to 
  40 
  

   per 
  cent 
  of 
  the 
  water 
  originally 
  in 
  the 
  sap. 
  1 
  

  

  The 
  sugar-making 
  season 
  is 
  short, 
  because, 
  as 
  soon 
  as 
  new 
  

   protoplasm 
  is 
  developed 
  in 
  great 
  abundance, 
  the 
  sap 
  no 
  longer 
  

   makes 
  acceptable 
  sugar. 
  Maple 
  trees 
  may 
  be 
  used 
  from 
  year 
  to 
  

   year 
  indefinitely 
  without 
  apparent 
  injury 
  due 
  to 
  the 
  withdrawal 
  

   of 
  sap, 
  but 
  the 
  stem 
  may 
  be 
  weakened 
  by 
  too 
  frequent 
  boring 
  

   at 
  one 
  level, 
  and 
  the 
  wound, 
  though 
  it 
  heals 
  in 
  one 
  or 
  two 
  

   years, 
  may 
  serve 
  as 
  a 
  place 
  of 
  entrance 
  for 
  disease 
  organisms. 
  

  

  FIG. 
  234. 
  A 
  Cuban 
  sugar-cane 
  field 
  

  

  Standing 
  cane 
  is 
  seen 
  at 
  the 
  left, 
  between 
  the 
  men 
  and 
  the 
  trees 
  ; 
  in 
  the 
  foreground 
  

  

  the 
  uieu 
  are 
  loading 
  sap-laden 
  stalks 
  upon 
  the 
  carts. 
  Note 
  the 
  heavy 
  soil 
  covering 
  

  

  of 
  leaves 
  that 
  have 
  been 
  stripped 
  from 
  the 
  sugar-cane 
  stalks 
  

  

  Sugar-maple 
  groves 
  are 
  being 
  planted 
  in 
  some 
  places 
  for 
  

   the 
  sugar 
  product, 
  but 
  other 
  plants 
  of 
  more 
  rapid 
  growth 
  and 
  

   larger 
  sugar 
  production 
  will 
  doubtless 
  prevent 
  maple 
  sugar 
  

   from 
  entering 
  largely 
  into 
  sugar 
  consumption. 
  The 
  distinctive 
  

   flavor 
  of 
  maple 
  sugar 
  and 
  sirup, 
  however, 
  will 
  enable 
  it 
  to 
  

   continue 
  as 
  a 
  highly 
  desired 
  article 
  of 
  commerce. 
  

  

  1 
  "The 
  Maple 
  Sugar 
  Industry," 
  Bulletin 
  S9, 
  Bureau 
  of 
  Forestry, 
  U.S. 
  

   Dept. 
  Agr., 
  1905 
  ; 
  tf 
  Maple 
  Sap 
  Sirup," 
  Bulletin 
  134, 
  Bureau 
  of 
  Chemistry, 
  

   U.S. 
  Dept. 
  Agr., 
  1910 
  ; 
  " 
  The 
  Production 
  of 
  Maple 
  Sirup 
  and 
  Sugar," 
  Farm- 
  

   ers' 
  Bulletin 
  516, 
  U.S. 
  Dept. 
  Agr., 
  1912. 
  

  

  