754 
Journal of Agricultural Research voi. xxiv, no. 9 
and the filters were then returned to the dish, dried, and ignited. The 
filtrate was added to the dish, evaporated to dryness and heated at low 
heat to constant weight in order to obtain the weight of ash. By means 
of dilute HCl, practically all of the ash was brought into solution, the 
residue being inappreciable. 
TabliB I.— Rough-lemon seedlings grown 45 days in solution cultures 
Ratio of Na and Ca in 
solution. 
Number 
of seed¬ 
lings 
analyzed. 
Composition calculated to a basis of 100 plants. 
Green 
weight. 
Dry 
weight. 
Ash. 
Ca. 
K. 
Na. 
Gm. 
Gm, 
Gm. 
Gm. 
Gm. 
Gm. 
100 Na:o Ca. 
48 
21. 83 
5 - 90 
0. 2781 
0. 0105 
o- 0515 
0. 0376 
98 Na;2 Ca. 
48 
26. 16 
6.83 
•3739 
•° 33 S 
.0587 
. 0420 
0 Na:ioo Ca. 
49 
38. 95 
8. 79 
• S873 
• I 2 S 9 
. 0609 
.0194 
The results of the first experiment (Table I) show that better plants 
were obtained in cultures containing calcium; in fact, both green weight 
and dry weight increased where the amount of calcium was increased. 
In the pure NaCl solution the root tips appeared stunted and brown in 
color. The sodium content of the plants was slightly greater in cultures 
containing 98 Na:2 Ca than in pure NaCl solution. In this respect the 
results agree with those of Reed (7), though not in regard to the relative 
dry weight of plants produced. 
Experiment 2 was begun April 27 and concluded June 7. The 
solutions were renewed at the same time as were those in experiment i. 
Grapefruit {Citrus grandis) seedlings were used. 
TabIvK II .—Grapefruit seedlings grown 42 days in solution cultures 
Ratio of Na and Ca in 
solution. 
Number 
of seed¬ 
lings 
analyzed. 
Composition calculated to a basis of zoo plants. 
Green 
weight. 
Dry 
weight. 
Ash. 
Ca. 
K. 
Na. 
Gm. 
Gm. 
Gm. 
Gm. 
Gm. 
Gm. 
100 Na:o Ca. 
29 
36. 29 
8 . 34 
0. 4807 
0. 0124 
0.0936 
0. 0547 
98 Na:2 Ca. 
38 
29. 62 
6 . 34 
. 4084 
. 0161 
.0850 
.0470 
0 Na:ioo Ca. 
42 
36. 20 
7. II 
•5195 
. 0646 
. 0948 
• 0235 
From the above table it appears that the 98 Na:2 Ca ratio had no 
superiority over the 100 Na:o Ca as measured by weight of plants pro¬ 
duced. This apparent contradiction to the foregoing experiment may 
be due to the fact that many of the seedlings in the pure NaCl solution 
died and were removed. Such seedlings were discarded, for it has been 
shown by Johnson (4) that absorption of ions may differ appreciably in 
living and in dead cells. This left only the best plants in this lot; conse¬ 
quently we are dealing with what may be regarded as an inherently 
superior lot of individuals, while in the other cases we are dealing with 
the entire population, weak and strong. 
In experiment 3, which was begun on May 4 and concluded on May 27, 
rough-lemon seedlings were grown in solutions of NaCl and CaClj. This 
