6o 
The  Anatomical  Method. 
f  Am.  Jour.  Pharm. 
1    February,  1907. 
ferce  and  Graminea  occur  also  within  the  Ranunculacece ,  further- 
more in  some  genera  of  Araliacem,  Caprifoliacece ,  Solanacece,  etc. 
It  is  thus  very  difficult,  if  possible,  to  point  out  such  characters 
as  may  be  possessed  by  a  certain  family  alone.  However,  if  we 
examine  the  anatomical  diagnoses  of  the  various  families,  in  which 
some  of  these  peculiarities  are  to  be  found  besides  in  the  Ranun- 
cidacecB,  we  then  notice  that  only  one  or  two  of  these  may  occur  at 
the  same  time  and  accompanied  by  other  characters  not  known  from 
this  family. 
A  family  that  has  very  many  anatomical  characters  in  common 
with  others  is  that  of  the  Composite?.  In  this  family  we  notice  the 
superficial  development  of  cork;  the  prismatic  or  needle-shaped 
crystals  of  calcium  oxalate  ;  the  resiniferous  and  the  articulated 
lacticiferous  ducts ;  the  numerous  types  of  hairs,  and,  finally,  the 
occurrence  of  mestome-strands  in  the  pith,  of  leptome  alone  or  with 
hadrome.  By  some  of  these  characters  the  family  may  be  distin- 
guished, in  spite  of  the  fact  that  none  of  these  are  especially  peculiar 
to  the  family.  It  is  the  structure  in  general  of  the  Composite^  that 
makes  them  so  very  distinct  among  the  other  plants. 
When  compared,  for  instance,  with  the  closely  allied  Campann. 
lacece,  the  Composites  show  themselves  remarkably  distinct,  even  if 
the  principal  features  be  identical  to  both.  In  the  Campanulaceoe 
we  meet  with  the  same  distribution  of  the  mestrome-strands  in  the 
pith,  with  or  without  hadrome ;  we  notice  the  occurrence  ot  articu- 
lated laticiferous  ducts,  the  presence  of  inulin,  etc.  But  the  Campa- 
nnlacea  lack  crystals  of  calcium  oxalate  and  resiniferous  ducts;  they 
possess,  on  the  other  hand,  sphaerocrystals  and  the  very  peculiar 
cystolithic  hairs. 
The  application  of  the  anatomical  method  means  a  continued 
comparison  and  a  study  of  plant-structures ;  it  has  proved  to  be  very 
useful,  however  ;  besides  that,  it  teaches  us  so  very  much  about  the 
organization  of  the  plants,  illustrated  by  the  structures  and  functions 
of  the  various  tissues. 
Brookland,  D.  C,  December,  1906. 
