326 
North  American  Loniferce. 
Am.  Jour.  Pharm. 
June,  1896. 
the  leaf  and  about  midway  between  the  epidermal  and  the  hypo- 
dermal  cells.  The  circle  of  strengthening  cells  about  the  reservoir 
were  observed  to  have  their  walls  moderately  thickened.  The  cells 
of  the  endodermis  were  large  and  had  their  walls  somewhat  thick- 
ened.   Interior  to  the  endodermis  were  no  fibrous  elements,  except 
Fig.  j/,  cross-section  of  stem,  two  years  old,  of  Pinus  glabra,  magnified  100 
diameters.  A,  portion  of  remaining  epidermis;  b,  thickish-  walled  periderm; 
c,  secretion  reservoir  in  cortex  ;  d,  bast  layer;  e,  cambium;  f,  medullary  ray  in 
secondary  xylem  ;  g,  lacuna.  Drawing  from  specimen  that  had  been  treated 
with  ferric  chloride  solution  in  absolute  alcohol. 
those  contained  in  the  small  xylem  bundles.  The  transfusion 
tissue,  interior  to  the  endodermis,  and  the  folded  mesophyll,  exte- 
rior to  it,  presented  no  peculiar  features. 
A  cross-section  of  a  twig  of  three  years'  growth  showed  on  the 
exterior  fragments  only  of  the  epidermis,  and  of  a  few  layers  of 
