Am.  Jour.  Pharm.  \ 
August,  1896.  J 
North  American  Conifer cb. 
415 
rich  in  tannin,  and  containing  also  crystals  of  calcium  oxalate.  The 
thick  layer  of  parenchyma  interior  to  this  contained  only  a  resin 
passage,  numerous  scattered  resin  cells,  and  some  cells  containing 
crystals  of  calcium  oxalate.    In  the  bast  layer  were  tannin  cells, 
Fig.  42. — Cross-section  from  stem,  two  years  old,  of  Picea  pungens,  magni- 
fied 75  diameters.  A,  epidermis  ;  6,  hypoderma  ;  c,  thin-walled  parenchyma, 
containing  but  little  tannin,  except  in  its  inner  layer  ;  d,  periderm  layer  ;  e, 
tannin  cell  in  cortex;  f,  secretion  reservoir;  g,  bast  layer  of  bark;  h,  cambium 
zone  ;  /,  ring  of  growth  ;  k,  secretion  reservoir  in  xylem. 
arranged  as  in  the  other  species,  in  tangential  rows.  A  small 
amount  of  tannin  was  noticed  in  the  medullary  ray  cells  and  about 
the  secretion  reservoirs  in  the  wood.  In  other  respects  the  xylem 
presented  no  important  peculiarities. 
