358 Bottomley . — The Effect of Organic Matter on the 
weeks the plants in Series II had completely filled their dishes, so they 
were all halved as exactly as possible and the dry weight of one half of 
each dish estimated. This was repeated at the end of the eighth and 
eleventh weeks respectively. The experiment lasted for twelve weeks 
altogether, and the following figures were obtained : 
Table III. 
No . of ■ Series I . Series II . 
Leaves Detmer's Solution . Detmer's Solution + Bacterized Peat , 
at end „ Dish Number . Dish Number . 
of 
1 
2 
3 
4 
5 
Mean . 
6 
7 
8 
9 
10 
Mean . 
1 st week 
15 
13 
12 
H 
14 
13.6 
12 
17 
16 
15 
l 9 
15.8 
2nd ,, 
21 
20 
J 7 
20 
18 
19.2 
21 
25 
24 
21 
27 
23.6 
3 rd „ 
29 
27 
24 
29 
28 
27.4 
32 
34 
3 i 
33 
36 
33-2 
4th „ 
4 * 
40 
41 
40 
42 
40-8 
51 
54 
53 
5 6 
55 
53-8 
5 th ), 
48 
49 
45 
52 
48 
48.4 
64 
73 
62 
73 
73 
69.0 
6th ,, 
62 
69 
61 
69 
62 
64.6 
92 
107 
105 
104 
114 
104.4 
7 th » 
84 
98 
84 
no 
92 
93-6 
142 
136 
144 
148 
J 5 2 
144.4 
8th ,, 
120 
144 
128 
1 56 
148 
J 39-2 
212 
236 
232 
256 
252 
237.6 
9th „ 
152 
180 
152 
180 
164 
165.6 
272 
336 
304 
344 
348 
320.8 
loth ,, 
160 
180 
152 
192 
168 
170.4 
284 
376 
344 
388 
372 
35 2 -8 
nth ,, 
160 
192 
168 
216 
176 
182.4 
320 
400 
384 
45 6 
408 
393-6 
12th ,, 
168 
224 
176 
240 
176 
196-8 
392 
440 
408 
496 
464 
440-0 
It will be observed that the rate of growth of the plants diminished in 
both series towards the end of the experiment, owing to the lowering of the 
, temperature during October and November. The figures obtained for the 
dry weights of the whole of the plants in the two series, calculated from 
the weights of the halves on the three occasions on which the plants were 
divided, are as follows : 
Table IV. 
Weight of 
Series I . 
Series II . 
Plants in 
Dish Nu ? nber . 
Dish Number . 
mg . at end of i 
2 
3 
4 
5 
Mean . 
6 
7 
8 9 
10 
Mean . 
7th week 
8o-o 
83.2 
88.8 
92.6 
84.4 
86.0 
169.2 
148.4 
156.8 154.4 
158-0 
157-4 
8th „ 
104-0 
105-6 
95-6 
132.0 
117*2 
1 10.9 
276.0 
465.6 
2136 
232-8 249.6 
243-2 
243.0 
nth „ 
140-8 
147.2 
I 5 °- 4 
161-6 
142-4 
148.5 
556-8 
526.4 574.4 
549-2 
532-5 
The number of leaves in each dish at the beginning of the experiment) 
neglecting buds, was ten, and the average weight of the sets was 10-15 mg. 
This corresponds to an average weight for 100 leaves of 101-5 mg. at the 
beginning of the experiment. Comparing this with the calculated weight 
of 100 leaves at the end of the seventh, eighth, and eleventh weeks respec- 
tively, the following results are obtained : 
Table V. 
Series I . 
Calculated 
Series II . 
Calculated 
Average No . 
Average 
Weight of 
Average No . 
Average 
Weight of 
of Leaves . 
Weight . 
100 Leaves . 
of Leaves . 
Weight . 
100 Leaves . 
mg . 
mg . 
mg . 
mg . 
At beginning 
10 
10.15 
101.5 
10 
10.15 
101.5 
7th week 
93-6 
86-9 
91-8 
T 44*4 
157-4 
109.0 
8th „ 
139-2 
no-9 
79-7 
237.6 
243-0 
102.3 
nth „ 
182.4 
148.5 
81.4 
393-6 
532-5 
J 35-3 
