460 
Journal of Agricultural Research voi. xxv, no. » 
TABLE II. —Acidity of the tops of corn plants of Series II, 37 to 44 days old, in poor con¬ 
dition, grown in the greenhouse in slightly acid sandy clay loam 1 
Strain No. 
Date of de¬ 
termination 
(June, 192 a). 
Titratable 
acidity (cc. 
N/aoNaOH). 
Pb 
Aver 
Acidity (cc. 
N /20 NaOH). 
ages. 
Ph 
972 .. 
{ X? 
5-7 
6.9 
5- 40 
5- 2 9 
} 6.3 
5- 34 
8 
6.4 
5 . 21 
] 
5<>7* • 
{ 
14 
(8.5) 
(5- 10 ) 
6.4 
5- 25 
15 
6.4 
5- 29 
J 
| 
8 
6-5 
5 . 28 
1 
Ji... 
13 
6.6 
5- 25 
6.4 
25 
i 
14 
6 . 2 
5 . 22 
J 
i 
1 
10 
6.5 
5- 33 
1 
129 . . 
12 
6 - 7 n 
5- 23 ^ 
\ 6.6 
5 . 28 
i 
i 
13 
( 9 . 0 ) 
(5- 10 ) 
J 
326 .. 
.j 
9 
6.7 
5- 30 
6 . 7 
5- 3o 
i 
8 
6.4 
5- 30 
315 ■ 
\ 
i 
9 
14 
5-9 
7-3 
5- 38 
5- 34 
6.8 
$• 33 
15 
7*5 
5- 30 
10 
7.0 
5- 23 
150*. 
12 
13 
7 . 2 
8.8 
5 -19 
5-10 
7- 5 
5-19 
13 
7.0 
5* 24 
113 .. 
8 
7*5 
5- IS 
7- 5 
5* IS 
Average. 
6.8 
5.26 
1 Measurements in parentheses are not included in the averages because they were made on exceptionally 
poor spindling plants, not typical of the row. # 
The outstanding feature of Table II is the high acidity of all the plants 
compared with the more vigorous ones of Table I. Additional evidence 
of an interrelationship of acidity and vigor of growth was afforded by 
the notes on relative development of some of the individual plants con¬ 
stituting the group. Some highly acid plants of 507 and 129, the meas¬ 
urements of which are inclosed in parentheses in the table and not aver¬ 
aged because the plants did not seem typical of the strains, were described, 
respectively, as “spindling stalk, narrow leaves, tips dying,” and “short 
and spindling, poorest of all.” Of the uniformly highly acid strains, 
No. 150 showed a tendency to become diseased in all the plantings, while 
No. 113 was nearly always at the bottom of the list in vigor. 
SERIES in 
To check the results given in Table II a third series had been planted 
between the rows of the second series before the plants were cut. The 
soil reaction was found to have become more acid, being P H 6.2 as com¬ 
pared to P H 6.5, the value obtained a month before. The plants grew 
even more poorly than those of Series II, having spindling stalks, and 
narrow leaves with dry, dead tips, the lowest dying early. The average 
height of the group did not reach 50 cm. until the seventh week when 
the plants were cut and found to have an average green weight of 44 gm., 
the same as that of the plants of Series II at six weeks. It was necessary, 
because of the small quantity of juice in each plant, to take from two to 
