440 
Structure  of  Our  Cherry  Barks. 
Am.  Jour.  Pharm. 
.  September,  1895. 
elements,  sprinkled  with  masses  of  sclerenchyma.  These  masses  are 
made  up  chiefly  of  stone  cells,  but  sometimes  contain  more  elon- 
gated elements,  which,  perhaps,  might  be  regarded  as  bast  fibres. 
They  are,  however,  much  shorter  than  bast  fibres  usually  are,  and 
Fig.  5. — Cross  section  of  stem  bark  of  Prunus  Mahaleb. 
every  gradation  between  them  and  stone  cells  may  be  observed. 
The  Assuring  along  the  bast  masses  is  conspicuous  in  the  cross-sec- 
tion. In  the  older  bark,  crystals  of  calcium  oxalate  are  so  abundant 
as  to  seriously   interfere   with  sectioning.     These  crystals  are 
