In regard to the times of flowering of plants, Mr. Meehan exhibited at a recent meeting of the Academy of Natural Sciences of Philadelphia, blooms of the Winter Aconite, Eranthus hyemalis, and the Snowdrop, Galanthus nivalis, which this year were blooming together on the 10th of April. In other seasons the same plants growing side by side, had given flowers of the Winter Aconite several weeks before the Snowdrop. The explanation was that some plants would start into growth at a lower temperature than others. The Snowdrop would remain at rest under a low temperature quite sufficient to excite the Aconite. In a season when the thermometer remained regularly lower than sufficient to excite growth in the Aconite, it remained quiescent until the warmer spring weather brought forward both plants together. These facts showed that no such a scheme as a floral calendar could be established, as the relative blooming of plants depended on accidents of temperature rather than on any fixed climatal conditions.