2209 
usually only during the night. Of course, if these 
flowers hope to receive visitors, and get their share of 
pollen, they must devise some means of making known 
their presence to those insects which are awake and at 
work in the darkness. 
You can understand that at night the brightest colors 
mouldbe useless. ~A- red) flower 1s less: easily < 
seen in the darkness than a white or a Te 
falls" “eat 
x i 
i) 
yellow one; so night-opening flow- 
ers nearly eee wear a white or 
yellow dress. 
And not only this: to make 
sure that they will not be overlooked, and so 
miss the chance of ripening their seeds, they 
send out a strong fragrance as soon as the 
night falls.) Through the deepest gloom this 
message of invitation reaches the wandering 
moth. 
Do you know the evening primrose 
(Fig. 238)? There ought to be no need 
of asking you this, for it is one of our com- 
monest wayside plants. But perhaps you have 
hardly noticed it, because ordinarily only at 
night is its flower wide awake. Fic, 238 
When the sun has set, this pale yellow blossom un- 
folds, and gives out a strong, sweet fragrance, which 
means that it is ‘fat home”’ to visitors. 
After one short summer night it dies. 
But during its little life the chances are that its invi- 
tation has been accepted by the pretty pink moth which 
oftentimes you find asleep in the faded flower cup. 
