404 L. KNUDSON AND E. W. LINDSTROM 
nitrogen was supplied at the rate of 1.7 grams of asparagin for each 5 Uters 
of culture solution. The seedlings were transplanted to the culture tubes 
on June 12 and the tubes were placed in the greenhouse. The experiment 
was concluded on July 30, at which time all the seedlings were dead. Very 
little difference was noted in the time of death of the seedlings. The 
data follow in table 2. 
In the preceding table the yield is given as dry weight of tops and roots. 
The residual seed remains were detached from the plant and not included 
in the weight. It is at once apparent that the addition of sugars makes for 
an increase in weight, but the substitution of asparagin for nitrates, while 
permitting equally good growth, apparently does not make conditions 
more favorable than they are in the solutions with nitrates. As noted by 
others, asparagin is a favorable source of nitrogen. 
Experiment j. The culture conditions remained similar to those of 
experiment i, but the plants were grown in the dark. The data follow in 
table 3. When supplied with sugars, the plants practically maintained 
their original weight, while the plant supplied with nutrients alone lost in 
weight, the loss being about 50 percent of the original dry weight of the 
seed. 
Table 3 
Culture Solution 
Original Weight of Seed 
(Milligrams) 
Total Dry Weight 
of Plant 
(Milligrams) 
Gain or Loss 
(Milligrams) 
Sucrose i percent 
133 
138 
+ 5 
Sucrose i percent 
121 
118 
- 3 
Glucose I percent 
132 
120 
— 12 
Pfeffer's 
164 
80 
-84 
Experiment 4. The plants were grown in water culture. For this 
purpose 500-cc. Erlenmeyer flasks were employed and the volume of solu- 
tion used was 500 cc. In addition to cultures with sucrose, cultures were 
also prepared in which a mixture of sugars was used composed of o.io 
mol. glucose, o.io mol. sucrose, and o.oi mol. arabinose. These latter 
cultures became contaminated near the close of the experiment, but the 
plants were much like those grown with 0.20 mol. sucrose. The seedlings 
were transplanted to the culture flasks on March i and the experiment 
was concluded on April 25. The detailed data follow in table 4. 
Table 4 
Culture Solution 
Culture 
No. 
Original 
Dry 
Weight 
of Seed 
(Milli- 
grams) 
Dry 
Weight 
of Tops 
(Milli- 
grams) 
Dry 
Weight 
of Roots 
(Milli- 
grams) 
Dry 
Weight 
of Seed 
Residuum 
(Milli- 
grams) 
Total 
Dry 
Weight 
(Milli- 
grams 
Gain or 
Loss 
(Milli- 
grams) 
Pfeffer's 
35 
133 
45 
7 
27 
79 
- 54 
Pfeffer's 
36 
123 
54 
7 
18 
79 
- 44 
Pfeffer's - 
-|- 0.2 mol. sucrose 
37 
129 
170 
60 
27 
257 
+ 128 
Pfeffer's - 
-|- 0.2 mol. sucrose . 
38 
126 
80 
50 
26 
156 
+ 30 
