Am.  Jour.  Pharm. 
December,  1914. 
}         Belladonna  and  Hyoscyamus.  535 
fix  the  biennial  races  and  to  free  them  of  annual  species  or  to  free 
the  annual  races  of  biennial  individuals. 
Holmes,  in  considering  the  occurrence  of  annual  plants  in  the 
biennial  henbane  fields  of  England,  states  that  "the  seeds  of  the 
capsules  last  formed  are  often  deficient  in  vitality  and  the  plants 
produced  from  them  flower  the  first1  year,  hence  the  occurrence  of 
annual  plants  among  the  biennial." 
In  discussing  CEnothera  Lamar kiana  (a  plant  which  possesses  the 
semi-latent  alternating  annual  and  biennial  habit)  De  Vries  says  that 
he  found  about  the  same  number  of  annual  and  biennial  individuals 
from  the  upper  and  lower  fruits  of  the  same  spike,  and,  furthermore, 
he  draws  the  conclusion  from  his  work  on  Trifolium  pratense 
quinquej  olium  that  the  better  the  seeds  are  fed  on  the  plant  the 
greater  is  the  development  of  the  anomaly  on  the  individuals  pro- 
duced by  them.  Poor  seeds  give  rise  to  atavists,  good  ones  to  ex- 
treme variants. 
If  we  accept  the  quite  general  belief  that  perennial  and  biennial 
plants  are  of  older  origin  than  annual  plants,  then  we  cannot  con- 
sider the  annual  henbane  as  atavistic.  On  the  choice  of  seeds  in 
selection  De  Vries  states,  after  weighing  the  evidence  of  a  large 
number  of  workers,  as  well  as  his  own,  that  "when  we  are  dealing 
with  semi-latent  or,  in  general,  with  highly  variable  characters  a 
selection  of  seeds  either  by  their  size  and  weight  or  by  their  place 
of  origin  on  the  plant  is  to  be  recommended  in  many  cases,  and  the 
general  rule  seems  to  be  that  the  place  of  origin  of  the  best  seeds 
will  also  be  that  of  the  desired  variants."  There  are  some  cases  in 
which  this  rule  does  not  apply,  as  in  Trifolium  incarnatum.  In  this 
latter  plant  De  Vries  found  that  the  reverse  of  the  general  rule  held 
good,  and  the  result  of  this  work  was  so  strikingly  different  from 
all  other  that  he  leaves  the  explanation  an  open  question.  This 
occurrence  of  the  annual  form  of  Hyoscyamus  niger  in  English 
henbane  fields  is  probably  due  to  hybridization  (which  will  be 
discussed  later  in  this  paper)  rather  than  to  semi-latent  characters 
in  the  biennial  Hyoscyamus. 
I  will  now  describe  my  own  experimental  attempts  to  bring  out 
semi-latent  characters  in  Hyoscyamus.  All  plants  grown  outside 
were  cultivated  in  the  Medicinal  Plant  Garden,  College  of  Pharmacy, 
University  of  Minnesota. 
