^emteVPi9i4m'}    The  Germination  of  Belladonna  Seed.  505 
There  appears  to  be  no  relationship  between  the  size  of  the  seed 
and  its  germinating  power.  This  must  not  be  taken  to  indicate  that 
a  relationship  does  not  exist  between  the  size  of  the  seed  and  the  vigor 
and  strength  of  the  plant. 
The  heavy  seeds  are  by  far  the  best.  The  percentage  of  ger- 
mination of  the  light  seeds  is  very  small.  Separation  of  these  inert 
seeds  can  be  readily  effected  by  immersing  the  seed  in  water  and  dis- 
carding those  which  do*  not  sink.  The  proportion  of  light  and  heavy 
seed  from  each  individual  plant  varies  greatly.  This  may  be  due 
partly  to  carelessness  in  picking  the  berries,  as  unripe  berries  contain 
light  and  worthless  seeds.  The  question  of  drying  is  also  of  impor- 
tance. The  berries  must  be  thinly  scattered  and  dried  in  a  well- 
ventilated  room,  in  order  to  reduce  molding  to  a  minimum.  It  is 
probable  that  a  certain  percentage  of  the  seed  in  a  fully  developed 
berry  is  inert,  which  would  account  to  some  extent  for  the  relatively 
low  percentage  of  germination  of  the  average  belladonna  seed. 
Color  appears  to  be  no  criterion  of  the  value  of  the  seed  as 
regards  germinative  power.  The  brown  seeds  have  a  better  appear- 
ance, but  apparently  the  gray  ones  have  equal  vitality. 
While  other  investigators  have  found  that  treatment  with  con- 
centrated sulphuric  acid  from  one  to  ten  minutes  is  of  benefit,  experi- 
ments with  various  strengths  of  acid  for  periods  ranging  from  one 
to  sixty  minutes  showed  that,  as  a  whole,  the  treatment  is  not  of  any 
great  value.  The  germination  was  accelerated  in  some  instances,  but 
no  material  increase  in  actual  germination  was  noted. 
Treating  seeds  with  hydrogen  peroxide  was  found  to  be  of  very 
material  benefit.  Eighteen  and  twenty-four  hours  gave  better  results 
than  longer  treatment.  A  60  per  cent,  solution  of  the  commercial 
hydrogen  peroxide  gave  the  best  results.  The  concentrated  solution 
was  the  least  beneficial. 
Scratching  the  seed  coats  by  shaking  in  a  bottle  with  powdered 
glass  and  by  rubbing  between  sheets  of  emery  paper,  while  of  some 
benefit,  was  not  nearly  as  beneficial  as  the  peroxide  treatment. 
