"L. B. 0," Denver, Col., says: " I have a cactus of the cereus family, don't know the name, but the leaf is broad and flat, blossom white; it has had several blossoms during the summer, but they have all opened in the evening and closed before daylight. This week it has had three more, but instead of opening as usual in the evening they opened in the forenoon about eight o'clock and remained open until, from two to three o'clock in the afternoon. If any of your correspondents or anyone else can give me any light on the subject it will be gladly received through the Monthly. I have been a reader of your Monthly for several years but have noticed nothing of this kind in it."

[This is not a Cereus proper, but probably an Epiphyllum, or an Phyllocactus, to which genera the leaf-like cactuses mostly belong. The fact of its variation in flowering is valuable. There is evidently no constitutional time of flowering in plants, so as to enable us to construct " floral clocks," but what the external influences are which govern the time, are not yet known. - Ed. G.M.]