= srowth of 
ao ABSORPTION AND EXCRETION OF SALTS BY ROOTS. 
solution was such that lateral roots developed, providing an absorb- 
ing system at least comparable in extent and efficiency with the 
root systems in the other solutions. 
The mean concentration of all the equivalent solutions after growth 
Wis eee aM 
2,000,000" 
43 M 
2,000,000" 
The distilled water culture had a concentration after 
Equilibrium concentration for magnesium alone 
48 M : : 
(experiment 1) was 2,000,000" for calcium alone (experiment 2) 
28 M 
7,000,000' It will be noticed that in no case were culture solutions 
in experiment 5 exhausted beyond the equilibrium concentration 
for calcium alone. 
EXPERIMENT 6. 
Experiment 6 included a series of equivalent solutions of the 
varying from 75 Mg to 65 Mg+10Ca. The 
tration — 
concentratio 500,000’ 
duration was nine days; temperature at beginning 20.5°, at end 19°. 
TasBLE VI.—Statement of results, experiment 6. 
Number of culture ......... 1 2 3 4 5 
COM POSitlOM: ss 5. ane ee 10 Mg. 75 Mg. 74 Mg+1 Ca. | 73 Mg+2 Ca. | 72 Mg+3 Ca. 
Concentration: ; 
10M 75M 75M 75M 75 M 
Before growth.........- 500, 000 500, 000 500, 000 500, 000 500, 000 
eer 16M 75M 43 M 42M 60M 
After growth..........- 500, 000 500, 000 500, 000 500, 000 500, 000 
Number of culture -........ 6 if 8 9 10 
Composition) s--eee ee eee 71 Mg+4 Ca. | 70Mg+5 Ca. | 69 Mg+6 Ca. | 68 Mg+7 Ca. | 67 Mg+8 Ca. 
Concentration: 
75M 75 M 75M 75 M 75M 
Betore Brow UN See. 500, 000 500, 000 500, 000 500, 000 500, 000 
51M 37 M 37 M 27 M 39M 
After growth..........- 500, 000 500, 000 500, 000 500, 000 500, 000 
Number of culture ......... 11 12 13 14 15 
Gorpeeition se emenanee 66 Mg+9Ca. | 65Mg+10Ca,| 10 Ca. 1Ca. Pa 
Concentration: 
75M 75 M 10M M 
he oe _75 M_ _75 M_ oe aed 
Beloreenwt 500, 000 500, 000 500, 000 500, 000 0 
23 M 14M 10M 12M 23 M 
After growth..........- 500, 00 500, 000 500, 000 500, 000 500, 000 
231 
