Am  Jour.  Pharm. 
November,  1914. 
The  Germination  of  Belladonna  Seed. 
503 
of  the  peroxide  seems  to  have  been  to  induce  a  uniformity  in  the 
germination  rather  than  an  acceleration  or  an  actual  increase  in 
percentage.  From  these  experiments  and  from  those  with  sulphuric 
acid  it  seems  that  when  working  under  conditions  such  as  those 
described  the  effect  of  treating  the  seeds  with  chemicals  is  to  induce 
a  uniformity  or  spontaneity  in  the  germination.  The  seeds,  however, 
seem  to  require  as  much  time  to  begin  germination  as  the  untreated 
seeds. 
As  regards  the  concentration  of  the  peroxide  used,  it  is  evident 
that  neither  the  concentrated  nor  the  greatly  diluted  material  is  of 
as  much  benefit  as  the  medium  strengths.  Tt  will  be  seen  from 
Figure  8  that  the  60  per  cent,  solution  gave  the  best  results.  The 
80  and  40  per  cent,  solutions  gave  results  very  much  alike,  while  the 
20  and  100  per  cent,  solutions  had  the  least  effect. 
The  time  of  treatment  does  not  seem  to  make  any  great  difference. 
The  18-  and  24-hour  treatment  gave  very  similar  results,  while  the 
48-hour  treatment  was  not  quite  so  effective.  It  is  evident  that  there 
is  no  benefit  in  treating  the  seeds  longer  than  18  hours,  and  it  is 
possible  that  a  shorter  period  would  be  just  as  effective. 
The  Effect  of  Scratching  the  Seed  Coats. 
Many  seeds  germinate  very  slowly,  owing  to  their  hard  and 
thick  coats,  which  do  not  admit  of  a  rapid  permeation  of  moisture 
and  air  into  the  seed.  Such  seeds  have  often  been  benefited  by 
scratching  the  surface  by  some  mechanical  means,  so  as  to  hasten  the 
absorption  of  moisture,  with  a  consequent  acceleration  of  the  ger- 
mination. 
To  determine  the  effect  of  such  methods  on  belladonna  seeds,  a 
quantity  of  the  seed  was  shaken  in  a  bottle  with  powdered  glass  for 
one  and  a  half  hours.  Another  quantity  was  rubbed  gently  between 
two  sheets  of  fine  emery  paper.  One  hundred  seeds  from  each  lot 
were  planted  as  a  test.   The  following  table  shows  the  result : 
Table  XVI. 
Comparative  Germination  of  Belladonna  Seed  Scratched  with  Powdered  Glass  and 
Emery  Paper.   Seeds  Sown  February  16th. 
Treatment  of  seed 
Percentage  of  germination 
March  13 
March  19 
March  25 
April  2 
April  9 
April  16 
Check  (untreated) . . . . :  
2 
3 
5 
•  l6 
25 
33 
Shaken  with  powdered  glass . 
3 
18 
21 
34 
45 
47 
Rubbed  with  emery  paper. .  . 
0 
1 1 
17 
22 
26 
28 
