34-6  Fast-growing  Variety  of  Cinchona. 
vigorous  habits  of  growth,  and  at  a  little  distance  it  was  difficult  to 
discriminate  between  them.  As  they  developed,  however,  it  was  found 
that  the  one  with  slightly  pubescent  leaves  yielded  much  more  quinia 
in  the  bark  than  the  other.  I  suggested,  for  distinction's  sake,  calling 
this  the  var.  pubescens,  which  has  unfortunately  since  become  changed 
into  C.  pubescens,  How.,  an  entirely  erroneous  designation. 
Referring  to  the  bark  sent  both  to  Dr.  de  Vrij  and  to  myself  in  1873, 
Mr.  Mclvor  says,  "This  bark  is  taken  from  a  hairy-leaved  variety  of 
C.  officinalis.  It  is  a  tree  of  wonderful  growth.  It  produces  enor- 
mously thick  bark,  and  the  tree  is  not  injured  by  wind.  The  tree 
from  which  I  now  send  you  the  bark  is  only  five  years  old.  It  is 
twenty-six  feet  high,  and  has  a  stem  of  sixteen  inches  in  circumfer- 
ence at  the  ground,  and  the  bark  now  sent  you  is  taken  in  a  strip  from 
the  stem  to  the  height  of  about  twelve  feet  from  the  ground.  This 
tree  grows  at  least  twice  as  fast  as  C.  succirubra.  The  bark  of  this 
variety  which  I  sent  to  Dr.  de  Vrij  was  taken  from  a  tree  grown  at  a 
high  elevation  and  with  a  N.  W.  exposure.  The  bark  now  sent  you 
is  taken  from  a  tree  growing  at  a  low  elevation  with  a  N.  £.  exposure. 
Dr.  de  Vrij  found  the  bark  of  this  species  to  yield  10*67  per  cent,  of 
total  alkaloids,  with  4  72  of  crystallized  sulphate  of  quinia.  If  under 
all  conditions  this  bark  is  found  to  yield  this  amount  of  alkaloids,  and 
especially  quinia,  it  is  certainly  the  best  plant  we  can  grow  ;  being 
hardy  and  of  rapid  growth  and  perfectly  free  from  canker  and  other 
diseases  to  which  the  officinalis  and  especially  the  calisaya  are  liable.  I 
therefore  sincerely  hope  that  you  will  be  able  to  confirm  Dr.  de  Vrij's 
results,  and  if  this  occurs  in.  the  two  barks  taken  from  different  posi- 
tions of  elevation,  it  will  establish  the  value  of  the  species  beyond 
doubt." 
The  examination  which  I  made  quite  confirmed  and  even  surpassed 
the  results  obtained  by  Dr.  de  Vrij,  as  the  notes  I  have  preserved  indi- 
cate a  produce  equal  to  6'00  sulphate  of  quinia,  5*00  sulphate  of  cin- 
chonidia,  cinchonia  and  amorphous  alkaloid  i'20  per  cent.  Even  this 
was  exceeded  after  an  additional  year's  growth.  In  June,  1874,  Mr. 
M.  writes,  "  I  take  the  liberty  of  again  sending  you  some  bark  of  C. 
pubescens.  This  sample  is  of  the  narrow  strips  left  on  the  same  tree 
from  which  I  took  the  bark  sent  to  you  in  December  last.  If  not 
giving  you  too  much  trouble,  I  would  very  much  like  to  know  what 
this  bark  yields,  the  more  so  [as  some  persons]  have  been  trying  to 
