Am.  Jour.  Pharm. 
September,  1895. 
Structure  of  Our  CJierry  Barks. 
445 
The  bark  has  the  bitterness  and  astringency  of  the  official 
species,  but  much  less  of  the  aromatic  quality. 
Often  the  portions  of  the  wood  adhering  to  a  medicinal  bark 
afford  characters  which  aid  in  identification.  Between  the  wood  of 
Prunus  Mahaleb  and  that  of  the  official  species  there  are  marked 
structural  differences.  The  ducts  of  the  former  are  much  larger 
and  also  less  evenly  distributed,  being  most  abundant  and  largest 
adjacent  to  and  on  the  exterior  side  of  the  ring  of  growth,  so  that 
the  rings  of  growth  are  rendered  much  more  conspicuous  to  the 
eye. 
The  Stem  Bark  of  Primus  Avium. — The  bark  of  this  species  is 
smoother  and  lighter  colored,  being  reddish-brown  on  the  twigs  of 
the  second  or  third  year,  and  deep  gray  or  reddish-gray  on  the 
trunk.    The  lenticels  on  the  twigs  are  much  fewer  than  in  the  official 
species,  but  they  are  still  present  and  enormously  increased  in  size 
in  trunks  6  inches  or  more  in  diameter.  They  appear  as  lenticular, 
transversely  elongated,  corky  patches,  often  2  inches  or  more  in 
length.  The  outer  bark  may  be  easily  stripped  off  transversely  in 
broad  bands,  exposing  the  deep  green  middle  bark,  and  the  corky 
layer,  in  turn,  may  be  easily  split  into  thin  lamellae,  corresponding 
to  the  concentric  stratification  lines  seen  in  the  cross-section. 
The  inner  bark  shows  the  wavy  medullary  rays,  terminating  very 
obliquely  at  the  exterior,  the  wavy  bands  of  compressed  sieve  tissue 
in  the  older  portions,  and  the  Assuring  between  the  medullary  rays 
and  the  bast  masses,  which  are  shown  in  most  species  of  cherry;  but 
it  differs  from  the  official  species  and  from  some  others  in  the 
decidedly  fibrous  character  of  the  bast  layer.  There  are  not  only 
scattered  and  very  tortuous  lignified  fibres  in  its  outer  portions,  or 
O 
Fig.  io. — Starch  from  stem  bark  of  Prunus  Avium. 
