﻿NATURAL 
  RUBBER 
  — 
  COOK 
  391 
  

  

  PROPAGATION 
  OF 
  CASTTLLA 
  FROM 
  PERMANENT 
  BRANCHES 
  

  

  The 
  specialized 
  branching 
  habits 
  must 
  be 
  recognized 
  in 
  order 
  to 
  

   appreciate 
  the 
  fact 
  that 
  Castilla 
  is 
  readily 
  propagated 
  from 
  cuttings 
  

   of 
  the 
  permanent 
  branches. 
  Cuttings 
  of 
  lateral 
  branches 
  would 
  not 
  

   serve, 
  even 
  if 
  roots 
  were 
  formed, 
  since 
  lateral 
  branches 
  have 
  no 
  vege- 
  

   tative 
  buds. 
  Many 
  cases 
  were 
  encountered 
  in 
  southern 
  Mexico 
  in 
  1902 
  

   where 
  roadside 
  Castilla 
  trees 
  had 
  been 
  planted 
  as 
  fence 
  stakes, 
  and 
  

   had 
  grown 
  into 
  large 
  trees. 
  

  

  Propagation 
  from 
  cuttings 
  is 
  a 
  cultural 
  expedient 
  that 
  may 
  be 
  ap- 
  

   plied 
  to 
  Castilla 
  in 
  the 
  event 
  that 
  suitable 
  methods 
  of 
  mechanical 
  ex- 
  

   traction 
  are 
  developed 
  and 
  a 
  rapid 
  extension 
  of 
  production 
  from 
  

   Castilla 
  is 
  attempted. 
  Abundant 
  material 
  would 
  be 
  available 
  in 
  dis- 
  

   tricts 
  where 
  abandoned 
  plantations 
  still 
  exist, 
  and 
  such 
  cuttings 
  could 
  

   be 
  shipped 
  readily 
  if 
  needed 
  in 
  other 
  localities. 
  

  

  With 
  Castilla 
  grown 
  in 
  forest 
  formation 
  and 
  the 
  trees 
  lumbered 
  out 
  

   for 
  mechanical 
  extraction 
  of 
  the 
  rubber, 
  the 
  smaller 
  limbs 
  of 
  the 
  more 
  

   productive 
  trees 
  might 
  be 
  utilized 
  in 
  new 
  plantings. 
  Time 
  and 
  labor 
  

   might 
  be 
  saved 
  in 
  thus 
  avoiding 
  the 
  need 
  of 
  seed 
  beds, 
  transplanting, 
  

   and 
  caring 
  for 
  young 
  seedlings. 
  Sprouts 
  that 
  grew 
  from 
  the 
  stumps 
  

   of 
  productive 
  trees 
  also 
  might 
  be 
  used 
  for 
  propagation 
  with 
  no 
  loss 
  of 
  

   time 
  in 
  obtaining 
  the 
  advantages 
  of 
  selection. 
  

  

  Although 
  Castilla 
  grows 
  generally 
  as 
  a 
  forest 
  tree, 
  it 
  is 
  rarely 
  found 
  

   in 
  deep 
  forests, 
  but 
  is 
  like 
  the 
  related 
  trumpet 
  tree 
  or 
  Cecropia 
  in 
  

   being 
  better 
  adapted 
  to 
  relatively 
  open 
  "second-growth" 
  forests, 
  on 
  

   lands 
  previously 
  cleared 
  and 
  planted 
  for 
  a 
  season 
  or 
  two, 
  under 
  the 
  

   native 
  system 
  of 
  agriculture. 
  

  

  FOREST 
  ADAPTATIONS 
  OF 
  THE 
  PARA 
  RUBBER 
  TREE 
  

  

  The 
  natural 
  adaptations 
  of 
  a 
  plant 
  are 
  clues 
  to 
  its 
  cultural 
  require- 
  

   ments. 
  The 
  seedling 
  and 
  sapling 
  stages 
  of 
  the 
  Para 
  rubber 
  tree 
  show 
  

   several 
  peculiar 
  characters 
  that 
  render 
  them 
  specially 
  adapted 
  to 
  

   undergrowth 
  conditions 
  in 
  tropical 
  forests. 
  Many 
  types 
  of 
  plants 
  

   are 
  definitely 
  specialized 
  to 
  live 
  as 
  undergrowth, 
  and 
  the 
  development 
  

   of 
  undergrowth 
  vegetation 
  in 
  the 
  forests 
  of 
  the 
  Amazon 
  valley 
  is 
  

   probably 
  greater 
  than 
  in 
  any 
  other 
  region. 
  The 
  seedlings 
  of 
  forest 
  

   trees 
  live 
  at 
  first 
  as 
  undergrowth 
  plants, 
  and 
  have 
  their 
  share 
  of 
  

   specially 
  adapted 
  characters. 
  Unless 
  these 
  adaptations 
  are 
  recognized, 
  

   several 
  features 
  in 
  the 
  behavior 
  of 
  the 
  young 
  Para 
  rubber 
  plants 
  may 
  

   not 
  be 
  understood. 
  

  

  Some 
  of 
  the 
  specialized 
  shade 
  plants 
  require 
  protection 
  and 
  do 
  

   not 
  thrive 
  in 
  the 
  open, 
  while 
  others 
  can 
  grow 
  in 
  open 
  places 
  but 
  with 
  

   certain 
  changes 
  of 
  accommodation, 
  such 
  as 
  shortening 
  the 
  joints 
  of 
  

   the 
  stems, 
  branching 
  closer 
  to 
  the 
  ground, 
  reducing 
  the 
  leaf 
  surfaces, 
  

  

  