It is interesting to learn that some blossoms open 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 would be useless. A red flower is less easily seen in the darkness than a white or a yellow one; so night-opening flowers nearly always 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 commonest wayside plants. But perhaps you have hardly noticed it, because ordinarily only at night is its flower wide awake. [Illustration: FIG. 238] When the sun has set, this pale yellow blossom unfolds, and gives out a strong, sweet fragrance, which means that it is “at home” to visitors. After one short summer night it dies. But during its little life the chances are that its invitation has been accepted by the pretty pink moth which oftentimes you find asleep in the faded flower cup. The moth visitor has brought its hostess the pollen from another blossom, and has powdered the pistil’s four spreading tips, so that the little primrose seeds below get the needed touch of life, and the short life of the flower has not been in vain. If you keep on the lookout, you are likely to come across one of these yellow flowers with the sleepy pink moth inside its cup. I have caught this little fellow napping so often, that I have wondered if the nectar of the evening primrose might not have the effect of a sleeping potion. But after all, I suppose that pretty pink moths, like boys and girls, are likely to be dull and sleepy in the daytime if they have been up too late the night before. [Illustration: Decoration] HORRID HABITS Did you ever know that some plants manage to attract insects in ways that are quite disgusting to us human beings? While spending a morning in the woods, some of you may have noticed an odor so unpleasant that you were driven to find another resting place. Perhaps you thought that this unpleasant smell was caused by the decaying body of some dead animal; but had you known the truth, you would have laid the blame where it rightly belonged. And where was that, do you think?