28 
AMERICAN JOURNAL OF BOTANY 
[Vol. io. 
were grown during a period of very unfavorable climatic conditions. There 
was an unusual amount of cloudiness, as is very evident from the total 
number of hours of sunshine and the correspondingly low absorption of 
radiant energy. The mean temperature for the growth period was also 
lower than that regarded as optimum for the growth of wheat. Under 
more favorable growing conditions it is possible that the results herein 
reported would be different. 
The data for the hydrogen-ion concentration of type III solutions before 
growing cultures are taken from the work of McCall and Haag (12). The 
data for the hydrogen-ion concentration determinations of the solutions 
after the plants had been grown in them for the last 3j-day period, and the 
total dry weight per culture for the sand and water cultures, are given in 
table 4. 
Table 4. Showing Hydrogen-ion Concentration of Type III Solutions before Growing 
Wheat, after the Last 3%-day Interval, and the Total Dry Weight of Tops 
and Roots of Sand and Water Cultures 
Solution 
Number 
Before 
Growing 
Cultures 
After Growing Cultures 
Total Dry Weight 
Tops and Roots 
Water 
Sand 
Water 
Sand 
III 
pH 
pH 
pH 
Grams 
Grams 
R1S1. 
4.1 
5.98 
679 
12.527H 
17.459H 
S2. 
37 
5-32 
6.72 
10-577 
12.737 
S3. 
3-6 
5-05 
6.64 
7744 
3.876L 
S4. 
3-6 
4-39 
6-34 
0.323L 
6.544L 
S 5 . 
3-6 
4.83 
6.08 
0.171L 
4.036L 
S6. 
3-5 
3-65 
6.12 
0.123L 
2.726L 
R2S1. 
4.1 
7.20 
6.99 
18.558H 
12.723 
S2. 
37 
5-90 
6.81 
i 5 - 35 °H 
19.539H 
S3. 
3-6 
5.56 
674 
9.580 
12.652 
s 4 . 
3.6 
5-07 
5-98 
2.170 
13.622H 
S5. 
3-5 
5.12 
5-88 
0.278L 
7-534 
R3SI. 
4.1 
7.20 
7.03 
12.654H 
10.248 
S2. 
37 
6.98 
6.88 
13707H 
I 5 - 303 H 
S3. 
3-6 
574 
6.50 
6.361 
I 4732 H 
s 4 . 
3-6 
5-24 
6.44 
0.497L 
12.283 
R 4 Si. 
4.1 
6.98 
7.06 
11.274 
7.320L 
S2. 
37 
6-57 
7 -i 5 
11.655 
11.528 
S3. 
3-6 
5-90 
6.49 
0.640 
11.880 
R5S1. 
4.1 
7.08 
7-33 
11.310 
11.403 
S2. 
37 
6.94 
6.91 
9765 
10.885 
R6Sl. 
3-9 
7.92 
6.98 
9.256 
8.599 
Shive’s R5C2. 
4.4 
5-54 
6.30 
8.145 
7.500 
(1.75 atm.). 
541 
6.47 
10.720 
6.667 
The data presented in table 4 show that before growth this solution 
had a rather acid reaction. After being in contact with the plants for only 
Si days there was a decided change in the hydrogen-ion concentration. 
