﻿NATURAL 
  RUBBER 
  

  

  By 
  O. 
  F. 
  Cook 
  

  

  [With 
  20 
  plates] 
  

  

  CONTENTS 
  

  

  Page 
  

  

  Why 
  the 
  two 
  principal 
  rubber 
  trees 
  are 
  confused 
  365 
  

  

  Coming 
  of 
  the 
  rubber 
  age 
  367 
  

  

  A 
  new 
  realm 
  of 
  human 
  attainment 
  368 
  

  

  Service 
  of 
  rubber 
  to 
  science 
  369 
  

  

  Rubber 
  discoveries 
  accidental 
  370 
  

  

  The 
  first 
  European 
  to 
  appreciate 
  rubber 
  371 
  

  

  La 
  Condamine 
  in 
  Brazil 
  and 
  Guiana 
  372 
  

  

  A 
  basic 
  discovery 
  in 
  extracting 
  Para 
  rubber 
  latex 
  373 
  

  

  Scope 
  of 
  Ridley's 
  discovery. 
  374 
  

  

  Explaining 
  the 
  wound 
  response 
  375 
  

  

  Commercial 
  surveys 
  of 
  wild 
  rubber 
  375 
  

  

  Genera 
  related 
  to 
  Castilla 
  377 
  

  

  Genera 
  related 
  to 
  Para 
  rubber 
  377 
  

  

  Evaluation 
  of 
  rubber 
  trees 
  377 
  

  

  Reasons 
  for 
  preferring 
  tree 
  crops 
  378 
  

  

  Rubber 
  as 
  a 
  garden 
  crop 
  379 
  

  

  Problems 
  of 
  rubber 
  latex 
  380 
  

  

  Rubber 
  by 
  rule 
  of 
  thumb 
  380 
  

  

  Rubber 
  and 
  near-rubber 
  382 
  

  

  Rubber 
  without 
  latex 
  382 
  

  

  Rubber-forming 
  cells 
  in 
  Castilla 
  latex 
  384 
  

  

  Castilla 
  handicapped 
  by 
  an 
  enzyme 
  384 
  

  

  Latex 
  separate 
  from 
  sap 
  386 
  

  

  Specialized 
  branches 
  and 
  leaves 
  in 
  Castilla 
  387 
  

  

  Two 
  forms 
  of 
  branches 
  in 
  Castilla 
  388 
  

  

  Specialized 
  leaves 
  of 
  dimorphic 
  branches 
  389 
  

  

  Two 
  preliminary 
  leaf 
  forms 
  in 
  Castilla 
  390 
  

  

  Propagation 
  of 
  Castilla 
  from 
  permanent 
  branches 
  391 
  

  

  Forest 
  adaptations 
  of 
  the 
  Para 
  rubber 
  tree 
  391 
  

  

  Branching 
  habits 
  of 
  Para 
  rubber 
  tree 
  393 
  

  

  Inermittent 
  growth 
  of 
  trunk 
  393 
  

  

  Leaves 
  arranged 
  in 
  rosettes 
  394 
  

  

  Many 
  leafless 
  metamers 
  394 
  

  

  Spongy, 
  perishable 
  seeds 
  395 
  

  

  Leaves 
  of 
  seedlings 
  delicate 
  395 
  

  

  i 
  Much 
  of 
  this 
  material 
  Is 
  recast 
  from 
  previous 
  papers 
  and 
  reports 
  by 
  the 
  same 
  writer 
  in 
  publications 
  

   of 
  the 
  U. 
  8. 
  Department 
  of 
  Agriculture. 
  A 
  bibliography 
  is 
  appended. 
  Titles 
  of 
  some 
  of 
  the 
  papers 
  are 
  

   mentioned 
  in 
  the 
  text, 
  with 
  other 
  references 
  by 
  date 
  only. 
  

  

  363 
  

  

  