Am.  Jour.  Pnarm. ) 
February.  1907.  J 
The  Anatomical  Method, 
57 
one  of  the  great  results  gained  by  the  use  of  the  microscope  is  the 
discovery  of  internal  characters  of  value  to  the  distinction  of  species. 
Thus  when  our  study  and  comparison  of  the  external  characters 
may  fall  short,  valuable  assistance  may  sometimes  be  rendered 
through  a  microscopical  examination. 
In  botany  the  anatomical  method  has  been  in  use  for  very  near  a 
century  ;  however,  it  is  only  recently  that  the  anatomical  investiga- 
tion has  become  methodically  applied  in  the  service  of  systematic 
botany.  This  one  chapter  of  plant-anatomy  thus  plays  an  important 
role  by  being  of  practical  use  ;  however,  it  represents  besides  at  the 
same  time  a  prominent  place  in  scientific  botany  by  enlarging  our 
knowledge  of  plant-structures. 
The  anatomical  method,  so  far  as  concerns  the  identification  of 
plants,  is,  of  course,  not  a  new  one.  In  pharmacy,  in  phyto-paleon- 
tology  and  especially  in  cryptogamic  botany,  the  anatomical  method 
has  been  applied  for  many  years.  But  in  systematic  botany,  as 
stated  above,  as  a  means  of  distinguishing  the  higher  plants,  the 
methodical  application  of  anatomical  characters  is  somewhat  modern. 
The  history  of  botany  tells  us  about  the  earliest  suggestions  as 
to  its  possible  application,  and  the  earliest  attempts  to  discover  and 
appreciate  the  internal  structures.  Linnaeus  spoke  of  "  formae  et 
structurae"  ;  De  Candolle  and  Endlicher  separated  the  Monocotyledones 
from  the  Dicotyledones  by  means  of  their  structural  divergences ;  Mar- 
tius  knew  of  the  peculiar  structure  of  the  wood  in  Conifers ;  Mirbel, 
as  early  as  1810,  wrote  an  anatomical  monograph  of  the  Labiatce, 
followed  soon  by  Chatin,  Regnault,  Duval- Jouve,  and  others.  The 
methodical  application  of  anatomical  characters  in  higher  plants  is, 
on  the  other  hand,  more  recent,  the  impulse  being  given  by  Radl. 
kofer  and  Vesque,  who  demonstrated  in  a  most  clear  and  concise 
way  that  anatomical  characters  are  not  only  very  useful,  but  in  a 
number  of  cases  absolutely  necessary  for  scientific  classification  of 
plants.  From  that  time  the  botanical  literature  shows  us  the  enorm- 
ous results  gained  in  later  years  through  the  use  of  the  microscope : 
the  broadened  field  in  systematic  botany  and  the  rapid  increase  in 
the  recording  of  anatomical  distinctions  of  genera,  of  species,  and 
even  of  families. 
The  anatomical  method  has  also  gained  universal  recognition 
in  works  on  pharmacology.  How  would  it  be  possible  to  ascertain 
the  true  nature  of  dried  or  pulverized  drugs  unless  by  means  of  a 
