58  The  Anatomical  Method.  {^i^^iw^' 
microscopical  examination  ?  Broken  rhizomes,  roots  or  stems,  as 
they  often  appear  in  the  shape  of  drugs,  often  resemble  superficially 
each  other  to  such  an  extent  that  it  seems  impossible  or  at  least 
extremely  difficult  to  decide  whether  such  specimens  are  roots  or 
stems,  or  even  leaves.  This  first  step,  however,  is  only  elementary, 
and  requires  but  little  botanical  knowledge ;  a  microscopical  exam- 
ination soon  shows  us  what  they  are,  stems,  roots  or  leaves.  The 
difficulty  comes  in,  when  the  question  is  to  decide  whether  some 
given  specimens  really  belong  to  a  certain  species,  or  whether  they 
are  something  else  and  of  lesser  or  no  value.  To  settle  such  questions 
involves  more  than  an  ordinary  botanical  knowledge,  and  it  is  here 
that  the  anatomical  method  comes  in  as  the  most  reliable  guide,  in 
the  shape  of  a  microscopic-anatomical  or  micro-chemical  analysis. 
But,  plant-structures  are  manifold  ;  in  some  genera  the  leaves  are 
the  only  organs  that  possess  structures  sufficiently  characteristic  for 
the  anatomical  determination  of  the  genus  or  species;  in  others, 
both  the  stems  and  roots  may  be  necessary.  Some  certain  plant- 
families  are,  on  the  other  hand,  so  thoroughly  characteristic  in  their 
structures  that  either  the  stems  or  the  leaf  may  suffice  for  the  iden- 
tification. To  utilize  such  anatomical  characters  requires,  however, 
a  large  amount  of  literary  research,  and  the  literature  on  this  sub- 
ject is  indeed  very  scattered.  An  important  publication  has,  mean- 
while, been  offered  by  Dr.  Solereder,  who  has  gathered  the  most 
essential  points  known,  so  far,  from  anatomical  botany ;  we  find  in 
his  work:  "  Systematische  Anatomie  der  Dicotyledonen  "  a  most 
complete  representation  of  the  various  structures  possessed  by  these 
plants,  arranged  systematically,  described  methodically.  From  this 
important  work  the  student  who  is  familiar  with  plant-anatomy 
can  gather  much  information,  so  as  to  be  able  to  identify  a  number 
of  plants  anatomically. 
Let  us  now  present  some  few  examples  of  the  application  of  this 
method  in  order  to  demonstrate  the  importance  of  anatomical  char- 
acters. The  family  Ra?iunculacece  is  so  well  known  to  students  of 
pharmacology,  since  several  of  the  genera  occupy  quite  a  prominent 
place  among  the  officinal  plants,  and  several  are  known  for  their 
poisonous  properties. 
A  cross- section  of  the  rhizome,  of  the  stem  above  ground,  and 
of  the  petiole  shows  in  this  family  a  certain  structure  of  the  mestome- 
strands,  which  otherwise  is  almost  exclusively  known  from  the 
