A Castilloa  tree  eight  years  old  should  yield  an  average  of  175 
grams  = lbs.  of  rubber.  In  1900,  2,849  castilloas  yielded  7 
plculs  = 924  lbs.  which  sold  for  2,100  florins  = §844.20.  A neat 
little  income  is  derived  from  the  sale  of  seeds,  the  usual  price  being 
6 francs  per  kilogram  (3,000  or  4,000  seeds).  They  are  packed  in 
layers  of  charcoal  dust  and  will  keep  for  twenty  days.  Many  seeds 
are  shipped  from  Loebang,  particularly  to  Sumatra,  where  the 
culture  of  Castilloa  elastica  has  been  begun  on  large  scale,  as  at 
Tebbing  Tenggi,  Deli,  near  the  north-western  extremity  of  the 
Island. 
I'o  return  to  the  details  of  the  tapping  done  under  Dr.  V.\N 
RomburGh’s  supervision,  the  weight  of  latex  obtained  from  six  of 
the  trees  tapped  on  two  days  was  as  follows  : — 
I St  day. 
2nd  day. 
d'otal 
First  two  trees 
...  grams  28 
130 
Second  two  trees 
,,  220  - 
290 
.MO 
Third  two  trees 
...  ,,  125 
205 
330 
I'otal  373 
Ot  1 
998 
The  result  in  dry  Caoutchouc  was  340  grams  for  the  first  day^s 
tapping  and  600  grams  for  the  second,  or  a total  of  940,  equal  to 
slightly  over  2 pounds,  of  a quality  then  valued  at  5 florins  per 
kilogram  (91  c.  a pound).  The  two  trees  indicated  in  the  table 
as  giving  the  largest  yield  were  planted  in  1884,  and  are  not  else- 
where mentioned  in  Dr.  Spire’s  article. 
Dr.  Spire  learned  from  Dr.  Van  Romburgh  that  in  i886  there 
were  planted  at  the  Botanic  Station  at  I'jidjerock  60  castilloa 
seedlings,  supplied  by  Mr.  Hofl.AND,  already  mentioned.  Half  were 
planted  in  moist  and  swampy  land,  and  the  remainder  in  a high 
and  dry  location.  The  former  did  not  thrive,  and  were  trans- 
planted. In  1891  they  all  fruited  and  20,000  seeds  were  gathered. 
The  details  of  planting  are  not  given,  but  in  1893  there  were 
10.000  trees  standing  as  the  result.  Later  plantings  were  made  from 
seeds  from  the  same  source,  so  that  by  1900  there  were  about 
26.000  trees  standing,  but  none  had  been  tapped  at  last  accounts. 
In  August,  1901,  Dr.  SPIRE  visited  the  Castilloa  plantations  at 
Pamanoekan.  On  the  premises  of  Mr.  Van  Gent,  and  situated 
near  his  coffee  factory,  was  a tract  planted  with  rubber  in  argillaceous, 
ferruginous  soil  which  has  been  burnt  over  at  one  time  with  a 
view  to  erecting  buildings  there.  The  plants  were  about  10  feet 
apart,  but  had  attained  an  average  height  of  2 meters  and  the 
crowns  were  touching  each  other.  In  the  same  vicinity  another 
and  larger  tract  of  50  bouws  (87^  acres)  had  been  planted  for  19 
months.  At  the  same  date  the  proprietor  had  planted  Castilloa 
st.:edlings  along  paths  in  his  coffee  estate,  and  these  had  attained 
an  average  height  of  4 meters.  At  one  time  a thousand  Castilloa 
trees  on  his  plantation  had  been  attacked,  apparently  by  some 
fungus  growth,  and  were  removed  and  burned. 
Dr.  Spire  also  visited  the  plantations  of  Mr.  Dinet,  at  Loebang, 
where  Ficus  elastica  and  Castilloa  were  growing  mi.xecl;  about  18 
