124 
Structure  of  Cimicifuga. 
Am  Jour  Pharrn. 
March,  1895. 
The  parenchyma  both  of  the  rhizome  and  roots  contain,  if  the 
drug  is  gathered  in  autumn,  as  should  be  the  case,  a  considerable 
quantity  of  rather  fine-grained  starch,  as  shown  in  Figs,  j  and  4* 
The  starch  grains  are  more  commonly  simple  and  rounded,  or  some- 
what angular,  with  a  central  or  subcentral  not  usually  conspicuous 
hilum,  and  only  rarely  showing  concentric  markings.  Many  of  the 
grains,  however,  are  compound,  in  twos,  threes,  or  occasionally  even 
in  masses  composed  of  several  grains,  very  rarely  as  many  as  nine 
or  ten. 
The  roots  afford  an  interesting  microscopical  study  and  reveal  a 
structure  which  is  quite  characteristic.    If  a  section  be  made  a  little 
Fig.  4. 
way  back  of  a  root-tip,  another  near  its  middle  and  a  third  near  its 
base,  the  primary  structure  of  the  central  bundle  and  the  secondary 
changes  it  undergoes  may  be  easily  traced.  The  primary  bundle  is 
usually  tetrarch  or  possesses  four  xylem  rays,  but  is  sometimes  tri- 
arch  or  pentarch.  Fig.  5  shows  a  tetrarch  bundle  from  a  young 
portion  of  a  root  in  which  the  bundle  is  but  little  altered  by  secon- 
dary changes.  A  wavy  zone  of  cambium  has  only  just  been  formed 
between  the  phloem  masses  and  over  the  ends  of  the  xylem  rays. 
In  Fig.  6  the  secondary  changes  have  progressed  much  farther, 
the  whole  bundle  is  much  increased  in  size  by  growth  in  the  endo- 
dermis,  in  the  pericambium  and  particularly  in  the  cambium  zone. 
The  inner  ends  of  the  xylem  rays  have  grown  by  the  formation  of 
