Am.  Jour.  Pharm.  \ 
January,  1897.  / 
Gelsemium. 
companying  drawings  may,  perhaps,  more  clearly  and  more  briefly 
describe  these  three  parts  of  the  plant  than  any  written  description 
can  do. 
In  an  examination  of  cross-sections  of  the  stem,  rhizome  and  root 
of  the  gelsemium,  we  find  the  following  microscopical  characters 
and  difference  of  structure.  In  the  stem  (Fig.  i,  A)  are  found  com- 
paratively large  bundles  of  bast  (b)  near  the  wood,  just  outside  the 
cambium.  In  the  rhizome  (Fig.  i,  B)  the  bast  is  arranged  near  the 
corky  layer,  and  in  an  interrupted  ring,  rather  than  in  bundles.  In 
Fig.  3. — Gelsemium.    Powder  of  root,    a,  wood  tissue  ;  b,  parenchyma  of 
cortex  ;  c,  cork  cells  ;  d,  cambium  cells. 
the  root  (Fig.  i,  C)  the  bast  is  entirely  absent,  but  there  are  several 
layers  of  cork.  The  following  table  shows  the  corresponding  tissues 
in  the  three  plant  parts  : 
Stem. 
e,  Epidermis. 
c,  Collenchyma, 
p,  Parenchyma. 
b,  Bast. 
s,    Sieve  tissue. 
ca,  Cambium. 
w,  Wood  tissue. 
vy   Vascular  tubes. 
Pi,  Pith. 
mt  Medullary. 
Rhizome. 
Epidermis. 
Collenchyma. 
Parenchyma. 
Bast. 
Sieve  tissue. 
Cambium. 
Wood  tissue. 
Vascular  tubes. 
Pith. 
Medullary. 
Root. 
Parenchyma. 
Sieve  tissue. 
Cambium. 
Wood  tissue. 
Vascular  tubes. 
Fig.  4.  shows  a  cross-section  of  the  pith  in  the  rhizome ;  here  the 
division  into  four  parts  is  shown.  It  seems  that,  as  the  rhizome 
advances  in  age,  the  pith  becomes  less  and  less  conspicuous,  until 
