Dec. 15, 1925 
Nitrogen Metabolism in Etiolated Corn Seedlings 1155 
200 c. c. each were oxidized according to Kjeldahl’s method; the 
remaining 100 c. c. were used for qualitative tests as well as for 
acidity estimation (first series). In order to obtain a more con¬ 
centrated extract suitable for the trials reported in the subsequent 
pages, another series of extracts was prepared, in which 50-gram 
portions of flour were treated with hot ammonia-free water, kept on 
the water bath for 15 minutes, and then centrifuged. The solid 
residues were extracted two more times. The three extracts were 
made up to 500 c. c. in 25 c. c. portions, the nitrogen of which was 
determined according to the Kjeldahl method. The results in 
question are recorded in Table III. 
Table III. — Percentage of nitrogen extracted by water from the various seedlings 
No. 
10 
Conditions of germination 
Dura¬ 
tion 
Days 
3 
3 
Substratum 
Sand... 
.do_ 
Average_ 
Sand.. 
_do. 
Average- 
Paper.._.. 
_do.. 
Average. 
Paper. 
_do. 
Average- 
Paper_ 
_do_ 
Average... 
Paper_ 
_do_ 
Average. 
Paper. 
.—do_ 
Average. 
Tem¬ 
pera¬ 
ture 
Paper. 
_do_ 
Average_ 
a 
27 
27 
Treatment 
None.. 
_do. 
None.. 
_do. 
None.. 
_do. 
None_. 
_do. 
None.. 
_do. 
Uspulun. 
_do... 
Uspulun. 
_do... 
Uspulun. 
_do... 
Nitrogen extracted (first 
series) on the basis of— 
Oven- 
dried 
lings 
Per cent 
0.845 
.840 
.990 
,434 
432 
433 
Origi¬ 
nal 
oven- 
dried 
Per cent 
0.419 
.417 
,418 
808 
808 
,808 
1.014 
1.006 
.965 
.928 
.947 
1.000 
746 
746 
746 
823 
836 
.830 
643 
644 
644 
813 
782 
798 
Total 
nitro¬ 
gen of 
lings 
Per cent 
49.39 
48.77 
49.08 
52.63 
52.51 
52.57 
25.22 
25.09 
25.16 
44.18 
44.18 
44.18 
47. 76 
48.50 
48.13 
39.05 
39.10 
39.08 
**53.01 
51.00 
52.01 
50.56 
52.53 
51.45 
Nitrogen extracted 
(second series) on the 
basis of— 
Oven- 
dried 
lings 
Per cent 
0.382 
.370 
376 
722 
762 
742 
964 
919 
942 
.749 
749 
941 
955 
974 
955 
.965 
Origi¬ 
nal 
oven- 
dried 
seed 
Per cent 
Total 
nitro¬ 
gen of 
seed¬ 
lings 
Per cent 
0.369 
.358 
364 
703 
685 
795 
758 
777 
815 
793 
804 
22.22 
21.52 
21.87 
39.53 
41.63 
40.58 
46.14 
43.96 
45.05 
42.05 
42.05 
53.18 
51. 71 
52.45 
50.98 
50.02 
50.50 
A glance at Table III shows at once that the percentage of nitrogen 
that could be extracted by water increases as the germination pro¬ 
gresses. Thus, the seedlings which grew on sand at 27° for 3 days 
yielded an extract which contained 49.08 per cent of water-soluble 
nitrogen, calculated to their total nitrogen. This figure rose to 52.57 
