8o Adams .— The Effect on Certain Plants of 
Average height 
Average height 
Tallest on • 
Total 
on 9 June. 
on 7 July. 
7 J ul y- 
weight. 
mm. 
mm. 
mm. 
grm. 
L 1 
26.9 
34 I *3 
380 
13.720 
L 2 
26.4 
4 I 7-7 
482 
16-470 
L 3 
27-6 
45 1,2 
5 00 
15.400 
Average 
27-0 
4 ° 3-4 
454 
1 5- 1 97 
D 1 
24-S 
307-9 
355 
3 6 5 
15.670 
D 2 
27-1 
3 I 3'9 
13.700 
r >3 
25.8 
321.2 
355 
13.710 
Average 
25.9 
3 I 4-3 
35 8 
14.360 
While the unshaded plants were at the beginning of the experiment on 
9 June 4*2 per cent, taller than the darkened set. at the end of the experi¬ 
ment on 7 July the unshaded lot were 28-3 per cent, taller than the 
other set. 
Wheat , ic)2o. 
The period of darkening was similar to that of Flax from 9 June to 
5 July and covered altogether twenty-seven hours. 
The seeds were sown on 31 May. On 8 June the number of seedlings 
was reduced to ten in each pot. The heights of the seedlings were 
measured on 9 June, while on 6 July the total weight of the stem and 
leaves was determined for each set. The figures were: 
Average height 
Weight on 
on 9 June. 
6 July. 
mm. 
grm. 
L 1 
112.0 
28-370 
L 2 
104.2 
25.800 
L 3 
118.5 
30.250 
Average 
111.6 
28.140 
Di 
1 * 4-9 
26-000 
D 2 
106.6 
24.150 
T) 3 
102.5 
28.070 
Average 
108-0 
26-070 
The average height of the unshaded plants on 9 June was 3-3 percent, 
above that of the darkened set. The weights were presumably in the same 
proportion. On 6 July the average weight of the unshaded plants was 
7’9 per cent, above that of the others. 
Sunflozver , 7920. 
The periods of darkening were similar to those of Flax from 9 June to 
6 July. On 7 July the plants were darkened for one hour, making the 
total time of covering altogether twenty-nine hours. 
The seeds were sown on 31 May. On 7 June the seedlings were 
reduced to ten in each pot. On 9 June the heights of the seedlings were 
