Treatment of Cotton Seed 
67 
an open dish and in Experiments 3 to 6 they were kept in tightly stoppered 
bottles. The seeds were germinated in test tubes and at a temperature of 
about 25° C. Each lot tested in each experiment consisted of 50 seeds and 
the percentage of germination and the percentage of seeds which developed 
diseased seedlings was determined for each lot at intervals of 6 to 8 days, 
but only the total percentages obtained at the time the germination test 
was discarded are given here. The results of these experiments are pre¬ 
sented in Table VII. 
In two tests as high or higher germination was obtained with the seeds 
which had been kept in the single gases as with those stored in air. In 
all remaining tests the treated seeds gave slightly lower germination than 
the untreated seeds. The differences, however, are slight, and the tests 
show that cotton seed can suspend aerobic respiration and live in the ab¬ 
sence of free oxygen for at least fourteen months. 
This situation is not unusual among seeds. Houdas 06 found no reduction 
in germination of seeds of Gerbera Jamesoni after ten years in atmospheres 
of hydrogen and carbon dioxide. Becquerel 4 and others have shown that 
seeds may live several months or years in total absence of air, and Laurent 42 
and Guillaumin 27 found that seeds of a number of common plants, par¬ 
ticularly oleagenous kinds, stored in high vacuum for periods of 5 and 7% 
years were conserved better than when stored in air. Babcock 2 found that 
air dired corn containing 10 per cent of moisture can be stored in CO, for 
a year without harm but under similar storage corn containing 20 per cent 
of water loses its power to germinate in less than two months. Edquist 20 
found that grain can be stored in an atmosphere of pure nitrogen and 
carbon dioxide without injury to the grain, but the eggs of weevils and other 
insects are prevented from developing. 
In regard to the effect of the treatment on the vitality of the anthracnose 
fungus, the results of the tests with seed produced in different years are 
highly discordant. In Experiment 1, in which seed grown in 1921 were 
stored in hydrogen gas the percentage of anthracnose, computed on the 
basis of the number of seeds put to germinate, at the end of seven months 
of storage in the gas was found to be 32 in the untreated and in 8 in the 
treated seeds and at the end of 14 months of storage the percentage was 
20 for the untreated and 2 for the treated seed. In this experiment, a 
very pronounced reduction but incomplete suppression. of disease appears 
to have resulted from storage of the seeds in hydrogen. In Experiment 
2, which differed for Experiment 1 in the single condition that C0 2 was 
used instead of H 2 , 32 per cent of anthracnose was found in untreated and 
26 per cent in treated seed after 7 months of storage and 20 per cent was 
found in the untreated as compared with 2 per cent in the treated after 
14 months of storage in the gas. The reductions are much less pronounced 
than in Experiment 1 except for the longest period of storage in the two 
gases. In Experiments 3 and 4 some reduction in the amount of disease 
cccurred in the seeds stored in H 2 and C0 2 but the amount is much less 
than in Experiments 1 and 2. Again, the action of the hydrogen appears 
to be more efficacious than the C0 2 'in reducing disease. In Experiments 
5 and 6 in which seed of the 1923 crop were treated, no reduction in viability 
of the anthracnose had occurred after 4 months storage in either hydrogen 
or carbon dioxide. 
