376 
LEWIS KNUDSON 
The results of experiment 3 are similar to those of the preceding experi- 
ments. There is the usual increase in reducing sugars; the reaction of the 
solution at the outset was very slightly acid (P[H] 6.7), and at the conclusion 
slightly alkaline (P[H] 7.25 to 7.3) 
Incubation experiments were made as in the previous experiments. 
Table 3. Corn. Duration of experiment, J2 days. 
Culture Number 
Sugar as Su- 
crose at End 
(Grams) 
Sucrose Used 
by Plant 
(Grams) 
Reducing 
Sugar at End 
(Grams) 
Gain in Reduc- 
ing Sugar 
(Grams) 
P[H] at Con- 
clusion of Ex- 
periment 
16 
4.891 
0.940 
0.476 
0.376 
7-3 
17 
4.550 
1. 181 
0.400 
0.300 
7-30 
18 
4.912 
0.819 
0.375 
0.275 
7.25 
19 
4.912 
0.819 
0.571 
0.471 
7.25 
Control, no plant 
5-731 
O.IOO 
6.70 
The duration of the incubation experiment was 14 days. Toluene 2 percent 
was added as the antiseptic agent, and the temperature of incubation was 
35° C. No increase in reducing sugar over that found in the culture solution 
was noted after the period of incubation. 
Experiment 4. This experiment was like the preceding. Canada field 
pea was used and the results appear in table 4. 
Table 4. Canada field pea. Duration, Sept. 4 to Sept. 22: 18 days. 
Culture 
Dry Weight 
Reducing 
Gain in 
Culture Solution 
Roots 
Tops 
Total 
Sugar Pres- 
Reducing 
Number 
ent 
Sugars 
(Grams) 
(Grams) 
(Grams) 
Pfeffer's solution + sucrose 
I 
0.221 
0.254 
0.475 
839 
0.333 
+ " 
2 
0.186 
0,322 
0.508 
877 
0.371 
" + " 
3 
0.223 
0.277 
0.500 
820 
0.314 
" + " 
4 
0.200 
0.260 
0.460 
876 
0.370 
" + " 
no plant 
506 
I 
O.II3 
0.216 
0.339 
No reducing 
2 
0.127 
0.309 
0.436 
sugars in 
these 
3 
0.083 
• 0.169 
0.252 
solutions 
4 
0.099 
0.169 
0.268 
Experiment ^ . Culture in distilled water. In order to determine whether 
or not the character o the nutrient solution had any special significance 
with respect to the increase in reducing sugars, an experiment was made 
using in place of Pfeffer's solution merely distilled water to which was added 
I percent sucrose. Canada field pea was used and the duration of the 
experiment was 18 days. The conditions and methods of the experiment 
were similar to those of the preceding experiments. 
Only one culture remained uncontaminated. The green weight of the 
plant was 1.35 grams, the reducing sugar in the culture solution (1000 cc.) 
at the conclusion of the experiment was 293 milligrams, while in the control 
there was only 138 milligrams; there was an increase therefore of 155 
milligrams in the culture solution. 
