Am.  Jour.  Pharm. 
November,  1894. 
Structure  of  Geranium  Maculatum. 
519 
an  inch  at  their  base,  and  may  spring  from  any  part  of  the  surface  of 
the  rhizome,  but  more  abundantly  from  the  sides  and  lower  surface. 
They  may  attain  a  length  of  five  inches,  but  average  somewhat 
shorter.  When  dry  they  are  brittle,  and  in  commercial  specimens 
of  the  drug  only  the  bases  of  the  roots  are  found  present  on  the 
rhizome.  Both  the  rhizome  and  roots  are  without  odor,  and 
possess  a  purely  astringent  taste. 
A  transverse  section  of  the  rhizome  shows  a  large  pith,  a  distinct 
cambium  zone,  which  is  seldom  circular,  approaches  much  nearer 
the  surface  at  some  points  than  at  others,  and  connects  a  few  vasal 
bundles  that  are  usually  situated  at  very  unequal  distances  apart. 
The  phloroglucin  test  shows  no  lignified  tissues  except  in  the  xylem 
of  these  bundles,  and  here  only  the  vasiform  tissues  are  stained,  no 
wood-cells  being  developed.  The  inner  layer  of  the  bark  shows  no 
evident  radial  structure.  The  outer  bark  is  composed  of  a  thin 
layer  of  cork  made  up  of  cells  considerably  elongated  in  a  tan- 
gential direction.  The  exterior  of  this  layer  is  rough  and  irregular 
by  reason  of  the  scaling  away  of  the  outside  tiers  of  cells. 
Fig.  3. 
