A.m.  Jour.  Pharm.  \ 
July,  1897.  J 
North  American  Conifer  ce. 
355 
than  two  years  old,  the  secondary  cork  formations  had  invaded  the 
inner  layer  of  the  bark  and  bands  of  cork  were  observed  crossing 
at  various  angles  the  medullary  rays.    The  cork  in  both  was  colored 
Fig.  57. 
Fig-  57- — Small  portion  of  cross-section  of  bark  of  Tsuga  Mertensiana,  mag- 
nified about  50  diameters,  c,  c,  c,  bands  of  secondary  cork  ;  a,  intervening 
dead  tissues,  composed  of  sieve  and  parenchymatous  elements,  and,  like  the 
other  species,  rich  in  tannic,  resinous  and  coloring  matters  ;  s,  .^"[groups  of 
stone  cells  ;  m,  m,  relatively  large,  fusiform  medullary-ray  cells  ;  b,  band  of 
large  parenchymatous  cells  ;  cr,  crystal  cell ;  ca,  cambium  cells. 
