VIIl, C, 1 
Broivn: Growth of Elodea 
13 
In Table VI are given the results of an experiment similar to 
the last except that only two strengths of Knop's solution were 
used and the experiment run twenty-five days. There is a close 
similarity between the results of the two experiments. 
Table VI. 
Growth of Elodea in tap water and Knop's 
solution, April 5 to 20. 
No, of plant. 
Growth In- 
■^ 
Tap 
water. 
0.5 
standard. 
1 
standard. 
1 
Cm. 
10.7 
ILl 
11.7 
11.2 
14.6 
10.6 
13.9 
11.8 
14.2 
11.1 
Cm. 
11.3 
17.9 
26.4 
18.6 
10.2 
14.6 
16.4 
15.5 
21.2 
17.7 
Cm. 
17.9 
18.6 
11.2 
17.2 
17.0 
15.3 
22.2 
18.3 
1 
18.3 
23.9 
2 
3 
4. 
5... 
6-. _ 
7 
8 
9- 
10 
Total 
120.9 
12.1 
169.8 
17.0 
179 9 
X 1 V* V 
18.0 
On the ten.th of April an experiment was started with a series 
of six three-liter jars containing respectively tap water and five 
strengths of Knop's solution. The basis of the Knop's solution 
was the same as in the last two experiments. Five plants 10 
cm long and without roots were put in each jar, and no COj 
passed through any of them. The growth of the individual plants 
for twenty-five days is given in Table VII. 
Table VII.- 
— Growth of Elodea in tap water and Knop's 
solution without addition of CO2* 
No. of plant. 
Growth in— 
Tap 
water. 
0.5 
standard. 
1 
istandard. 
2 4 
standard, standard. 
1 
1 
5 
standard. 
1 
' ^ 
L8 
1.2 
2.1 
0.9 
L7 
Cm. 
2.4 
3.1 ; 
2.6 
2.8 
2.8 
Cm. 
2.4 
5.6 
3.9 
3.1 
3.3 
Cm. 
2.4 
3.6 
5.2 
3.7 
Cm. 
4.2 
2.8 
5wl 
6.6 
5.8 
Cm. 
5.6 
4.8 
4.6 
3.3 
6.0 
2 
3 
4 
61 
t 
Total 
7.7 
L5 
13.7 
2.5 
18.3 
3.6 
19.7 
3.9 
24.5 i 24.3 
4.9 4.8 
Averag-e _. 
^^P ^^M ^^M ^^fr 
^^H V ^^F 
^^ w ^^^ 
