﻿NATURAL 
  RUBBER 
  — 
  COOK 
  407 
  

  

  The 
  suppression 
  of 
  its 
  terminal 
  buds 
  places 
  Eucommia 
  in 
  complete 
  

   contrast 
  with 
  the 
  tropical 
  rubber 
  trees, 
  where 
  specialization 
  is 
  ac- 
  

   complished 
  very 
  largely 
  by 
  suppression 
  of 
  all 
  the 
  lateral 
  buds 
  in 
  the 
  

   early 
  stages 
  of 
  growth. 
  The 
  simple 
  primary 
  trunk 
  of 
  the 
  Para 
  rub- 
  

   ber 
  tree, 
  without 
  any 
  twigs 
  or 
  scars 
  of 
  branches, 
  represents 
  a 
  complete 
  

   suppression 
  of 
  the 
  vegetative 
  buds, 
  like 
  the 
  trunk 
  of 
  a 
  palm, 
  with 
  only 
  

   the 
  terminal 
  bud 
  serving 
  for 
  vegetative 
  growth. 
  

  

  THE 
  BALATA 
  TREE 
  

  

  The 
  balata 
  tree 
  of 
  South 
  America, 
  first 
  noted 
  in 
  French 
  Guiana 
  by 
  

   Aublet 
  in 
  1775, 
  apparently 
  extends 
  through 
  several 
  neighboring 
  coun- 
  

   tries. 
  It 
  is 
  one 
  of 
  the 
  near-rubbers 
  that 
  seems 
  worthy 
  of 
  being 
  utilized 
  

   on 
  a 
  much 
  larger 
  scale. 
  The 
  balata 
  gum 
  is 
  similar 
  to 
  gutta-percha, 
  

   and 
  although 
  not 
  elastic 
  like 
  rubber, 
  is 
  flexible 
  and 
  tough, 
  even 
  when 
  

   rolled 
  very 
  thin. 
  In 
  the 
  opinion 
  of 
  manufacturers 
  experienced 
  in 
  the 
  

   use 
  of 
  both 
  gums, 
  balata 
  would 
  have 
  been 
  valued 
  as 
  highly 
  as 
  gutta- 
  

   percha 
  if 
  regular 
  supplies 
  had 
  been 
  available. 
  Although 
  the 
  balata 
  

   gum 
  has 
  had 
  commercial 
  status 
  for 
  nearly 
  a 
  century, 
  the 
  tree 
  remains 
  

   little 
  known, 
  with 
  even 
  its 
  botanical 
  identity 
  still 
  in 
  question. 
  Leaves 
  

   and 
  fruits 
  of 
  balata 
  from 
  an 
  experiment 
  at 
  Bayeux, 
  Haiti, 
  are 
  shown 
  

   in 
  natural 
  size 
  in 
  plate 
  16. 
  The 
  stock 
  may 
  have 
  come 
  from 
  British 
  

   Guiana. 
  The 
  growth 
  of 
  balata 
  has 
  been 
  reported 
  as 
  very 
  slow, 
  which 
  

   doubtless 
  is 
  true 
  of 
  the 
  forest 
  trees, 
  but 
  the 
  growth 
  in 
  Haiti 
  was 
  com- 
  

   parable 
  with 
  that 
  of 
  the 
  rubber 
  trees. 
  

  

  The 
  name 
  given 
  by 
  Aublet 
  was 
  Achras 
  balata, 
  which 
  Gaertner 
  

   placed 
  as 
  Mimusops 
  balata 
  in 
  1807, 
  a 
  designation 
  that 
  has 
  been 
  widely 
  

   used. 
  A 
  different 
  name, 
  Manilkara 
  bidentata, 
  appears 
  in 
  Record's 
  new 
  

   work 
  on 
  "Timbers 
  of 
  the 
  New 
  World," 
  adopted 
  from 
  writers 
  who 
  in- 
  

   ferred 
  that 
  Aublet's 
  balata 
  was 
  not 
  a 
  native 
  tree 
  in 
  French 
  Guiana, 
  but 
  

   had 
  been 
  introduced 
  from 
  Mauritius. 
  Such 
  an 
  introduction 
  is 
  not 
  

   implied 
  in 
  Aublets 
  statement, 
  which 
  merely 
  associates 
  the 
  Guiana 
  

   balata 
  with 
  a 
  tree 
  previously 
  seen 
  in 
  Mauritius, 
  where 
  Aublet 
  had 
  spent 
  

   several 
  years. 
  Two 
  localities 
  in 
  Mauritius 
  were 
  noted, 
  but 
  no 
  Guiana 
  

   locality, 
  which 
  may 
  simply 
  mean 
  that 
  the 
  tree 
  was 
  well 
  known 
  at 
  

   Cayenne. 
  Aublet's 
  description 
  is 
  brief, 
  but 
  parallel 
  to 
  those 
  of 
  the 
  

   sapote 
  and 
  the 
  sapodilla, 
  as 
  species 
  of 
  Achras. 
  

  

  The 
  similarity 
  of 
  the 
  leaves 
  and 
  flowers 
  of 
  balata 
  in 
  plate 
  16 
  with 
  

   those 
  of 
  the 
  sapodilla 
  in 
  plate 
  18 
  leaves 
  little 
  doubt 
  that 
  the 
  trees 
  are 
  

   closely 
  related. 
  They 
  belong 
  to 
  the 
  sapota 
  family, 
  a 
  remarkable 
  group 
  

   of 
  tropical 
  trees, 
  some 
  of 
  them 
  attaining 
  great 
  size, 
  producing 
  edible 
  

   fruits, 
  useful 
  latexes, 
  and 
  valuable 
  woods, 
  very 
  heavy, 
  hard, 
  and 
  dura- 
  

   ble. 
  Some 
  of 
  the 
  famous 
  South 
  American 
  "milk 
  trees," 
  those 
  known 
  

   as 
  massaranduba, 
  also 
  are 
  included 
  ; 
  the 
  latex 
  is 
  potable 
  and 
  is 
  reported 
  

   by 
  many 
  travelers 
  as 
  pleasant 
  and 
  wholesome. 
  The 
  lucuma 
  of 
  Peru, 
  

  

  