The more we study flowers, the more clearly does it become evident that their rich colours, beautiful perfumes, and sweet nectar are really baits to entice insects to visit them. More than this, even the very marks in certain flowers point to where the insect will find the nectar, just as signposts on country roads direct us to the place we wish to find. Have you noticed that flowers which have gaudy colours, like the tulip, foxglove, or hollyhock, often have no smell, whilst insignificant flowers, as the mignonette, privet, or forget-me-not, give off beautiful scents? The first kind attract insects by their colour, but the second by their fragrance. Certain flowers have their nectaries at the base of the corolla, as the geranium; others have tiny little glands, or bags, on their petals, like the buttercup. You will know that flowers open and close at different hours--in fact it is almost possible to tell the time by watching them. The little daisy is so called, for it is the “day’s eye,” and it closes at sunset; but the evening primrose is only just waking when the daisy is going to sleep. Who does not know that honeysuckle gives off its sweet fragrance in the evening-time? The reason for these facts is this. The daisy is open during the daytime, because it is visited and fertilised by insects who come only during the hours of daylight. The evening primrose is fertilised by moths which fly in the twilight and evening, and so it has no need to be awake by day. We can easily see, too, that the tube-like flower of the honeysuckle is far too long for the tongue of the little bee to reach its nectar, and the corolla is so narrow that she cannot creep down it. So the honeysuckle relies for fertilisation on moths, who have far longer tongues than bees, and it emits the lovely smell at evening-time to attract them. [Illustration: PLATE XXXVII Nasturtiums] CHAPTER XLIII HOW FLOWERS PROTECT THEIR NECTAR A whole volume could be written on the marvellous contrivances of flowers, but we must be content to describe a few. It is a wonderful subject, and one which you yourselves will be able to study quite easily. Have you ever wondered why cup-shaped flowers--the harebell, the snowdrop, and many others--droop their heads? It is because they would become filled with rain or dew if they did not do so, and thus their nectar would be spoiled, and insects would no longer visit them. For the same reason daisies will close their petals when dark clouds come up, and will remain closed until the sun shines again. Have you ever seen a flower of the white dead nettle? It actually protects its nectaries with one of its petals, which overhangs the others, and acts like a little umbrella.