370 
Digitalis  Hairs. 
f  Am.  Jour.  Pbarm. 
\      August,  1911. 
2-  to  5-celled  and  vary  in  length  from  145/x  to  435/x.  The  cells  are 
quite  slender,  being  9  to  13  times  as  long  as  broad.  In  other  cases 
they  are  much  shorter  and  broader,  being  twice  as  long  as  broad.  The 
apex  is  usually  obtuse  or  slightly  rounded,  and  seldom  acute.  (Fig. 
3,  A.)  In  some  specimens  the  end  cell  is  characteristically  curved  or 
crooked  (Fig.  3,  C).  Again  the  end  cells  of  these  long  hairs  may  be 
nearly  spherical  and  of  a  glandular  character  (Fig.  3,  B). 
The  glandular  hairs  in  the  crude  drug  found  on  the  market 
usually  possess  a  short  i -celled  stalk  and  a  globular  glandular  head 
consisting  of  one  or  two  cells  (Fig.  3,  D).  In  some  specimens  these 
are  relatively  few,  or  wanting  entirely,  while  in  other  speci- 
mens they  are  quite  numerous,  being  about  25  to  the  square  milli- 
meter. The  greatest  interest  is  in  the  long-stalked  glandular  hairs 
(Fig.  3,  B),  which,  in  some  specimens  of  leaves  from  cultivated 
plants,  largely  replace  the  long  non-glandular  hairs.  One  may 
count  upon  a  single  cross-section  about  one  half  millimeter  long, 
one  complete  non-glandular  hair  ;  three  long-stalked  glandular  hairs  ; 
the  basal  cells  only  of  nine  hairs,  and  eleven  short-stalked  glandular 
hairs.  The  impression  that  one  receives  from  seeing  slides  of  this 
character  is  that  the  hairs  of  digitalis  are  chiefly  of  the  glandular 
type. 
One  of  the  most  unusual  characters  which  has  been  observed 
in  certain  specimens  of  crude  drug,  has  been  the  formation  of  an 
extra  epidermal  layer.  It  would  be  interesting  to  know  the  potency 
of  preparations  made  from  a  drug  of  this  kind.  In  presenting  this 
paper  at  this  time  I  have  done  so  in  order  to  call  attention  tO'  the 
fact  that  the  pharmacognostical  study  of  this  drug  has  by  no  means 
been  exhausted.  What  is  probably  needed  here  is  some  statistical 
work  in  regard  to  the  occurrence  of  the  several  types  of  hairs  and 
their  relative  distribution  in  different  specimens  of  the  drug  the 
pharmacological  efficiency  of  which  is  being  determined. 
LITERATURE  CITED. 
'  C.  Hartwich  and  P.  Bohny  :  Apotheker  Zeitung,  1906  (Vol.  21),  pp.  231,  232. 
August  V.  Vogl :    Kommentar  zur  achten  Ausgabe  der  Osterreichischen 
Pharmakopoe,  1908,  p.  91. 
^  Henry  George  Greenish:    The  Microscopical  Examination  of  Foods  and 
Drugs,  1910,  p.  136. 
*A.  Tschirch  and  O.  Oesterle :    Anatomischer  Atlas  der  Pharmakognosie 
und  Nahrungsmittelkunde,  Lief.  15,  p.  319. 
