256 
Breeding  for  Atropine. 
f  Am.  Jour.  Pharm. 
June,  1917. 
lation  could  be  demonstrated,  the  advantage  of  observing  thousands 
of  individuals  rather  than  hundreds  would  be  at  hand. 
The  breeding  plot  contained  500  individuals  which  were  chosen 
from  a  lot  of  several  thousand  seedlings.  The  seed  from  which  these 
plants  were  grown  had  been  imported  from  Germany  and  no  previous 
history  of  them  was  known.  They  were  sown  in  the  greenhouse  in 
January  and  potted  off  in  the  usual  manner.  Those  used  for  the 
breeding  plot  wrere  chosen  only  because  of  uniform  size  and  ap- 
parent vigor.  Some  of  the  features  of  the  plant  were  recorded  on  a 
card  at  the  time  of  setting  out.  These  included  size  in  its  first  and 
second  weeks,  and  when  adult;  the  blooming  date,  color,  size  of  leaf 
and  of  root,  and  any  other  facts  which  seemed  likely  to  be  of  interest. 
The  plot  contained  five  rows  with  100  plants  in  each  row  numbered 
chronologically  and  recorded  on  individual  cards.  These  plants  were 
examined  once  each  week  for  the  first  three  weeks  and  then  as  often 
as  the  data  on  the  cards  required.  The  soil  on  which  the  plants  grew 
was  a  heavy  clay  loam  with  a  clay  subsoil  and  had  received  no  treat- 
ment except  a  heavy  application  of  stable  manure  during  the  winter. 
The  leaves  were  gathered  at  the  usual  time — just  as  the  flowers 
are  opening — and  enough  leaves  were  allowed  to  remain  to  mature 
the  fruit  pods.  The  leaves  were  then  air  dried  on  drying  racks  in 
bundles  corresponding  to  the  plant  from  which  they  were  taken, 
after  which  they  were  assayed  for  alkaloidal  content.  The  error  in- 
cident to  this  process  was  minimized  by  running  the  assays  in  dupli- 
cate. Of  the  400  samples,  15  were  discarded  because  too  small,  or 
because  they  were  spoiled  in  assaying.  The  alkaloidal  content  of  the 
remaining  samples,  expressed  in  percentages,  was  as  follows : 
Alkaloidal  Content,                                                 Number  of  Samples. 
.O-.09  .'   4 
.1-.19   8 
.2-29  :   26 
■3-39   83 
•4-49   94 
-5--5Q   65 
.6-.6g   42 
•7-79   26 
•8-.89   25 
•9--99   6 
1.0-    6 
385 
Mean  =  .507;    <r  =  .ig^. 
