534  Cinchonas  of  U,  S.  Commerce.        I  ^"N-LvTifso"™* 
C.  cord'ijolia:  Thickest  fibres  average  mm.  073.  Resin-cells  few. 
Medullary  rays  large-celled.  Fibres  small  (sometimes  few),  in  mostly 
single  lines  of  2  to  4,  with  some  staff-cells,  in  some  regions  the  fibres 
are  dark  red-brown,  becoming  bright  rose-red  with  KOH. 
Laticiferous  ducts  present.  C.  purpurea:  Thickest  observed 
fibres  average  mm.  -106.  Numerous  resin  cells.  Medullary  rays 
broadly  wedge-shaped.  Fibres  in  groups  of  3  to  5,  with  some  staff- 
cells. 
(6'.  pubescens :  Numerous  resin-cells.  Medullary  rays  broad.  Fibres 
large,  in  groups  of  2  to  3,  with  staff-cells.) 
scrobiculata :  Numerous  resin-cells.     Fibres  verv  numerous,,  in 
uninterrupted,  usually  single  lines.) 
(  C.  glandulifera :  Few  resin-cells.) 
(C.  peruviana :  Resin-cells,  laticiferous  ducts  and  fibres  small.  Many 
fibres  inciuiplttely  filled,  in  lines  of  2  to  6.) 
Of  the  >pecies  in  parentheses  we  have  had  so  few  specimens  that 
our  acquaintance  with  them  is  necessarily  slight. 
The  following  portions  of  descriptions,  used  and  noted  in  determin- 
ing species,  have  been  taken  from  Berg: 
Covered  C.  calisaya^  Wedd.  Bark  from  the  branches  in  quills.  On 
outside  dark  brown,  in  places  milk-white,  with  longitudinal  ridges  and 
deep  longitudinal-  and  cross-markings,  which  form  hollow  squares. 
Fracture  short  and  brittle.  Periderm  hard,  brittle  and  dark  brown. 
Bast  indistinctly  radially  striate.  Periderm  consists  of  flat,  tangentially- 
stretched  cells,  which  contain  a  reddish-brown  substance.  Middle  bark 
consists  of  tangentially-stretched  cells,  which  contain  starch  and  a 
brownish  red  sap,  which  on  drying  adheres  to  the  cell-walls.  The 
parenchyma  of  the  bast  rays  have  the  same  contents  as  cells  of  the 
middle  hark;  occasionally,  separate  cells  are  filled  with  a  crystalline 
powder  of  oxalate  of  lime. 
Uncovered  C.  calisaya  (or  older  bark).  Flat,  occasionally  covered 
with  brittle,  dark  brown  bork  scales  in  layers.  Where  these  are  absent 
are  shell  like  indentures.  Fracture  short  and  brittle.  Bast-cells  dis- 
tinct, in  quite  close  radial  rows.  The  bork-scales  consist  of  alternate 
layers  of  periderm  and  dead  Dark,  whose  inner  layers  already  belong  to 
^  That  is,  the  l)a^t  coveied  with  the  middle  and  corky  layers ;  usually  the  younger 
bark.  When  flat  pietes  have  at  ka^t  the  laticiferous  ducts  lelt  they  Lelong  to  the 
variety  holi^iana. 
