296 
Breeding  Medicinal  Plants. 
Am.  Jour.  Pharm. 
July,  1913. 
the  average  for  the  ten  being  0.51  per  cent.  Of  the  same  number 
of  individuals  from  the  plant  yielding  0.65  per  cent.,  a  range  of 
from  0.43  per  cent,  to  0.77  per  cent,  was  obtained,  the  average  in 
this  case  being  0.65  per  cent.  In  the  first  group  seven  of  the 
ten  plants  tested  exceeded  the  parent  in  alkaloidal  yield,  while  in 
the  second,  only  five  exceeded  the  parent.  It  is  of  interest  to  note 
that  the  lowest  limit  (0.43  per  cent.)  was  found  in  the  progeny 
Fig.  11. 
Breeding  plot  of  Stramonium. 
of  the  high  yielding  plant  (0.65  per  cent.),  the  lowest  limit  in  that 
of  the  low  yielding  plant  (0.47  per  cent.)  being  0.44  per  cent. 
The  most  promising  feature  of  this  experiment  in  its  present  stage 
is  the  greater  average  yield  obtained  over  that  from  wild  plants 
from  the  same  locality.  A  mixed  sample  of  leaves  from  uncul- 
tivated plants  of  Datura  tatula  gave  a  yield  of  only  0.35  per  cent, 
in  comparison  with  average  yields  of  0.51  and  0.65  per  cent,  from 
selected  plants.    These  latter  figures  might  also  be  compared  with 
» 
