442  Structure  of  Our  Cherry  Barks.  {^pieTbe?!1^' 
numerous,  and  the  bast  fibres  somewhat  better  differentiated.  They 
are  still  few  in  number,  however,  as  compared  with  the  stone  cells, 
xrr 
I&  CL 
-C 
-J 
Fig.  7. — Cross  section  of  bark  of  Prunus  Mahaleb,  including  outer,  middle  and 
outer  portion  of  inner  bark. 
