356 
Journal of Agricultural Research 
Vol. II, No. 5 
ments involving, with controls, some 3,500 plants, were equally ineffec¬ 
tive and inconsistent in their results. 
But the spores are not at all injured by even more severe treatments. 
Table III, Nos. 11 to 18, inclusive, gives the results of these tests per¬ 
formed with the spores on March 7, 1913. It might even be said that 
the development of conidia proceeded better in the plates containing 
-treated spores, probably on account of the absence of contaminations, 
these being for the most part killed by the treatment. It is possible that 
a longer treatment, even with less concentrated solutions, would have 
killed the spores (Herzberg, 1895, p. 30), but this would be likely to 
injure the seed as well. 
Table III .—Results showing the effect of various formalin and copper-sulphate treat¬ 
ments on the viability of the spores of the head-smut organism 
Serial No. 
Treatment. 
Duration 
of test. 
Number 
counted. 
Germination. 
Duration. 
Method. 
Min. 
Days. 
Per cent. 
I 
Control, not treated.... 
( 3 
681 
4. I 
l 7 
No increase. 
2 
34 
0.16 per cent formalde- 
/ 3 
0 
hyde solution. 
1 7 
I, OOO 
1. 6 
3 
33 
0.24 per cent formalde- 
f 3 
0 
hyde solution. 
l 7 
Q 
4 
60 
0.16 per cent formalde- 
j 3 
0 
hyde solution. 
l 7 
0 
5 
60 
0.24 per cent formalde- 
/ 3 
0 
hyde solution. 
1 7 
0 
6 
Control, not treated.... 
541 
53 -i 
i 7 
No increase. 
7 
60 
0.16 per cent formalde- 
/ 3 
0 
hyde solution. 
\ 7 
Trace(?). 
8 
Control, not treated.... 
I 3 
Slight. 
1 7 
Slight. 
9 
60 
0.16 per cent formalde- 
/ 3 
0 
hyde solution. 
1 7 
Q 
10 
60 
0.24 per cent formalde- 
} 3 
0 
hyde solution. 
i 7 
0 
11 
Control, soaked 30 
minutes. 
28 
1, 068 
5 * 2 
12 
30 
0.76 per cent copper- 
sulphate® solution... 
28 
1,044 
5 *o 
13 
30 
1.52 per cent copper- 
sulphate solution.... 
28 
1,034 
5 * 2 
14 
30 
2.52 per cent copper- 
sulphate solution.... 
28 
I, OOO 
4.0 
IS 
Control, soaked 60 
minutes. 
28 
1,034 
4*5 
16 
60 
0.76 per cent copper- 
sulphate solution.... 
28 
I, OOO 
1.8 
i 7 
60 
1.52 per cent copper- 
sulphate solution.... 
28 
I, OOO 
5*0 
18 
60 
2.52 per cent copper- 
sulphate solution.... 
28 
1,000 
6.0 
a Copper sulphate = CuSC>4. 
