dark place.  The closing of the flowers may, however, be retarded for a whole day by removing the bud before it is fully open and placing it in water.  The stems are almost cylindrical, with four to seven slight ridges, or angles, which bear numerous tufts of wool and short stiff spines.  Roots are thrown out from all parts of the stem, even when not in contact with anything.  The flowers are developed on the sides of the stems, principally the younger, shorter ones; the flower tube is about 4 in. long by 1 in. in diameter, and is covered with short brown scales and whitish hairs; the calyx is 1 ft. across, and is composed of a large number of narrow sepals of a bright yellow colour inside, brown on the outside; the petals are broad, pure white, and arranged in a sort of cup inclosing the numerous yellow stamens and the club-shaped stigma.  The flower has a delicious vanilla-like odour, which perfumes the air to a considerable distance.  Flowers in July.  Native of the West Indies.  Introduced 1700, at which time it is said to have been cultivated in the Royal Gardens at Hampton Court.

C. Lemairii (Lemaire’s); Bot.  Mag. 4814.—­In the size and fragrance of its blossoms, and also in the brilliancy of its colours, this species rivals C. grandiflorus; differing in the following particulars:  the tube is covered with large green, crimson-edged scales instead of small brown scales and white hairs; the sepals do not spread out in a star-like manner, as in C. grandiflorus, and they are tinged with crimson; the stem of the plant shows a bluntly triangular section, and the angles are marked with a row of distant spines instead of the clusters of spines and wool in C. grandiflorus.  In all other particulars, these two species are almost identical, so that where space is limited either the one or the other will be sufficient to represent both.  C. Lemairii was introduced into England through Kew, whither a plant was sent in 1854 from the Royal Botanical Garden of Hanover, under the name of C. rostratus.  It blossoms in the Kew collection every June, the flowers lasting for several hours after sunrise.  Seeds are freely ripened by this plant.  Native of Antigua (?)

C. Macdonaldiae (Mrs. MacDonald’s); Bot.  Mag. 4707.—­A magnificent Cactus, producing flowers often 14 in. in diameter, with the same brilliant colours as are described under C. Lemairii.  The stems are slender, cylindrical, not ridged or angled, bearing at irregular intervals rather fleshy tubercles instead of spines, and branching freely.  Its flowers are produced on both young and old stems, several crops appearing in the course of the summer when the treatment is favourable.  Roots are not so freely thrown out from the stems of this kind, and as the latter are slender and very pliant, they may be trained round a balloon trellis, so as to form handsome pot specimens, which, when in flower, may be carried into the house, where their large, beautiful flowers may be enjoyed.  Writing of this species over thirty