Night Flowers 997 
would be undistinguishable in the dark, and there- 
fore useless. 
Whoever tries to gather red currants or straw- 
berries by twilight will. find that the red of the 
fruit, so noticeable by day, now blends undis- 
tinguishably with the green of the leaves. Long 
before real darkness comes, the most conspicuous 
of daytime colors vanishes into the shadows. But 
a very small object, if it be white, can be seen in 
the darkest hours of a moonless night. This the 
night-flowers seem to have learned, for they are 
all white or pale-yellow. 
Their distinguishing charm is their sweetness. 
Honeysuckle, tuberose, day-lily, stephanotis, night- 
blooming cereus—what scents for a Sybarite are 
here! The evening primroses have a delicious 
fragrance, and the diurnal primroses have none. 
There are two nocturnal species of silene, both 
sweet-scented, while the nine or ten diurnal spe- 
cies are all odorless. Even the despised jimson- 
weed blossom lures the moths by a delicate per- 
fume which is lost directly we gather it, in the 
rank odor of the broken stem. 
The closing time of these night-flowers, like the 
time of their expansion, is variable. It may de- 
pend partly upon the vigor of the plant, its age, 
