Am.  Jour.  Pharm. 
June,  1896. 
North  American  Coniferce. 
323 
a  periderm,  composed  at  its  outside  of  stone  cells,  in  one  or  two 
layers,  and  interiorly  of  thin-walled  cells,  including  a  cork  cambium, 
all  rich  in  tannic  matters.  Interior  to  the  periderm  layer  was  a  con- 
siderable thickness  of  parenchyma,  composed  mostly  of  large,  tan- 
gentially  elongated  cells,  a  large  proportion  of  which  contained 
Fig.  29,  cross-section  of  stem  of  Pinus  resinosa,  two  years  old,  magnified  100 
diameters.  A,  epidermis;  b,  thick  walled  periderm  cells;  c,  tannin  cell;  d,  bast 
layer;  e,  cambium;  f,  secretion  reservoir  in  xylem;  g,  lacuna;  h,  secretion 
reservoir  in  bark.  Drawing  from  specimen  that  had  been  treated  with  anhy- 
drous ferric  chloride,  dissolved  in  absolute  alcohol,  for  the  purpose  of  showing 
the  distribution  of  tannin. 
tannin.  The  secretion  reservoirs  found  in  this  area  were  similar  in 
character  to  those  already  described  in  other  species. 
In  the  xylem  the  secretion  reservoirs  were  observed  to  be  dis- 
posed more  or  less  evidently  in  circles. 
Tannic  matters  appeared  to  be  distributed  very  much  as  in  the 
