187 
strongly-scented flowers. The combined result of five experi- 
ments was:—In damp air, 5 flowers with strong scent, 3 fairl 
strong, 2 slight; in dry air, 2 fairly strong, 4 slight. Three of 
these experiments were made in shade and two in sunlight.* 
A comparison of the behaviour of flowers in sunlight and in 
shade shows that sunlight favours the production of scent, both 
as regards earlier occurrence, number of flowers, and strength of 
odour. In four experiments the difference of time was from 
balf-an-hour to two hours, and the numbers of flowers were :—In 
sun, 2 with strong scent, 8 fairly strong, 2 slight; in shade, 
1 fairly strong, 6 slight. 
Flowers kept in the dark were found to remain unscented in 
most cases. In experiments made on five days, when strong or 
e shade temperature in the Laboratory was 52° F. on the 
coldest day, and 70° F. on the hottest. These differences 
e¢ higher temperature placed in damp air, and at 12.30 p 
from those in Ps air, it: in the cooled air no scent had developed 
by 2.30 p.m. he ice was then removed, and the flowers from 
s 
10) f ev * . Rete, 
peed that a temperature of 75° to 80° F. slightly Siete Soret 
the unfavourable influence of darkness on the production s 
ent, 7.e compared with the lower temperatures of the 
action of a given amount of the scent when distributed in damp ai 
