\ 
462    .  Gleanings  i)i  3Iaf('ria  3fedic(j.  rAm.jour  pimrm. 
^  \      Sept.,  1882. 
oately  wrinkled,  light  green,  occasionally  yellowish,  short-i)etiolate, 
somewhat  revolute  on  the  margin,  pellucid-punctate,  the  venation 
observable  on  the  lower  surface,  while  on  the  upper  surface  only  the 
midrib,  and  in  the  larger  leaves  also  a  few  secondary  nerves  are  seen ; 
they  are  almost  inodorous,  but  when  rubbed  are  agreeably  aromatic, 
and  have  an  aromatic,  afterwards  strongly  bitter  taste. 
The  cuticle  is  particularly  prominent 
upon  the  upper  surface;  the  palisade 
cells  form  two  rows,  occupying  scarcely 
one-third  of  the  thickness  of  the  leaf, 
J  and  contain  occasionally  a  group  of  crys- 
tals ;   the  mesophyll   consists  of  loose, 
f irregularly    branched    parenchyma,  and 
rarely  contains  crystals ;  the  globular  oil 
glands,  with  deep  yellow  contents,  are 
C'liekeu  leaves,  natural  size,   scattered    under   the   cuticle    upon  the 
a,  upper  surface.   6,  lower   upper  and  lower  surface. 
■  The  virtues  of  cheken  leaves  reside  in 
the  tannin  and  volatile  oil. — Phar.  Centraihalle,  1882,  No.  29. 
The  bark  of  Rhmnnus  pursJiiana  has  been  examined  microscopically 
hy  Dr.  J.  Moeller.  The  corky  layer  is  about  '045  mm.  thick,  and 
consistst  of  8  or  12  rows,  somewhat  flattened,  rather  thick- walled,  but 
not  sclerotic  cells.  The  parenchyma  of  the  })rimary  bark  is  tangen- 
tially  elongated,  partly  of  a  collenchymatic  character,  free  from  second- 
;ary  cork,  and  contains  scattered  groups  of  roundish  stone  cells,  w^ith 
very  thick  walls,  and  accompanied  by  single  rhombohedric crystals;  the 
thin- walled  parenchyma  contains  numerous  groups  of  crystals.  The 
inner  bark  consists  of  medullary  rays  composed  of  two  or  three  rows 
of  thin- walled,  somewhat  radially  elongated  cells,  and  of  broader  bast 
rays  in  which  the  parenchyma  cells  are  coarsely  dotted  upon  the  radial 
and  horizontal  walls,  and  loosely  united  in  a  tangential  direction ;  the 
sieve  tubes  are  larger,  irregularly  angular,  and  united,  to  the  number 
of  4  or  6,  by  means  of  coarsely  porous  sieve  plates,  and  on  the  radial 
sides  marked  with  roundish  sieve  fields;  the  bast  fibres  form  alternate 
groups  of  two  or  three  rows,  extending  into  few  bast  rays,  and  are 
surrounded  by  crystal  cells.  The  medullary  parenchyma  contains  a 
crummy  lemon-yellow  substance,  which  dissolves  in  water  with  a  yel- 
low, and  in  cold  ])otassa  solution  with  a  dingy  red  color.  (See  also 
^^Am.  Jour.  Phar.,''  1879,  p.  165.) 
