CINCHONA  CULTIVATION  IN  BENGAL. 
423 
6.  The  average  growth  for  the  year  of  the  ten  measured  plants 
of  C.  calisaya  planted  in  June,  1867,  at  Rishap,  has  been  52 
inches,  which  represents  the  average  growth  of  all  the  plants  in 
the  plantation  catalogued  as  Q.  calisaya.  But  several  important 
varieties  are  included  under  the  name  C.  calisaya^  and  the  tree 
variety  raised  by  seed  in  February,  1867,  and  planted  out  in 
June,  1867,  has  attained  a  height  of  12  feet  in  October,  1869, 
and  a  tree  of  this  age,  lately  cut  down,  has  produced  two  pounds 
of  dry  bark. 
7.  As  fully  explained  by  Dr.  T.  Anderson  in  his  annual  cin- 
chona report  in  Bengal  for  the  year  ending  31st  March,  1868, 
the  exceeding  steepness  of  the  hills,  combined  with  the  large 
rainfall,  prevents  any  tilth  on  these  cinchona  plantations.  The 
grass  and  low  jungle  having  been  cut  close,  the  young  cinchona 
plants  are  planted  out  in  the  permanent  plantations.  The  weeds 
having  been  merely  headed  down,  not  eradicated,  grow  with 
great  strength  in  a  moist  and  warm  climate,  and  continual  scour- 
ing of  the  young  plantations  is  necessary.  This  is  the  chief  ex- 
pense under  this  system  of  cultivation. 
8.  C.  succirubra  and  0,  calisaya  (tree  variety)  grow  so  freely, 
that  by  the  third  year  the  young  trees  in  the  plantations  are  all 
locked  ;  they  then  crush  the  jungle  beneath  them,  and  can  take 
care  of  themselves,  and  little  further  expense  upon  them  is  called 
for. 
9.  But  C.  officinalis  shows  no  inclination  to  become  a  tree  at 
these  plantations ;  it  remains  a  shrub  with  very  scanty  foliage, 
and  even  on  the  plantations  which  are  five  years  old,  there  con- 
tinues the  same  expenditure  in  scouring. 
10.  C.  succirubra  and  C.  calisaya  are  planted  about  1200  to 
the  acre ;  C.  officinalis  about  4000  to  the  acre. 
11.  In  the  fifth  year  of  growth  in  permanent  plantation  an 
acre  of  C.  officinalis  carries  less  than  one-fourth  the  bark  carried 
by  an  acre  of  C.  succirubra,  and  costs  more  than  four  times  as 
much  annual  expenditure.  Moreover,  the  C.  officinalis  then  ap- 
pears disinclined  to  grow  much  larger,  whereas  (7.  succirubra 
will  clearly  grow  into  a  considerable  tree. 
12.  J  calculate  that  at  present  it  has  not  been  discovered  how 
to  grow  0.  officinalis  to  economic  profit  at  Rungbee.    I  there- 
