26 ABSORPTION AND EXCRETION OF SALTS BY ROOTS. 
TaBLE IV.—Statement of results, experiment 4. 
No. of culture .... 1 2 3 4 5 6 7 
Composition...... Mg. 10 Mg. 9 Mg+Ca. |8 Mg+2Ca.| 7 Mg+3Ca.| 6 Mg+4Ca.| 5Mg+5Ca. 
Concentration: . 
Bef h 100 M 100 M 100 M 100 M 100 M 100 M 100 M 
Chore Erow ua 05000 50, 000 50, 000 50, 000 50, 000 50, 000 50, 000 
After erowthe om 97M 93 M 91M 91M 90 M 91M 
500, 000 50, 000 50, 000 30, 000 50, 000 50, 000 50, 000 
No. of culture .... 8 9 10 11 12 13 14 
: ne ay A eens Distilled 
Composition... .-. 4Mg+6Ca.|] 3 Mg+7 Ca.|2Mg+8Ca.}| Mg+9 Ca. 10 Ca. Ca. ee 
Concentration: 
Bef a 100 M 100 M 100 M 100 M 100 M 100 M 
clorelzrow chal) -aen0p 50, 000 50, 000: 50, 000 50, 000 500, 000 Y 
After growth. 90 M 91 M $1 M 92 M 94M 70 M 17 M 
50, 000 50, 000 50, 000 50, 000 50, 000 500, 000 500, 000 
Fig. 14.—Seedlings of culture 13, experiment 3. 
These results show, as did those of experiment 3, (1) that absorp- 
tion from solutions containing magnesium and calcium in the ratio 2 
is about the same as from equivalent solutions of calcium alone; (2) 
that the most efficient absorption is from solutions containing mag- 
231 
