Am.  Jour.  JPharru.  t 
February,  1907.  J 
The  Anatomical  Method. 
59 
Monocotyledones.  The  vessels  and  the  other  elements  of  the  had- 
rome  are  here  arranged  in  the  shape  of  the  letter  V,  with  the  point 
toward  the  pith,  and  with  the  arms  partly  enclosing  the  leptome. 
Pceonia,  however,  makes  an  exception,  since  the  mestome-bundles 
show  in  this  genus  the  ordinary  structure  with  the  hadrome  flattened 
where  it  borders  on  the  leptome,  and  not  surrounding  this.  In 
several  of  the  herbaceous  and  woody  species  of  this  family  a  more 
or  less  continuous  zone  of  stereome  surrounds  the  mestome-strands, 
thus  separating  these  from  the  cortical  parenchyma. 
If  we  examine  the  leaves  we  notice  that  the  stomata  lack  sub- 
sidiary cells,  and  that  they  are  surrounded  by  several  ordinary 
epidermis  cells  ;  furthermore  that  the  palisade-tissue  in  some  certain 
species  shows  the  remarkable  structure  of  "  arm-palisades,"  first 
described  by  Haberlandt.  Aconitum  Napellus  and  dissectum,  but 
not  A.  uncinatum  show  this  structure,  likewise  Caltha,  Trollius, 
several  species  of  Anemone,  Clematis  and  Pceonia. 
The  hairs  show  a  very  simple  structure  in  this  family,  being  mostly 
unicellular,  even  when  developed  as  glandular  hairs.  Internal  glands 
are  not  known  from  the  family,  but  in  Eranthis  and  Helleborns  the 
parenchyma  of  the  rhizomes  and  roots  does  contain  an  oily  matter ; 
besides  that,  the  stems  and  roots  of  Coptis,  Hydrastis,  Xanthorhiza 
and  certain  species  of  Thalictrum  contain  yellow  berberine. 
One  of  the  most  interesting  and  striking  characters  is,  however* 
to  be  found  in  the  stem  of  certain  herbaceous  genera,  as,  for  instance, 
Ac  tee  a,  Cimicifuga  and  Thalictrum.  In  these  the  mestome-bundles 
are  not  located  in  one  circular  band  and  are  not  surrounded  by  a 
pericycle  or  an  endodermis  so  as  to  represent  a  central  cylinder,  a 
stele,  as  in  other  Dicotyledones  with  normal  structure.  But  we  find 
in  these  genera  two  or  more  irregular  bands  of  mestome-bundles, 
with  no  arrangement  so  as  to  constitute  a  stele.  In  other  words,  we 
meet  with  an  astelic  axis,  a  term  proposed  by  Van  Tieghem,  and 
such  structure  is  very  rare  among  the  Dicotyledones. 
There  are  thus  several  characters  by  which  this  family  may  be 
distinguished,  even  if  it  does  share  some  of  these  with  genera  of 
other  families.  For  instance,  the  V-shaped  outline  of  the  hadrome, 
which  recurs  in  some  of  the  Fumariacece,  Plumbaginecz  and  Com- 
posite. Also  the  unicellular  glandular  hairs  are  known  from  other 
families:  Malvacece,  Tiliacece,  Rutacece,  etc.  The  peculiar  shape  of 
the  palisade-cells  so  very  characteristic  of  Eilices,  Equisetacece,  Coni- 
