Dee. 15, 1925 
Nitrogen Metabolism in Etiolated Corn Seedlings 
1151 
was done, the moisture within the germinator being maintained by 
a pan filled with water and placed at the bottom of the germinator. 
A small portion of the seed, to be mentioned subsequently, was 
planted in pots filled with sand which was thoroughly washed and 
contained but a negligible quantity of nitrogen. This seed, too, 
was placed in a dark room at the temperature of 27° C. 
Tests with three samples of seed planted in sand at the temperature 
of 27° C. gave 93, 93, and 95 per cent germination. Two other 
samples in which the seed was put between moist absorbent paper 
towels and kept at 30° C. gave 95 and 90 per cent germination, thus 
proving the high quality of the seed. 
One difficulty encountered in the work was the molding of the 
seedlings. Whereas seedlings which were allowed to grow from two 
to four days were practically free from mold, those which grew for 
a longer period were more or less covered by a growth of fungi, 
among which RJiizopus nigricans was conspicuous. In an attempt 
to do away with the fungi the corn seed was treated with a 0.25 
{ >er cent solution of uspinun (a chlorophenol mercury compound) 
or 30 minutes, at the expiration of which the seed was washed with 
water and immediately planted with the aid of an uspulun-treated 
spatula. This treatment, although helpful to a certain extent, did 
not obviate the difficulties entirely. Nor could the appearance of 
fungi be prevented by spraying with mercuric chloride solution 
(1 : 1,000). Whether untreated or uspulun-treated seed was allowed 
to germinate, in each case only material free from mold was taken 
for work. The seedlings, including the seed, were dried in an electric 
drying oven at 60° C. for from two to three days, after which they 
were ground in a mill until all had passed through a 40-mesh sieve, 
and put into jars ready for use. 
The total nitrogen was estimated by the Gunning modification 
of the Kjeldahl method. 
The protein nitrogen was determined according to Stutzer’s 
method as outlined in previous publications (6, 7, 8 ). 
The nonprotein nitrogen was estimated by determining the nitrogen 
in the filtrate from the protein precipitate, as obtained by means of 
Stutzer’s copper solution (20), or it was calculated by difference 
from a hundred. 
The methods for estimation of acid amides, amino acids, polypep¬ 
tides and other constituents will subsequently be described in this 
paper. 
The results secured are recorded in the following tables. 
EXPERIMENTAL DATA 
An examination of Table I shows that the protein nitrogen fell 
rapidly with the progress of germination. Thus, from 95.68 per 
cent in the ungerminated seed, calculated on the basis of the total 
nitrogen, it fell to 77.63, 60.74, 61.95, and 57.36 per cent after 2, 4, 
5, and 8 days, respectively, in the untreated seedlings with the paper 
substratum. Similarly, in the uspulun-treated seedlings the protein 
nitrogen decreased to 61.07, 54.52, and 55.26 per cent after 4, 5, and 
8 days, respectively. That the protein nitrogen fell very rapidly 
from 95.68 per cent in the seed to 58.02 per cent in the seedlings which 
were grown in sand for but 3 days may be attributed to the consid¬ 
erably higher moisture conditions of the sand seedlings. 
