Fig.  4. — A  mixture  sold  as  ground  black  pepper  :  A,  stone  cells  of  olive 
endocarp;  S,  corn  and  wheat  starch  grains  ;  B,  stone  cells  of  pepper  hulls  ;  C, 
fragments  of  seed  coat  and  pericarp  of  cayenne  pepper;  L,  crystals  of  calcium 
sulphate  which  separate  on  mounting  the  specimen  in  25  per  cent,  sulphuric 
acid. 
