Treatment of Cotton Seed 
59 
Table VI gives the data pertaining to these tests. In Experiment 1 seed of 
the 1919 crop was stored over concentrated H 2 S0 4 in a desiccator dish. The 
seed were placed in the desiccator on July 21, 1920, approximately 9% months 
after the seed had been harvested. Lots 1 and 2 were removed 58 and 139 
days later respectively and although they had lost 10.2 per cen tand 10.8 per 
cent of their initial weight as water they still contained a high percentage of 
seeds with viable anthracnose. Lot 3 was removed from the desiccator after 
210 days and at that time 20 per cent of the 50 seeds which were put to 
germinate or 28 per cent of the 35 seeds which did germinate still contained 
viable elements of the anthracnose fungus, while only 6 per cent of the 
seedlings of the check developed anthracnose. At the end of 269 days, when 
lot 4 was removed, the anthracnose had very largely disappeared from the 
treated seed, but even then, more than twice as many seedlings in the treated 
lot became diseased as in the untreated. The seed was by this time 18 y 2 
months old and had lost 11 per cent of their initial weight as water. Dry 
weight determinations made in the usual way on untreated seed gave an aver¬ 
age of 10.88 per cent and indicate that 11 per cent represents the total initial 
water content of the seeds. This is a far more complete desiccation than is 
brought about by the dry heat treatments effective for freeing seed from 
anthracnose. 
In Experiments 3 and 4. seeds of the 1920 crop were put to desiccate over 
con. H 2 S0 4 and Ca0 2 . The experiments were begun on July 12, 1921, when 
the seeds were approximately 9% months old and the first lot was removed 
from each desiccator 71 days later. When untreated seed were tested on 
April 6, 1921, approximately 97 days before they were put to desiccate, seed¬ 
lings from 52 per cent of the seeds developed anthracnose. By July 30, 1921, 
18 days after the experiments were started, the percentage of diseased seed¬ 
lings in undesiccated seed had dropped to 34, and by August 15, 1921, this 
percentage had fallen to 10. At the time the first lot was removed from the 
two desiccators, namely, September 21, 1921, the anthracnose had completely 
lost its viability in the untreated seeds while it was still alive and capable 
of growth in 36 per cent and 26 per cent of desiccated seeds in the two ex¬ 
periments. The percentage of anthracnose found in untreated seed on July 
30 was maintained till September 21 in desiccated seed, whereas in untreated 
seed it had completely died out by the latter date. The total water content 
of the seeds as indicated by a dry-weight determination was 9.6 per cent of 
their initial weight. The seeds of lot 1, Experiment 3, lost 8.7 per cent of 
their weight or 90.6 per cent of their total water content during the 71 days 
they were in the desiccator. Thus it appears from Experiment 3 that the 
vitality of the anthracnose fungus was prolonged approximately 53 days by 
removal of the greater part of the water from the seeds. 
In Experiment 5, seeds of the 1921 crop were put over con. H 2 S0 4 in a 
desiccator on January 19, 1922, at which time they were 3 y 2 months old. Lot 
1 was removed at the end of 196 days and at that time the percentage of 
diseased seedlings was slightly greater in the treated lot than in the un¬ 
treated check. When lot 2 was removed, 28 per cent of the 50 seeds put 
to germinate or 46 per cent of the 35 seeds which did germinate by the end 
of 17 days in the desiccated lot were found to be carrying living elements 
of the anthracnose fungus, while at the same time the fungus was still 
