Am.  Jour.  Pharm.  \ 
October,  1896.  j 
North  American  Conifer ce. 
563 
MICROSCOPICAL  STRUCTURE. 
Sections  of  a  twig  six  years  old  were  examined.  There  were 
rather  numerous  resin  passages  in  the  middle  bark,  a  few  large 
mucilage  cells,  and  numerous  tannin  cells  of  smaller  size.  The 
Fig.  50. — Part  of  cross-section  of  stem  of  Abies  Nordmanuiana,  magnified  75 
diameters,  a,  tannin  cell  in  outer  portion  of  cortex  ;  b,  secretion  reservoir 
surrounded  by  tannin-bearing  cells  ;  c,  tannin  cell  in  bast  layer  ;  d,  cambium 
zone  ;  e,  xylem  ;  /,  ring  of  growth  ;  g,  mucilage  cell  in  middle  bark. 
tannin  cells  of  the  inner  bark  were  of  larger  size  than  those  of 
adjacent  tissues,  and  mostly  arranged  in  radial  and  tangential  rows, 
though  less  distinctly  so  than  in  A.  balsamea.    No  lignified  tissues 
