i 
now  amounts  to  70,000  of  which  15,000,  are  from  ii  to  12  years 
old. 
After  arriving  upon  the  plantation  and  fitting  up  the  labo- 
ratory required  for  the  examination  of  the  latex,  and  the  testing  of 
rubber  on  the  spot,  my  first  concern  was  to  ascertain  the  exact 
species  of  the  Castiiloa  on  the  plantation.  This  appeared  to  me 
all  the  more"’  important,  as  there  is  one  species  of  Castiiloa  known 
which  yields  plenty  ol  latex,  but  one  containing  no  rubber  and 
there  appear  to  be  several  varieties  yielding  either  a poor  qualitv, 
or  very  little  rubber.  Of  course,  coming  on  the  plantation  in  the 
rainy  season,  when  the  trees  bear  ludther  flowers  nor  seeds,  was 
not  exactly  calculated  to  facilitate  the  botanical  determination,  and 
I was  therefore  compelled  to  make  a fairly  close  study  of  the 
morphological  and  physiological  feature  of  the  trees.  On  the  other 
hand,  it  had  to  be  borne  in  mind  the  iact  that  the  whole  of  our 
present  day  information  respecting  the  botanical  characteristics  of 
the  various  species  of  Castiiloa,  and  the  respective  value  of  each  of 
them  for  cultivation  purpose's,  are  in  quite  a hopeless  state  of  con- 
fusion. 
According  to  the  usual  description,  Castiiloa  elastica  is  a tree 
growing  to  a height  of  from  36  to  54  feet,  the  trunk  at  about  3 fet't 
above  ground  attaining  to  a diameter  nf  from  24  to  48  inches. 
I he  bark  is  smooth  and  velh.)w,  the  wood  soft  and  ptmishable.  Tlu‘ 
lca\esare  from  6 to  12  inches  in  length,  of  a clear  and  brilliant 
green,  and  their  lower  side  is  more  or  less  co\ered  with  a growth 
of  line  brown  hairs.  \'ery  characteristic  of  Castiiloa  elastica  is  the 
phenomenon  known  as  dimorphism  of  the  branches  and  which  con- 
sists in  the  branches  which  sj)ring  from  the  tree  at  an  angle  of  45 
degrees  at  a certain  point  rather  abruptly  taking  up  a horizontal 
position.  1 purposely  omit  entering  here  upon  a discussion  ol  tlu* 
flowers  and  fruits  of  Castiiloa  tdastica  as  a c'ornparison  ol  their 
characteristics  with  those  produced  by  the  trees  at  has  Cascadas, 
is  at  the  present  moment  not  j)Ossit)le.  CkoS.S,  the  well  known 
Kew  botanist,  describes  these  trees  as  growing  to  a height  of  from 
160  to  180  feet,  with  a diameter  of  5 f(‘et,  but  he  gives  no  informa- 
tion r(\spe('ting  the  ag(‘  of  these  trees.  In  all  probability  these  trees 
were  an  enormous  age,  to  be  reckoned  bv  centuri(*s  rather  than 
tens  of  years,  j.  II.  llART,  wSuperintendent  Royal  Botanic  (iardens, 
rrinidad,  states  that  the  oldest  C'astilloa  tree  there,  is  over  75  fe('t 
high  and  has  a girth  of  4 feet  at  three  f(*et  above  ground.  Som<‘ 
trees  13  \'(‘ars  old  are  from  58  to  60  inches  in  girth.  .Against  these 
two  authoi  ities  we  possess  however  the  certain  information  that  in  ! 
Mexico,  Monduras,  Nicaragua  and  Rcuador,  the  height  ol  Castiiloa 
elastic'a  \ aries  between  40  and  60  ft^tt.  ; 
d h(*re  are  a number  of  other  spt!cies  or  varieties  of  Castiiloa, 
w ith  regard  to  which  a considt'rable  amount  of  uncertainty  exist,  j 
Indeed,  only  one  of  these,  C.tiniu^  //enisley,  is  satisfactorily  estab- I 
lished  as  a distinct  and  different  species,  which,  moreover,  al- J 
though  containing  a large  quantity  of  latex,  yields  no  India  rubber  f 
at  all.  I'iie  C.  described  by  CotJJXS  as  being  found  I 
in  the  isthmus  is  consiflered  by  several  very  competemt  authorities* 
