When a plant is approaching its state of perfection, when its organs of nourishment are completely developed, and its vegetation is most luxuriant, then arrives the time of flowering, which has been aptly termed “the joy of plants.” The most superficial observer must have noticed how different is the season of flowering of individual plants, and how each month is adorned with its particular flowers. When the intense cold of January confines us to our houses, the Black Hellebore, or Christmas Rose, unfolds its dazzling white blossoms; in February, the innocent Snowdrop presents to us her elegant cup. In the same month the Hazel puts forth its catkins, and not rarely the early-blooming Crowfoot shows the blue tips of its clusters of blossom. March boasts a richer Flora; then the Violet delights us with its fragrance; the Mezereon offers its peach-coloured flowers, and the Primrose leads on a long train of the charming children of Spring. These now continue to advance in increasing numbers, displaying, especially in May and June, their highest splendour; till at length the Meadow Saffron takes leave of inclement Autumn, and, saturated with rain, the Mosses acquire fresh vigour, and open to the botanist a new field for investigation. Not less different than the period of flowering is the time of the opening and shutting of flowers. Some plants habitually open and close their flowers by turns; others are governed in these respects by the weather; others again, by the length or shortness of the day: while some open and shut at certain hours, and thus furnish materials for composing the Dial of Flowers.