THE  AMERICAN 
JOURNAL  OF  PHARMACY. 
NOVEMBER,  1880. 
SPECIES  OF  CINCHONA  OCCURRING  IN  U.  S.  COM- 
MERCE, AND  NOTES  ON  THEIR  MICRO-BOTANICAL 
DETERMINATION;  WITH  ORIGINAL  DRAWINGS. 
By  J.  C.  Reeve,  Ph.C.i 
Of  the  accessible  literature  on  the  subject  of  cinchonas,  as  a  prac- 
tical g-iide,  the  National  Dispensatory  of  Stille  and  Maisch  has  been 
found  the  most  useful.  This  is  because  it  states  no  doubts,  excludes 
all  barks  but  those  that  are  at  all  likely  to  be  met  with  here,  and 
straightens  out  the  frequent  tangles  of  nomenclature.  The  aim  cf  this 
paper  has  been  to  state  experience  in  practical  work  done  on  a  limited 
variety  of  barks  in  a  limited  space  of  time,  and  to  aid,  if  possible,  begin- 
ners in  this  field. 
The  bark  of  the  genus  cinchona  consists  of: 
1st.  The  liber  or  inner  layer  (endophloeum)  consisting  of  paren- 
chyma, in  which  is  found  the  liber  fibres  [Bastrdhren  or  Bast%ellen  of 
the  Germans).  The  medullary  rays  {Markstrahlen)  pass  into  the  bark, 
dividing  this  layer  into  the  bast  rays  [Baststrahlen).  The  Fullgewebe  is 
the  "filling  tissue"  of  parenchyma  of  these  rays.  In  the  bast  rays  are 
also  found  the  "stafF  cells,"  stafF-formed  stone  cells"  of  Berg's  Atlas,^ 
or  incomplete  fibres  of  the  Dispensatory;  synonymous  terms,  as  shown 
by  the  fact  that  there  is  but  one  corresponding  structure  in  the  bark, 
and  that  the  two  writers  use  the  terms  interchangeably. 
2d.  The  middle  or  primary  layer,  middle  bark  (mesophlcEum,  green 
layer),  or  outer  bark.  In  the  parenchyma  of  this  layer  are  the  lati- 
ciferous  vessels  [Saftrohren  of  Berg,  lacunae  of  Pereira),  not  anastomos- 
ing as  in  true  laticiferous  tissue,  but  separate,  and  mostly  of  large  size.  * 
Here  are  also  both  thick-  and  thin-walled  cells,  containing  a  substance 
of  resinous  aspect;  but  undoubtedly  it  is  only  the  thicker  walled  that 
are  the  resin-cells  of  the  classification  of  the  Dispensatory;  the  term 
1  Communicated  by  the  Michigan  University  School  of  Pharmacy. 
^"Anatomischer  Atlas  zar  Pharmazeutischen  Waarenkunde." 
34 
