Am.  Jour.  Pharm.  ( 
Jaly,  1913.  ( 
Breeding  Medicinal  Plants. 
301 
The  early  flowering  individuals  noted  in  the  table  are  being 
utilized  for  breeding  purposes,  in  the  hope  of  obtaining  either 
annuals  or  biennials  of  a  higher  and  more  uniform  quality.  Mixed 
samples  of  leaves  collected  from  plants  of  the  first  year's  growth 
of  all  varieties  studied  have  been  biologically  tested.  Many  of 
the  varieties  test  equally  as  high  as  good  commercial  drug,  and 
some  of  them  even  exceed  this  article  in  relative  strength,  as 
indicated  by  the  above  method.  Others  have  proven  extremely 
inactive,  the  poorest,  as  indicated  by  the  physiological  tests,  being 
only  one-sixth  as  active  as  the  best. 
In  addition  to  the  biological  tests,  the  external  characters  must 
also  be  closely  observed.  Upon  a  basis  of  leaf  forms,  the  genus 
is  easily  divided  into  two  groups.  One  of  these  is  characterized 
by  broad,  rough  leaves  and  includes  such  varieties  as  purpurea, 
monstrosa,  alba,  gloxinioides  and  others.  They  vary  greatly  in 
physical  characters,  and  apparently  hybridize  with  considerable 
ease.  The  other  group  is  .characterized  by  narrow,  smooth  leaves 
and  includes  such  forms  as  lanata,  ambigua,  grandiHora,  sibirica, 
canadensis  and  others.  The  members  of  this  group  vary  little 
in  external  characters,  and  hybridize  with  considerable  difficulty. 
The  diversity  of  leaf  forms,  as  noted  for  individuals  of  the 
same  species  or  variety,  is  indicated  for  two  forms,  in  Figure  IV. 
Each  leaf  was  taken  from  a  different  plant.  The  variations  in 
size,  shape,  margin,  petiole,  surface  and  color  seem  too  great  and 
diversified  to  be  explained  as  individual  variabilities.  Breeding 
and  the  examination  of  a  large  number  of  plants  will  evidently 
clear  up  this  point. 
The  foregoing  is  only  expected  to  serve  as  a  suggestion  to 
those  who  may  be  interested  or  have  the  opportunity  to  observe 
or  investigate  medicinal  plants.  Much  good  will  have  resulted  if 
better  crude  drugs  of  vegetable  origin  can  be  produced  from  the 
wild  forms,  by  an  application  of  the  rapidly  advancing  views  of 
the  practical  breeder.  It  is  only  just  that  the  demands  upon  the 
plant  kingdom  should  be  exhausting,  and  such  will  not  be  the  case 
until  medicinal  plants  are  included  in  the  category  of  the  plant 
breeder. 
Botanical  Department,  Eli  Lilly  &  Company, 
Indianapolis,  Indiana,  January  18,  1913. 
