Sept. x6,1918 
Resistance of Seeds to Desiccation 
53i 
Table: IV.— Additional data on germination tests begun on September 5, 1917, after 
seven months * drying —Continued 
Item. 
Pelissier wheat. 
Sudan grass. 
Johnson grass. 
Cal¬ 
cium 
oxid. 
Sul¬ 
phuric 
acid. 
Control. 
Cal¬ 
cium 
oxid. 
Sul¬ 
phuric 
acid. 
Control. 
Cal¬ 
cium 
oxid. 
Sul¬ 
phuric 
add. 
Control. 
Percentage germina- 
tion in 3 days. 
73 
76 
80 
82 
88 
92 
12 
19 
38 
Percentage germina- 
tion after third day.. 
5 
4 
4 
4 
4 
0 
40 
4 ^ 
40 
Number of coleoptiles 
emerged in 3 days... 
11 
157 
Maximum length of 
0 
coleoptile on third 
day.cm.. 
5 
0. 4 
0.4 
0. I 
0. 1 
O. 0 
Average number of 
roots on third day... 
2. 0 
2. 0 
I. Q 
Maximum length of 
roots on third day, 
cm. 
2. 2 
■2. c 
4.2 
2, I 
0 
*2. O 
0 J 
O’ w 
The small number and short length of coleoptiles emerged on the 
third day from barley samples which had been stored over lime are 
unusual, as the lots dried over lime did not appear to so poor advantage 
in any other tests. Except with respect to the development of the 
coleoptile, little difference appears between the dried lots and the control 
lots. This difference, however, at least in case of Sudan grass, is not 
wholly the result of a lower moisture content at the time of beginning 
the germination tests, as a similar difference appeared in the tests begun 
on November 25, although with these tests the seeds were left out of 
the desiccators to absorb water from the air for two days before the 
germination tests were begun. 
The percentages of Johnson grass seeds germinating in three days in 
case of the tests begun on September 5 showed the effect of the low 
initial moisture content of the dried lots, but no such difference appeared 
in the tests begun on November 25 after two days out of the desiccator. 
The results outlined in this paper show that all of the seeds used by 
the present authors, as well as radish seeds as reported by Waggoner, 
are 1 much more resistant to desiccation than is consistent with Ewart's 
hypothesis. All of these seeds were dried to 1 per cent of moisture or 
less without injury; and in the case of Johnson grass seed reduction of 
the moisture to 0.1 per cent had no injurious effect. Nearly all of the 
Kentucky bluegrass seeds were still capable of germinating, though 
with much reduced energy, after the removal of the last trace of water 
by vacuum desiccation at ioo° C. None of the seedlings produced 
were kept for further growth, but there seems to be no reason to suppose 
that the dried seeds, except those of bluegrass with the most extreme 
desiccation, would produce any less vigorous plants than those which 
were not dried. 
