altering the Daily Period of L ight. 
83 
In the frame which was constantly exposed to light the first flower 
opened on 5 July, on 11 July there were fifteen plants in flower, and on 
• 12 July there were sixteen plants in flower. 
In the darkened frame the first flower did not open until 11 July, while 
on 12 July two plants were in flower. 
Wheat in Frame, 792/. 
One row of seeds was sown in each frame on 23 May, and on 2 June 
twenty-six plants were left in each row. 
In the uncovered row five plants were in ear on 7 July, and on 11 July 
there were twenty-two in ear. The first ears, three in 'number, in the 
covered row did not make their appearance until 11 July. 
The plants were pulled up on 13 July and gave the following results: 
Plants exposed to light 
Plants covered 
Average 
Tallest 
Total 
No. oj 
plants 
in ear. 
Total No. 
height. 
plant. 
weight. 
of ears. 
mm. 
mm. 
grm. 
497-5 
780 
127-57 
25 
49 
316-8 
479 
99.22 
11 
11 
Soy Bean in Frame, 1921. 
One row of seeds was sown in each frame on 23 May, and twenty-five 
plants were left in each row on 2 June. This number was reduced to 
twenty-three on 13 June. 
In the uncovered row two came into flower on 5 July, and on 7 July 
three were in flower. In the covered row the first plant came into flower 
on 7 July. 
The plants were pulled up on 13 July and were measured and weighed 
with the following results : 
Average 
Tallest Total 
No. of plants 
height. 
plant. weight. 
in flower. 
mm. 
mm. grm. 
Plants exposed to light 
258-2 
394 255.15 
23 
Plants covered 
340-3 
475 283.50 
22 
The plants in the 
covered row 
were growing in slightly better soil. 
The figures should be compared with those obtained from the plants grown 
in the open ground, which are given farther on. 
Experiments in Open Ground, 1921. 
In order to keep all the factors except the amount of light as nearly as 
possible the same, it was found desirable to use wooden boxes for the purpose 
of excluding light from each set of experimental plants. The use of wooden 
coverings tended to lessen the difference in temperature and relative 
O l 
G 2 
♦ 
