56 
The  Anatomical  Method. 
(  Am.  Jour.  Pharm. 
\    February,  1907. 
EXPLANATION  OF  PLATES. 
PI, ATE  I. 
Fig.    i.  Stem  leaf  of  Spigelia  Marilandica. 
Fig.   2.  Stem  leaf  of  Ruellia  ciliosa. 
Fig.    3.  Basal  leaf  of  Phlox  ovata. 
Fig.   4.  Stem  leaf  of  same. 
Fig.   5.  Spigelia  Marilandica  ;  epidermis  of  leaf  from  below  the  midrib. 
Fig.   6.  Same  species  ;  hair  of  leaf  from  below  the  midrib. 
Fig.  7.  Same  species  ;  transverse  section  of  leaf.  Bp.  =  epidermis  of  upper, 
Ep.s-  =  epidermis  of  lower  face  ;  P  ==  palisade-tissue  ;  P1  =  pneu- 
matic tissue. 
Fig.   8.  Ruellia  ciliosa  ;  transverse  section  of  leaf ;  letters  as  above. 
PLATE  2. 
Fig.  9.  Spigelia  Marilandica  ;  epidermis  from  lower  face  of  leaf,  showing  the 
stomata. 
Fig.  10.  Ruellia  ciliosa  ;  epidermis  from  lower  face  of  leaf,  showing  a  cysto- 
lithe,  a  glandular  hair  and  a  stoma. 
Fig.  11.  Same  species  ;  cross-section  of  leaf,  showing  epidermis  with  a  glandular 
hair. 
Fig.  12.  Phlox  ovata  ;  epidermis  from  lower  face  of  leaf. 
Fig.  13.  Same  species  ;  a  hair  from  margin  of  leaf. 
Fig.  14.  Same  species  ;  transverse  section  of  leaf,  showing  the  thick-walled 
epidermis  along  the  margin. 
Fig.  15.  Same  species  ;  a  glandular  hair  from  above  the  midrib. 
THE  ANATOMICAL  METHOD. 
By  Theo.  Holm. 
The  object  of  the  anatomical  method  is  to  apply  such  microscopic- 
anatomical  and  micro-chemical  characters,  observable  in  the  organs 
of  animals  and  plants,  to  the  systematic  distinction  of  these.  When 
we  remember  the  enormous  number  of  species  that  are  known  at 
present,  and  the  steady  increase  of  new  ones,  it  does  not  seem 
strange  that  naturalists  have  felt,  and  long  ago,  the  necessity  of  aug- 
menting the  modes  of  distinguishing  the  species.  The  systematic 
method,  which  confines  itself  to  merely  external  morphological 
characters,  was  quite  sufficient  and  satisfactory  in  earlier  days,  when 
only  a  limited  number  of  species  were  known,  and  so  long  as  the 
systematists  did  not  look  beyond  the  distinction  externally  of  their 
species.  But  in  recent  years  systematists  have  to  deal  with  a  much 
larger  number  of  species,  and  are  no  longer  satisfied  with  a  mere 
superficial  knowledge  of  these.    Something  more  is  desired,  and 
