1920] 
DUGGAR—H-ION CONCENTRATION AND NUTRIENT SOLUTIONS 31 
TABLE XV 
(Series 4, II—Corn [moist, low temperature]) 
SALT REQUIREMENTS AND H-ION CONCENTRATION IN RELATION TO GROWTH 
Total | Gr. wt. | Total | Greatest Pu 
No. Mri d gr. wt. | of roots | dry wt. | length 
1101008 | (gms.) | (gms. | (gms.) | (cm.) | Initial | After gr. 
1 AcO 8.77 | 3.25 1.007 15.83 3.4 5.6 
2 Ac /5 22.81 8.44 1.703 22.98 4.6 6.0 
3 Ac /10 23.10 | 8.94 1.521 22.78 5.8 6.2 
4 Ac 1/ 21.97 | 6.9 1.933 21.75 3.35 5.8 
5 Ac 3/ 11.28 | 2.82 1.303 15.65 3.15 6.0 
6 AcNa 19.30 | 7.91 1.744 20.56 3.45 6.0 
7 AcM 27.56 | 10.69 2.078 22.72 5.4 6.0 
8 BcO 18.90 | 7.50 1.828 20.64 6.6 6.4 
9 Be /5 31.99 | 14.50 2.508 23.51 7.4 5.9 
10 Be /10 28.63 | 14.54 2.213 21.84 8.6 7.0 
11 Bc 1/ 23.61 7.74 2.423 24.14 6.4 4.8 
12 Be 5/ 27.80 | 10.60 2.464 23.44 3.2 6.0 
13 Be 10/ 15.50 | 6.20 1.366 16.19 2.8 5.6 
14 Bek; /10 36.30 | 6.44 2.950 23.50 7.0 5.7 
15 26.03 | 10.11 2.699 23.57 7.3 7.4 
16 CcO 34.60 | 11.02 2.763 24.66 4.2 7.6 
Le Ce /5 28.47 9.72 2.350 23.59 6.4 7.6 
18 Cc /20 20.90 6.75 1.868 20.10 7.6 8.6 
19 Cc 1/ 23.52 7.55 1.966 23.40 3.6 7.6 
20 Ce 5/ 21.22 6.70. |. 1.687 22.15 3.2 7.6 
21 CcNa 24.60 9.07 2.090 19.74 4.2 7.6 
below Pg 4 there is definite diminution of growth in every in- 
stance, except Bw 5/. AwM seems to be distinctly out of 
harmony in this group. The suggestion from culture Bw /10 is 
that under these climatie conditions a relatively low degree of 
alkalinity, probably about Pg 8, would represent the limit for 
most favorable growth in a on thus constituted. 
The results with corn grown in a moist atmosphere at a high 
temperature are perhaps more erratic than in any other section 
of the work. At least with the data at hand it is extremely 
difficult to interpret these results. It would appear that the 
best growth is in culture Ac /5, and it is closely followed by 
Ce 5/, the last solution being close to the usual limit of growth in 
respect to hydrogen ion concentration. In both these cases the 
increase in the growth over that in BcK;/10, AcM, and BcO is 
