1172 
Journal of Agricultural Research 
Vol. V, No. 25 
removing micro-organisms from cottonseed. The seeds were placed in 
a large glass-stoppered bottle containing concentrated sulphuric acid 
and glass beads. After shaking for two minutes, the seeds were removed 
with a platinum loop and washed in boiled water. From the data 
it seems that infection is from some source other than the seed. 
It has been shown repeatedly that the addition of green manure to 
soil is followed by an enormous increase in the number of bacteria. 
Aside from the increase in bacterial food, the green manure carries 
with it a great number of bacteria (6, 8, 21). Tests with bacteria-free 
green manures failed to eliminate the injury. 
About 16 pure cultures of bacteria were isolated from diseased seeds 
and green-manured soil. In order to test the effect of these various 
micro-organisms on germination, sterilized green-manured soil was 
inoculated with the various species of bacteria and seeded. The tests 
were carried out in triplicate, using bacteria-free seed of cotton, peanut, 
and soybeans. Here, again, bacteria failed to show any effect on the 
germination of oil seeds. In addition to the pure cultures used in the 
above experiment, a study was made with four laboratory stock cul¬ 
tures, Bacillus fluorescens liquefaciens, B. subtUis , B. mesentericus vulgatus , 
and Streptothrix bucallis . Heavy inoculations of these organisms did 
not injure the germination of cottonseed or soybeans. This agrees with 
the results of earlier workers (12, 13, 15, 18)—that is, bacteria grown 
on rich nitrogenous media do not injure seed germination. An exception 
to this is noted with cracked or injured seeds. 
EFFECT OF FUNGI 
• 
From a study of tests carried out with various combinations of ster¬ 
ilized soil, green manure, and seeds free of micro-organisms, it was found 
that the harmful factor occurs chiefly in soil. The data in Table XIV 
show very conclusively the position of injury. 
Table XIV .—Effect of fungi on the germination of cottonseed 
No. 
Treatment. 
Germination. 
1 week. 
2 weeks. 
3 weeks. 
Relative. 
1 
2 
3 
4 
Sterilized soil, 1 per cent of sterilized clover. 
Sterilized soil, 1 per cent of unsterilized 
clover. 
Per cent. 
20 
15 
Per cent. 
70 
45 
Per cent. 
70 
45 
Per cent. 
IOO 
64 
Unsterilized soil, 1 per cent of sterilized 
clover. 
Unsterilized soil, 1 per cent of unsterilized 
clover. 
It seems that the harmful agent is found both in soil and in plant 
tissue, although it is much more prevalent in soil. The results of later 
tests confirm this statement. 
