498  The  Germination  of  Belladonna  Seed,    j  A^*f£ v^lm' 
to  the  treatment.  It  is  evident  that  contact  with  concentrated  (92.5 
per  cent.)  sulphuric  acid  destroys  the  germinating  power  almost 
completely  if  continued  longer  than  ten  minutes.  Treatment  with 
75  per  cent,  acid  may  be  continued  for  thirty  minutes  without  injury, 
which  is  also  true  of  the  50  per  cent.  acid.  When  the  acid  is  below 
50  per  cent,  the  time  of  contact  up  to  one  hour  seems  to  be  imma- 
terial. It  is  noteworthy  that  only  the  seeds  treated  with  concentrated 
and  75  per  cent,  acid  showed  any  germination  on  April  24th,  twenty- 
four  days  after  sowing.  In  the  following  week,  however,  the  seeds 
which  received  treatment  with  the  50  and  25  per  cent,  acids  showed 
about  the  same  germination  as  the  others,  and  from  then  on  they 
continued  to  show  to  better  advantage. 
In  order  to  indicate  more  clearly  what  concentration  of  acid 
and  what  length  of  treatment  are  the  most  desirable,  the  data  are 
arranged  in  the  following  tables. 
Table  XII. 
Total  Germination  of  all  Seeds  Treated  with  92.5,  75,  50,  and  25  Per  Cent.  Sulphuric 
A  cid  for  Different  Lengths  of  Time. 
Treatment 
Germination 
Number 
Per  cent. 
4-24 
5-1 
5-8 
5-15 
5-22 
4-24 
5-1 
5-8 
5-15 
5-22 
A1A2A3A4 . 
12 
33 
65 
68 
70 
5 
17.8 
27.1 
28.3 
29.2 
B1B2B3B4 . 
6 
31 
91 
93 
96 
2-5 
13 
37-9 
38.7 
40. 
C1C2C3C4 . 
0 
18 
108 
126 
135 
O 
7-5 
45 
52.5 
56.2 
DiD2D3D4 
0 
21 
no 
115 
116 
0 
8-75 
45-8 
47-9 
48.3 
Table  XIII. 
Total  Germination  of  all  Seeds  Treated  for  1,  10,  30,  and  60  Minutes  with  Sulphuric 
Acid  of  Various  Strengths. 
Germination 
Treatment 
Number 
Per  cent. 
4-24 
5-1 
5-8 
5-15 
5-22 
4-24 
5-1 
5-8 
5-15 
5-22 
AxBidDx 
I 
17 
102 
115 
126 
O.4 
7- 
42.5 
47-9 
52.5 
A2B2C2D2 
IO 
46 
131 
135 
138 
4.2 
19.2 
54-6 
56.2 
57-5 
AsBsCsDs 
7 
28 
93 
100 
100 
2.9 
II.7 
38.7 
41.7 
4i>7 
A4B4C4D4 
0 
11 
47 
5i 
53 
0.0 
4.5 
19.5 
21.2 
22.1 
