Those who have not yet had an opportunity of visiting the horticultural establishments in the neighborhood of London, or the great flower shows, such as are held at the Crystal Palace, the Regent's Park, South Kensington, etc, where magnificent specimens of this plant are every year exhibited, can scarcely form a conception of the dimensions it attains in England, under a system of culture which is perfectly well-known and understood there.

It is not uncommon to see mignonette, trained in pyramids or other like shapes, measuring three to six feet in height, and this is none other than the common mignonette, grown in our gardens as an annual, which when left to itself never exceeds a foot or two in height at the most.

The arborescent character of the plant is the result of the mode of culture pursued and treatment if receives, not of any difference in species. It is true that by long-continued culture and assiduous care in the selection of the healthiest and finest seeds, plants are obtained which diverge slightly in point of size and vigor from the ordinary type, but they are not more arborescent than is the latter.

The following will be found the most advantageous method of growing tree mignonette. In April or May, take some pots about five inches across, and in each put three, four, or five seeds, and set the pots on a hot-bed, or on a shelf in the hothouse close to the light. The best compost is good light loam mixed with about a quarter of its volume of well-rotied dung, so as to form a black mould, to which is added a certain proportion of wood charcoal, and, if procurable, a little builder's rubbish or broken plaster. The whole should be well mixed and allowed to settle so as to drain thoroughly. As soon as the plants are big enough to distinguish which of them is likely to attain the largest size, the latter is retained, and the rest pulled up. As the roots grow and touch the sides of the pot, the plant is shifted from time to time into larger-sized pots. Care should be taken to tie out the plants as they grow, and to pinch out all blooms as soon as they show themselves. The equilibrium of growth should be carefully watched, and any branches showing a disposition to outgrow their neighbors should be stopped by pinching.

As the season advances and the sun gets more powerful, the plants are put in a more shady place with a good moist temperature, as in a deep frame or a glass-house with a northerly aspect. If they were left in a dry atmosphere exposed to the sun, the wood would set, the growth would be checked, and the plant would blossom at once. Care should be taken that the growth does not receive a check. In August or September the plants are allowed to flower, if intended for autumnal or winter shows. If very large specimens are desired, the largest and finest plants should be pricked out singly, when about thirty inches high, in large-sized pots in the compost above described. Cow-dung should be mixed with the latter, unless it be given mixed with water, at successional waterings, which is a better plan. The best method of all is to set out the plants as standards in a border in a greenhouse, in a compost of the same kind as that used in pots. The plants should only be allowed to bear a few flowers during the first winter, attention being paid chiefly to putting them into shape by pinching and tying out. To form tall standards, a single stem only should be left and all shoots stopped at the third leaf.

The fourth or fifth uppermost shoots, choosing those which are closest together, are kept on to form the head. They are pinched out to make them ramify, and the shoots are tied out to a frame of iron wire or wicker-work. When the plants are raised in pots, shifting should be discontinued as soon as flowering commences. - M. Oscar Cus, Diplomate of the School of Horticulture at Gendbrugge, Belgium.