Fig,  jj. —Small  portion  of  cross-section  of  bark  of  Tsuga  Canadensis,  mag- 
nified about  50  diameters,  c,  c,  c,  secondary  cork  formation  ;  a,  dead  phloem 
tissues  rich  in  coloring,  resin  and  tannic  matters  ;  s,  s,  stone  cells ;  m,  mt 
medullary  rays  ;  cr,  crystal  cell ;  ca,  cambium  ;  st,  bands  of  starch-bearing 
parenchyma  cells. 
